The study, published in PeerJ, used an autonomous wave glider equipped with an underwater acoustic recorder to monitor the East Florida Shelf for two months. The wave-powered platform traveled through coastal waters while continuously recording sounds, creating a mobile listening station that could operate for much longer than a conventional boat-based survey. In total, the instrument captured nearly 62 hours of underwater sound, and dolphins were detected in more than 1,600 recordings. The researchers then compared dolphin vocalizations with environmental variables such as water depth, temperature, salinity, currents, chlorophyll-a concentration, biological productivity and human-generated noise.

Dolphin sounds provide researchers with a window into behavior that is often impossible to observe directly. Whistles are generally associated with communication and social activity. Individual dolphins can produce distinctive signature whistles that help them maintain contact, while groups may exchange calls as they travel, coordinate behavior or interact. Echolocation operates differently. Dolphins emit rapid sequences of broadband clicks and interpret the returning echoes to determine the location, distance, size and movement of objects. This biological sonar allows them to navigate in darkness and locate prey even when visibility is poor.

The Florida recordings revealed that these two acoustic behaviors were associated with different parts of the coastal environment. Whistle activity was detected more often in nearshore waters and was influenced by location, temperature, overall sound levels and chlorophyll-a concentration. Chlorophyll-a is commonly used as an indicator of microscopic plant productivity in the ocean. Areas with higher productivity can support more complex food webs, potentially affecting where fish gather and where dolphins encounter favorable conditions for social activity. The analysis identified two especially prominent zones of predicted whistle activity near St. Augustine and Ponce Inlet, with additional areas near Melbourne Beach and north of Ponce Inlet.

Echolocation produced a contrasting pattern. Dolphin clicks were concentrated in waters extending from Melbourne to Ponce Inlet and offshore toward Long John Reef. These areas also contained abundant sound-producing fish, raising the possibility that dolphins were using acoustic information generated by their prey while hunting. Many marine fish produce sounds through movements of muscles, bones or swim bladders, and those signals can travel through the water. If dolphins can detect such sounds, they may be able to use them as cues to locate productive feeding areas before prey comes into view. The overlap does not prove that dolphins were deliberately tracking fish sounds, but it provides a compelling direction for future research.

The study also found mismatches between fish acoustic activity and dolphin detections. Such mismatches may indicate that fish reduce or alter their sound production when dolphins are nearby, creating a form of acoustic concealment. In this underwater version of a surveillance game, predators may listen for prey while prey listen for predators. “Everybody is snooping on everybody else,” said Greg O’Corry-Crowe, a research professor at FAU Harbor Branch and a National Geographic Explorer. The observation raises a broader question about marine communication: whether dolphins are eavesdropping on fish and whether fish can recognize the acoustic presence of dolphins well enough to change their behavior.

The timing of detections varied as well. Dolphin activity was higher in March than in April, potentially reflecting seasonal movements of different populations along Florida’s Atlantic coast. The researchers caution that acoustic detections alone cannot identify every species, group size or specific behavior with certainty. Nevertheless, repeated patterns across space and time can reveal where dolphins are likely to spend energy communicating, traveling or searching for prey. Combining acoustic observations with oceanographic data gives scientists a way to estimate habitat use even when animals remain submerged and out of sight.

Human noise complicates this acoustic world. Vessel traffic can mask dolphin whistles, reducing the distance over which calls can be detected by other dolphins. The same masking effect can also make it harder for researchers to identify animals in acoustic recordings. Some areas with high predicted whistle activity overlapped with waters experiencing substantial vessel noise, suggesting that important social habitat may also be exposed to persistent disturbance. When communication becomes less reliable, dolphins may need to call more loudly, repeat signals or change the timing of their interactions, potentially increasing the energetic cost of maintaining contact.

Autonomous platforms such as wave gliders offer a powerful way to investigate these challenges. Unlike short boat-based surveys, which provide snapshots of animal activity, a wave glider can remain at sea for weeks and sample broad areas with relatively limited human intervention. Its recorder effectively extends the researcher’s hearing into an environment that humans cannot directly experience. “The ocean is filled with sounds that humans rarely hear,” said Laurent Chérubin, a research professor at FAU Harbor Branch and the study’s senior author. Continuous monitoring can expose patterns that would otherwise disappear between occasional observations, helping scientists distinguish persistent habitat preferences from brief encounters.

The researchers say that acoustic monitoring could ultimately support marine conservation by identifying dolphin feeding grounds, social areas and regions where human activity creates the greatest risks. The approach may be especially valuable in coastal waters, where dolphins, fish, shipping and recreation overlap within a limited space. By combining dolphin vocalizations with prey sounds and measurements of the physical ocean, scientists can begin to map habitat from the animals’ perspective. Every whistle, click and fish call becomes part of a larger ecological signal—one that could help determine where protection, vessel-management measures or further study are most urgently needed.

Subject of Research: Animals

Article Title: Differential acoustic habitat use in delphinids along the Florida Atlantic coast

News Publication Date: 31-Jul-2026

Web References: Florida Atlantic University Harbor Branch Oceanographic Institute; PeerJ article; https://doi.org/10.7717/peerj.21547

References: Carvalho et al., “Differential acoustic habitat use in delphinids along the Florida Atlantic coast,” PeerJ, DOI: 10.7717/peerj.21547

Image Credits: W. Noke Durden, NOAA Fisheries

Keywords

Dolphins, bioacoustics, echolocation, marine mammals, acoustic habitat, dolphin communication, fish sounds, marine conservation, autonomous wave glider, Florida Atlantic coast, vessel noise, foraging ecology, coastal ecosystems

Published in Regional Studies in Marine Science, the study examines how R. maritima survives in mosquito impoundments, engineered wetlands separated from the lagoon by dikes and water-control structures. These systems are managed through Rotational Impoundment Management, a process that periodically reconnects them with the lagoon. The resulting fluctuations in water level, salinity and water quality create difficult conditions for seagrasses, but they also provide a natural experiment: species that persist there must tolerate repeated environmental disruption and rapidly changing habitat conditions.

Over three years, researchers monitored naturally occurring R. maritima populations at two locations within Bee Gum Point Nature Preserve. They measured seasonal changes in plant coverage and biomass while recording environmental conditions that could influence growth and reproduction. The team also analyzed sediment samples for dormant seeds and conducted controlled laboratory experiments to determine which environmental signals trigger germination. In parallel, plants collected from the preserve were grown in aquaculture tanks at the FAU Harbor Branch Seagrass Nursery, where scientists tracked their development, flowering, seed production and potential for large-scale cultivation.

The field observations revealed that R. maritima follows a sharply seasonal annual life cycle. Plants grew mainly from late winter through spring, flowered during the warmer part of the year and then largely disappeared above the sediment during summer. This dieback could easily be mistaken for permanent local extinction. However, the population returned in subsequent years, demonstrating that the visible plants represent only one phase of a broader life-history strategy. The species’ persistence depended on what remained below the surface after the shoots and leaves had vanished.

That hidden survival system was a persistent seed bank embedded in the sediment. Seeds remained viable through periods when the impoundments experienced flooding, high salinity and deteriorating water quality, allowing the population to regenerate when conditions improved. Laboratory trials showed that reduced salinity, especially exposure to freshwater, strongly stimulated germination. The finding indicates that freshwater pulses may act as an ecological cue, signaling a temporary window in which conditions are favorable for seedlings to emerge and establish before the next period of environmental stress.

“Ruppia maritima has a remarkable ability to persist through disturbance,” said Rachel Brewton, Ph.D., senior author and an assistant research professor at FAU Harbor Branch. “Even when the plants disappear above ground, the population can persist as a seedbank in the sediment, waiting for conditions to become favorable.” This capacity is particularly significant in the Indian River Lagoon, where restoration sites may not remain stable long enough for conventional planting methods to succeed. A seed bank can preserve genetic material through unfavorable seasons and release new plants when hydrological conditions shift.

The species also performed well under nursery conditions. Plants transplanted into aquaculture tanks became established, reproduced and produced viable seeds while maintaining a seasonal growth pattern similar to that observed in the wild. Most notably, the cultivated population has remained self-sustaining since it was established in 2021. “That ability to regenerate from a persistent seed bank, combined with its successful cultivation in our seagrass nursery, is what makes this species particularly interesting from a restoration perspective,” said Richard Mulroy, a study co-author and biological scientist at FAU Harbor Branch.

The researchers say R. maritima could function as a pioneer species in degraded parts of the lagoon. Rather than replacing mature seagrass communities, it could be introduced into bare or disturbed areas where its rapid seasonal growth and tolerance of fluctuating conditions might help begin the recovery process. By stabilizing sediment, adding habitat structure and influencing local water conditions, early colonizers can potentially make sites more suitable for other seagrass species. “The goal of restoration is not simply to put seagrass back—it is to create the conditions for a functioning ecosystem to recover,” Brewton said.

The results also point toward seed-based restoration as a promising alternative or complement to transplanting adult plants. During the experiments, R. maritima seeds remained viable during prolonged exposure to high salinity and germinated after freshwater treatment, suggesting that seeds could be collected, stored and propagated before deployment. The approach could improve the timing and scale of restoration, but field trials are still needed to determine how seeds and nursery-grown plants perform under natural conditions. Researchers will next test planting methods, identify suitable environmental windows and evaluate whether the species can help rebuild seagrass habitat in the Indian River Lagoon and other disturbed estuaries. The study was supported by the U.S. Fish and Wildlife Service’s Coastal Program, with matching support from the Indian River Land Trust, and was dedicated to the memory of research professor M. Dennis Hanisak, Ph.D.

Subject of Research: Not applicable

Article Title: Ecology and restoration potential of Ruppia maritima in a managed mosquito impoundment of the Indian River Lagoon, Florida, USA

News Publication Date: 18-Jul-2026

Web References: Florida Atlantic University, https://www.fau.edu/; FAU Harbor Branch Oceanographic Institute, https://www.fau.edu/hboi/; FAU Harbor Branch Seagrass Nursery, https://www.fau.edu/hboi/research/marine-ecosystem-conservation/coral-reefs/seagrass-nursery-and-marine-botany/

References: Regional Studies in Marine Science, DOI: 10.1016/j.rsma.2026.105271

Image Credits: FAU Harbor Branch

Keywords: Seagrasses, Ruppia maritima, Indian River Lagoon, seagrass restoration, seed banks, marine conservation, aquatic ecology, water quality, ecological resilience, aquaculture, mosquito impoundments, estuaries

The Queen Conch Mobile Lab is engineered to bolster conservation initiatives by nurturing up to 2,000 juvenile queen conch annually. This mobile hatchery is wholly self-contained, designed to operate in remote coastal communities across the Caribbean that lack permanent aquaculture facilities. With a footprint measuring approximately 26 feet by 8 feet, the lab is solar-powered and equipped with sophisticated saltwater and aeration systems, capable of maintaining optimal water conditions essential for the delicate early life stages of queen conch larvae. This mobility allows it to be deployed where it is needed most, connecting directly to local seawater sources to sustain the entire lifecycle from egg to juvenile.

The lab’s operational success was marked in April, when CEI researchers introduced the first queen conch egg masses, witnessing the subsequent hatch of tiny veliger larvae — a critical rite of passage for the species. Over a 21-day larval period, these microscopic free-swimmers underwent metamorphosis into juveniles, transitioning from the planktonic stage into benthic, seagrass-associated organisms. This metamorphic shift is triggered by biochemical signals from seagrass detritus, an essential habitat for the species’ survival. Thus far, the lab has produced approximately 200 newly metamorphosed juveniles from the initial egg cohort, with over 100 additional individuals from subsequent batches completing this vital development phase.

Queen conch (Lobatus gigas) plays a pivotal ecological role in the Caribbean’s seagrass beds by grazing on algae and maintaining the health and balance of these underwater meadows, which serve as critical habitats for myriad marine species. Due to decades of overfishing and habitat degradation, queen conch populations have plummeted, resulting in their current “threatened” status under the U.S. Endangered Species Act. Historically, the Caribbean harvested roughly 31,000 tons annually, representing an economic value nearing $39 million per year, demonstrating the species’ significance not only ecologically but also socioeconomically. Without intervention, scientific projections forecast that commercial populations in The Bahamas could collapse within the next decade to decade and a half.

Megan Davis, Ph.D., director of the Queen Conch Lab at FAU Harbor Branch and a leading aquaculture research professor, emphasizes the broader implications of this project: “This mobile hatchery is more than just a technological achievement; it embodies the convergence of science, community engagement, and conservation with a shared vision of restoring and preserving queen conch populations. The hatch marks a pivotal step in actively cultivating the next generation to repopulate and rejuvenate the vital seagrass ecosystems they inhabit.”

The queen conch’s reproductive biology underscores both its resilience and fragility. From April through September, individual females can deposit up to 10 gelatinous egg masses, each containing upward of 500,000 eggs. These masses hatch nocturnally, releasing veliger larvae which rely on oceanic currents and microalgae for nourishment during their planktonic stage. However, harsh natural mortality rates mean fewer than 1% survive to adulthood. Typically, queen conch reach sexual maturity in 4 to 5 years, characterized by the thickening of their shell lip to a noticeable 9 to 15 millimeters. Longevity can extend to 40 years, during which the shell continuously grows with the animal.

Following metamorphosis within the lab, the juveniles will be transferred to grow-out tanks where they are nurtured on a highly specialized diet consisting of natural diatoms and a proprietary seaweed-based gel. This controlled feeding regime ensures optimal growth rates and health, necessary for survival post-release. Juveniles will grow to an approximate size of 7 to 9 centimeters before acclimatization in secure pens. This final rearing phase facilitates adaptation to natural conditions before eventual restoration into their native seagrass beds, where they will contribute to the ecological balance.

Community involvement lies at the heart of the Queen Conch Mobile Lab initiative, transcending mere scientific output. The lab anticipates engaging as many as 1,500 visitors annually, including local residents, fishers, students, and interns. This holistic approach fosters environmental stewardship through education, hands-on workforce training, and aquaculture skills development. According to Becky Holt, assistant director at the Queen Conch Lab, the project serves as an inspirational nexus where diverse groups converge to exchange knowledge and celebrate conservation successes firsthand. The lab has become a beacon of hope and a hub for sustainable marine science practices deeply intertwined with the cultural fabric of the Caribbean.

The collaboration between FAU Harbor Branch and CEI draws on decades of expertise and a shared commitment to community-based solutions. CEI’s long-standing environmental science programs and revered queen conch research provide an invaluable foundation for the mobile lab’s success. Together, the partnership is pioneering a replicable model for conservation aquaculture that may well revolutionize marine restoration efforts throughout the Caribbean.

This pilot program is part of a broader vision orchestrated by FAU Harbor Branch to establish a network of community-operated queen conch farms spanning multiple Caribbean nations. Since launching its first mobile hatchery in 2022, the Queen Conch Lab has expanded operations to Puerto Rico, Jamaica, Curaçao, and additional Bahamian sites. These mobile labs encapsulate a transformative approach to marine conservation, seamlessly integrating scientific innovation with community empowerment.

Davis and Holt’s groundbreaking work was recognized in 2025 by the Global Seafood Alliance with the Responsible Seafood Innovation Award in Aquaculture. Their achievements underscore the critical importance of decentralizing restoration science and actively involving local communities in safeguarding marine biodiversity. The sustained success and scaling of these initiatives represent a hopeful pathway toward recovering queen conch populations and preserving marine ecosystems that sustain regional economies and cultural identities.

The project benefits from funding by the Longer Tables Fund, a philanthropic endeavor founded by chef and humanitarian José Andrés. Additional foundational support came from The Moore Bahamas Foundation, underscoring the vital role of philanthropic partnerships in advancing sustainable aquaculture innovations. Together, science, conservation, and community stewardship are converging to create a resilient future where queen conch populations not only survive but thrive for generations to come.

Subject of Research: Marine Conservation and Aquaculture of Queen Conch (Lobatus gigas)

Article Title: Revolutionizing Caribbean Marine Conservation: The Queen Conch Mobile Lab Launches on Eleuthera

News Publication Date: Information not provided

Web References:

• Florida Atlantic University: https://www.fau.edu/
• FAU Harbor Branch Oceanographic Institute: https://www.fau.edu/hboi/
• The Island School’s Cape Eleuthera Institute: https://islandschool.org/cape-eleuthera-institute/about-us-cei/
• Queen Conch Lab: https://www.queenconchlab.com/

Image Credits: FAU Harbor Branch Oceanographic Institute

Keywords: Aquaculture, Fisheries, Aquatic Animals, Endangered Species, Fisheries Management, Ecology, Aquatic Ecology, Marine Ecology, Marine Conservation, Laboratories

Shark bycatch occurs when sharks are unintentionally caught on fishing hooks intended for other commercially valuable species such as tuna or swordfish. The consequences of bycatch extend beyond mere numbers; sharks play a critical role in marine ecosystems, and their slow growth and low reproductive rates render them particularly vulnerable to population declines. The removal of sharks from the environment disrupts ecological balance, compromises marine biodiversity, and jeopardizes the long-term sustainability of fisheries. Moreover, sharks caught inadvertently often die and are discarded, resulting in both ecological harm and substantial financial losses for fishermen due to damaged gear and wasted bait.

Dr. Kajiura’s shark deterrent device addresses this dual problem by selectively repelling sharks from baited hooks through the creation of a galvanic electric field. Unlike previous shark deterrents that tend to be cost-prohibitive and cumbersome for commercial fisheries to implement, this device harnesses the natural bioelectrical sensitivity of shark species. The device consists of a zinc and graphite element integrated into fishing hooks, which, when submerged in seawater, generates a mild electric field that is perceived by sharks and discourages them from approaching the bait. Importantly, this repellent effect is selective—target fish species remain unaffected, ensuring the fishery’s catch composition is not compromised.

This selective electrosensory deterrence is groundbreaking because it capitalizes on a biological trait unique to sharks, known as the ampullae of Lorenzini, specialized electroreceptors that allow sharks to detect electrical signals in the ocean. By emitting a signal in the range that repels sharks but is not disturbing to teleost fishes, the device operates with precision and environmental sensitivity. Field testing has demonstrated impressive results, with shark catch rates reduced by up to 69%, a substantial improvement over existing methods. These findings suggest that Dr. Kajiura’s device could serve as an innovative tool that supports both the conservation of shark populations and the economic viability of commercial fisheries.

The development of this shark repellent device marks a notable technological stride within the field of marine conservation, offering a solution that balances ecological preservation with commercial practicality. The approach is characterized by its affordability, simplicity, and scalability. Utilizing readily available materials and easily integrable into current fishing gear, it overcomes the barrier of complexity that often impedes the adoption of conservation tools in commercial operations. The device’s design is a testament to the potential of translational research in biological sciences, combining rigorous scientific inquiry with technological innovation to address real-world challenges.

The significance of this project is amplified by the comprehensive iterative development process Dr. Kajiura’s team is conducting. Beyond laboratory prototype development, the device undergoes precision Computer-Aided Design (CAD) modeling and manufacturing through CNC milling techniques, ensuring its robustness and efficiency. These precision fabrication methods enhance the prototype’s durability and reliability, critical parameters for fishing gear subjected to harsh oceanic conditions. Extensive field trials with active commercial fisheries provide essential data to refine the device, adapting it to the practical demands and feedback of fishermen, thereby enhancing user adoption potential.

This initiative is supported by Florida Atlantic University’s Innovation Pilot Award Program, which funds early-stage research projects with commercial promise. The program’s seeding of innovation bridges the gap between conceptual scientific discoveries and the practical deployment of market-ready technologies. Such institutional backing is vital for projects like Dr. Kajiura’s shark repellent, facilitating the transition from laboratory success to scalable industry implementation. This synergy between academic research and industry vitalizes the translation of technologically innovative ideas into solutions that deliver societal and environmental benefits.

Beyond its immediate commercial implications, the device has wider environmental relevance. By reducing shark bycatch, marine ecosystems stand a better chance of maintaining their intricate balance, thus preserving biodiversity and ecosystem services. The reduction of bycatch also curtails gear damage and financial losses frequently incurred by fishermen, aligning environmental stewardship with economic incentives. Sustainable fisheries that integrate such technologies can be models for responsible natural resource management, meeting increasing global demand for seafood while mitigating ecological impact.

The global market for longline fishing gear is robust and expanding, valued at approximately $2.5 billion in 2023, with projections estimating growth to over $4 billion by 2032. This growth is propelled by rising seafood consumption and the continuous investment in technologies aimed at enhancing fishing efficacy and sustainability. Dr. Kajiura’s device fits strategically within this market trajectory, offering an innovative, cost-effective measure to improve catch selectivity and environmental responsibility, traits highly sought by fisheries worldwide. Its successful commercialization could catalyze a paradigm shift in how bycatch mitigation is approached commercially and ecologically.

“This innovation exemplifies an elegant fusion of biology and engineering,” remarked Dana Vouglitois, Senior Associate Director of FAU’s Office of Technology Development. “It capitalizes on the intrinsic sensory mechanisms of sharks to solve a pressing environmental problem with practicality and precision.” Such syncretism of scientific insight and technological application underscores the transformative potential of interdisciplinary research to tackle complex global challenges like overfishing and species conservation.

Dr. Kajiura emphasizes the collaborative dimension of his project, highlighting the critical involvement of commercial fishermen in the testing phase. Their experiential knowledge informs the refinement of the device, ensuring its functionality aligns with operational realities. This feedback loop enhances device usability and acceptance, critical factors for widespread adoption. The project thus exemplifies an inclusive, user-centered approach to technology development in marine environmental science.

The potential impact of Dr. Kajiura’s research extends beyond the immediate reduction of shark bycatch; it represents a critical step toward more sustainable and ecologically informed fisheries management. By enabling selective capture of target species while protecting apex predators, the device contributes to the resilience of marine food webs and supports long-term fishery sustainability goals. This innovation aligns with global efforts to balance biodiversity conservation with sustainable resource utilization, a cornerstone of contemporary environmental policy and practice.

In conclusion, Florida Atlantic University’s support of this pioneering research highlights its commitment to fostering innovations with tangible societal and ecological impact. Dr. Kajiura’s shark deterrent device exemplifies how fundamental scientific understanding can translate into practical solutions that address conservation and commercial challenges simultaneously. As development progresses towards commercial production, this technology promises to be a game-changer in reducing bycatch and promoting sustainable fishing globally, illustrating the power of research-driven innovation to shape a more sustainable future for marine ecosystems and human communities alike.

Subject of Research: Development of a selective shark deterrent device to reduce bycatch in commercial longline fisheries.

Article Title: Innovative Electric Field Device Repels Sharks to Reduce Bycatch in Commercial Fisheries

News Publication Date: 2024

Web References:

• Florida Atlantic University Division of Research: https://www.fau.edu/research/
• Innovation Pilot Award Program: https://www.fau.edu/research-admin/technology-development/innovation-pilot-award-program/
• Stephen Kajiura Profile: https://biology.fau.edu/directory/kajiura/index.php

Image Credits: Stephen Kajiura, Florida Atlantic University

Keywords: shark deterrent, bycatch reduction, longline fisheries, electrosensory system, marine conservation, sustainable fisheries, zinc-graphite galvanic device, marine ecosystem, technology development, fishing gear innovation, bioelectrical field, environmental sustainability

At the crux of this investigation lies aragonite saturation, a pivotal metric that signifies the water’s capacity to sustain calcifying organisms like oysters, clams, and other shellfish. Aragonite is a crystalline form of calcium carbonate essential for shell and skeleton formation. When saturation levels decline below certain thresholds, these animals face physiological stress, resulting in inhibited growth, weakened shells, and increased vulnerability to environmental pressures and predation. The research team embarked on a comprehensive measurement campaign between 2016 and 2017, systematically sampling throughout the Indian River Lagoon to map the spatial and temporal variations in aragonite saturation relative to nutrient loading, salinity, and other water chemistry parameters.

The interdisciplinary methodology combined two complementary approaches. First, a broad geographic survey spanned from the northern reaches of the Lagoon, where nutrient concentrations and algal bloom occurrences are elevated, down through southern sections influenced by freshwater inflows from rivers and canals. This gradient provided a natural laboratory to observe how distinct environmental pressures modulate aragonite saturation. Second, the team implemented high-frequency weekly sampling at three strategically chosen sites that represented contrasting salinity regimes and differing anthropogenic impacts—urban canals, agriculturally influenced river mouths, and a relatively pristine reference station with robust ocean exchange.

The results, recently published in Marine Pollution Bulletin, elucidated critical correlations. Northern sections with pronounced nutrient enrichment exhibited suppressed aragonite saturation, partly driven by recurrent harmful algal blooms and associated microbial respiration that elevate dissolved carbon dioxide, acidifying the water column. Conversely, freshwater incursions in the southern reaches diluted the mineral content and lowered salinity, independently reducing saturation states despite lower nutrient inputs. These findings underscore a dual mechanism: nutrient pollution intensifies carbon-driven acidification, while freshwater inflows act through physical dilution, both converging to threaten calcifiers.

Coastal acidification arises when ambient and biologically produced carbon dioxide dissolves in estuarine waters, forming carbonic acid. This process reduces pH and depletes carbonate ion availability crucial for shell synthesis. Unlike open-ocean acidification driven predominantly by atmospheric CO₂, estuarine systems like the Indian River Lagoon experience enhanced variability due to land-based inputs of nutrients and freshwater, sluggish water exchange, and localized biological activity. The study’s nuanced understanding of these intertwined drivers signifies a notable advancement in coastal biogeochemistry, filling critical knowledge gaps about acidification within shallow, dynamic estuarine environments.

Dr. Rachel Brewton, a lead co-author, emphasizes the ecological stakes: “Declines in aragonite saturation slow organisms’ shell formation, rendering them more fragile and jeopardizing survival. This cascade reverberates across trophic levels, influencing fish populations, marine mammals, and ultimately the livelihoods of human communities reliant on these fisheries.” Such biological ramifications resonate broadly, as shellfish serve not only as ecosystem engineers and food resources but also as indicators of estuarine health.

These findings carry profound implications for estuary management worldwide. As human activities intensify coastal nutrient inputs through urban runoff, agriculture, and wastewater discharge, the synergistic effect on carbonate chemistry accelerates ecosystem degradation. The study’s authors advocate for integrated water quality management strategies targeting nutrient load reductions and controlled freshwater inflows. By addressing these dual challenges, restoration efforts may halt or even reverse acidification trends, bolstering resilience among vulnerable shell-building populations.

Technological innovation plays a pivotal role in ongoing environmental stewardship. Florida Atlantic University’s Indian River Lagoon Observatory Network of Environmental Sensors (IRLON) now incorporates cutting-edge pH and CO₂ monitoring capacities, enabling near real-time computation of aragonite saturation. This continuous data stream empowers scientists and resource managers to detect early-warning signals of acidification hotspots, forecast ecosystem responses, and tailor mitigation measures with unprecedented precision.

Moreover, by elucidating the chemical fingerprints underpinning estuarine acidification, this research opens pathways for comparative studies in similar ecosystems grappling with coastal eutrophication and freshwater perturbations globally. It also highlights the necessity of multidisciplinary approaches that marry chemical oceanography, ecology, and hydrology to unravel complex environmental puzzles.

Dr. Brian Lapointe, senior author, notes, “Our work reveals that acidification in estuaries is not a uniform phenomenon but varies intricately with nutrient loading, salinity, and local biological processes. Understanding these mechanisms allows targeted intervention, which is critical given the accelerating pace of coastal environmental change.” The study thus marks a crucial turning point, spotlighting the hidden chemistry compromising one of Florida’s premier natural treasures.

In conclusion, the Indian River Lagoon exemplifies how intricate chemical and ecological interactions govern estuarine health. The emergence of coastal acidification as a silent threat underscores the urgent need for comprehensive monitoring, informed management, and public awareness. As shellfish continue to shrink and seagrass beds retreat, the urgency for actionable solutions intensifies. This pioneering research not only advances scientific understanding but also serves as a clarion call to safeguard estuaries worldwide before these fragile ecosystems reach tipping points beyond recovery.

Subject of Research: Not applicable

Article Title: Coastal eutrophication and freshwater inputs drive acidification in the Indian River Lagoon, Florida

News Publication Date: 12-Jan-2026

Web References:

• Florida Atlantic University Harbor Branch Oceanographic Institute: www.fau.edu/hboi
• Indian River Lagoon Observatory Network of Environmental Sensors (IRLON): https://www.fau.edu/hboi/research/marine-ecosystem-conservation/irlo/irlon/
• Marine Pollution Bulletin article DOI: http://dx.doi.org/10.1016/j.marpolbul.2025.119175

References:
Brewton, R., Lapointe, B., Conkling, M., Kaiser, B.R., Davis, K.S., Jiang, M. (2026). Coastal eutrophication and freshwater inputs drive acidification in the Indian River Lagoon, Florida. Marine Pollution Bulletin. DOI: 10.1016/j.marpolbul.2025.119175

Image Credits: Credit: FAU Harbor Branch

Keywords

Estuaries, Acidity, Chemical properties, Salinity, Environmental chemistry, Carbon emissions, Pollution, Water pollution, Pollutants, Anthropogenic carbon dioxide, Ecology, Ecosystems, Aquatic ecosystems, Coastal ecosystems, Wastewater, Water quality, Shellfish, Aquatic animals