Ashley is catching cownose rays to tag them with an acoustic transmitter and using the network of listening stations established in her research area to passively track where the rays move through their different life stages. Ashley works in Apalachicola Bay, a large and highly productive estuary in the north-east Gulf of Mexico that is also a biodiversity hotspot and federally-designated National Estuarine Research Reserve. Her study on the movement patterns of these rays, which are highly migratory and vulnerable to overfishing, comes at an important time after an unregulated fishery has led to the population’s collapse.
Fifteen years ago I visited the Georgia Aquarium on opening day and began using it as my window into the underwater world. Looking into the eyes of elusive species that I may never otherwise have a chance to see drew me into finding out more about them. While working in various aquariums, I have gained invaluable experience educating visitors of all ages about a diverse assemblage of marine species and have enjoyed innumerable exchanges about what we as humans can do to become conscious marine stewards and support efforts to protect the earth’s aquatic ecosystems. These conversations...
The main objective of this study is to define the spatial use habits of cownose rays in Apalachicola Bay, Florida, in a bid to provide the opportunity for effective species management while guiding efforts in local oyster restoration projects.
The Atlantic cownose ray is highly migratory and vulnerable to overexploitation. It has become difficult to manage this species due to limited behavioural data in the Gulf of Mexico. Historical implication in the collapse of several fisheries led to an unregulated cownose ray fishery with immeasurable population effects. As oyster restoration is becoming heavily pursued, now is a crucial time to launch a ray movement study to clearly define the potential interaction between rays and oysters.
The cownose ray is an extremely vulnerable species, due to the fact that individuals reach maturity at the age of four to five years and then only give birth to one pup each year. When a population declines, it therefore takes a long time to recover. While detailed movement studies of this species have been conducted along the eastern US coast, movement and space use data in the Gulf of Mexico are limited, contributing to the fact that no official stock assessment has ever been carried out. As key life-history traits differ between populations in the Atlantic and Gulf, it is likely that there are also behavioural differences in their movements and use of space. There are no existing data regarding seasonal residency or movement of cownose rays in Apalachicola Bay. However, it is likely that they are affected by fishing pressure from shrimp trawls during their seasonal window of bay use. Cownose rays are considered meso-predators, eating primarily hard-shelled invertebrates such as clams and oysters, and are preyed upon by larger species of sharks. Reports of cownose rays depleting commercial oyster stocks in Chesapeake Bay, although challenged in the literature, led to the creation of a large and unregulated cownose ray fishery as pushed for by commercial fishermen, dubbed the ‘Save the Bay, Eat a Ray’ campaign. In the absence of an official stock assessment, impacts from this fishery were immeasurable, which is particularly jeopardising for a species so vulnerable to overexploitation. It is dangerous to allow crucial data gaps regarding spatial use and migratory habits to linger, especially in highly migratory meso-predators that are interacting with several different ecological habitats over different life stages.
The aims of the project are:
This project has revealed a lot of interesting information about the species, including locating a pupping and mating area that has been used repeatedly for multiple consecutive summers. Tracking data has also revealed unique movement and habitat use patterns across sex and life stage.
Understanding ecological dynamics within this critical ecosystem is essential to the long-term conservation of species in the community. This study aimed to describe the movement behaviour of cownose rays throughout the Apalachicola Bay system, including seasonal presence, changes in habitat use across sex and life stage, and assessment of cryptic species presence. Movement data will be collected until Summer 2024. There is still a strong need for further investigation of cownose ray movement behaviour and ecology in the Gulf of Mexico. Additional knowledge gained about the species through studies such as this one can provide new insights into species behaviour that can be used in potential future species assessments and conservation initiatives.
Outside the USA, The Bahamas is the only place where Critically Endangered smalltooth sawfish can reliably be found. Tristan wants to ensure that protection measures in The Bahamas are understood and enforced as far as sawfish are concerned to close the current gap between policy and the people. He’ll be using aerial surveys, sonar and BRUVs, combined with interviews that draw on local knowledge, to identify essential sawfish habitats that need protection. Engaging with the community through workshops and by training students and meeting with government, Tristan intends to advocate for smalltooth sawfish protection throughout The Bahamas’ territorial waters.
Steven and Kevin are using genetic techniques to understand how Caribbean reef shark populations are connected across the extent of their range. Populations of this Endangered shark are in decline generally, but where they are managed and there is effective protection, their numbers are stable. With the integration of the correct information, Steven and Kevin are convinced that we can give Caribbean reef sharks a better shot at recovery and population stabilisation. They will also explore any barriers to connectivity, looking to the future recruitment and recovery of these sharks.
With very little information available about Endangered sicklefin devil rays, their seasonal aggregations at sea mounts in the Azores give Sophie an opportunity to learn more about their lives. She will be collecting satellite-tracking data that show how they move in the Azores’ exclusive economic zone. The information she collects will be used to develop maps of how the rays are using the zone and to identify essential areas that multiple species use. With this information at hand, Sophie hopes her work can contribute to a network of marine protected areas.