The study, led by Josie F. Chandler of James Cook University and colleagues, quantified daily feeding rates for 565 individual starfish across five regions of the central, northern and far northern Great Barrier Reef, from Townsville and Cairns to Lizard, Princess Charlotte Bay and Cape Grenville. Between March 2023 and March 2024, the team conducted 208 Scooter-Assisted Large Area Diver-based surveys, a novel method in which divers use underwater scooters to cover large reef areas efficiently. In total, more than 2,600 fresh feeding scars were measured, each attributed with confidence to a single starfish feeding in isolation.

The feeding mechanism of the crown-of-thorns starfish is central to understanding its destructive potential. Like other sea stars, it can evert its stomach through its mouth and spread it over the surface of a coral colony, digesting living tissue externally. When fully extended, the stomach covers a planar area roughly equivalent to the starfish’s oral disc, but it can drape over complex three-dimensional surfaces such as branching corals. This means the actual amount of tissue consumed increases with the structural complexity of the prey, which helps explain the starfish’s well-documented preference for tabular and corymbose Acropora corals, the very corals most vulnerable to bleaching and storm damage.

To translate simple field measurements into ecologically meaningful quantities, the researchers used genus-specific calibration curves developed for 15 distinct coral morphotaxa. Each fresh feeding scar, identifiable by sloughing tissue, mucous coverage or bare white skeleton not yet colonised by turf algae, was measured for maximum diameter with a flexible tape. These linear dimensions were converted into two-dimensional planar area and three-dimensional tissue surface area. The number of days over which scars were assumed to accumulate was standardised according to scar persistence: five days during summer surveys, when water temperatures ranged from 27 to 31 degrees Celsius, and seven days during winter surveys, when temperatures ranged from 24 to 26 degrees Celsius.

Analysing the data required a combination of machine learning and mixed-effects statistics. Boosted Regression Tree algorithms were first used to identify which of ten candidate predictors, including body size, population density, coral cover, Acropora cover, season, month, water temperature, latitude, region and reef, had the strongest influence on feeding rates. Generalized linear mixed effects models were then fitted for three separate metrics: the number of coral colonies consumed, the combined planar area of all feeding scars, and the total three-dimensional tissue surface area consumed. The final models included starfish body size category, total coral cover category and population density, with site as a random effect.

The results were unambiguous. Body size was the strongest and most consistent predictor of daily feeding across all three metrics, with rates increasing markedly from the smallest size class, up to 15 centimetres, to the largest, above 40 centimetres. The predicted daily planar area consumed across all starfish averaged 164.04 square centimetres, with individual values ranging from just 1.58 to a remarkable 2,135.29 square centimetres per day. When expressed as three-dimensional tissue surface area, the mean rose to 900.46 square centimetres per day, with extremes approaching 7,421 square centimetres. Perhaps most striking, the largest starfish at sites with more than 50 percent coral cover consumed an average of 221.99 square centimetres of planar coral area per day, more than ten times the 18.86 square centimetres consumed by smaller individuals at sites with less than 15 percent coral cover.

Just as revealing was what did not matter. Population density, season, water temperature and latitude showed no significant effect on daily feeding rates, challenging long-standing assumptions in outbreak models that treat every starfish as an equal unit of destruction. Seasonal variation in feeding has been proposed in earlier work, potentially driven by temperature-mediated metabolic demand or seasonal gametogenesis, but this study’s design, spanning eight degrees of latitude and allowing temperature effects to be examined in isolation from reproductive cycles, found no such link. The authors caution that the observed temperature range was relatively narrow at two to three degrees Celsius, and laboratory studies have shown starfish metabolism does rise with temperature, suggesting ocean warming could still increase feeding pressure under future climate scenarios.

The influence of coral cover operated in an unexpected way. While the area of coral consumed increased significantly at high-cover sites, the number of colonies preyed upon did not. This indicates that starfish on coral-rich reefs are not attacking more colonies, but rather consuming larger bites from bigger, structurally complex colonies. Because branching corals such as Acropora pack far more tissue surface area into a given footprint than massive corals do, high-cover reefs effectively supercharge individual feeding rates. In this study, 78 percent of the variation in total coral cover was explained by Acropora cover alone. The findings align with previous research showing that when Acropora abundance exceeds 30 percent, crown-of-thorns starfish exhibit strong site fidelity and homing behaviour, whereas on prey-poor reefs they roam widely in search of food.

The absence of a density effect is also scientifically significant. Density-dependent feeding is well documented in other echinoderms, particularly sea urchins, but the starfish densities observed here, ranging from 1.69 to 73.68 individuals per hectare, are moderate compared to catastrophic outbreaks exceeding 1,000 starfish per hectare recorded elsewhere. The authors suggest that behavioural shifts tied to crowding may only emerge at extreme densities, or that per-capita feeding may simply be insensitive to density and instead governed by prey availability. Measuring individual feeding rates also becomes inherently difficult at very high densities, when feeding scars cannot reliably be matched to specific individuals.

Beyond its ecological insights, the study delivers a practical tool for reef managers. Because the size categories used match those routinely recorded by Great Barrier Reef culling teams, and the coral cover categories align with protocols of the Great Barrier Reef Marine Park Authority and the Australian Institute of Marine Science Long-Term Monitoring Programme, the predicted feeding rates can be applied immediately to existing survey datasets. Managers can combine local population size-structure with coral cover data to estimate cumulative feeding pressure in real time, forecast coral loss as either benthic area or tissue surface area, and reassess intervention thresholds. This replaces the older, cruder approach of assuming uniform per-capita feeding, which the new data show can badly misestimate the true impact of an outbreak.

The findings also carry a deeper warning about the future of the reef. If Acropora-dominated environments are essential for sustaining high starfish densities and rapid individual feeding, widespread coral loss from bleaching could eventually impose natural constraints on outbreaks, as starving populations in prey-depleted environments may collapse. Conversely, any recovery of complex coral habitats could amplify the destructive capacity of starfish that remain. The study’s context-dependent, size-structured feeding estimates offer a substantially more accurate foundation for modelling coral mortality, prioritising culling effort and, ultimately, buying time for one of the world’s most iconic ecosystems as it faces the compounding pressures of predation and climate change.

Drupella snails are small muricid gastropods with an outsized impact on tropical reefs. Since outbreaks were first documented in the 1980s in Japan, the Philippines and Western Australia, these snails have become increasingly recognised as major drivers of coral loss. The scale of the damage can be staggering. In Ningaloo Marine Park in Western Australia, extensive grazing by Drupella was linked to mean reductions of 86 percent in coral cover on reef flats and back-reef areas between 1980 and 1987, along with a 47 percent decline on a monitored fore-reef slope. Beyond directly stripping coral tissue, the snails wound their prey in ways that allow pathogens to enter, facilitating the transmission of diseases such as brown band disease on the Great Barrier Reef. Outbreaks are often fueled by human pressures: overfishing removes natural predators such as wrasse, triggerfish, snapper and pufferfish, while climate-driven stressors like warming seas, nutrient enrichment, sedimentation and pollution weaken corals and create ideal conditions for snail populations to explode.

What makes the new observations particularly significant is that Drupella is typically thought of as a specialist predator of scleractinian corals, especially branching Acropora species. Fire corals, by contrast, are not true corals at all. They belong to the hydrozoan genus Millepora, order Anthoathecata, and possess stinging cells called nematocysts that deliver painful stings and can deter many would-be predators. Of the 16 Millepora species recognised worldwide, six occur in Indonesian waters. Milleporids grow quickly and reproduce prolifically, allowing them to compete aggressively for space, sometimes overgrowing and killing neighbouring stony corals. Yet they also play crucial ecological roles, providing nursery habitat for juvenile fish and shelter for a wide range of symbiotic invertebrates, including crabs, barnacles and scallops, some of which occur nowhere else.

The new study, led by Febrianne Sukiato of Luminocean and SeaChange Indonesia, with Kok Lynn Chew of Coralku Solutions and Tanya Toofany of the University of Bremen and the Leibniz Centre for Tropical Marine Research, documents the interaction at Gili Asahan, a site within the Gita Nada Marine Protected Area. The reef there ranges from a shallow flat at 1 to 4 metres depth down a slope to a sandy bottom at 14 to 16 metres, with roughly 40 to 60 percent coral cover and at least 136 morphologically identified scleractinian species. The site has a history of overfishing and pearl farming, and local conservation group SeaChange Indonesia has been running coral restoration work that includes targeted removal of Drupella from stony corals.

On 4 July 2025, during a scuba survey lasting 90 minutes, the team inspected mature Millepora colonies with a minimum diameter of 50 centimetres scattered across the shallow reef flat. Snails were found on all six colonies examined, representing three fire coral species: Millepora dichotoma, M. tenera and M. intricata. In total, the researchers removed 122 Drupella snails using scissors and long tweezers, carefully extracting the animals to avoid breaking the fragile fire coral branches. The snails were identified to genus based on shell morphology; species-level identification was deliberately not attempted, since several Drupella species have highly similar shells and reliable identification typically requires detailed taxonomic or molecular analysis.

The evidence of active feeding was compelling. Adult snails, defined as those exceeding 2 centimetres in shell length, were found tucked deep within the complex skeletal recesses of the fire coral colonies, and white feeding scars were visible directly beneath them, exposing the bare skeleton where tissue had been scraped away. In two cases, the researchers observed what appeared to be aggregations spilling over from the Millepora colonies onto adjacent Acropora colonies, where active feeding was documented on the corner of the stony coral facing the fire coral. The direction of movement was inferred from this spatial pattern, although continuous behavioural observations were not performed, so the researchers caution that movement direction could not be definitively confirmed.

Perhaps the most intriguing pattern was the age structure of the snail aggregations. Adults dominated all six colonies, with most measuring between 20 and 25 millimetres in shell length and the largest reaching 28 millimetres. Juveniles, ranging from 14 to 19 millimetres, were present in five of the six colonies but consistently in lower proportions. The number of snails per colony did not correlate with colony volume; the researchers calculated ellipsoidal colony volumes and found essentially no relationship with snail counts, with a coefficient of determination of just 0.0252. Given the limited sample size, occurrences were reported descriptively rather than subjected to species-level statistical comparisons.

The predominance of adults inside fire coral colonies suggests what the researchers describe as a possible ontogenetic shift in habitat use and prey choice, likely driven by feeding plasticity, refuge availability and energetic demands. The reticulate skeleton of Millepora is riddled with deep cavities that could offer adult snails shelter from predators and protection from waves and currents, meaning the fire coral may serve a dual role as both refuge and secondary food source. Juveniles, which face higher energetic demands for growth, may preferentially target more nutritious prey such as Acropora, consistent with earlier studies showing that young Drupella exhibit distinct prey preferences and occupy different coral hosts than adults. Body size is known to strongly influence foraging behaviour in gastropods under resource limitation, and Drupella are known to relocate frequently within and between colonies, sometimes within days, producing highly dynamic group sizes.

Chemical cues may also help explain the movement between coral genera. Stressed or overgrown Acropora are known to release compounds that attract corallivorous gastropods, and Drupella have been shown to move more than a metre overnight in response to such signals. At Gili Asahan, fire coral colonies form bushes 30 to 150 centimetres wide that grow right beside stony corals in the shallows, creating ideal staging conditions. The authors propose that adult Drupella may use Millepora as a refuge or staging habitat before exploiting nearby, chemically detectable stony coral prey. Millepora’s own competitive dominance could even reinforce this dynamic: by overgrowing and stressing adjacent acroporids, the fire coral may enhance the chemical signalling that draws snails to its neighbours, indirectly facilitating its own expansion, at least until sustained snail predation offsets those gains.

Interestingly, the researchers note that the Drupella sampling at Gili Asahan did not coincide with periods of siltation or thermal stress, suggesting that the use of Millepora in this case was not driven by an absence of preferred prey. This contrasts with earlier reports from the Gulf of Eilat in the Red Sea, where large aggregations of Drupella cornus initially fed on Acropora and Pocillopora damicornis before switching to Millepora dichotoma and other unusual prey following prey scarcity, and where snails were recorded on reefs dominated by Acropora–Millepora assemblages. Similar prey-switching in response to bleaching has been documented at Koh Tao in Thailand, where Drupella turned to previously avoided taxa such as fungiid corals and Pavona after bleaching wiped out Acropora. The Lombok observations suggest fire coral consumption may occur even when preferred prey remains available.

The ecological implications could be far-reaching. Millepora populations are already vulnerable to climate change. In the U.S. Virgin Islands, a marine heatwave eliminated 84 percent of a newly established milleporid community, and in the Maldives, fire coral zones lost during the 1998 bleaching event have only recently re-emerged in the country’s far north. At Gili Asahan itself, anecdotal observations suggest that after the 2016 mass bleaching event, reefs south of the study site shifted from stony coral dominance to Millepora. Added mortality from Drupella could therefore compound thermal stress on fire corals, reducing habitat availability for the fish and invertebrates that depend on them and further destabilising reef food webs already strained by warming temperatures and ocean acidification.

The authors stress that their findings, being based on limited, qualitative field observations, should be interpreted with caution. They call for research to quantify the prevalence, severity and feeding rates of Drupella on Millepora across broader spatial scales, and they recommend nocturnal surveys, since Drupella are primarily active at night. Genetic or morphometric identification of collected snails would also help clarify species-level patterns, as the taxonomy of Drupella remains under revision; recent work has even suggested that what has been called Drupella cornus may actually comprise two distinct species. Continued monitoring, the team argues, is essential for understanding these emerging trophic dynamics and for informing targeted removal efforts. As outbreaks of these voracious snails intensify across the Indo-Pacific, fire corals, long overlooked as snail prey, may need to be added to the watch list.

A team led by Prof. Oren Levy from Bar-Ilan University, alongside international collaborators, emphasizes the necessity of merging the rigor of ecological science with the emotional and cultural power of creative disciplines. This interdisciplinary approach aims to translate complex environmental data into impactful visual and experiential messages that resonate deeply with diverse audiences, thereby fostering public engagement and catalyzing meaningful conservation actions.

The article highlights how artistic mediums such as environmental installations, documentary films, music, graphic design, and public art have successfully communicated the urgency of coral reef conservation. Particularly, design disciplines are recognized for their potential to distill intricate ecological information into compelling narratives. Graphic designers transform scientific datasets into captivating visual stories, product designers incorporate reef-inspired biomimicry into everyday objects, and fashion designers connect marine ecological beauty with consumer behaviors, raising awareness through textiles and campaigns.

Beyond aesthetics, this fusion provides a channel to embed coral reef conservation into collective cultural consciousness. Landscape architects, for example, draw inspiration from coral morphologies to create public spaces that foster environmental appreciation. This convergence of art, science, and community underscores coral reefs’ multifaceted value extending beyond ecological function to include socio-economic and cultural dimensions.

To spearhead this vision, the Coral Art-Science Consortium was established—a nonprofit coalition of scientists, artists, educators, policymakers, and community leaders collaborating to amplify coral reef awareness. The consortium’s digital platform serves as a global hub for creative projects, educational resources, and participatory initiatives designed to empower broader audiences and promote philanthropic support.

This novel framework reflects an urgent need: addressing the coral reef crisis demands not only ecological restoration and scientific innovation but also a transformation in public perception and political action. The consortium envisions exhibitions, public events, citizen-science programs, and digital storytelling as vital tools to galvanize collective responsibility.

Ultimately, the authors advocate a paradigm shift in environmental communication that harnesses the emotive potential of artistic expression alongside scientific evidence. By bridging empirical research and human experience, this approach aspires to build a global movement that sustains coral reefs for future generations.

Subject of Research: Coral reef conservation through interdisciplinary collaboration of science and art
Article Title: Communicating coral: Art and science for global reef action
News Publication Date: 8-Jul-2026
Web References: https://coralartscience.org/, https://www.science.org/journal/sciadv
References: DOI 10.1126/sciadv.aej6847
Image Credits: Ana Saborio
Keywords: coral reefs, conservation, art-science collaboration, environmental communication, climate change, ecological restoration, public engagement, design

Hawksbill turtles exhibit remarkable navigation skills, evoking wonder in marine biologists who study their migratory patterns. They use visual cues, the Earth’s magnetic fields, and ocean currents to traverse the vast expanses of the Caribbean Sea. Their migratory routes are pivotal not just for the survival of their species, but also for maintaining the health of coral reef ecosystems, as they contribute to the control of sponge populations and promote coral growth when they feed on these organisms.

Recent research has shed more light on the complex interplay between the nest sites and foraging grounds of these turtles. Through satellite tracking studies, scientists have meticulously mapped their journeys between nesting sites in areas like Utila, Honduras, and their feeding grounds scattered across the Western Caribbean. These findings reveal that these turtles are not merely solitary wanderers, but they engage in intricate patterns that echo the currents of the oceans they inhabit.

Much of the focus in this groundbreaking research is centered around the special inter-nesting areas that hawksbills utilize. These regions, often associated with specific oceanographic features, provide safe havens that allow turtles to recuperate and gather energy before embarking on the next leg of their journey. Understanding the significance of these areas is crucial since many face threats from human activities, including coastal development and pollution.

Hawksbill turtles are often seen gliding gracefully through vibrant coral reefs, and their presence is more critical than ever in maintaining the ecological balance within marine environments. This article reviews their foraging behaviors, particularly during peak feeding seasons when food sources become abundant following the seasonal ebb and flow of marine life. The turtles seem to congregate in hotspots, suggesting a social dimension to feeding—one that merits further exploration by researchers.

In exploring their migratory routes, researchers underscore the impact of climate change on ocean currents and the ramifications this has on hawksbill turtles’ migration. Rising ocean temperatures, altering wave patterns, and changing salinity levels directly affect the routes these turtles take and their overall health. Such insights into their adaptability—or lack thereof—raise critical questions about their long-term survival given the consistent threats posed by anthropogenic changes.

The funding from various organizations, including the Boyd Lyon Sea Turtle Fund and the USFWS Marine Turtle Conservation Fund, has been instrumental in advancing research on these magnificent creatures. The collaborative efforts of scientists from the US, Honduras, and Costa Rica foster a comprehensive understanding of hawksbill turtle behavior and ecology, paving the way for conservation strategies that can protect not only these turtles but also the rich biodiversity they support.

Moreover, enhancing public awareness about hawksbill turtles’ plight is integral to their conservation. Engaging local communities and stakeholders helps diminish conflicts while advocating for sustainable practices that protect these turtle habitats. By promoting eco-tourism and responsible fishing practices, communities can benefit economically while contributing to the preservation of these sea turtles and their environment.

As scientists continue to gather data, the adoption of advanced technologies becomes prevalent. Drones, underwater cameras, and other cutting-edge tools allow researchers to monitor hawksbill turtles with unprecedented precision. This technology not only aids in tracking their movements but also provides vital information about their interactions with varying marine environments.

Attention to the threats these turtles face cannot be overstated. Habitat loss, climate change, illegal trade, and plastic pollution pose significant risks to their populations. Each of these issues underscores the necessity for an integrated global response. The success of hawksbill turtle conservation goes hand in hand with fostering international cooperation and commitment to marine protection policies.

In summary, the exploration and understanding of hawksbill turtles in the Western Caribbean underscore the intricate balance of marine ecosystems and the urgent need for conservation efforts. As they navigate their oceanic home, these turtles embody resilience—a quality worth nurturing as we strive to protect their futures and the habitats they rely on. With the ongoing research, activism, and public awareness, there is hope for these turtles and the oceans they grace.

Subject of Research: Migratory routes and foraging grounds of hawksbill turtles in the Western Caribbean
Article Title: Inter-nesting area use, migratory routes, and foraging grounds for hawksbill turtles (Eretmochelys imbricata) in the Western Caribbean
News Publication Date: 12-Mar-2025
Web References: Link to article DOI
References: Details from collaborative research funded by various conservation organizations.
Image Credits: ProTECTOR, Inc., CC-BY 4.0

Keywords: Hawksbill turtles, migration, conservation, Western Caribbean, satellite tracking, marine ecosystems.