The transition from single-reference genomes to multi-accession assemblies represents a fundamental shift in how marine biologists conceptualize genetic diversity in macroalgae. Traditional reference genomes, while invaluable for initial annotation and basic comparative studies, inherently capture only the haplotype of a single individual. This limitation becomes particularly pronounced in species with high levels of structural variation, where presence-absence differences, copy-number changes, and large inversions are common. In crop science, it is well established that such structural variants often carry a significant portion of the adaptive and agronomic signal, influencing traits like yield, disease resistance, and environmental tolerance. However, the extent to which this holds true for seaweeds remains an open question, treated in current literature as a hypothesis requiring rigorous empirical testing rather than a settled fact. The development of graph pangenomes offers a solution to this limitation by integrating multiple accessions into a unified data structure that preserves the full spectrum of genomic variation. This approach allows researchers to distinguish between core genes, which are present in all individuals of a species, and accessory genes, which are present in only some. The accessory genome is particularly important for climate resilience, as it often contains genes involved in stress response, nutrient acquisition, and symbiotic interactions. By resolving these differences, pangenomics provides a more accurate map of the genetic landscape, enabling the identification of specific alleles that may confer advantages under changing environmental conditions.

Seascape genomics complements pangenomics by providing the spatial context necessary to interpret genetic variation. This field integrates genomic data with environmental variables to identify locally adapted populations and connectivity pathways across marine landscapes. By analyzing the distribution of adaptive alleles across different geographic locations, researchers can pinpoint populations that have evolved specific traits in response to local stressors, such as temperature fluctuations or salinity changes. This spatial resolution is crucial for understanding how climate change is reshaping the genetic structure of seaweed populations. Temporal genomics further extends this analysis by examining how these genetic patterns have changed over time. By comparing genomic data from different time points, scientists can measure the rate of contemporary evolution and identify recent evolutionary responses to climate change. This longitudinal perspective is essential for predicting future adaptation potential and identifying populations that may be particularly vulnerable to rapid environmental shifts. The combination of seascape and temporal genomics allows for a dynamic view of population genetics, moving beyond static snapshots to capture the ongoing process of adaptation.

While genomic data provides the blueprint for potential adaptation, the actual physiological response to stress is mediated by complex regulatory networks that extend beyond the DNA sequence. Transcriptomics, the study of gene expression, has been widely used to identify stress-responsive genes in seaweeds. However, differential expression data alone rarely resolves which specific alleles confer resilience or how that resilience varies across different environments. To address this, complementary omics layers are being integrated into the analysis. Epigenomics examines chemical modifications to DNA and histones that regulate gene expression without altering the underlying sequence. These epigenetic changes can provide a mechanism for rapid adaptation to stress, allowing organisms to adjust their phenotype in response to environmental cues. Metabolomics and proteomics offer insights into the biochemical and protein-level responses to stress, respectively. These layers can reveal the functional consequences of genetic variation, such as the production of antioxidant compounds, the remodeling of cell walls, or the activation of heat-shock proteins. Despite their potential, proteomic and metabolomic coverage of macroalgae remains significantly thinner than transcriptomic coverage, representing a major gap in the current evidence base. Closing this gap is a priority for future research, as it will provide a more complete picture of the physiological mechanisms underlying climate resilience.

The translation of molecular insights into practical applications for breeding and restoration requires rigorous validation through multiple experimental approaches. High-throughput gametophyte screening allows for the rapid assessment of genetic variation in early life stages, identifying individuals with desirable traits before they reach maturity. Chlorophyll fluorescence phenotyping provides a non-invasive method for measuring photosynthetic efficiency and stress tolerance, offering a direct link between genetic variation and physiological performance. Functional genomics techniques, such as gene editing and overexpression, enable the direct testing of the role of specific genes in stress response. Common-garden studies, where individuals from different populations are grown under controlled conditions, help to disentangle genetic from environmental effects on trait expression. Heatwave mesocosms simulate acute thermal stress in a controlled environment, allowing researchers to observe the short-term responses of seaweeds to extreme conditions. Finally, field trials are essential for validating the performance of candidate genotypes in real-world environments, where multiple stressors interact in complex ways. Only through this multi-tiered validation process can researchers confidently identify traits that are both adaptive and deployable in breeding or restoration programs.

The application of validated traits to genomic selection and climate-resilient cultivars represents a significant advance in seaweed aquaculture. Genomic selection uses genetic markers to predict the breeding value of individuals, allowing for the selection of superior genotypes without the need for extensive phenotyping. This approach can accelerate the development of cultivars with enhanced tolerance to heat, salinity, and other stressors. Provenance-based restoration involves the use of locally adapted genotypes in restoration efforts, ensuring that the restored populations are well-suited to the local environment. Assisted gene flow, the deliberate movement of genetic material between populations, can be used to introduce adaptive alleles into vulnerable populations, enhancing their resilience to climate change. However, these interventions must be implemented with careful consideration of genetic diversity, biosecurity, and long-term genomic monitoring. The introduction of non-native genotypes can pose risks to local ecosystems, and the loss of genetic diversity can reduce the long-term adaptive potential of populations. Adaptive management, which involves continuous monitoring and adjustment of interventions based on observed outcomes, is crucial for ensuring the success and sustainability of these efforts.

The integration of pangenomics, seascape genomics, and multi-omics approaches provides a comprehensive framework for advancing seaweed genomics from resource development to a predictive, translational pipeline. This framework emphasizes the importance of considering the full spectrum of genetic variation, the spatial and temporal context of adaptation, and the functional consequences of genetic differences. By addressing the current gaps in proteomic and metabolomic data and by rigorously validating candidate traits through multiple experimental approaches, researchers can develop a more robust understanding of the mechanisms underlying climate resilience. This understanding can then be applied to the development of climate-ready seaweeds, supporting resilient aquaculture and marine forest restoration. The challenges are significant, but the potential benefits are immense. As ocean temperatures continue to rise and marine heatwaves become more frequent and intense, the need for climate-resilient seaweeds will only grow. The integrated approach outlined here offers a path forward, combining the power of genomics with the rigor of experimental validation to create a new generation of seaweeds capable of thriving in a changing ocean.

Subject of Research: Integrated genomic and multi-omics approaches for developing climate-resilient seaweeds for breeding and restoration

Article Title: Climate-ready seaweeds: pangenomics, seascape genomics, and multi-omics for breeding and restoration

Article References: Subbiah, S. K., & Thaliyakkattil, S. C. (2026). Climate-ready seaweeds: pangenomics, seascape genomics, and multi-omics for breeding and restoration. Discover Oceans, 3(1), 68. https://doi.org/10.1007/s44289-026-00183-9

Image Credits: AI Generated

DOI: 10.1007/s44289-026-00183-9

Keywords: seaweeds, kelp, pangenomics, seascape genomics, multi-omics, climate resilience, genomic selection, marine forest restoration, structural variation, aquaculture, epigenetics, phenotyping

The motivation is stark. Synthetic pesticides, including organophosphates, carbamates, organochlorines, and pyrethroids, have long been the default tool for protecting crops, but their overuse carries serious consequences. According to figures cited from the United Nations Environment Programme and the World Health Organization, roughly three million people suffer pesticide poisoning each year and around 200,000 die, particularly in low- and middle-income countries. Chronic exposure has been linked to endocrine disruption, neurotoxicity, type 2 diabetes, cancers, Parkinson’s and Alzheimer’s diseases, infertility, and leukemia. In the environment, residues degrade water quality, kill non-target organisms such as bees and earthworms, damage soil biodiversity, and drive pest resistance, which in turn demands ever-higher doses.

Against this backdrop, the global biopesticide market, valued at 5.75 billion dollars in 2022, is projected to reach 17.57 billion dollars by 2030, growing at roughly 15 percent annually. Algae occupy a distinctive niche within this expansion because they are photosynthetic biofactories that secrete an enormous range of secondary metabolites under stress. The review organizes these into several major classes. Terpenoids, the largest class of natural products with more than 50,000 identified structures, are synthesized in algae via the methylerythritol phosphate pathway in the chloroplast and the mevalonate pathway in the cytosol. Red algae are particularly prolific producers, and sesquiterpenes and monoterpenes from Cladophora and Chaetoceros have shown insect-repellent effects by acting on insect sensory organs.

Alkaloids, nitrogen-rich heterocyclic molecules produced mainly by dinoflagellates and cyanobacteria, induce severe oxidative stress in target pests, generating reactive oxygen species that damage DNA and trigger programmed cell death. Compounds such as 12-epi-hapalindole E isonitrile from Fischerella, calothrixin A from Calothrix, and saxitoxin from diatoms illustrate the chemical arsenal. Phenolic compounds, including phlorotannins and bromophenols abundant in seaweeds, target metabolic enzymes and cell membranes in pathogens while simultaneously priming plant defense pathways. Polyketides, built by polyketide synthases through condensation and reduction reactions, account for roughly a quarter of known bioactive compounds from marine macroalgae and include herbicidal and antifungal agents such as cryptophycins from Nostoc. Peptides, whether assembled by non-ribosomal peptide synthetases or ribosomally and modified afterward, add antimicrobial and nematocidal potency, although their sensitivity to degradation remains a formulation challenge.

The mechanisms of action are genuinely multi-target, which matters because single-site toxicity is what drives rapid resistance in conventional pesticides. Algal compounds disrupt pest neurology and metabolism, destroy microbial cell membranes, inhibit photosynthetic electron transport in weeds, and interfere with quorum sensing, the chemical communication system bacteria use to coordinate infection. Cyanobacterin from cyanobacteria disrupts photosynthetic electron transport in pea chloroplasts, while Fischerellin A from Fischerella muscicola suppresses fungal pathogens including Pyricularia oryzae and Phytophthora infestans. Cyanobacterial metabolites such as microcystin-LR inhibit protein phosphatases PP1 and PP2A, key regulatory enzymes, and anabaenopeptins block zinc-dependent carboxypeptidases. Indirectly, algal polysaccharides elicit systemic plant resistance through jasmonic acid and salicylic acid signaling and strengthen cell walls via the phenylpropanoid pathway.

The biological evidence spans every major pest category. On the antibacterial front, Dunaliella salina hexane extracts rich in beta-carotene reduced disease incidence in Pseudomonas syringae-infected tomato plants by 65.7 percent and severity by 77 percent in in vivo assays, while soft rot symptoms in treated tomato and zucchini fruits fell to 5.3 and 12.6 percent compared with 90.6 and 100 percent in controls. Against fungi, Nostoc ethanolic extracts completely inhibited Sclerotinia sclerotiorum in tomato, and a large screening of 280 microalgal strains found that 45 percent inhibited at least one phytopathogenic fungus or oomycete, with cyanobacteria showing the highest activity at 64 percent. Sulfated polysaccharides such as carrageenans, fucoidans, and ulvans block viral adsorption and entry, protecting plants against cucumber mosaic and tobacco mosaic viruses by eliciting immunity rather than direct toxicity.

Nematode and insect control show equally striking results. Dry powders from the seaweeds Spatoglossum variabile, Stokeyia indica, and Melanothamnus afaqhusainii reduced gall formation and blocked root penetration by the root-knot nematode Meloidogyne incognita in eggplant and watermelon, in some cases matching the commercial nematicide carbofuran. Stoechospermum polypodioides caused nearly 80 percent mortality in Meloidogyne javanica, the highest among 21 species tested. In insects, halogenated monoterpenes from the red alga Plocamium telfairiae killed 80 percent of German cockroaches, and a petroleum ether extract of Nostoc muscorum showed an LC50 of just 155.22 ppm against the devastating fall armyworm Spodoptera frugiperda. As herbicides, the rare sugar 7-deoxysedoheptulose from Synechococcus elongatus blocks the shikimate pathway, the same target as glyphosate, inhibiting cyanobacteria, yeasts, and land plants alike.

What sets this review apart is its willingness to confront the economics. Techno-economic analyses for algal biopesticides are scarce, so the authors built conceptual scenarios for a 1000-liter cultivation system run over ten cycles. A conventional biorefinery using synthetic medium cost 6,792 dollars in operating expenses but generated only about 82 dollars of biopesticide revenue, a clear failure. Replacing 75 percent of the medium with wastewater cut operating costs to roughly 306 dollars while boosting biomass productivity to 2.41 grams per liter, yet a single-product strategy still fell short. Only a multi-product biorefinery, co-extracting pigments, antioxidants, and biopesticides from the same biomass, approached commercial viability, generating over 900 dollars across ten cycles and buffering the economics against yield fluctuations. Earlier work cited in the review supports the concept: Chlorella thermophila grown in dairy wastewater yielded both a biopesticide effective against rice blight pathogens and a 28 percent biocrude oil yield from the residual biomass.

The obstacles to commercialization remain formidable. Large-scale algal cultivation demands enormous quantities of water and nutrients; extraction often relies on expensive technologies and organic solvents; algal extracts can be unstable under field conditions of heat, light, and rain; and their slow, sometimes inconsistent action discourages farmers who need rapid knockdown. Regulatory pathways add another layer of complexity, with the United States Environmental Protection Agency requiring less data under FIFRA than the European Union does under Regulation EC 1107/2009, where biopesticides face data requirements comparable to those for synthetic chemicals. There is no universal regulatory model, and the resulting fragmentation slows global commercialization. The authors also caution that many laboratory results, particularly antibacterial and antiviral findings, rest on in vitro assays with model organisms rather than plant pathogens, and that resistance development in target pests has rarely been systematically tested.

The review’s conclusion is measured rather than triumphal. Algal biopesticides are unlikely to displace established products such as Bacillus thuringiensis or spinosad in the near term; instead, their most realistic role is as complements within integrated pest management, where their multifunctionality, simultaneous pathogen suppression, immune priming, and stress tolerance enhancement, offers the greatest value. The authors call for substantial field trials, CRISPR-based engineering of algal strains to boost specific compounds, nano-formulations to improve stability and targeted delivery, synergistic extract cocktails, and genomic and metabolomic profiling to identify biosynthetic pathways. If those pieces come together, the humble photosynthetic organisms that have thrived in oceans and ponds for billions of years may finally take their place in the farmer’s toolkit, turning wastewater into crop protection and helping agriculture wean itself off its most toxic chemistry.

Subject of Research: Algal bioactive compounds as multi-target biopesticides for sustainable crop protection

Article Title: Algal bioactive compounds for next-generation biopesticides: a multi-target resource for sustainable pest management

Article References: Adetunji, A. I., Ojwach, J. D., Goswami, R. K., Rawat, I., & Bux, F. (2026). Algal bioactive compounds for next-generation biopesticides: a multi-target resource for sustainable pest management. Environmental Science and Pollution Research, 33(30), 15179-15210. https://doi.org/10.1007/s11356-026-38228-3

Image Credits: AI Generated

DOI: 10.1007/s11356-026-38228-3

Keywords: algae, biopesticides, cyanobacteria, seaweeds, sustainable agriculture, crop protection, terpenoids, alkaloids, phenolic compounds, techno-economic analysis, integrated pest management, wastewater cultivation

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