Seagrasses are among the ocean’s most valuable coastal ecosystems, yet they are also among the most imperilled. These flowering plants form underwater meadows that stabilise sediment, attenuate waves and protect coastlines from erosion, sequester carbon, improve water quality by reducing turbidity and even suppress pathogens through antimicrobial metabolites. They support biodiversity that underpins fisheries and food security, from nursery grounds for commercial species to foraging habitat for wading birds. Globally, seagrass populations are in steep decline, and the United Kingdom has fared worse than most: historic losses have been estimated at up to 92 percent of former extent, with a further 39 percent lost since the 1980s. Low water quality, elevated nitrogen and physical disturbance continue to threaten the remaining meadows.

Scotland, and Orkney in particular, remains a stronghold for UK seagrass, making it a critical region for both protection and restoration. Yet Orkney’s subtidal Zostera marina distributions are poorly mapped, hampering efforts to assess status, change, threats and conservation priorities. Sanday sits within the Sanday Special Area for Conservation—10,977 hectares where destructive fishing methods are banned to protect seals and habitat features—alongside the East Sanday Ramsar site, which covers 1,515 hectares of coastal and intertidal bird habitat. Despite abundant predicted seagrass habitat and a deep maritime culture, almost none of the island’s seagrass had been scientifically surveyed.

The research team, led by Joseph S. Boyle of the University of Oxford’s School of Geography and the Environment together with colleagues from Project Seagrass, GEOMAR, Universitas Indonesia, Sound Seas and Oxford, framed their approach around a theoretical distinction drawn from human geography. Building on Yi-Fu Tuan’s concept of space versus place and Henri Lefebvre’s triad of perceived, conceived and lived space, they treated the biophysical distribution of seagrass as “space,” the spatial pattern of human activities as “social place,” and the emotional and cognitive values people attach to locations as “experiential place.” Conventional mapping, they argue, captures space but not place, producing what they call “thin” maps that marginalise place-based knowledge.

To capture both, the researchers ran ten participatory mapping workshops between May and June 2023, reaching 32 participants through purposive snowball sampling—roughly one in fifteen of Sanday’s adult residents. Each workshop lasted between 59 and 156 minutes and produced large A1 paper maps of the island’s coastline. Participants first amended a blank map in deference to their own expertise, then marked biophysical features as points, drew current and past seagrass distributions as polygons with felt-tip pens (dotted lines for former meadows), and collectively freelisted and colour-coded 39 distinct coastal and marine activities. Finally, they spatialised personal values as points using sticky notes, often anchored to places or memories, with workshop audio recorded to capture the stories behind them.

The technical mapping that followed was equally rigorous. Digitised activity polygons were buffered using fuzzy GIS methods—scale-appropriate buffers of 25, 50 and 75 percent of each polygon’s area square root were applied every five percent increments from the polygon edge—to accommodate the non-crisp logic of hand-drawn maps, then clipped to the coastline at the relevant tide state and rasterised onto a 400-square-metre grid to produce heatmaps for each activity. Workshop dialogue was coded deductively against Stephen Kellert’s 2005 typology of coastal relational values using NVivo software.

The biophysical side of the study combined local knowledge with field survey and remote sensing. Guided by workshop-derived information, strandline surveys, satellite imagery at 1.2-metre resolution and a 2014 habitat suitability model based on sediment, bathymetry and wave exposure, the team walked 119 person-kilometres of strandline, then verified seagrass presence by snorkelling along 39 kilometres and kayaking 12 kilometres more. Drone surveys with a WingtraOne carrying an RGB61 camera flew at 75 metres—yielding a one-centimetre ground sampling distance—covering 668 hectares over 379 kilometres of flight and capturing 13,500 images, which were processed into orthomosaics with Pix4Dfields and analysed in QGIS.

The results were striking. The team “found” or rediscovered two meadows absent from all prior records and from the 2014 habitat model: a 2.7-hectare meadow at Backaskaill Bay and an 18.2-hectare meadow at Otterswick, totalling 20.9 hectares. Crucially, the model overpredicted seagrass, suggesting unfeasibly large areas with unsuitable substrate and wave exposure—parameters that local residents understood well—while field surveys confirmed seagrass precisely where local knowledge indicated it. Protection coverage, however, is incomplete: the Otterswick meadow and its historic extent fall entirely within the Special Area for Conservation, but 56 percent of the Backaskaill Bay meadow—1.5 hectares, or 7.2 percent of Sanday’s total seagrass—lies outside its boundaries and therefore remains unprotected from destructive fishing practices, with no Ramsar protection from terrestrial runoff either.

The activity mapping revealed a seascape far richer than the commercial fisheries that typically dominate marine spatial planning data. Of 39 recorded activities, 15 were consumptive and 24 non-consumptive, ranging from fishing, crabbing and shellfish gathering to swimming, watersports, wildlife watching, archaeology and even playing the recorder to seals. Overall activity—both consumptive and non-consumptive—corresponded with seagrass distributions, with crabbing and spoot gathering (razor clams, Ensis ensis or Ensis siliqua) showing particularly strong co-location. Notably, commercial activities such as creeling, scalloping and shell sand mining showed little to no overlap with seagrass, occurring instead in deeper waters, rocky areas or on beaches—a finding that underscores how MSP’s usual economic focus can miss broader social–ecological interactions. The researchers also note that green crab, associated with seagrass beds, can damage seagrass, meaning that crabbing may indirectly suppress a potential stressor and link a consumptive activity to restoration benefit.

Place values proved varied and abundant but spatially diffuse overall, with every value in Kellert’s typology expressed in at least 70 percent of workshops. When analysed individually, however, two value types clustered near seagrass: humanistic values, reflecting strong emotional bonds with nature, and scientific values, concerning understanding of living systems through both formal and informal observation. The humanistic clustering at Backaskaill Bay was driven in part by the 1994 mass sperm whale stranding, mentioned in four workshops and commemorated by a new picnic area with a life-size whale sculpture. At Saville, adjacent to the Otterswick meadow, residents spoke of peace and calm in Sanday’s most sheltered bay, alongside years of biodiversity and erosion monitoring—including the sudden disappearance and reappearance of an entire beach at nearby Whitemill Bay.

Synthesising seagrass extent, habitat protection, compatible activities and co-located values, the team proposes three restoration priority sites as a starting point for community deliberation. Otterswick, sheltered and best protected, hosting Sanday’s largest meadow and dense humanistic and scientific values, is deemed most suitable for large-scale restoration. Backaskaill Bay offers a smaller, more exposed and deeper meadow with strong shellfishing links but requires Special Area for Conservation extension and careful collaboration with fishers; the authors suggest high-density planting over the small area may mitigate disturbance risks. Kettletoft Bay, near Sanday’s largest settlement, has no extant meadow but seemingly suitable habitat in a value-dense location, historically hosting the island’s highest concentrations of spoot gathering—a potentially higher-risk, higher-reward site that could support dwindling shellfisheries and eco-cultural restoration.

The study’s deeper contribution lies in its methodology. By integrating local knowledge and social data throughout all stages of social–ecological mapping, the researchers demonstrate a transferable methodology for restorative marine spatial planning—the practice of designating ocean space to promote social–ecological recovery with justice and sociocultural considerations at its core. Local knowledge proved cost-effective, replicable and reliable even where participants expressed low confidence and limited seagrass awareness, with the plant known locally as “mallow” and featuring in placenames and historic thatching practices. The authors caution that their findings are a first step: participation should ideally begin at the normative stage of planning, before deciding whether restoration is even desirable, and broader engagement will be needed. But as global biodiversity targets demand equitable and effective restoration, this small island’s blend of memory, drone imagery and community knowledge offers a template for how the ocean’s missing human layer might finally be mapped.

The stakes in the region are rising. Colombia’s Caribbean waters hold promising offshore hydrocarbon prospects, and the country’s National Hydrocarbon Agency has said Colombia could position itself as a regional leader in offshore energy. Yet the same sea and its coastline — fishing ports, tourism beaches, mangrove-fringed lagoons — remain highly vulnerable to spills, whose environmental, social and economic consequences can ripple for years. Earlier research has tied Caribbean oil pollution to damage in mangroves and fisheries, and Colombia’s oceanographic community has spent two decades building spill-prediction tools for its own waters. In response, DIMAR has been developing a new ecosystem of climate services for Colombia that, unusually for the field, extends to maritime oil spills. The effort sits within SIPSEM, the Integrated Forecasting System for Maritime Safety, an initiative designed to turn observations and numerical models into products that port captains, naval commanders and environmental agencies can actually use during emergencies. The work, carried out as part of the lead author’s doctoral research, needed a rigorous test case, and the Amuay spill provided one: a real, well-documented transboundary event whose evolution could be checked years later against independent satellite records and coastal measurements.

At the heart of the system sits GNOME, a Lagrangian trajectory model developed by NOAA’s Office of Response and Restoration and used by spill responders worldwide. The model has been applied to incidents from Mumbai’s harbor to the Gulf of Mexico, but rather than solving the full equations of ocean motion for the oil itself, GNOME treats a slick as thousands of virtual particles — tiny, independent tracers — that are pushed across the sea surface by whatever current and wind fields the modeler supplies. A stochastic term mimics sub-grid turbulence, smearing each particle cloud in a way that reflects the chaos of real eddies, while the model also propagates uncertainty in the forcing data, generating a best-estimate trajectory flanked by minimum- and maximum-regret bounds. Those bounds matter operationally: a responder deciding where to place containment booms cares less about a single predicted path than about the envelope of plausible ones. GNOME does not attempt detailed oil chemistry — evaporation, emulsification and other weathering processes are handled separately — but speed is its virtue. Within minutes it can address the urgent, deceptively simple question that dominates the first hours of a spill: where is the oil going, and when will it get there?

The quality of any trajectory forecast, however, lives and dies by its inputs, and the Colombian team threw an unusually diverse set at the problem. For winds, they drew on the Climate Forecast System version 2 (CFSv2), NOAA’s coupled atmosphere-ocean modeling system, and on satellite scatterometer winds archived by CERSAT, the Centre ERS d’Archivage et de Traitement, France’s satellite oceanography data center. For ocean currents, they tested three very different engines: the Copernicus Global Ocean Physics Reanalysis (GLORYS), an eddy-resolving global reanalysis built on the NEMO ocean model; the Hybrid Coordinate Ocean Model (HYCOM), which blends vertical coordinate systems to represent everything from shallow shelves to open-ocean gyres; and the Navy Coastal Ocean Model (NCOM), a coastal circulation model developed for U.S. Navy operations. The rationale for this shotgun approach is that oil at the sea surface obeys two masters. Currents supply most of the drift, but wind pushes the slick along — responders often estimate wind-driven drift at a few percent of the wind speed — and no single dataset captures every eddy, jet and upwelling filament in a basin as energetic as the Caribbean. Running GNOME under multiple atmospheric and oceanic combinations is, in effect, a homegrown ensemble forecast.

The Caribbean makes that hedging essential. The basin is flushed from east to west by the Caribbean Current, but its surface circulation is far more intricate than a conveyor belt: mesoscale eddies shed and drift across the region, interacting with the narrow, wind-driven coastal upwelling off Colombia’s Guajira Peninsula and with the Caribbean Counter Current, which can reverse the flow along the shelf edge. Decades of research — from early descriptions of eddy development and motion in the Caribbean Sea to recent analyses of the basin’s eddy variability — have documented how these swirling features can trap drifting material, spin it in circles for weeks or eject it toward the coast in sudden bursts. For an oil slick, the difference between beaching in one fishing village and missing the coast entirely can hinge on an eddy a hundred kilometers offshore. Global ocean models that resolve such structures imperfectly can therefore diverge quickly, which is precisely why the researchers wanted to quantify how sensitive their forecasts were to the choice of current and wind fields.

To judge the simulations, the team assembled an independent record of what the oil actually did. Radar imagery from the European Sentinel-1 satellites formed the backbone: synthetic aperture radar is acutely sensitive to oil because thin crude films damp the millimeter-scale capillary waves that normally roughen the sea surface, leaving slicks as dark, smoky patches against a brighter ocean. Radar has its pitfalls — calm-wind patches, rain cells and natural films can masquerade as oil — so the team cross-checked it with optical imagery from Landsat 8 and from Planet’s high-resolution constellation, though cloud cover limited the optical sensors at times. On the ground, laboratory and field reports from DIMAR’s marine environmental protection program documented hydrocarbon contamination along the Colombian coast as the slick arrived. Stitching optical and radar satellites to in-situ sampling gave the researchers something rare in spill science: a multi-sensor, ground-truthed picture of a transboundary spill against which model trajectories could be scored.

The verdict was encouraging. Run across the different atmospheric and oceanic forcing combinations, the GNOME-based system effectively replicated the spill’s arrival date on the Colombian coast and the areas affected, producing trajectories that aligned closely with the satellite observations. That timing matters most of all: the moment oil makes landfall is the moment that determines whether containment equipment reaches the right beach before the slick does. The model’s skill, however, was not uniform. Its performance proved contingent on the spill’s initial conditions — where, when and how much oil was released — and on which forcing data were used. That sensitivity is both a warning and a lesson: a trajectory forecast is a chain whose weakest link may be the assumed release point of a slick that no one observed in its first hours, or a current field that misplaces a single eddy. For the Colombian-Venezuelan Caribbean, at least, the study concluded that the chain held together well enough to be trusted for the decisions that matter most in an emergency, even as the authors caution that ongoing efforts to sharpen prediction accuracy remain essential.

For responders, the practical meaning is direct. A validated configuration gives Colombian authorities a defensible way to decide, within hours of a reported spill, where to deploy containment booms, which beaches and mangrove forests to prioritize for protection, and where to stage skimmers and dispersants. The tool’s potential reach is unusual, too: the researchers note that the approach could support extended forecast horizons at sub-seasonal timescales, effectively turning spill forecasting into a branch of the growing discipline of ocean-weather prediction, in which marine current outlooks are issued much like meteorological forecasts. That framing places the work squarely within the broader climate-services movement, which aims to convert raw scientific data into information tailored to real decisions — from farmers choosing planting dates to coast guards positioning equipment before a storm. A spill model that only scientists can operate is of little use at three in the morning during a refinery accident; one wired into an operational maritime-safety system, the authors argue, can serve everyone.

None of this removes the uncertainty inherent in a turbulent sea, and the authors are explicit that continued work to improve accuracy is essential to strengthening oil-spill emergency response in the years ahead. Better estimates of spill volume and location in the critical first hours, denser satellite coverage and higher-resolution coastal currents would all tighten the envelope of predicted shorelines. But the broader message of the Amuay retrospective is difficult to miss: the ingredients for credible transboundary spill forecasting already exist, and they are inexpensive — GNOME is free, and its atmospheric and oceanic forcing datasets are openly archived — so any maritime nation with the will can assemble them. As offshore development accelerates across the Caribbean, the region’s oceanographers have demonstrated that when the next tanker fails or the next refinery leaks, the question of where the oil will go no longer needs to be answered with guesswork. It can be answered, with measured caveats, by physics.

This environmental menace is receiving heightened attention as the Virginia Institute of Marine Science (VIMS) and William & Mary’s Batten School of Coastal & Marine Sciences, through the National Fishing Trap Removal, Assessment, and Prevention (TRAP) Program, spearhead coordinated efforts to remediate the issue. The program recently announced an allocation of $1.8 million across 13 projects nationwide, aiming to target the removal of thousands of derelict fishing traps and to develop data-driven solutions that can inform sustainable fisheries management.

Ghost traps primarily originate from commercial trap fisheries, which annually generate more than $1 billion in landings across the U.S. These traps are lost due to interactions between fishing vessels and gear, tumultuous storms, or structural degradation over time. Despite being abandoned and inaccessible to fishermen, these traps retain their function, continuing to ensnare both target and non-target species inadvertently. Such unchecked fishing leads to unregulated mortality, disrupts marine ecosystems, and undercuts future fishery yields — a costly externality that has often been overlooked.

The economic ramifications are staggering. Findings from a 2016 study posited that the removal of merely 10% of derelict crab pots and lobster traps could translate to an additional $831 million in global seafood landings each year. This statistic underscores both the severity of ghost fishing and the lucrative potential of targeted removal programs. Yet effective mitigation requires more than localized cleanups; it demands a comprehensive framework melding scientific research, community engagement, and policy innovation.

Responding to this challenge, the National TRAP Program received a significant $8 million, four-year grant from NOAA’s Marine Debris Program in 2023 to administer national efforts. This funding facilitates standardized data collection, regional cleanup initiatives, and the development of predictive models that quantify environmental and economic outcomes. By building a centralized database, the program enables cross-regional analysis of trap accumulation drivers, bycatch rates, and habitat impacts, providing a robust evidence base to guide regulatory reforms and industry practices.

During its inaugural year, the TRAP Program distributed $1.4 million among 11 projects, enabling the removal of over 7,000 derelict traps—amounting to more than 300,000 pounds of submerged debris. This success reflects a strong collaboration between scientists, local fishers, and conservation groups. These early interventions not only improve marine ecosystem health but also create employment opportunities, predominantly benefiting commercial fishers displaced by the side effects of ghost fishing.

Looking ahead, the 2026 funding round will allocate $1.8 million to thirteen new projects in states ranging from Maine to California. The collective goal is to remove in excess of 8,000 ghost traps. Beyond gear retrieval, the program emphasizes adaptive reuse and recycling of recovered materials to foster circular economy principles within fishing communities. By embedding local knowledge and stakeholder participation, the TRAP Program invigorates a grassroots approach to a global marine conservation issue.

The data gathered through these projects is slated for detailed statistical evaluation by the Policy Innovation Lab, a collaboration between VIMS and the University of Georgia’s Carl Vinson Institute of Government. Their analyses will dissect ecological and economic variables pertaining to derelict traps, unraveling the socio-environmental drivers behind gear loss and offering policy prescriptions for enhanced prevention, such as gear modifications, improved reporting, and storm resilience standards.

Several projects highlight innovative methodologies. For example, side-scan sonar technology allows precise identification of trap locations in turbid waters, facilitating targeted removals with minimal habitat disturbance. Meanwhile, SCUBA surveys enable direct diver recovery of traps in sensitive habitats inaccessible to surface vessels. These complementary approaches maximize both efficiency and conservation outcomes.

Engagement of commercial fishers as active participants in removal operations leverages their local expertise and fosters economic resilience, particularly during off-season periods. Several initiatives incorporate employment provisions that support displaced fishers while simultaneously addressing marine debris. This dual benefit model is critical for sustainable fisheries management, blending ecological restoration with social equity.

Additional outreach includes rigorous pre- and post-removal environmental monitoring, quantifying the efficacy of ghost trap removal efforts on resource recovery. Data outputs contribute to nationwide databases, enabling scalable replication of successful strategies and informing marine spatial planning initiatives aimed at minimizing ghost fishing impacts.

By harmonizing science, stakeholder collaboration, and policy innovation, this concerted effort offers a beacon of hope against the pervasive problem of ghost fishing. This multi-million dollar investment not only safeguards the marine environment and fishery economics but also galvanizes a national movement toward responsible ocean stewardship and the revival of coastal communities dependent upon these invaluable marine resources.

Subject of Research: Marine conservation and fisheries sustainability focusing on derelict fishing gear (“ghost traps”)

Article Title: Battling the Underwater Menace: National Efforts to Eradicate Derelict Ghost Traps from U.S. Coastal Waters

News Publication Date: 2024

Web References:

• National TRAP Program website: https://trapprogram.org/
• Virginia Institute of Marine Science news: https://www.vims.edu/newsandevents/topstories/2024/trap-subawards-announcement.php
• NOAA Marine Debris Program: https://marinedebris.noaa.gov/

Image Credits: Jordan Salafie, Oyster Recovery Partnership

Keywords: Fisheries, Conservation ecology, Marine resources, Natural resources conservation

Mangrove ecosystems, with their intricate, aerial root systems adapted to saline environments, act as formidable natural buffers against storm surges by dissipating wave energy and reducing floodwater velocities. These coastal forests allow saltwater to be filtered into freshwater and foster essential ecological functions. Despite covering an estimated 600,000 acres in Florida’s southern coastal zone, mangroves have often been overlooked in economic valuations for flood risk management. This study addresses that critical gap by simulating the spatially variable protective effects of mangroves on specific coastal property portfolios.

The results are staggering: mangroves reduced combined surge and flood damage estimates by approximately $725 million during Hurricane Irma and by $4.1 billion during Hurricane Ian. Annually, for Collier County alone, the study predicts that mangroves contribute an approximate $67 million in avoided storm surge losses. These figures are grounded in sophisticated, industry-grade computational models that integrate hydrodynamic surge data with property vulnerability profiles, thereby providing stakeholder-relevant insights for insurance, urban planning, and conservation policies.

One of the most novel findings is the spatial heterogeneity in mangrove protection. While properties situated landward of mangrove belts consistently benefit from reduced surge depths and financial losses, those located seaward—directly in front of mangroves—sometimes experience elevated risks. This paradox arises from altered wave reflection and flow patterns where mangroves influence the physical oceanographic conditions in complex manners that may amplify localized flooding for some coastal frontiers. Therefore, risk assessments must consider this nuanced spatial variability rather than assuming uniform mangrove benefits.

The research harnessed state-of-the-art catastrophe risk models commonly used in the insurance industry, a first for ecological coastal defenses. Moody’s RMS provided essential modeling infrastructure, combining hydrodynamic simulation outputs with property-level exposure data to estimate the economic impact of storm surges with and without mangrove cover. This collaboration bridges natural science and risk finance, highlighting how incorporating ecosystem services into financial risk models can elevate ecosystem conservation as a tangible, economically defensible strategy.

Dr. Siddharth Narayan, the study’s lead author and a professor of coastal studies at ECU, emphasizes the real-world utility of these findings. Comparing the Florida mangrove results with previous findings in the northeastern US for salt marsh wetlands during Hurricane Sandy, Narayan stresses that nature-based solutions provide measurable reductions in property damage—between 14 to 30 percent in surge-induced loss due to mangrove presence in Florida. This quantification enables stakeholders from policymakers to insurers to recognize mangroves as cost-effective, scalable climate adaptation tools.

Florida’s coastal environment, characterized by sprawling expensive developments and increasing hurricane intensities, is particularly susceptible to surge-induced flood hazards. Mangroves play a pivotal ecological and physical role in this context, filtering pollutants, stabilizing sediments, and buffering storm impacts. However, this study underscores that preservation efforts must be strategic, taking into account where property developments occur relative to natural barriers. Developing in front of mangroves can undermine the very protection these forests offer, heightening risk exposure for storm impacts.

The study situates itself within a broader scientific discourse that increasingly recognizes the dual role of natural habitats as both ecological treasures and critical infrastructural assets. By translating the flood mitigation capacities of mangroves into dollar values understood by insurance and real estate markets, the research aims to steer funding and regulatory incentives toward mangrove conservation. This could have far-reaching implications for coastal resilience planning as sea level rise and storm frequency escalate under climate change.

Funding support from the Walton Family Foundation, the Herbert W. Hoover Foundation, AXA Research Fund, and the National Science Foundation enabled this interdisciplinary collaboration, bringing together experts in coastal ecology, risk modeling, and conservation. The multi-institutional team included prominent figures such as CCCR’s director Michael Beck, whose leadership emphasizes that valuation of ecosystem services is crucial because society protects what it values monetarily.

Expanding beyond Florida, the modeling framework developed offers a replicable blueprint for assessing mangrove benefits globally in tropical and subtropical coastlines. As more regions confront increasing exposure to severe tropical cyclones and their attendant flood risks, integrating these natural defenses into spatial planning and insurance underwriting can substantially reduce economic losses and safeguard vulnerable communities.

The study also serves as a cautionary message regarding the unintended consequences of coastal development in mangrove-rich environments. Urban and infrastructure projects located seaward of mangroves could disrupt natural flow regimes and diminish overall coastal resilience, emphasizing that future planning must be underpinned by robust geospatial risk analyses that consider ecosystem interactions with storm surge dynamics at a granular level.

In conclusion, this pioneering research bridges ecological science and financial risk analysis to demonstrate the immense, spatially diverse flood protection benefits of mangroves in Florida. It challenges traditional hard-engineered flood defenses by illustrating that natural ecosystems, when preserved and intelligently integrated into coastal management, can offer cost-effective and sustainable solutions against escalating climate threats. Mangroves are not merely biodiversity hotspots but indispensable frontline defenders that save billions of dollars in property losses during hurricanes, a true testament to the power of nature-based resilience.

Subject of Research: Not applicable

Article Title: The spatially variable effects of mangroves on flood depths and losses from storm surges in Florida

News Publication Date: 14-Oct-2025

Web References:
https://www.cell.com/cell-reports-sustainability/fulltext/S2949-7906(25)00227-7

References:
Narayan, S., Thomas, C.J., Nzerem, K., Matthewman, J., Shephard, C., Geselbracht, L., Beck, M.W. (2025). The spatially variable effects of mangroves on flood depths and losses from storm surges in Florida. Cell Reports Sustainability. DOI: 10.1016/j.crsus.2025.100531

Image Credits: Image by J. Kendall-Bar, UC Santa Cruz

Keywords: Climate change mitigation, Risk reduction

Kelp forests are complex marine ecosystems found worldwide, particularly thriving in temperate coastal waters such as those off the Pacific coast of North America, the United Kingdom, South Africa, and Australia. These underwater forests serve as crucial habitats for numerous marine species, supporting biodiversity and providing economic value through fisheries. Additionally, kelp forests play an essential role in carbon sequestration, absorbing CO2 and helping mitigate global climate change. Acting as natural coastal buffers, they also protect shorelines from erosion by dissipating wave energy, underscoring their ecological and socioeconomic importance.

However, escalating marine heatwaves—exacerbated by anthropogenic climate change—have inflicted catastrophic damage on kelp forests, especially along the West Coast of North America. The 2014–2016 North Pacific marine heatwave, dubbed “the Blob,” caused unprecedented warming of ocean waters, resulting in widespread kelp mortality. Compounding this thermal stress is the surge in sea urchin populations, which have proliferated following sharp declines in predatory sea stars. These overgrazing urchins effectively devastate kelp habitats, hindering natural recovery processes and threatening the long-term stability of these ecosystems.

In this context, MPAs have emerged as a promising tool to enhance ecological resilience. MPAs are designated sections of the ocean where human activity, particularly fishing, is regulated or restricted to protect habitats and marine biodiversity. However, the level of protection varies widely among MPAs, ranging from fully no-take reserves to areas permitting considerable extractive activities, including destructive fishing practices like bottom trawling. The UCLA study has focused on MPAs with explicit restrictions on fishing, providing a clearer understanding of how such regulatory measures impact kelp forest dynamics.

By analyzing 54 MPAs and their corresponding reference sites along California’s coast, researchers compared kelp forest cover from 1984 to 2022 using satellite imagery. This rigorous comparative approach allowed them to isolate the effects of MPAs on kelp resilience to heat stress, distinguishing between resistance (avoiding loss) and recovery (regaining cover) after marine heatwaves. The study confirms that kelp within MPAs demonstrated greater post-heatwave recovery relative to unprotected sites, especially notable in southern California, where heat stress and ecological pressures are often more severe.

The mechanisms behind this enhanced recovery appear linked to the protection of key predator species within MPAs. Species such as lobsters and sheephead fish, which prey upon herbivorous invertebrates like sea urchins, help control urchin populations and reduce overgrazing. In the absence of these predators, unchecked urchin populations can decimate kelp stands. Thus, MPAs indirectly support kelp regeneration by maintaining the integrity of trophic interactions critical to ecosystem balance. This trophic cascade demonstrates the intricate connections between species that underlie ecosystem resilience.

Despite these encouraging findings, the researchers caution that the protective effect of MPAs is not uniform across all sites. Variability in environmental conditions, MPA management quality, enforcement efficacy, and local oceanographic features influence outcomes. For example, areas characterized by localized upwelling tend to be cooler and nutrient-rich, fostering kelp populations with greater thermal tolerance, thereby naturally enhancing resilience. Strategically situating MPAs in such dynamic environments could maximize conservation effectiveness.

Moreover, the study highlights the importance of integrating kelp forest monitoring into long-term conservation strategies and global biodiversity frameworks. The Kunming-Montreal Global Biodiversity Framework, adopted at COP15 in 2022, sets ambitious targets to safeguard at least 30% of marine and terrestrial habitats by 2030. This research underscores the utility of kelp forests as bioindicators that reflect ecological health and climate resilience in marine protected systems, thereby providing valuable feedback for adaptive management and policy formulation.

Co-author Emelly Ortiz-Villa, a PhD researcher at UCLA’s Department of Geography, emphasizes that MPAs help buffer kelp against climate-induced disturbances, offering ecosystem services beyond just conservation. The study’s evidence suggests that MPAs not only support biodiversity preservation but also bolster ecosystem functions critical to human well-being, such as carbon sequestration and coastal protection. This multifaceted benefit strengthens the case for expanding and effectively managing MPAs in a warming world.

Senior author Professor Kyle Cavanaugh adds that the results have significant implications for conservation planning. MPAs should be prioritized in regions poised to exhibit natural resilience—such as areas with frequent upwelling events or kelp populations adapted to warmer temperatures—to optimize the return on investment in ocean conservation. Understanding spatial and ecological nuances will be critical to designing MPAs that can withstand escalating climate threats and foster robust marine ecosystems.

The study also draws attention to the pitfalls of designating MPAs without enforcing adequate protections. Many so-called MPAs globally permit activities detrimental to ecosystem health, diminishing their potential to contribute to resilience. Robust enforcement, clearly defined management regulations, and community engagement are necessary components of successful MPAs that can mitigate the increasing frequency and intensity of marine heatwaves.

Looking ahead, the research team advocates for further investigation into the drivers of uneven MPA effectiveness. Identifying the interplay of biological, physical, and managerial factors will equip stakeholders with knowledge to tailor conservation efforts adapted to local environmental realities. Such adaptive management is essential as climate change accelerates and marine ecosystems face unprecedented threats.

This landmark study vividly illustrates the critical role of spatial management in safeguarding the future of kelp forests, ecosystems integral to marine biodiversity and carbon cycling. As the ocean continues to warm, strategies that integrate MPAs with broader climate mitigation efforts offer a beacon of hope for protecting these vibrant underwater forests and the myriad species and communities that depend on them.

Subject of Research: Not applicable
Article Title: Marine protected areas enhance climate resilience to severe marine heatwaves for kelp forests
News Publication Date: 19-Aug-2025
Web References: http://dx.doi.org/10.1111/1365-2664.70112
Image Credits: Ortiz-Villa et al.
Keywords: Marine ecology, Marine conservation, Marine ecosystems, Climate change