DTA submits petition to list the Whitepotted Eagle Ray under the U.S. Endangered Species Act.
The Defend Them All Foundation has submitted a Petition to list the Whitespotted Eagle Ray (Aetobatus narinari) as endangered under the U.S. Endangered Species Act (“ESA”) and to designate critical habitat for the species within U.S. waters.
ABOUT THE EAGLE RAY
Whitespotted eagle rays are benthivorous, hard-prey specialists that feed mostly on bivalves, gastropods, and large crustaceans by using their mandible and specialized jaws to crush their shells (Ajemian et al. 2012, at 13; Serrano-Flores et al. 2018). In foraging for food, whitespotted eagle rays use their long, bill-like snouts to stir up and restructure seabed sediment, eliminating particles through their gills: a process—known as bioturbation—providing smaller predators with access to otherwise buried invertebrates (Suchanek & Colin 1986, at 29). It is not uncommon for small fish to trail eagle rays for increased foraging opportunities (Flowers et al. 2021, at 116). Bioturbation results in the “nutrient release from the sediment into the water column,” providing “an important ecosystem function” by “fuelling planktonic primary production” (Biles et al. 2)
Whitespotted eagle rays have a low reproductive capacity and late maturity (occurring at approximately four to six years) causing them to be highly vulnerable to overfishing (Cerutti et al. 2018, at 237; Dulvy et al. 2021, at 7; Swider et al. 2017, at 437; Bassos-Hull et al. 2014, at 1054; DeGroot et al. 2021, at 18). Reproduction is “matrotrophic viviparous and litters [are between] 1-5 pups, with an average of 3 produced annually after a 12-month gestation” (Dulvy et al. 2021, at 7).
CURRENT STATUS
The IUCN categorizes the tope shark as Endangered based on an estimated population reduction of 50–79% over the past three generation lengths (30 years) (Dulvy et. al., 2021). As a species that occurs in coastal inshore waters where fishing pressure is substantial, the whitespotted eagle ray is vulnerable to human activity (Dulvy et al. 2021, at 8). Dramatic declines in the species’ wild populations have been primarily attributed to the continued overexploitation of the species as target and bycatch in fisheries (Id.). Habitat degradation and a lack of comprehensive critical legal and regulatory protections are further exacerbating pressures driving the species to extinction (Id. at 9-10).
HABITAT, RANGE, AND MIGRATORY BEHAVIORS
The Whitespotted Eagle Ray’s range is limited to the Atlantic Ocean (Dulvy et al. 2021, at 1). Along the Western Atlantic, the species can be found from “Cape Hatteras, North Carolina, USA to Rio de Janeiro, Brazil, including the Gulf of Mexico, the Bahamas, and the Caribbean Islands” (Id.). In the Eastern, Central, and Southeast Atlantic this species is believed to “range from Mauritania south to Angola, and possibly South Africa” (Id.).
Whitespotted eagle rays (Aetobatus narinari) are primarily distributed in the neritic zone, which extends from the low-tide mark to the edge of the continental shelf, in tropical to warm-temperate waters (Dulvy et al., 2021, p. 16; Asmus & Asmus, 2011, p. 3, 8). This species is often associated with coral reef ecosystems and can be found in lagoons and estuaries (Dulvy et al., 2021, p. 1). They are benthopelagic, meaning they inhabit the water column near the seabed, from the surface down to 60 m depth (Dulvy et al., 2021, p. 1).
Whitespotted eagle rays typically inhabit Hard Bottom habitats, which include mixed communities of algae, sponges, octocorals, and stony corals. These habitats are present in subtidal, intertidal, and supratidal zones and are inhabited by sessile, planktonic, epifaunal, and pelagic plants and animals. Infaunal organisms are also present in the interstitial soft bottom substrate (Florida Fish and Wildlife Conservation Commission, 2010, p. 296).
Whitespotted eagle ray populations may be resident or migratory/transient (Sellas et al. 2015, at 1; Brewster et al. 2020, at 2). For example, Gulf Coast whitespotted eagle rays exhibit increased migratory and transient behaviors when compared to Atlantic Coast rays, which remain primarily within the Indian River Lagoon (DeGroot et al. 2021, at 17). As a result, Atlantic Coast rays spend greater than five times the amount of time inshore, regardless of size, than Gulf coast rays (Id. at 10). “Immature [Atlantic Coast] rays spen[d] significantly more time,” about 91.5 percent, “inside the [Indian River Lagoon] compared to [their] mature counterparts,” about 60.2 percent (Id. at 1). The rays of the Gulf Coast “conduct repetitive annual migration patterns, heading south from Sarasota[, Florida,] starting in fall and returning to the area in early Spring” (Id. at 17). This trend provides the potential for mature whitespotted eagle rays to be caught outside of protected areas, thereby putting the species at increased risk of extinction.
THREATS
The Whitepotted Eagle Ray meets many of the criteria for listing as an endangered species. Among its primary threats are habitat loss and overutilization, though it also faces threats from disease or predation and an inadequacy of the existing regulatory mechanisms.
Habitat Loss
Chondrichthyes (sharks and rays) are considered highly susceptible to anthropogenic pressures near coastlines and in offshore environments (Leonetti et al. 2020, at 1). This is especially true for migratory species like the whitespotted eagle ray, which are susceptible to threats range wide (Dulvy et al. 2021, at 9-10; DeGroot et al. 2021, at 17). Destructive fishing practices, coastal development, and climate change are especially harmful to the whitespotted eagle ray due to its swimming and feeding behaviors, as well as to the benthic ecosystems upon which the rays rely (Dulvy et al. 2021, at 9; Branch et al. 2013, at 178).
Destructive Fishing Practices
Dredging and trawling degrade and destroy critical whitespotted eagle ray habitat and reduce foraging opportunities for the species (Trawling Takes a Toll, American Museum of Natural History). These practices are especially harmful to the whitespotted eagle ray because of the species’ site affinity (DeGroot et al. 2021, at 18). Along with the possible direct mortality of marine fish, suspended sediment causes increased physiological stress and sublethal responses, which creates behavioral changes and impacts foraging and predation (Wenger et al. 2016, at 973–76). Contamination and noise impacts are also associated with these destructive fishing practices (Id. at 977–79)
Coastal and Ocean Development
A decline in the quality of neritic marine habitats occupied by the whitespotted eagle ray has been observed, and is expected to continue, as pollution and coastal development plague coastlines throughout the Atlantic region (Dulvy et al. 2021, at 9). The whitespotted eagle ray is especially vulnerable to habitat modification because they live, breed, and feed in shallow coastal habitats including lagoons, estuaries, and coral reefs (Id. at 7). Corals, seagrasses, and other seafloor features are vulnerable to disturbances and are extremely slow to recover (Id. at 7). Disturbing these habitats reduces features that the species relies on to hide and hunt as well as the environment their prey are found (Cerutti et al. 2018, at 238).
With “as much as 27 percent of monitored coral reef formations … lost,” and “as much as 32 percent … at risk of being lost within the next 32 years,” the whitespotted eagle ray is facing increasing threats due to habitat loss and population fragmentation (Weier 2021; DeGroot et al. 2021, at 2). In some places, such as off the Florida Reef Tract, offshore coral reef cover is “≤ 5% since the 1997/98 El Niño on offshore reefs and has continued to decline” (Manzello et al. 2015).
Climate Change
Anthropogenic climate change threatens corals through elevated temperatures, which lead to bleaching events and the spread of coral disease, as well as through ocean acidification, which reduces larval survival and impedes reef formation and maintenance (Pörtner et al. 2019, at 61).
Ocean acidification has led to lower aragonite saturation levels, making it “difficult for certain organisms to build and maintain their skeletons and shells” (Climate Change Indicators in the United States: Ocean Acidity, U.S. Environmental Protection Agency, at 1). “The largest decreases in aragonite saturation have occurred in tropical waters” (Id. at 2). Consequently, this decrease in aragonite will negatively affect the marine food web, making it more difficult for the whitespotted eagle ray, and other species, to find adequate food sources (Branch et al. 2013, at 178). By reducing the availability of key chemicals including aragonite and calcite, ocean acidification also will hinder the ability of corals to build skeletons, reducing white-spotted eagle ray habitat (Fabry et al. 2008, at 416; Kroeker et al. 2013, at 1884; Parker et al. 2013, at 652-53).
Water temperature fluctuations significantly influence the behavior and migration patterns of the whitespotted eagle ray, suggesting that climate change-induced ocean warming will directly affect the species (Osgood et al. 2021, at 1). These temperature increases are expected to alter ray behavior by causing rays to move into deeper water (See Flowers et al. 2021, at 116-17). This will result in rays incurring “fitness costs through the inability to find food, increased predation risk …, and/or increased competition with other mesopredators” (Id. at 117). The increased temperatures are expected to affect the “rates of feeding, metabolism, growth, and even the life span of fish and other aquatic biota” (Havens 2015, at 3). Therefore, the frequency and intensity of predator-prey interactions may be reshaped by climate change, leading to more predation of the whitespotted eagle ray (Id.; Ashton et al. 2022, at 1215).
Overutilization
Directed fisheries and bycatch in coastal inshore and estuarine waters pose the greatest threat to the whitespotted eagle ray (Dulvy et al. 2021, at 8). The species is susceptible to a variety of fishery hazards, ranging from bottom trawling at the seafloor level to gillnets in the water column, resulting in persistent and sustained threats to the survival of the species.
Inshore gillnet fisheries are prominent throughout the species’ range and are particularly problematic as the whitespotted eagle ray’s swimming behavior increases its likelihood of entry and entrapment in gillnets (Id. at 1, 8-9). Globally, whitespotted eagle rays are commonly targeted by traditional gillnet and industrial shrimp trawl fisheries (Id. at 1). Once caught, the species is “retained and sold fresh and consumed locally” (Id. at 2). The species is also vulnerable to negative interactions with shellfish farming operations given the rays’ molluscan diet (Id. at 1, 8-9).
Fishing pressure is substantial and often unregulated across a majority of the species' range, particularly in the Gulf of Mexico, the Caribbean Sea, and the Eastern Central and Southeast Atlantic Ocean along the coast of Africa (Dulvy et al. 2021, at 8).
The whitespotted eagle ray is also captured for use in public aquarium displays and the marine aquarium trade (Dulvy et al. 2021, at 9). However, little data regarding the take of rays for this purpose are available.
Disease or Predation
Although disease and predation are not considered primary threats to the whitespotted eagle ray, other stressors including climate change, habitat degradation and destruction, and mishandling during fisheries interactions may increase rays’ susceptibility to disease and parasites. A number of parasitic relationships are known to occur, with trematodes (Thaumatocotylepse udodasybatis), which infects the skin, being most common (Aetobatus narinari - Discover Fishes, Florida Museum; see Castro 1996; Trematoda (Flukes), Encyclopedia). Clemacotyle australis and Decacotyle octona n. comb. have also been observed in the bronchial cavity and gills of the species (Aetobatus narinari - Discover Fishes, Florida Museum). Marine leeches Branchellion torpedinis have also been found on pelvic fins (Id.).
Rays infected with parasites exhibit “stressful behavior,” displayed by: “tips of the pectoral fins [to be] kept high above the median line during swimming; spinning movements where the body was held in a vertical position; tail and pelvic fins … angled upwards during swimming; jumping out of the water …; swimming against the current …; upside down swimming …; regular resting on the bottom; [and] … the ventral side” scratching against surfaces (Janse & Borgsteede, at 153). “This behavior caused haemorrhages on the tips and sides of the pectoral fins and on the skin under the pectoral girdle” (Id. at 154).
Predators, such as the tiger shark, lemon shark, bull shark, silver tip shark, and great hammerhead shark, feed on the whitespotted eagle ray (Aetobatus narinari - Spotted Eagle Ray, University of the West Indies; Aetobatus narinari - Discover Fishes, Florida Museum). “Sharks have also been reported to follow [white]spotted eagle rays during the birthing season, feeding on newborn pups” (Id.).
Inadequacy of Existing Mechanisms
Throughout the whitespotted eagle ray’s range, regulatory mechanisms fail to protect the species from climate change, fishing, and other threats to its continued existence. Additional protections including those afforded by the Endangered Species Act will be required for the species’ conservation. There is no in-place research and monitoring plan, no in-place water protection, no in-place species management, and no in-place education, which contribute to the species’ continued decline (Id. at 17). Additionally, extant regulations remain inadequate to protect the whitespotted eagle ray from the myriad threats associated with climate change.
Fishery Regulations
In light of concerns over the conservation of whitespotted eagle rays and the important role the species plays in maintaining a balanced marine ecosystem, Florida has prohibited the utilization of this species through different methods, which include harvest, possession, landing, purchase, sale, or exchange (Florida Administrative Code: 68B-44.004; Dulvy et al. 2021, at 10). Targeted fishing for elasmobranchs continues elsewhere, however, using passive gear like gillnets and longlines that will catch whitespotted eagle rays (Roskar et al. 2020). Thus, enhanced legal and regulatory protections at the national and international levels are urgently needed to protect wild populations of whitespotted eagle rays from further decline due to habitat loss, overutilization, and other threats (Dulvy et al. 2021, at 9-10).
Despite classification as a state-protected species in Florida for more than two decades under the Florida Administrative Code, the population of whitespotted eagle rays has not increased substantially (Id. at 10). These prohibitions do not apply to lawful harvest in nearby state and federal waters. Therefore, the current state-level protection is inadequate because the protection only applies to whitespotted eagle rays that are captured in Florida state waters, which are “from shore to 3 nautical miles on the Atlantic and from shore to 9 nautical miles on the Gulf” (Boundary Maps and Management Zones, Florida Fish and Wildlife Conservation Commission). Federal protection is necessary because this species is harmed by numerous fisheries and a unified conservation effort “could contribute to conservation of the species” (Dulvy et al. 2021, at 10).
Internationally, “only 13 of the top 20 shark-fishing nations [have] completed and implemented [National Plans of Action] for elasmobranchs,” leaving the whitespotted eagle ray vulnerable on a global scale (Dulvy et al. 2021, at 9-10). Much of the “progress towards the implementation of these actions have stalled since 2011 due to a lack of funding and support” (Id. at 10).
Climate Change Regulations
Regulatory mechanisms are woefully insufficient to address climate change-related threats to the whitespotted eagle ray. Existing national and international regulatory climate change mechanisms are non-binding and, even if adhered to by all parties, fail to mandate greenhouse gas emission reductions sufficient to protect rays from climate change-related effects including ocean warming and ocean acidification. These failings are compounded by the recently enacted Inflation Reduction Act, which mandates massive oil and gas leasing in the United States (Inflation Reduction Act, Pub. L. No. 117-169 (2022)).
In a past analysis, NMFS concluded that existing regularly mechanisms aimed at reducing greenhouse gas emissions were “inadequate” to avert climate-related threats to species (Endangered and Threatened Wildlife and Plants: Final Listing Determination on Proposal to List 66 Reef-Building Coral Species and to Reclassify Elkhorn and Staghorn Corals). With respect to international agreements, the agency found it “unlikely that Parties would be able to collectively achieve, in the near term, climate change avoidance goals outlined via international agreements” (Id.). In addition, “none of the major global initiatives appeared to be ambitious enough, even if all terms were met, to reduce GHG emissions to the level necessary to” avoid impacts to imperiled species (Id.). Circumstances on the international front have not changed materially since the agency’s review.
The primary international agreement on climate action is the United Nations Framework Convention on Climate Change (UNFCCC). Adopted at the Rio Earth Summit in 1992, it has to date been ratified by 190 countries. The most recent agreement covering UNFCCC countries, the Paris Agreement, was ratified in 2016 and took effect in 2020. According to the UNFCCC, “[t]he Paris Agreement builds upon the Convention and for the first time brings all nations into a common cause to undertake ambitious efforts to combat climate change and adapt to its effects” (Paris Agreement to the United Nations Framework Convention on Climate Change).
Scientists predict increases of 2°C or more would result in “‘dangerous’ [to] ‘extremely dangerous’ climate change” (Anderson & Bows 2011, at 20). Projected impacts include the disappearance of Arctic summer sea ice, irreversible melting of the Greenland ice sheet, an increased risk of extinction for 20-30% of species on Earth, and “rapid and terminal” declines of coral reefs worldwide (Veron et al. 2009, at 1428; Jones et al. 2009, at 484; Climate Issues Update, The Economics of Ecosystems and Biodiversity; Hare et al. 2011, at S1; Warren et al. 2011, at 1-2; Frieler et al. 2013, at 165). The Paris Agreement seeks to avoid such dangerous harms by aiming to limit warming to 1.5°C. Humans already have warmed the planet 1.0°C over the pre-industrial level, and at the current rate we likely will reach 1.5°C of warming between 2030 and 2052 (Masson-Delmotte et al. 2018, at 6).
Despite its adoption of the 1.5°C threshold, the Paris Agreement does not do enough to shield the marine species including rays from the harmful effects of climate change, including ocean warming and ocean acidification (Olhoff et al. 2019, at XIII). Additionally, signatories have not yet effected the changes necessary to achieve the Agreement’s goals (Id.). According to a recent analysis by the United Nations, current commitments will result in warming of approximately 2.5-2.9°C by 2100 (Nationally Determined Contributions under the Paris Agreement, United Nations Framework Convention on Climate Change (UNFCCC)). According to Simon Stiell, Executive Secretary of the United Nations Framework Convention on Climate Change, “[w]e are still nowhere near the scale and pace of emission reductions required to put us on track toward a 1.5 degrees Celsius world” (Schonhardt 2022).
In the United States, federal agencies have failed to fully capitalize on existing authority under domestic law to reduce greenhouse gas emissions to levels that would be protective of species. The U.S. government repeatedly has acknowledged that its rules do not go far enough to notably reduce the nation’s greenhouse gas emissions (Final Environmental Impact Statement: Medium- and Heavy-Duty Fuel Efficiency Improvement Program, Nat’l Highway Traffic Safety Administration (NHTSA), at 3-95; Standards of Performance for Greenhouse Gas Emissions for New Stationary Sources: Electric Utility Generating Units, U.S. Envt’l Protection Agency (EPA), at 22,401). The government’s refusal to utilize existing laws such as the Clean Air Act and Energy Policy and Conservation Act to force needed greenhouse gas reductions renders them inadequate mechanisms to protect the whitespotted eagle ray from the effects of climate change.
ESA LISTING IS URGENTLY NEEDED
The whitespotted eagle ray (Aetobatus narinari), a species identified as Endangered by the IUCN, continues to face pressures from habitat loss, overutilization, and inadequate protections. Overfishing, habitat degradation and destruction, climate change, dredging, and other threats continue to drive the species towards extinction. As such, the whitespotted eagle ray meets the criteria for listing under the ESA. Listing is essential to ensure the whitespotted eagle ray’s survival and persistence.
Special thanks to Kristin Carden, Ph.D./J.D. for the invaluable insight and contributions.
We would also like to thank the following students for the production of this petition and their assistance in researching the Whitespotted Eagle Ray:
Hunter Collins, University of San Diego School of Law
Julia Laquidara, Florida International University College of Law