Endangered species

First confirmed sighting of endangered sicklefin devil ray off the US Atlantic Coast

Rare 12ft sicklefin devil rays have been documented off the US east coast, from Florida to New York. This is the first confirmation of this elusive, endangered species in the region.

Written by Oceanographic Staff

A new study, led by Jessica Pate from the Marine Megafauna Foundation (MMF), has shown that 12ft wide sicklefin devil rays (Mobula tarapacana) are present off the US Atlantic coast. Listed as Endangered by the IUCN, this is the first time these huge, elusive rays have been documented in the eastern US.

The study was initiated when MMF scientist and US Country Manager, Jessica Pate, received a photo of a sicklefin devil ray from a Florida scuba diver, Jeff Joel, in 2018. This prompted her to start a collaboration between MMF, NOAA Fisheries, and Normandeau Associates Inc., compiling sightings from diverse datasets including scuba divers, social media platforms, aerial surveys, and reports from fisheries observers. This collaborative effort highlights the significance of data sharing and citizen science in the study of rare and endangered species.

The new research documents 180 sightings and 361 individual sicklefin devil rays, gathered between 1996 and 2022 in the waters off the US east coast and Gulf of Mexico. 

Julia Wilmott from Normandeau Associates Inc. said: “Normandeau is delighted that they could contribute to this body of knowledge. This is an example of how important it is to freely share data. In this case, we utilized data collected to assist in the responsible siting of offshore wind projects by the Bureau of Ocean Energy Management and the New York State Energy Research and Development Authority, all of which help to further our understanding of the species that inhabit our oceans.”

Jessica Pate added: “The original impetus for this study was a citizen science report sent to the Florida Manta Project, which led to sightings in other databases. One sighting even involved a video of a devil ray accidentally swimming into a commercial saturation diver’s airline in the darkness! People often don’t know that these rays exist – they’ve sometimes been confused with manta rays, which are even more gigantic. This study shows how non-scientists often make really important observations, and contribute to the conservation of endangered species.”

Understanding the distribution of endangered species is crucial for effective management and conservation. This study sheds light on potential overlap between the sicklefin devil ray and fisheries in the US Atlantic, highlighting areas where the species may be at greater risk of accidental capture by industrial longlines.

Prior to July 2019, US fisheries observers did not classify accidental catches of rays to their actual species. With accurate species representation in future bycatch data, researchers and conservationists can better understand the impact of fisheries on these devil rays and make informed management decisions.

Pate further commented: “Little is known about sicklefin devil rays in the United States. This study highlights how incidental observations and observer data can provide vital knowledge on rare, vulnerable, and difficult to study species. We hope this encourages other researchers and managers to examine regional databases for information on other data-poor species.”

The study, entitled Multiple datasets confirm range extension of the Sicklefin Devil Ray Mobula tarapacana in the western North Atlantic Ocean off the eastern United States, was published in the Journal of the Marine Biological Association of the United Kingdom. It opens up a new research frontier for scientists eager to study this elusive giant, and paves the way for better conservation strategies to protect the species.


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Written by Oceanographic Staff

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