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:
Anna is collecting genetic information from white shark fin clips to assess this species’ population size in South Africa. Using close-kin mark-recapture analysis instead of traditional methods, she hopes to provide an accurate account of South Africa’s white shark population size. She also aims to develop a monitoring protocol that can use genetic samples collected during shark net and drumline patrols by the KwaZulu-Natal Sharks Board. This information is needed in South Africa, where the conservation of a protected species is balanced against concerns about bather safety, and where sharks are caught in bather protection gear.
Faqih is filling the gaps in the scant knowledge of giant guitarfish in Java’s Karimunjawa National Park marine protected area (MPA). Karimunjawa is located near Northern Java’s main fishing grounds, but evidence of giant guitarfish caught in some of the use-zones of the MPA hints that the park may be a sanctuary for the species. Managing giant guitarfish in Karimunjawa requires species-specific information.
Faqih’s project is a socio-ecological one to help inform management and draws on new information about relative abundance and distribution, historical occurrence and fishing pressures to paint a contemporary picture of the species in the park.
Cindy wants to know if bonnethead sharks in the Eastern Pacific constitute a third, cryptic species. The Bonnethead complex need clarification in all its distribution range, and Panama is a key country to solve this question since we have the Caribbean sea and the Pacific Ocean. By collecting fin clip samples to compare species at the genetic level and collecting specimens to compare how they look (morphology), Cindy hopes to resolve the taxonomy of Sphyrna tiburo vespertina – that is, whether it’s a cryptic third species for bonnetheads in the region. Her information can help update the IUCN Red List for bonnetheads and improve fisheries policies in Latin America where bonnethead sharks are commonly caught.