The first cluster of questions concerns the physical environment itself. Floating structures interact with waves, winds, and currents in ways that fixed-bottom infrastructure does not, and those interactions grow more complex as arrays expand. A single moored platform responds to its local sea state in relatively predictable ways; a dense field of hundreds of platforms reshapes the wave climate around itself, alters near-surface currents, and modifies sediment transport and coastal processes downstream. The authors ask how collective array effects on hydrodynamics can be quantified, modeled, and monitored at scales that matter for regulators and coastal communities. Existing numerical tools were largely developed for isolated structures or for atmospheric flow in wind farms, and translating them to coupled wave-structure-current systems remains an open computational challenge. Field data are equally scarce, because most operating installations are small, young, and instrumented primarily for turbine performance rather than environmental science.

A second set of questions addresses mooring and anchoring, the connective tissue of any floating development. Anchoring systems must hold massive structures in place through storms that can generate fifty-meter waves in the open North Atlantic or Pacific, and they must do so for decades with minimal intervention. The authors probe whether current mooring designs, anchor types, and seabed interaction models are adequate for the deeper waters and harsher climates where floating platforms promise their greatest advantages. Beyond engineering reliability, anchoring raises spatial questions: anchor footprints, scour marks, and mooring lines occupy and disturb the seafloor in ways that can conflict with trawl fisheries, submarine cables, and sensitive habitats such as cold-water coral and seagrass meadows. Whether shared anchoring between neighboring platforms, dynamic positioning, or novel tension-leg concepts can reduce that footprint while maintaining safety is one of the ten questions the authors highlight as underexplored.

Material durability and maintenance logistics form a third pillar of the agenda. Fixed offshore wind turbines are serviced by vessels that dock against static foundations; floating platforms move, and their motion complicates access for technicians, cranes, and spare parts. The authors ask how inspection, repair, and end-of-life decommissioning can be performed economically on structures that may sit sixty or more nautical miles offshore in deep water. Corrosion in the splash zone, fatigue in dynamic export cables that flex with platform motion, and biofouling on submerged components all accelerate degradation in ways that laboratory testing has only partially captured. The economics are unforgiving: maintenance costs that seem tolerable for a pilot project can erode the levelized cost advantage that justifies floating technology in the first place. Whether the industry can standardize components, automate inspections with autonomous vessels and drones, and design for disassembly are questions the authors frame as decisive for commercial viability.

The perspective also confronts the ecological consequences of industrializing the ocean surface. Floating arrays shade the water beneath them, altering light penetration, primary productivity, and the behavior of fish, seabirds, and marine mammals. Artificial structures act as fish aggregation devices, potentially attracting species into hazardous zones while providing novel substrate for colonization that may spread invasive organisms. Electromagnetic fields from cables, operational noise, and the physical presence of mooring lines add further layers of disturbance. The authors ask how cumulative impacts should be assessed when multiple floating developments, shipping lanes, and fisheries overlap in the same marine region, and whether mitigations such as deliberate habitat enhancement or seasonal operational adjustments can be designed on evidence rather than optimism. Because most environmental studies to date cover small installations and short observation windows, the honest answer, the authors suggest, is that the sector does not yet know how ecosystems will respond at the scale now being proposed.

Social and governance questions occupy an equally prominent place in the analysis. Ocean space is not empty: it is fished, navigated, culturally significant, and in many jurisdictions subject to overlapping and contested property rights. The authors ask how coastal communities can participate meaningfully in siting decisions, how benefit sharing should work when floating developments are often visible from shore, and how conflicts with existing maritime users can be resolved fairly. They also highlight the regulatory patchwork confronting developers, with permitting regimes that differ across nations and rarely anticipate hybrid platforms that combine energy generation with aquaculture or hydrogen production. The question of whether governance frameworks can evolve quickly enough, and whether international coordination bodies can harmonize standards for structures that may cross exclusive economic zones through their mooring footprints or cable corridors, is presented as a test of whether ocean governance institutions designed in the twentieth century can manage twenty-first century technologies.

Financing and risk constitute another of the ten questions. Floating developments require capital commitments measured in billions of dollars, yet insurers and investors lack the actuarial history that supports fixed offshore wind or onshore renewables. The authors ask what evidence standards financial institutions will demand, how insurance markets will price novel risks such as mooring failure in extreme storms, and whether public funding mechanisms can bridge the demonstration gap between pilot arrays and bankable commercial projects. Supply chain readiness compounds the problem: specialized steel fabricators, port facilities capable of assembling and launching large platforms, and a trained offshore workforce all remain in short supply. Whether ports can be upgraded quickly enough, and whether standardization of platform designs can unlock the manufacturing efficiencies that transformed solar photovoltaics, emerges as a question with profound implications for how fast deployment can actually proceed.

The authors also turn to integration and hybridization, asking how floating platforms can best be combined with each other and with the wider energy and food systems. Co-locating floating wind with floating solar, wave energy converters, or offshore aquaculture promises synergies in infrastructure, cabling, and operations, but it also concentrates risk and complicates permitting and liability. Coupling floating wind with green hydrogen production offshore could relieve grid congestion, yet introduces new storage, transport, and safety challenges. Grid connection itself is a systemic question: export cables from deepwater sites are long, expensive, and technically demanding, and the question of whether shared transmission infrastructure, energy carriers such as ammonia and hydrogen, or innovative cable designs will dominate remains unresolved. How these choices interact with national energy planning and maritime spatial planning frameworks forms the penultimate entry in the authors’ list.

The final questions are arguably the most fundamental: who decides, and how do we know we are succeeding? The authors call for transparent, internationally coordinated frameworks for monitoring, data sharing, and adaptive management, so that lessons learned at one installation inform the next rather than remaining proprietary. They emphasize that the answers to all ten questions are not purely technical; they depend on values, institutions, and the willingness of industry, government, and research communities to invest in the unglamorous work of long-term observation and evidence synthesis. If the floating development sector treats these questions as obstacles to be minimized, the authors warn, it risks repeating the pattern of public backlash and regulatory whiplash that has slowed other marine industries. If instead it treats them as a research and governance agenda, the coming decade could establish floating platforms as a genuinely sustainable foundation for offshore energy and food production, expanded across the deep oceans where most of the planet’s renewable resource potential awaits.

Subject of Research: Critical scientific and governance questions for scaling up floating offshore developments

Article Title: Ten critical questions for scaling up floating developments

Article References: MacAfee, E. A., Bouma, T. J., van den Brink, M. A., van der Zanden, J., Weiler, C., Spaargaren, F., de Graaf-van Dinther, R., & Waals, O. (2026). Ten critical questions for scaling up floating developments. Nature Communications. https://doi.org/10.1038/s41467-026-77492-2

Image Credits: AI Generated

DOI: 10.1038/s41467-026-77492-2

Keywords: floating developments, offshore wind, floating solar, mooring systems, marine ecosystems, ocean governance, aquaculture, deepwater platforms, marine spatial planning, offshore maintenance, blue economy, renewable energy

The most striking finding documented in the retraction notice concerns the article’s reference list. The editor determined that the majority of the references cited in the paper appear to be non-existent. In practical terms, this means that a large share of the studies underpinning the review’s claims could not be traced to any real publication. Fabricated or hallucinated references of this kind have become a hallmark of text generated by large language models, which can produce fluent, plausible-looking citations that dissolve under scrutiny. When reviewers or readers attempt to locate the cited works, they find no matching titles, authors, journals or digital object identifiers. In this case, the density of apparently fictitious citations was judged sufficient to suggest that generative AI had been used in writing the manuscript, although that use was never disclosed by the authors.

The second pillar of the retraction concerned citation behaviour. The notice states that the authors numerously cited their own previous works, none of which were judged to be relevant to the published paper. Self-citation is not inherently improper; researchers frequently build on their own earlier findings, and in specialised fields a degree of self-referencing is expected. What troubled the editor in this instance was the combination of irrelevance and volume. Citation recycling of this sort can artificially inflate an author’s bibliometric profile, boost journal-level metrics and create a misleading impression of scholarly consensus around a topic. When the self-citations are also tangential to the subject matter, they add noise rather than substance, and they deprive readers of the genuinely relevant literature they would expect a review article to survey.

The retracted paper had been positioned as a synthesis of nutrigenomics research in fish, a field that sits at the intersection of genomics, nutrition and aquaculture science. Nutrigenomics, broadly defined, seeks to understand how dietary components interact with an organism’s genome, transcriptome, proteome and metabolome, and how those interactions shape growth, health and nutritional quality. Applied to farmed fish, the field promises to inform feed formulations that improve growth performance, disease resistance and the nutritional value of the final product for human consumers. With capture fisheries at or near their sustainable limits, aquaculture has become the fastest-growing animal food production sector worldwide, and the genetic optimisation of farmed species is a major research priority. A credible review of this landscape would have been a valuable resource for the community, which makes the integrity failure all the more consequential.

The authors of the retracted article were affiliated with several Indian research institutions, including the ICAR-Central Institute of Fisheries Education in Mumbai, the Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, the ICAR-Central Institute of Brackishwater Aquaculture in Chennai, and the College of Fisheries in Kishanganj under the Animal Science University in Patna. The retraction notice records that all authors disagree with the retraction. Disagreement is not unusual in retraction cases, and it does not by itself reverse an editorial decision. Under the guidelines that most publishers follow, the retraction notice remains permanently linked to the article, which stays online but is clearly watermarked as retracted so that readers who encounter it are not misled. The notice itself, published as an open-access document, has already recorded hundreds of accesses, reflecting the attention such cases now attract.

For the journal, the case underscores the difficulty of screening submissions in an era when generative AI tools can produce manuscripts that pass superficial readability checks. Peer review was designed to evaluate scientific merit, not to authenticate reference lists or detect machine-generated prose. Fabricated citations are often discovered only after publication, when readers attempt to follow up on the sources. Journals and publishers have been rolling out additional safeguards, including reference verification at submission, disclosure policies requiring authors to declare any use of AI in manuscript preparation, and clearer rules reserving authorship for humans who take responsibility for the work. The retraction notice in this case makes explicit that the undeclared nature of the suspected AI use was central to the decision, alongside the reliability problems it created.

The episode also highlights why retractions, though painful, are an essential part of the scientific ecosystem. The retracted review concerned a topic with real-world stakes: sustainable aquaculture and the nutritional improvement of farmed fish. Researchers, feed companies and policymakers who consult the literature on fish nutrigenomics rely on reviews to orient their work. A review built substantially on non-existent references cannot support that function, because its synthesis rests on evidence that does not exist. Leaving such a paper uncorrected would risk propagating false claims into downstream research, extension materials and even feed development decisions. By retracting the article and publishing a transparent notice, the journal protects the integrity of the record, even at the cost of acknowledging that a flawed publication slipped through.

The broader context is a rising tide of AI-related integrity cases across scientific publishing. Publishers have reported growing numbers of retractions in which fabricated references, nonsensical text or undisclosed AI assistance played a role. The phenomenon is not confined to any single discipline or region, and it has prompted international bodies to refine their guidance on authorship, disclosure and the responsible use of AI tools. At the same time, many researchers use AI legitimately, for language polishing, literature discovery or data analysis, provided that such use is transparent and that humans verify and take responsibility for the final content. The line drawn in this case was between undisclosed use that compromised the reliability of the manuscript and the disclosed, supervised use that publishers generally accept. The retraction notice suggests the authors crossed that line in ways that could not be remedied by correction.

For the aquaculture and nutrigenomics communities, the practical lesson is one of vigilance. Review articles shape research agendas, funding priorities and teaching materials, and their authority depends on the verifiability of every citation. Readers evaluating reviews in this field, as in any other, are increasingly advised to check that cited studies exist and genuinely support the claims attached to them, and to treat reference lists with the same critical attention once reserved for methods sections. The retracted paper’s promise, decoding the fish genome to make aquaculture more sustainable and more nutritious, remains a legitimate and active research goal pursued by many groups worldwide. What the retraction removes is not that goal, but a document that claimed to summarise it on unreliable foundations. The scientific record, corrected through the retraction notice now permanently attached to the article, is the mechanism by which that distinction is made clear to everyone who comes after.

Subject of Research: Retraction of a fish nutrigenomics review article over undeclared generative AI use and fabricated references

Article Title: Retraction Note: Fish nutrigenomics: unravelling the genetic code for sustainable aquaculture and improved nutritional benefits

Article References: Retraction Note: Fish nutrigenomics: unravelling the genetic code for sustainable aquaculture and improved nutritional benefits. (n.d.). https://doi.org/10.1186/s44315-026-00053-1

Image Credits: AI Generated

DOI: 10.1186/s44315-026-00053-1

Keywords: retraction, fish nutrigenomics, generative AI, research integrity, fabricated references, self-citation, aquaculture, Blue Biotechnology, Springer Nature, peer review, open access, sustainable aquaculture

The review, authored by Shao-Wei Ho, Ji-Yu Wu, Yu-Wei Chen, Chieh-Kai Yang and Wen-Ping Tsai of National Cheng Kung University in Taiwan, synthesizes recent advances across the major domains of marine science. Rather than cataloguing individual algorithms, the authors emphasize a common pattern: machine learning and deep learning models are enabling scientists to extract actionable knowledge from vast, high-dimensional and often messy ocean observations at scales that were previously unimaginable. Where traditional conservation relied on labor-intensive field surveys, laboratory analyses and satellite remote sensing that were slow, expensive and geographically constrained, AI-driven systems now process satellite imagery, acoustic recordings, underwater video and sensor streams in near real time. One striking example cited in the review: machine learning-based processing of coral reef imagery can run roughly two hundred times faster than manual analysis, allowing assessments that once took months to be completed in days.

At the technical heart of this transformation sit a handful of architectures, each suited to a different kind of ocean problem. Convolutional neural networks, or CNNs, excel at interpreting grid-like image data, learning hierarchical spatial features that progress from simple edges and textures to complex objects, which makes them the workhorse for classifying fish, corals and benthic invertebrates in underwater photographs. Long Short-Term Memory networks, a specialized form of recurrent neural network, use gating mechanisms to selectively retain information over long intervals, making them ideal for time-series forecasting of wave heights, tides, salinity and dissolved oxygen. Random Forest ensembles, which average predictions from many decorrelated decision trees, offer interpretable models for forecasting fish-habitat suitability and estimating chlorophyll-a concentrations. Segmentation networks such as U-Net and its nested variant U2-Net perform pixel-level delineation of coral reef boundaries, sea ice and oil slicks, while generative adversarial networks fill gaps in satellite time series and super-resolve ocean-color imagery.

The review’s analysis of the literature reveals just how dominant vision-based AI has become. CNN-based frameworks accounted for nearly sixty percent of image-based biodiversity studies, and their reported performance is remarkable. One deep learning system achieved 94.9 percent test accuracy in coral and fish recognition, exceeding the 89.3 percent accuracy of human experts on the same task. Coral image classification studies reported overall accuracies of 94.5 percent, with some classes reaching one hundred percent, and large-scale habitat mapping efforts achieved 83 to 94 percent similarity to expert assessments. Platforms such as TagLab, which applies CNN-based segmentation to annotate coral reef orthomosaics, documented roughly a ninety percent increase in identification speed compared with manual routines, while systems like AquaVision automatically detect invasive fish species in the Mediterranean and continuously update their models as new imagery arrives.

Acoustic monitoring is undergoing a parallel revolution. Marine mammals rely on vocalizations as their primary mode of communication, and passive acoustic monitoring systems now use machine learning classifiers to distinguish species-specific calls with high precision, enabling long-term, non-invasive surveillance of whales and dolphins. Deep learning extends this capability across broader frequency bands, enriching the analysis of entire underwater soundscapes. Meanwhile, autonomous underwater vehicles equipped with AI-based object detection are mapping deep-sea habitats inaccessible to divers, and few-shot learning techniques that generalize from limited labeled samples are helping researchers detect rare and endangered species in ecologically sparse datasets. Initiatives such as Seagrass Finder use deep learning on AUV video to map eelgrass, a critical resource for blue carbon accounting.

Fisheries management, long a battleground between productivity and sustainability, may be the domain where AI delivers the most immediate governance benefits. AI-powered electronic monitoring systems installed on fishing vessels use onboard cameras and deep learning algorithms to identify catch composition in real time, reduce bycatch and verify compliance with regulations. The review highlights AI-RCAS, a real-time catch analysis system that combines YOLOv10 object detection with ByteTrack tracking algorithms on embedded Jetson boards, analyzing catches in situ to support enforcement of total allowable catch limits. A lightweight MobileNet-based classifier reported up to 97 percent species-level accuracy in electronic monitoring pipelines, an edge-efficient design suited to resource-constrained vessels. Beyond enforcement, machine learning models trained on environmental and biological data forecast fish stock fluctuations, and reinforcement learning is being used to design adaptive harvest control rules that balance catch efficiency with conservation needs under uncertainty. Platforms like Global Fishing Watch apply pattern recognition to vessel tracking data to expose illegal, unreported and unregulated fishing, promoting real-time transparency across the global fleet.

In aquaculture, the fastest-growing food production sector on the planet, AI is optimizing everything from feeding to disease prevention. Smart feeding systems that monitor fish appetite, movement and water conditions have achieved feed cost reductions of twenty to thirty percent while improving growth rates. Computer vision algorithms detect early visual signs of disease such as lesions, discoloration and erratic swimming, while time-series models trained on water temperature, pH and oxygen data predict outbreaks before clinical symptoms appear. Hybrid deep learning architectures combining CNNs, LSTM networks and attention mechanisms have been proposed to predict nitrate concentrations in recirculating aquaculture systems, and Internet of Things platforms with edge AI continuously monitor water quality, triggering alerts before dangerous thresholds are breached.

Pollution detection and climate impact assessment round out the review’s application landscape. Deep learning models applied to Sentinel-2 and synthetic aperture radar imagery can distinguish oil slicks from optical lookalikes; one hyperspectral framework integrating CNN classification with DBSCAN clustering achieved 92.12 percent mean pixel accuracy while processing each image in under seven hundred milliseconds. AI models also classify floating plastics from hyperspectral satellite imagery, and machine learning has even outperformed humans in microplastic characterization, revealing labeling errors in infrared spectroscopy data. On the climate front, deep learning forecasters reported prediction accuracies exceeding 96 percent for variables such as dissolved oxygen and temperature in coastal time series, and AI-driven ecosystem models project species range shifts and potential collapse thresholds under different emissions scenarios, giving governments and conservation groups the foresight needed for proactive, climate-resilient planning.

The authors are careful, however, not to oversell the technology. Marine AI faces a web of intertwined challenges: ocean data remain fragmented, sparse and geographically imbalanced, especially in polar regions, the deep sea and developing coastal nations; models trained in one environment often degrade when transferred to waters with different turbidity, light or species composition; and the computational demands of deep learning raise both cost barriers and genuine carbon footprint concerns that could undermine the sustainability goals the technology serves. Many biodiversity-rich but technologically underserved regions lack the connectivity and infrastructure for real-time AI deployment, and the opacity of black-box models erodes trust among policymakers and coastal communities whose livelihoods depend on AI-informed decisions. The review calls for explainable AI techniques such as SHAP and Grad-CAM, human-in-the-loop oversight, lightweight and energy-efficient architectures, and federated learning approaches that train models across decentralized networks of buoys, gliders and autonomous vehicles without shipping raw data to central servers, preserving both privacy and bandwidth.

Looking forward, the most promising frontier may be the fusion of machine learning with physical ocean models through differentiable parameter learning and physics-informed neural networks, approaches that embed conservation laws directly into the training process and can cut calibration costs by orders of magnitude. Combined with multi-modal data integration spanning satellites, sonar, environmental DNA and in-situ sensors, and with federated edge intelligence deployed directly at sea, the authors argue that AI can shift marine governance from reactive crisis response to anticipatory, data-driven stewardship. The stakes could hardly be higher: healthy oceans underpin Sustainable Development Goal 14 and the wellbeing of millions. What this comprehensive review makes clear is that the algorithms are ready. The harder work now lies in building the open data infrastructure, ethical safeguards and international cooperation needed to put them to work for the ocean, everywhere, equitably and at scale.

Subject of Research: Applications of artificial intelligence, machine learning and deep learning techniques for sustainable marine resource management

Article Title: Leveraging artificial intelligence (AI) techniques for sustainable marine resources

Article References: Leveraging artificial intelligence (AI) techniques for sustainable marine resources. (n.d.). https://doi.org/10.1186/s44315-026-00054-0

Image Credits: AI Generated

DOI: 10.1186/s44315-026-00054-0

Keywords: artificial intelligence, machine learning, deep learning, marine biodiversity, sustainable fisheries, ocean conservation, aquaculture, marine pollution, climate change, coral reefs, federated learning, blue biotechnology

The research, led by Andreas Tsipourlianos and Katerina A. Moutou of the University of Thessaly in Greece, together with João C. R. Cardoso and Deborah M. Power of the University of the Algarve in Portugal, focused on two fish species of enormous commercial importance in Mediterranean aquaculture: the gilthead seabream (Sparus aurata) and the European seabass (Dicentrarchus labrax). These species are evolutionarily close relatives, yet they occupy ecologically distinct niches, making them an ideal comparative pair for dissecting how genome history and ecological lifestyle interact to shape the genetic architecture of core metabolism. Both species also possess well-annotated reference genomes, a prerequisite for the kind of rigorous comparative genomics the team undertook.

Teleost fishes carry a particularly rich evolutionary legacy in their DNA. Like all vertebrates, their ancestors experienced two rounds of whole-genome duplication deep in evolutionary time. Then, roughly 350 million years ago, the lineage that gave rise to modern teleosts underwent a third, teleost-specific genome duplication. These events doubled and redoubled the genetic raw material available to fish ancestors, creating thousands of duplicate gene pairs. Most duplicates are eventually lost, silenced by mutation, or repurposed for new functions. But some are retained, and understanding why certain duplicates persist while others vanish is one of the central questions in genome evolution. OXPHOS genes, with their tight dosage requirements and dual-genome coordination, represent an especially demanding test case for theories of duplicate retention.

Using comparative genomics across euteleost lineages, the researchers identified 23 multi-copy OXPHOS gene families in the gilthead seabream and 21 in the European seabass. This means that for a substantial number of the genes encoding the respiratory machinery, both fish carry more than one copy, or paralogue, in their nuclear genomes. Critically, the team was able to trace the origin of most of these duplicated families back to the teleost-specific genome duplication, demonstrating that this ancient genomic upheaval left a durable imprint on one of the most conserved metabolic pathways in biology. The finding challenges any assumption that core energy genes are immune to the effects of genome doubling.

Why would an organism keep two copies of a gene whose product must be produced in precise stoichiometric proportions to assemble a functional respiratory complex? The researchers tested a hypothesis that has gained traction in evolutionary biology: duplicate retention reflects a balance between dosage constraints, which favor keeping both copies active at reduced levels to maintain the correct overall output, and functional divergence, which allows one copy to specialize in a new context, tissue, or developmental stage. To examine this balance in action, the team turned to a life stage where energy demand is at its most extreme: early larval development.

Fish larvae are biological sprinters. Within days of hatching, they must grow rapidly, develop organs, begin swimming and feeding, and reorganize their metabolism from the yolk-dependent state of the embryo to the self-fueling physiology of a free-living organism. Mitochondrial energy production is central to every one of these transitions, and any disruption to OXPHOS function during this window can be lethal. This makes early development an ideal natural experiment for asking whether duplicated OXPHOS genes do the same work or different work.

The transcriptomics analysis revealed that paralogous OXPHOS genes do not behave uniformly. Some paralogues showed stable, coordinated expression patterns across development, consistent with the dosage-balance model: both copies contribute to maintaining the required output of the respiratory complexes. Others displayed a strikingly different behavior, being expressed only at specific developmental stages, suggesting that they have acquired stage-specific regulatory roles. This split personality among duplicates, with some copies serving as dosage partners and others as developmental specialists, provides direct evidence that functional diversification has shaped the OXPHOS repertoire of these fish since the teleost genome duplication.

The implications extend beyond evolutionary theory. Aquaculture is one of the fastest-growing food production sectors in the world, and gilthead seabream and European seabass are cornerstone species of Mediterranean fish farming. Larval survival is a persistent bottleneck in hatchery production, and energy metabolism is a key determinant of whether a larva successfully navigates the vulnerable early stages of life. By mapping which OXPHOS paralogues are deployed at which developmental moments, the study lays a molecular foundation for understanding, and potentially improving, larval performance under farming conditions. Genes that are switched on during critical developmental transitions could serve as markers of metabolic health or as targets for nutritional and environmental optimization.

The work also speaks to a broader question in biology: how do the mitochondrial and nuclear genomes, which are inherited in different ways and evolve at different rates, maintain their intricate partnership across hundreds of millions of years? Duplicated nuclear OXPHOS genes add another layer of complexity to this coevolutionary dance. If one nuclear copy diverges in function or expression, the mitochondrial components with which it interacts must remain compatible. The retention patterns documented in seabream and seabass suggest that this negotiation has produced a flexible but carefully balanced system, one in which redundancy provides resilience and specialization provides developmental precision.

Funding for the study came from the European Union through the H2020 PerformFISH project, which aims to integrate innovative approaches for competitive and sustainable performance across the Mediterranean aquaculture value chain, along with Portuguese national funds from the Foundation for Science and Technology. Larval samples were supplied by the Hellenic Centre for Marine Research in Crete, whose certified aquaculture facilities enabled the controlled developmental work underpinning the transcriptomic analysis. As the first comprehensive survey of OXPHOS paralogue evolution in euteleosts, the study opens a window onto how ancient genome doublings continue to echo through the metabolism of modern fish, and it suggests that the duplicated genes left behind by those events are not evolutionary leftovers but active, functionally relevant players in the energy economy of development. For a pathway as fundamental as oxidative phosphorylation, that flexibility may be exactly what allowed teleosts, the most diverse group of vertebrates, to radiate into nearly every aquatic habitat on the planet.

Subject of Research: Evolution and retention of duplicated oxidative phosphorylation genes in euteleost fishes

Article Title: Evolution and retention of oxidative phosphorylation paralogues in euteleosts: insights from gilthead seabream and European seabass

Article References: Tsipourlianos, A., Cardoso, J. C. R., Angelakopoulos, R., Kotoula, A., Power, D. M., Mamuris, Z., & Moutou, K. A. (2026). Evolution and retention of oxidative phosphorylation paralogues in euteleosts: insights from gilthead seabream and European seabass. BMC Genomics. https://doi.org/10.1186/s12864-026-13338-x

Image Credits: AI Generated

DOI: 10.1186/s12864-026-13338-x

Keywords: oxidative phosphorylation, OXPHOS, gene duplication, teleost genome duplication, gilthead seabream, European seabass, mitochondria, larval development, comparative genomics, transcriptomics, gene retention, aquaculture

The research arrives at a moment when maritime spatial planning, or MSP, has moved from an abstract academic concept to a binding legal obligation in many coastal states. The European Union’s MSP Directive, the marine spatial plans emerging across Asia, Africa and Latin America, and the target under the United Nations Convention on Biological Diversity to protect thirty percent of the ocean by 2030 all demand planning processes that can weigh industrial development against ecological integrity. Yet in practice, planners frequently lack a structured way to answer a deceptively simple question: which sectors depend on which ecosystem services, and what happens to human well-being when those services are degraded or displaced?

The framework addresses this gap by treating blue economy sectors not as isolated actors but as components of a coupled social-ecological system. Each sector, whether it is offshore renewable energy, commercial fishing, maritime transport, aquaculture, tourism or emerging industries such as floating infrastructure and deep-sea resource extraction, is mapped against a portfolio of ecosystem services drawn from established classification systems. These include provisioning services such as food and raw materials, regulating services such as climate regulation and coastal protection, and cultural services such as recreation, heritage and identity. By making these dependencies and impacts explicit, the framework turns what has often been an implicit, intuition-driven judgment into a transparent and auditable analytical structure.

What distinguishes the approach from earlier attempts at integration is its insistence on the socio-economic dimension. Maritime spatial planning has historically been dominated by ecological and engineering considerations, with human dimensions added late in the process or treated as constraints on otherwise technical decisions. The new framework elevates socio-economic priorities to a co-equal pillar of the analysis. Employment, food security, income distribution, cultural values, gender equity and regional development objectives are positioned as the evaluative criteria against which the consequences of sector-service interactions are judged. This means that a planning decision is no longer assessed only by its effect on a habitat or a species population, but by its cascading consequences for the livelihoods and priorities that those ecological functions underpin.

Technically, the framework operates as a structured chain of linkage analysis. In the first stage, sectors are characterized by their spatial footprint, resource demands and pressures on the marine environment, including physical disturbance, pollution, noise, greenhouse gas emissions and biological impacts. In the second stage, ecosystem services are identified and located, often using spatially explicit data layers that show where services are generated and who benefits from them. The third stage constructs the dependency and impact matrices, recording for each sector-service pair whether the sector relies on the service, degrades it, enhances it or competes with other sectors for it. The fourth stage connects these interactions to socio-economic priorities through indicators that can be monitored over time, allowing planners to track whether a given allocation of ocean space is delivering on declared policy goals.

This chain-of-linkages logic has significant practical advantages for planning authorities. It enables cumulative impact assessment to move beyond simply summing pressures and instead to trace how combined pressures alter service flows and, ultimately, human welfare. It supports scenario analysis, so that planners can compare, for example, an aggressive offshore wind build-out against a more diversified allocation that reserves space for small-scale fisheries and coastal protection habitats. It also creates a common language for stakeholders who often talk past one another. A fishing cooperative, an energy developer and a conservation agency can each locate their concerns within the same framework, which reduces the translation problems that have historically made marine planning negotiations slow and adversarial.

The framework is also designed with trade-off analysis at its core. The ocean cannot simultaneously maximize every use in every location, and the concept of the blue economy has been criticized, in some quarters, for promising growth without acknowledging the hard choices that growth implies. By forcing explicit recognition of which services are lost, degraded or gained under alternative planning scenarios, and by tying those changes to named socio-economic priorities, the framework makes trade-offs visible rather than hiding them in aggregated cost-benefit figures. This transparency matters for legitimacy. Coastal communities that see how their priorities were weighed, and where their interests were traded against others, are more likely to accept planning outcomes than communities confronted with decisions that appear to have emerged from a black box.

The study speaks directly to several urgent global policy conversations. The sustainable blue economy agenda promoted by international organizations envisions ocean industries as engines of development, but that vision is credible only if the ecological base of the economy is maintained. The framework provides a mechanism for operationalizing this conditionality: sectors can grow, but the analysis shows where growth erodes the service foundation on which other sectors and communities depend. Similarly, ecosystem-based management, long a guiding principle in marine policy, gains a concrete implementation pathway. Rather than remaining an aspiration, ecosystem-based management becomes a set of defined linkages, indicators and decision points that can be embedded in statutory planning processes.

The timing of the publication is notable. Global commitments to offshore renewable energy are accelerating, aquaculture is the fastest-growing food production sector in the world, and shipping volumes continue to rise even as nations pledge to decarbonize maritime transport. Meanwhile, the recently agreed international agreement on biodiversity beyond national jurisdiction, together with expanding networks of marine protected areas, is adding new layers of regulation to ocean space. Planning systems that were built for a quieter ocean now face simultaneous demands for industrial expansion, biodiversity protection and climate adaptation. The framework offers planners a way to integrate these demands systematically, rather than resolving conflicts case by case after they erupt.

For researchers, the framework opens a research agenda as much as it closes one. The authors’ structure invites empirical application in specific seascapes, where data on service distribution, sector pressures and socio-economic indicators can populate the linkage matrices and reveal whether the framework performs as intended under real institutional conditions. It also invites methodological development: the integration of ecosystem service models with ocean observation systems, the use of participatory mapping to capture local and Indigenous knowledge of service flows, and the coupling of the framework with optimization and simulation tools that can search for planning allocations satisfying multiple priorities at once. As more jurisdictions adopt legally binding marine plans, the demand for methods that can demonstrate the consequences of those plans for both ecosystems and people will only grow. This study provides a credible, general-purpose scaffold for meeting that demand, and its true test will be how quickly it moves from the journal page into the planning rooms where the ocean’s future is actually decided.

Subject of Research: A framework linking blue economy sectors to ecosystem services and socio-economic priorities for integrated maritime spatial planning

Article Title: Linking blue economy sectors to ecosystem services and socio-economic priorities: a framework for integrated maritime spatial planning

Article References: Pegorelli, C., Rayo-Luengo, S., Garcia-Onetti, J., de Andrés, M., Stojanovic, I., & Sanabria, J. G. (2026). Linking blue economy sectors to ecosystem services and socio-economic priorities: a framework for integrated maritime spatial planning. npj Ocean Sustainability. https://doi.org/10.1038/s44183-026-00238-6

Image Credits: AI Generated

DOI: 10.1038/s44183-026-00238-6

Keywords: blue economy, maritime spatial planning, ecosystem services, ocean governance, socio-economic priorities, marine policy, offshore renewable energy, aquaculture, ecosystem-based management, npj Ocean Sustainability, Linking, blue

The team chose zebrafish (Danio rerio) as their model organism, a small freshwater fish that has become a workhorse of modern biomedical research. Zebrafish share a striking degree of genetic similarity with humans, develop rapidly, and respond to waterborne chemicals in ways that are easy to monitor. Crucially, their gills—organs responsible for gas exchange, osmoregulation, and excretion—are in constant, direct contact with the surrounding water, making them exquisitely sensitive barometers of aquatic toxicity. Structural changes in gill tissue, such as epithelial lifting and the fusion of lamellae, are widely recognized biomarkers of sublethal stress.

To prepare the test material, the researchers harvested fresh Avicennia marina leaves from the Kalpakkam coast in Tamil Nadu, India. The leaves were shade-dried for up to ten days, ground into a fine powder, and soaked in 70 percent ethanol on an orbital shaker for 48 hours. After filtration and concentration in a water bath, the procedure yielded 2.47 grams of crude extract from 20 grams of starting material—a yield of roughly 12 percent. The extract was then dissolved into working concentrations of 0.5, 1.0, and 2.0 milligrams per liter for the fish exposure experiments.

Before the animal work, the team chemically profiled the extract. Fourier transform infrared spectroscopy revealed a rich palette of functional groups: a broad O–H stretching band at 3334.9 wavenumbers pointing to alcohols and phenolic compounds, aliphatic C–H stretches at 2924.5 and 2852.7 suggesting long-chain hydrocarbons and terpenoids, a carbonyl band at 1708 indicating aldehydes, ketones, or carboxylic acids, and aromatic C=C stretches at 1609 and 1515.1 consistent with flavonoids and other polyphenols. Additional bands assigned to C–O stretching of esters, alcohols, and carbohydrates rounded out a fingerprint typical of a phytochemically complex mixture.

The antioxidant credentials of the extract proved impressive in vitro. In the DPPH free radical scavenging assay, the extract neutralized more than 90 percent of radicals at the highest tested concentration of 125 micrograms per milliliter, closely matching the performance of a standard reference antioxidant. A parallel phosphomolybdenum assay for total antioxidant capacity showed the same concentration-dependent trend, with activity rising steadily across the tested range. The authors attribute this redox behavior to the extract’s abundant phenolics, flavonoids, tannins, and other electron-rich secondary metabolites, consistent with earlier reports of high total phenolic content in A. marina leaf extracts.

For the in vivo experiment, sixty healthy adult zebrafish, aged three to four months, were acclimated for two weeks under controlled conditions of 26 degrees Celsius, neutral pH, and a 14-hour light cycle. The fish were then randomly divided into four groups of fifteen: an untreated control and three treatment groups exposed to 0.5, 1.0, or 2.0 milligrams per liter of the extract for seven consecutive days in a static renewal system, with 80 percent of the water replaced daily. At the end of the exposure period, fish were humanely euthanized and their gill tissues dissected for histopathology and molecular analysis.

The histological findings told a cautionary story. Control gills displayed normal architecture with well-organized primary and secondary lamellae. At the lowest dose, 0.5 milligrams per liter, the changes were mild—slight epithelial lifting and minimal hyperplasia. At 1.0 milligrams per liter, moderate lamellar fusion and increased epithelial proliferation appeared. At the highest dose, 2.0 milligrams per liter, the damage became pronounced: extensive lamellar fusion, widespread epithelial lifting, hyperplasia, and partial loss of secondary lamellae. Lesion scores at this dose were significantly higher than in controls, and the pattern of injury resembles that seen in fish exposed to pesticides, detergents, and industrial effluents.

Molecular analysis, however, revealed a different dimension of the extract’s activity. Using quantitative real-time PCR with beta-actin as the housekeeping gene, the team measured expression of interleukin-10, a cytokine central to controlling inflammation. Compared with the control level of 1.0-fold, IL-10 expression dipped slightly to 0.7-fold at 0.5 milligrams per liter, but then rose significantly to 2.0-fold at 1.0 milligrams per liter and approximately 3.4-fold at 2.0 milligrams per liter. The dose-dependent upregulation indicates that moderate to high concentrations of the extract activate anti-inflammatory signaling pathways in gill tissue, likely through modulation of regulatory networks involving NF-kappaB and MAPK signaling.

The juxtaposition of strong IL-10 induction with visible tissue injury at the highest dose is the study’s most thought-provoking result. The authors suggest that even a robust anti-inflammatory response was insufficient to counteract direct phytochemical damage to the gill epithelium once concentrations exceeded a critical threshold. They note a parallel with quercetin, a flavonoid that enhances antioxidant defenses and suppresses pro-inflammatory cytokines in zebrafish at low doses but reverses these benefits at high doses. Many phytochemicals, in other words, are biphasic: beneficial within a therapeutic window, harmful beyond it. Excessive IL-10 itself carries risks, potentially suppressing host defenses and increasing susceptibility to secondary infections.

The study concludes that Avicennia marina leaf ethanolic extract holds genuine promise as a phytogenic immunostimulant for aquaculture, but only with careful dose optimization. The authors call for future work to isolate and characterize the specific bioactive constituents responsible for the observed effects, to conduct long-term toxicity studies across different developmental stages and environmental conditions, and to test efficacy against common aquatic pathogens in commercially important species beyond zebrafish. If those steps succeed, mangrove-derived compounds could eventually find their way into aquafeeds or water treatments as eco-friendly tools for fish health management—provided the fine line between immunostimulation and tissue damage is respected.

Subject of Research: Dose-dependent effects of Avicennia marina leaf ethanolic extract on IL-10 gene expression and gill histopathology in zebrafish

Article Title: Histopathological evaluation and gene expression of IL-10 in zebrafish (Danio rerio) gills exposed to Avicennia marina (Grey Mangrove) leaf ethanolic extract

Article References: Thirukkumaran, D., Santhosh, K., Ganapathy, D., & Sivaperumal, P. (2026). Histopathological evaluation and gene expression of IL-10 in zebrafish (Danio rerio) gills exposed to Avicennia marina (Grey Mangrove) leaf ethanolic extract. Blue Biotechnology, 3(1), Article 5. https://doi.org/10.1186/s44315-026-00056-y

Image Credits: AI Generated

DOI: 10.1186/s44315-026-00056-y

Keywords: Avicennia marina, zebrafish, IL-10, mangrove extract, histopathology, antioxidant, immunostimulant, aquaculture, gill tissue, qRT-PCR, anti-inflammatory, phytochemicals

The economic logic is straightforward. In many farmed species, sex determines how fast an animal grows and how much it is worth at harvest. Male Nile tilapia grow up to 40 percent larger than females, which is why all-male tilapia populations dominate commercial production. Male yellow catfish and giant freshwater prawns also outgrow their female counterparts, while in half-smooth tongue sole the relationship is reversed, with females reaching four times the size of males. Monosex culture exploits these differences by preventing premature maturation, eliminating uncontrolled breeding in grow-out ponds, reducing size variation, and improving feed conversion. Sterility offers a complementary benefit: energy that would otherwise be spent on gonads and spawning is redirected into somatic growth, and escaped fish cannot breed with wild relatives, protecting biodiversity from genetic introgression.

Conventional methods have delivered these advantages for decades, but each carries trade-offs. Hormonal sex reversal, typically using 17α-methyltestosterone or estradiol-17β administered through treated feed or immersion during the labile window of sex differentiation, is effective but raises concerns about hormone residues, worker safety, and consumer perception. Chromosome-set manipulation, including gynogenesis and androgenesis, can generate single-sex or clonal lines but demands specialized expertise. Triploidy, induced by thermal or pressure shocks to render Atlantic salmon, rainbow trout, and grass carp functionally sterile, remains the workhorse of reproductive containment. Yet triploid fish often pay a welfare price: studies have linked the extra chromosome set to cataracts, skeletal deformities, reduced aerobic capacity, lower survival, and growth that can fall to 75 to 90 percent of diploid levels. YY supermale technology in tilapia, in which sex-reversed females are crossed to produce males carrying two Y chromosomes, has proven commercially successful but depends on long breeding cycles and, in many strains, hormone treatment.

Genome editing changes the calculus. CRISPR/Cas systems use Cas proteins as molecular scissors guided by RNA to cut DNA at chosen sequences, and newer variants expand the toolkit considerably. Cas12a makes staggered cuts, Cas13 targets RNA, and catalytically dead Cas9 can regulate genes without cutting at all. Base editors convert single nucleotides without double-strand breaks, and prime editing enables versatile small modifications with fewer unintended insertions and deletions. In fish, these tools can target the genes that govern sex determination and germ cell survival. Disrupting male pathway genes such as dmrt1, amh, amhr2, gsdf, or the crustacean androgenic gland gene iag can push development toward all-female populations, while knocking out female pathway genes such as cyp19a1a, foxl2, or cyp17a1 can masculinize genetic females and yield all-male cohorts. Targeting dnd, a gene essential for primordial germ cell survival, produces fish that develop normally but carry no germ cells at all.

The proof-of-concept results are striking. In common carp, CRISPR knockout of cyp17a1 converted XX females into neomales with 60 to 85 percent penetrance, and all-female cohorts produced from these neomales grew 10 to 20 percent faster than mixed-sex controls. In Nile tilapia, dmrt1 knockout converted 70 to 100 percent of XY genetic males into neofemales, which were then used to generate YY supermales with 18 to 30 percent efficiency; their all-male offspring outweighed mixed-sex siblings by 10 to 30 percent. In the ridgetail white prawn, iag knockout caused male-to-neo-female sex reversal, although larval survival dropped by 20 to 50 percent, underscoring that crustacean editing remains experimental. Crucially, gene editing serves mainly to create founder broodstock; large-scale monosex production then proceeds through ordinary breeding, meaning the fish that reach dinner plates can be free of foreign DNA, a distinction that matters for regulators classifying such edits as SDN-1-type changes rather than transgenic GMOs.

Sterility engineering follows a similar logic but pairs editing with germ cell transplantation. Knocking out dnd ablates endogenous germ cells while leaving the somatic gonad intact, creating sterile recipients that act as living bioreactors. Donor spermatogonia or oogonia, harvested from elite or edited lines and optionally cryopreserved, are transplanted into these recipients, where they colonize the gonads and produce eggs or sperm carrying exclusively the donor genome. In rainbow trout, homozygous dnd knockouts supported donor germ cell colonization rates of 30 to 70 percent, with fertility restored in more than 60 to 90 percent of colonized recipients and donor-derived gamete production reaching 80 to 100 percent of wild-type levels, while the edited recipients themselves grew within 5 percent of normal fish. Germ cell-less mackerel hybrids have produced viable donor-derived offspring, and in Atlantic salmon, gonadal cell suspensions transplanted into triploid hatchlings generated functional donor-derived ovaries and sperm. Edited sterile salmon showed growth, stress response, and sea lice resistance equivalent to fertile diploids, outperforming triploids, which suffer higher deformity rates of 10 to 40 percent and greater environmental sensitivity.

Despite these advances, no genome-edited monosex or sterile fish line has yet achieved routine commercial production, and the review identifies five interlocking bottlenecks. First, the master sex-determining gene remains unknown in more than 80 percent of farmed fish species, making target selection speculative. Second, editing efficiency varies enormously, from under 1 percent to as much as 90 percent depending on species, target, and delivery method, with F0 mosaicism frequently exceeding 40 to 70 percent and forcing multi-generational breeding to stabilize edits, a slow process in salmon that take three to four years per generation. Third, delivery is a throughput bottleneck: manual embryo microinjection handles roughly 3,000 eggs per technician per day with post-injection survival often below 70 percent, inadequate for high-fecundity species like tilapia that produce 1,000 to 2,000 eggs per female. Fourth, germ cell transplantation success is highly species-dependent, exceeding 70 percent colonization in rainbow trout but falling below 20 percent in many marine teleosts. Fifth, regulation is fragmented: the European Union treats edited fish as GMOs regardless of whether foreign DNA is present, the United States applies a risk-based FDA framework for heritable genomic alterations, and China has begun distinguishing gene-edited plants from conventional GMOs while rules for edited animals remain unsettled.

The authors argue that overcoming these barriers requires convergence across disciplines rather than incremental biology. Machine learning models trained on comparative genomics, chromatin accessibility data, and single-cell gonad atlases could predict sex and fertility genes in non-model species, although such multi-omics resources remain scarce for most farmed taxa. Robotic microinjection arms, microfluidic embryo arrays, and electroporation of CRISPR ribonucleoproteins could scale editing beyond 50,000 embryos per day. AI-based imaging and behavior tracking could identify monosex or sterile candidates non-invasively, reducing culling. Global cryobanks of spermatogonia and oogonia paired with cloud-based genetic metadata could enable germplasm-on-demand, shipping elite donor cells to hatcheries with locally adapted sterile surrogates. On the policy side, the review advocates product-based regulation that judges the final trait, such as sterility or monosex status, rather than the editing process, citing Argentina, Brazil, and Japan as pioneers of this approach. Environmental validation is also essential, since temperature, hypoxia, and stocking density can shift sex differentiation and alter the performance of both triploid and edited stocks.

The review also confronts the ethical dimensions head-on. Off-target mutations, mosaicism, and developmental abnormalities can occur during protocol optimization, and heritable germline modifications raise questions about long-term consequences and human intervention in reproduction. Induced sterility itself has welfare implications that deserve study, and public scepticism toward gene-edited seafood persists even where the environmental credentials exceed those of hormone-based methods. The authors call for rigorous welfare assessment, transparent labelling, third-party environmental risk evaluation, and farmer and consumer co-design of deployment models. Their proposed two-tier platform separates genetic innovation, confined to breeding centers where stable edited lines are created and validated, from large-scale gamete production at hatcheries using sterile surrogate broodstock, decoupling genome editing from commercial seed supply while maintaining reproductive containment. The ultimate measure of success, they conclude, will not be editing efficiency or colonization rates but whether these tools deliver safe, affordable, environmentally sound seafood without compromising biodiversity or equity. If biological precision can be aligned with social responsibility, genome-edited monosex and sterile fish could become foundational to a climate-adaptive, circular aquaculture economy, much as hybrid seed systems transformed terrestrial agriculture.

Subject of Research: CRISPR-based genome editing and germ cell transplantation for producing monosex and sterile fish in sustainable aquaculture

Article Title: Engineering monosex and sterile fish for food production: from conventional methods to CRISPR-based precision

Article References: Min, Y., Sun, F., Wong, J., Lee, M., & Yue, G. H. (2026). Engineering monosex and sterile fish for food production: from conventional methods to CRISPR-based precision. Advanced Biotechnology, 4(3), Article 30. https://doi.org/10.1007/s44307-026-00128-5

Image Credits: AI Generated

DOI: 10.1007/s44307-026-00128-5

Keywords: aquaculture, CRISPR, genome editing, monosex fish, sterile fish, germ cell transplantation, surrogate broodstock, triploidy, Nile tilapia, Atlantic salmon, reproductive biocontainment, sustainable seafood

The core idea is deceptively simple. Rather than classifying seaweeds only by taxonomy or by their current commercial status, the framework characterizes each species by measurable functional traits: morphological features such as thallus size and branching, physiological features such as photosynthetic rates and nutrient uptake kinetics, and life-history features such as reproductive strategy and growth seasonality. In terrestrial agriculture, this trait-based approach has underpinned decades of crop improvement and ecological screening, allowing scientists to predict how a plant will perform under specific conditions without having to trial every individual genotype. The authors contend that seaweed science is now mature enough to apply the same logic, turning a scattered body of species-specific observations into a coherent, comparative discipline.

The need for such a framework becomes clear when one considers the structure of the seaweed farming industry. Global production is overwhelmingly concentrated in a handful of genera, including the kelp Saccharina and Undaria, the red algae Pyropia, Eucheuma, Kappaphycus, and Gracilaria, and the green alga Ulva. These cultivated species were largely domesticated from wild populations selected for availability and market demand rather than for optimized performance. Meanwhile, thousands of seaweed species remain uncultivated, many of which may possess traits, such as tolerance to warmer water, resistance to disease, rapid growth, or valuable biochemical compositions, that could make them superior candidates for future farming systems, particularly as ocean temperatures rise and cultivation expands into new biogeographic regions.

At the heart of the proposed approach is the recognition that no single trait determines success in aquaculture. A fast-growing species that cannot withstand wave exposure is a poor candidate for open-ocean farms; a hardy species with slow growth may never achieve commercial yields. Trait-based characterization allows these trade-offs to be made explicit. By compiling data on traits such as growth rate, temperature and salinity tolerance, nutrient requirements, epiphyte and pathogen susceptibility, ease of reproduction in hatcheries, and the mechanical properties of the thallus that determine how well a seaweed handles farm infrastructure, researchers can build comparative profiles that reveal which species are most likely to thrive under particular farming conditions and for particular markets.

The framework also speaks directly to one of the most pressing challenges in the field: climate resilience. Many of today’s workhorse species are cultivated near the thermal edges of their tolerance, and marine heatwaves have already caused significant crop losses in several producing regions. Selecting new candidates on the basis of thermal tolerance traits, rather than historical yield alone, could help the industry stay ahead of shifting ocean conditions. Similarly, as interest grows in offshore cultivation, where wave action and depth impose demands that nearshore farms do not, traits such as thallus robustness and attachment strength become decisive selection criteria that conventional species lists simply cannot capture.

Beyond environmental matching, trait-based screening can illuminate a species’ potential end-use. Seaweeds are farmed for wildly different purposes: nori for direct human consumption, carrageenan and agar-producing reds for hydrocolloid extraction, kelps for food ingredients and increasingly for applications in livestock feed and methane reduction. The biochemical profile of a species, its polysaccharide content, protein levels, pigment composition, and secondary metabolites, is itself a set of functional traits. Incorporating these biochemical characteristics into the framework means that candidate selection can be aligned with market opportunities from the outset, rather than discovering after years of agronomic development that a species is agronomically suitable but commercially unattractive.

The authors emphasize that building such a framework requires addressing significant data gaps. Trait information for seaweeds is patchy, fragmented across decades of phycological literature, and often measured with inconsistent methods that make cross-species comparison difficult. For many candidate species, even basic parameters such as maximal growth rate or reproductive biology in cultivation are unknown. The paper calls for coordinated efforts to standardize trait measurements, compile existing data into accessible databases, and prioritize trait characterization for species that show early promise. This is a familiar challenge in the history of trait-based ecology, where the value of comparative frameworks grew directly out of sustained investment in standardized measurement across research groups.

Another important dimension of the framework is its potential to support responsible innovation. Introducing new species into cultivation carries ecological risks, including the possibility of escapes, competition with native flora, and disease transmission. The authors argue that trait-based evaluation can incorporate risk-relevant traits, such as a species’ invasive potential, its reproductive dispersal capacity, and its host status for known seaweed pathogens, alongside performance traits. This integrated screening could help regulators and farmers distinguish between candidates whose domestication is ecologically prudent and those whose traits raise red flags, embedding biosafety into the earliest stages of candidate selection rather than treating it as an afterthought.

The social and economic geography of seaweed farming also figures in the analysis. A large share of global production occurs among smallholder coastal communities in Asia, and any expansion of the industry into new species and new regions will need to respect local capacities, infrastructure, and market structures. Traits such as the simplicity of a species’ cultivation cycle, the availability of seedstock, and the labor intensity of farm operations are directly relevant to whether a candidate species can be adopted by small-scale farmers. A framework that formalizes these practical traits alongside biological ones helps ensure that scientific selection translates into real-world adoption rather than remaining an exercise in laboratory optimization.

Looking forward, the trait-based approach opens doors to more quantitative and even predictive tools. As trait databases grow, statistical and machine-learning methods could identify combinations of traits that predict cultivation success, allowing researchers to screen large numbers of candidate species cheaply before committing resources to farm trials. The same data could guide selective breeding programs within promising species, identifying heritable traits that respond to improvement, much as crop breeders have done on land. In this sense, the framework is not merely a sorting exercise but a foundation for the deliberate domestication of a new generation of seaweed crops, bringing a level of intentionality to aquaculture that has so far been rare in the sector.

The broader significance of the work lies in its reframing of what seaweed farming could become. Today’s industry, for all its impressive growth, rests on a narrow biological base that is vulnerable to disease, climate shocks, and market fluctuations. Diversification is widely recognized as essential, but diversification without a principled selection process risks wasted investment and ecological harm. A trait-based framework offers a shared language for researchers, farmers, investors, and regulators to evaluate candidates systematically, compare trade-offs transparently, and prioritize the species most likely to succeed under the conditions of tomorrow’s oceans. As pressure mounts to expand sustainable marine food production, the ability to choose the right seaweed for the right place and purpose may prove to be one of the most consequential tools the industry acquires.

The analogy with terrestrial crop science is instructive because it highlights how long the payoff horizon for trait-based approaches can be. In agriculture on land, systematic trait screening preceded the green revolution’s yield gains by decades, and the seaweed sector is effectively at the beginning of that trajectory. Most cultivated seaweed genera have undergone little deliberate genetic improvement, meaning there may be substantial untapped potential even within currently farmed species once their traits are properly quantified and compared.

The framework also arrives at a moment when demand for seaweed products is diversifying beyond traditional food uses. Emerging applications, from biostimulants to alternative proteins, each favor different biochemical and physiological profiles, which strengthens the case for matching species to end-use through explicit trait data rather than trial and error. A species rich in specific polysaccharides, for example, may justify cultivation under conditions that would be uneconomical for a general-purpose food crop.

Finally, the perspective underscores a cultural shift within phycology itself. Much existing knowledge of seaweed biology resides in ecological studies of wild populations rather than in agronomic trials, and the proposed framework offers a route to translate that ecological understanding into cultivation insight. By treating traits as the common currency between wild ecology and farm performance, researchers can begin predicting how uncultivated species might behave in farm settings before expensive domestication programs begin, potentially shortening the path from ocean to aquaculture for promising new candidates.

Subject of Research: Using a trait-based framework to characterize farmed seaweeds and guide selection of new candidates

Article Title: Using a trait-based framework to characterize farmed seaweeds and guide selection of new candidates

Article References: Fong, C. R., Fong, P., & Froehlich, H. E. (2026). Using a trait-based framework to characterize farmed seaweeds and guide selection of new candidates. npj Ocean Sustainability. https://doi.org/10.1038/s44183-026-00239-5

Image Credits: AI Generated

DOI: 10.1038/s44183-026-00239-5

Keywords: trait-based, framework, characterize, farmed, seaweeds, guide, selection, candidates, scientific research

The heart of the new study is a technique called total infectome metatranscriptomics. Unlike targeted polymerase chain reaction assays, which can only detect organisms a researcher already suspects, RNA-based metatranscriptomic sequencing captures the full transcriptional activity of every microbe in a sample—RNA viruses, actively replicating DNA viruses, bacteria, fungi, and other eukaryotic microorganisms alike. Between 2021 and 2025, the team conducted epidemiological surveys across major grass carp-producing regions of China, including provinces in the Yangtze, Pearl, and Yellow River basins, confirming that OWS has spread well beyond its point of first documentation. From affected and healthy fish, the researchers dissected eight organs each—liver, spleen, kidney, intestine, gill, brain, muscle, and skin—and processed every organ as an independent sequencing library, generating 80 metatranscriptomes. After quality filtering and ribosomal RNA depletion, 8.09 billion high-quality reads remained, averaging 101.2 million per library, providing the depth needed for broad pathogen discovery.

The sequencing results revealed a strikingly complex microbial landscape. Across all libraries, the team identified 107 dominant microbial species: 32 viruses, 65 bacteria, and 10 eukaryotic microorganisms, spanning nine RNA viral supergroups, two DNA viral families, seven bacterial phyla, and seven eukaryotic phyla. Bacteria constituted the largest share of detected organisms at 60.7 percent, followed by RNA viruses at 22.4 percent, eukaryotes at 9.3 percent, and DNA viruses at 7.5 percent. Perhaps most tellingly, 68 of the 107 species—63.6 percent—were putatively novel, indicating that the majority of the grass carp-associated infectome had never been characterized before. Among the known and emerging agents were a grass carp hepacivirus, the first of its kind detected in this host; Chinook salmon nidovirus 1, previously reported only from salmonids; and a divergent aquareovirus the team named Shunde grass carp aquareovirus. Several parasitic eukaryotes from groups including Cnidaria, Euglenozoa, Fornicata, and Platyhelminthes also appeared in the dataset.

Detection alone, however, cannot establish causation—a lesson that has repeatedly frustrated disease investigators in aquaculture. To prioritize candidates, the researchers applied a comparative infectomics framework, quantifying microbial abundance as reads per million non-rRNA reads and retaining 33 taxa above a threshold of RPM ≥ 1. Differential abundance analysis, using a criterion of at least a fourfold change with a false discovery rate below 0.05, showed that overall microbial profiles clearly separated diseased fish from healthy controls. Among the enriched taxa, one organism stood out decisively: Flavobacterium psychrophilum was detected in every diseased individual, across multiple organs, and at its highest abundance in muscle and skin—precisely the tissues where OWS lesions were most severe. By contrast, parasitic eukaryotes such as Ichthyobodonidae, Trypanosomatidae, and Thelohanellus species showed inconsistent, sporadic occurrence, and the RNA viruses enriched in diseased fish phylogenetically clustered with invertebrate-associated lineages whose abundance correlated with parasite loads rather than direct infection of the fish.

With F. psychrophilum prioritized as the leading candidate, the team moved to experimental validation. The bacterium was isolated from lesion-associated muscle tissue of naturally diseased fish, yielding pale-yellow colonies on TYES agar after incubation at 15 degrees Celsius. Sequencing of the 16S rRNA gene placed the representative isolate, designated GC30-154, firmly within the F. psychrophilum clade with maximum bootstrap support. Healthy grass carp were then challenged by intramuscular injection with graded doses ranging from 10^4 to 10^8 colony-forming units. Control fish injected with buffer remained entirely healthy, while infected fish developed clinical signs beginning four days post-injection, with morbidity climbing in a dose-dependent fashion from 25 percent at the lowest dose to 100 percent at the highest. Mortality followed the same pattern, reaching 95 percent by day 18 in the highest-dose group, and the bacterium was successfully re-isolated from the lesions of deceased fish—satisfying key elements of Koch’s postulates.

The pathological picture in experimentally infected fish mirrored natural OWS with remarkable fidelity. Gross signs included focal erythema and swelling at the injection site, reddening around the pectoral-fin base, mild snout reddening, and tail erosion, while histopathology revealed severe muscle fiber degeneration, extensive vacuolation, and disruption of skin architecture—lesions closely resembling those in field cases, and concentrated in external and barrier tissues while liver, spleen, and kidney remained largely intact. Critically, the team then performed post-challenge total infectome analysis to rule out a role for secondary microbes in driving the experimental disease. Only F. psychrophilum appeared at consistently high abundance in infected animals, with the same muscle- and skin-dominant organ distribution seen in naturally diseased fish, while controls showed no signal whatsoever. The convergence of clinical signs, tissue pathology, mortality patterns, and infectome signatures established the bacterium as sufficient—and therefore the primary cause—of OWS.

A second layer of the investigation explained the disease’s peculiar seasonality. F. psychrophilum is classically regarded as a cold-water pathogen of salmonids, causing bacterial cold-water disease and rainbow trout fry syndrome, typically at temperatures below 10 degrees Celsius. Yet in grass carp the story was different. When challenged fish were held at constant temperatures of 10, 15, or 20 degrees Celsius, mortality was highest at 15 degrees—55 percent—with no deaths at the other temperatures during the observation period. More striking still was a temperature-shift experiment designed to mimic the overwintering-to-spring transition. Fish injected at 10 degrees and held there for 15 days showed no abnormalities; only when water temperature was gradually raised to 15 degrees did ulcers appear and mortality surge, reaching 95 percent within 14 days of warming. This thermal profile closely matches the late-overwintering and early-spring window in which natural OWS outbreaks occur, and it suggests the grass carp isolate may represent a host-adapted variant with altered temperature-dependent virulence.

Beyond the headline finding, the study carries broader implications for how infectious disease is investigated in complex systems. Aquatic environments teem with microbial diversity, and intensive aquaculture—shared water systems, high stocking densities, seasonal environmental stress—creates ideal conditions for polymicrobial communities to obscure etiology. The framework demonstrated here links epidemiological surveying, cohort-based comparative infectomics, targeted isolation, experimental infection, re-isolation, and post-challenge infectome validation into a coherent chain of evidence that converts unbiased pathogen discovery into causal inference. The authors emphasize that its success depends on careful attention to cohort representativeness, sampling coverage, and the detectability of pathogen-derived transcriptional signals, and that sampling and validation workflows must be tailored to the ecology of each disease system. Applied to OWS, the approach correctly demoted opportunistic eukaryotes and invertebrate-associated viruses that might otherwise have been mistaken for culprits, while flagging latent pathogen diversity—including novel hepaciviruses and nidoviruses—that could matter under future environmental or co-infection scenarios.

As aquaculture continues to expand and intensify worldwide, the connectivity between farming systems grows apace, raising the risk of pathogen transmission across previously separated host species and the emergence of new disease syndromes. The grass carp OWS resolution offers both a practical answer for producers—pointing toward surveillance and control of F. psychrophilum during spring warming—and a methodological template for wildlife, livestock, and even clinical medicine, where metagenomic detection increasingly outpaces causal interpretation. The study’s raw sequencing data have been deposited in a public aquatic pathogen platform, and all alignments and phylogenetic trees are openly available, reflecting the authors’ intent that the total infectome framework be adopted, adapted, and tested broadly. What began as an attempt to solve one stubborn disease in Chinese carp ponds may ultimately change how scientists everywhere distinguish the true cause of an outbreak from the microbial noise that surrounds it.

Subject of Research: A total infectome framework for resolving complex disease etiology in aquaculture

Article Title: A total infectome framework for resolving complex disease etiology in aquaculture

Article References: Xu, Y., Liu, H., Wu, W., Gu, Y., Zhang, N., Zhang, C., Zhou, R., Zhang, D., Weng, S., Shi, M., He, J., & He, J. (2026). A total infectome framework for resolving complex disease etiology in aquaculture. Advanced Biotechnology, 4(3), Article 31. https://doi.org/10.1007/s44307-026-00125-8

Image Credits: AI Generated

DOI: 10.1007/s44307-026-00125-8

Keywords: total, infectome, framework, resolving, complex, disease, etiology, aquaculture, scientific research

White seabass were once prized catch along the coast from central California to Baja California, but landings plummeted after 1950. Since 1983, California’s Ocean Resources Enhancement and Hatchery Program has spawned wild broodstock and raised juvenile fish to replenish wild populations. Yet larval rearing remains precarious: in past trials, Vibrio species — monitored using selective culture media — were associated with spikes in mortality. Hoping to tame the problem, the research team tested Sanolife® MIC, a commercial probiotic blend of three Bacillus species (B. subtilis, B. licheniformis, and B. pumilus) that has shown promise in shrimp and tilapia systems. The idea was simple: seed the tanks and live feed with beneficial bacteria to suppress pathogenic Vibrio and stabilize the microbial community during the vulnerable early feeding period.

The experiment followed larvae from the egg stage through 60 days post hatch (dph) in sixteen 320-liter fiberglass cone tanks, assigned to four treatment groups: rotifer feeding without probiotic, Artemia-only controls, probiotic-enriched Artemia, and probiotic added directly to rearing water. The team then deployed 16S rRNA amplicon sequencing on the V4 region of the bacterial genome, achieving an impressive average sequencing depth of 164,413 reads per sample. This allowed them to distinguish not just which bacteria were present, but how entire communities reorganized across time, treatment, and sample type — larval fish, culture water, and live feed.

The most important finding was what mattered most: time. When the researchers ran PERMANOVA tests on weighted UniFrac distances — a phylogenetically aware measure of community similarity — days since hatching explained by far the largest share of microbiota variability (R² = 0.202, p = 0.001). The larval microbiome is not a static assemblage but a moving target, remodeled as fish develop from yolk-sac larvae to fully weaned juveniles. Secondarily, the larval microbiota differed significantly from their surrounding culture water (R² = 0.063, p = 0.001), confirming that fish larvae are not simply bathed in — and colonized by — whatever bacteria float past them.

So did the probiotic work? In a word: partially. Sanolife® MIC did successfully incorporate its Bacillus strains into both the culture water and larval fish communities. Bacillaceae ranked among the top three most abundant families in probiotic-treated samples, and probiotic-treated Artemia became dominated by the added bacteria. But the treatment did not meaningfully reshape the broader microbial community, did not reduce Vibrio abundance, and did not improve larval growth or survival (14.2–18.1% survival at 56 dph, with no significant differences among treatments). Substituting rotifers for first-instar Artemia at first feeding also produced no significant shift in either larval or water microbiota. Differential abundance analysis using ANCOM-BC2 confirmed that only Bacillus and Brevibacillus changed between probiotic and control conditions.

What the team did find was a dramatic narrative of microbial succession. In the earliest feeding stages (5–18 dph), Vibrio surged to its peak abundance, coinciding with a sharp drop in bacterial alpha diversity — both evenness and Shannon diversity plummeted just after first feeding, then recovered and plateaued as larvae weaned onto dry feed. The dominant phyla throughout development were Pseudomonadota (Proteobacteria) and Bacteroidota (Bacteroidetes), alongside Bacillota and, from 18 dph onward, Campylobacterota. Nine genera changed significantly over time: marine taxa like Paracoccus, Poseidonibacter, Psychrobium, Colwellia, and Polaribacter increased, while Exiguobacterium, Vibrio, and Ligilactobacillus declined — likely outcompeted by slower-growing K-strategist bacteria as the gut matured.

Perhaps most concerning was the appearance of Tenacibaculum, a genus containing well-known fish pathogens responsible for tenacibaculosis, a disease causing significant economic losses in aquaculture globally. Tenacibaculum was initially overrepresented in culture water but did not colonize the larvae until 46 dph — late in the trial. The researchers note this genus has been found in association with skin lesions on juvenile white seabass. Neither Vibrio nor Tenacibaculum caused observable disease or mortality in this study, but their presence signals a latent threat: opportunistic pathogens ubiquitous in marine environments that could turn pathogenic during stressful events like handling, tagging, or transport.

The fish-water divide also told a fascinating ecological story. Larval fish harbored significantly more taxa associated with vertebrate guts — including Turicibacter, Kineothrix, Akkermansia, Bifidobacterium, Lactobacillus, and Ligilactobacillus — while culture water was dominated by free-living, particle-attached, and nitrogen-cycling marine bacteria like Polaribacter, Planctomycetaceae, and Halieaceae. Many of the fish-enriched taxa are recognized commensals or even candidate probiotics, suggesting the larvae actively cultivate a specialized internal community distinct from their external environment. Over half of the larval ASVs were shared with culture water, but composition differed sharply by unweighted UniFrac analysis.

The authors suggest the probiotic’s failure in this system may reflect dose, timing, or species-specific incompatibility, and future trials will test earlier administration at higher concentrations within the recirculating aquaculture system. Meanwhile, the detailed baseline map of the white seabass larval microbiome offers hatchery managers a diagnostic framework: tracking the 5–18 dph diversity crash and the rise of Tenacibaculum at later stages could flag windows of vulnerability before disease strikes. For a species whose recovery depends on millions of larvae surviving those first fragile weeks, knowing exactly when the microbiome wobbles — and which bacteria are circling — may prove as valuable as any feed formulation or tank design. The dataset is available under NCBI BioProject PRJNA1372260.

The findings carry weight beyond a single hatchery because larval fish microbiomes follow a recognizable developmental arc across marine finfish species. In Atlantic cod, for instance, early colonization is heavily dictated by live feed communities before host-driven selection takes hold, and the white seabass results echo that pattern: external sources matter most at first feeding, while the maturing gut progressively asserts its own selective pressures. This transition from environmentally dominated to host-specialized assemblages is thought to reflect anatomical and immunological maturation of the digestive tract, including the development of gut-associated lymphoid tissue and the gradual establishment of anaerobic niches that favor certain commensal lineages.

The diversity crash observed just after first feeding deserves particular attention from a physiological standpoint. A drop in Shannon diversity during a period of rapid dietary change suggests a temporary ecological bottleneck in which a small number of fast-growing, opportunistic taxa — Vibrio among them — exploit the nutrient pulse introduced by live feeds. Similar boom-and-bust dynamics have been documented in other marine larval systems, where r-strategist bacteria flourish briefly before slower-growing, more specialized competitors establish themselves. The eventual recovery and plateau of diversity indicates that the larval gut ecosystem is resilient, but the transient window of low diversity may represent a period of reduced functional redundancy, when a disturbance could more easily tip the community toward dysbiosis.

Methodologically, the study illustrates why culture-independent sequencing has become essential in aquaculture microbiology. Traditional monitoring with selective media such as TCBS agar captures only a narrow slice of the bacterial community and can misrepresent both the presence and abundance of target genera, since many Vibrio species grow poorly or atypically on such media while some non-target organisms produce false positives. Amplicon sequencing at the depth achieved here — averaging more than 160,000 reads per sample — resolves hundreds of amplicon sequence variants simultaneously, enabling the detection of taxa like Tenacibaculum that would never be flagged by Vibrio-selective screening. This broader lens is what allowed the researchers to identify a late-arriving potential pathogen that routine culture-based surveillance would likely have missed entirely.

The probiotic outcome also contributes to a growing body of evidence that probiotic efficacy in aquaculture is highly context-dependent. Bacillus-based products are attractive commercially because spore-forming strains survive feed processing and storage, and they have delivered measurable benefits in shrimp hatcheries and tilapia nurseries, including improved resistance to streptococcal infections. Yet the white seabass trial shows that successful colonization of the rearing environment does not guarantee community-level effects. The added Bacillus strains integrated into the existing microbial network without displacing residents, suggesting that established communities can absorb newcomers through functional redundancy or competitive exclusion. Factors such as dosing regimen, delivery route, water exchange rates, and the developmental stage at first exposure all plausibly modulate outcomes, which is why the authors advocate earlier and more intensive administration in follow-up trials.

For hatchery operations more broadly, the study underscores the value of longitudinal microbial monitoring as a management tool rather than a purely descriptive exercise. Because the larval microbiota proved far more sensitive to developmental time than to any experimental manipulation, routine sampling at standardized ages could establish expected community trajectories, with deviations serving as early-warning indicators of instability. The identification of gut-associated commensal genera enriched in the larvae — including lactic acid bacteria and Akkermansia-related taxa — also hints at candidate beneficial organisms native to white seabass that could eventually be developed into host-adapted probiotic formulations, an approach increasingly favored over generic commercial products in finfish aquaculture.

Subject of Research: Temporal dynamics of the larval microbiome in hatchery-raised white seabass under probiotic and live feed manipulation

Article Title: Temporal dynamics of the larval microbiota in hatchery-raised white seabass (Atractoscion nobilis) under probiotic and live feed manipulation

Article References: Kunselman, E., Stuart, K., Primus, A., Michelato, M., & Drawbridge, M. (2026). Temporal dynamics of the larval microbiota in hatchery-raised white seabass (Atractoscion nobilis) under probiotic and live feed manipulation. Blue Biotechnology, 3(1), Article 7. https://doi.org/10.1186/s44315-026-00058-w

Image Credits: AI Generated

DOI: 10.1186/s44315-026-00058-w

Keywords: white seabass, larval microbiome, probiotics, Sanolife MIC, Vibrio, Tenacibaculum, aquaculture, 16S rRNA sequencing, live feed, Artemia, hatchery, microbial succession