The lagoon of St Joseph Atoll provides a home for three ray species. Juvenile mangrove whiptail (Urogymnus granulatus), porcupine (U. asperrimus) and feathertail (Pastinachus ater) rays all inhabit the shallow waters around the atoll’s various islands. We tag these rays with small electronic (PIT) tags that become their ID numbers. We also measure them and take a tissue sample. As time goes by and we recapture individuals, we can learn about how many of them use the lagoon, where they go and how quickly they grow. All this is important information that helps us to understand how these rays use the site. We collect data for this project every month.
Since its inception in 2012, the SOSF-DRC has been managed and run by different people in various capacities. Lab managers, research officers and research assistants have been integral to the daily operations of the centre over these years and our long-term projects have been handed on from past to present management.
Currently the SOSF-DRC is run by Dr Robert Bullock and Henriette Grimmel in a joint-management capacity.
The following is a history of past management staff:
The key objective of this project is to develop an understanding of the ecology and population dynamics of the different ray species that use the St Joseph lagoon. We are looking specifically at the abundance of juvenile rays using the site, which areas of habitat are important to different ray species, and how they use the site to support their fitness and survival.
All three of the ray species using St Joseph Atoll are currently threatened with extinction and yet little is known about their behaviour and habitat use at the juvenile stage. This project should improve understanding of how rays use key refuge sites such as St Joseph, as well as which key habitat features are important to them. Data such as these are critical in defining conservation measures for threatened species and helping to mitigate population declines.
Rays are a group of elasmobranch fishes related to sharks. Despite being more numerous, they receive comparatively little attention and, to date, research into rays lags behind that into sharks. Rays are key predators in the ecosystems they inhabit and many species, including those inhabiting St Joseph Atoll, are at risk of extinction. Effective conservation for rays requires accurate information about their ecology, habitat use and behaviour. Understanding the juvenile life stages is particularly important for ensuring the stability of populations into the future. Mark-recapture studies are a popular means of estimating population sizes and survival rates and, more recently, the use of unmanned aerial vehicles has been adopted as a way to estimate the abundance of rays using particular sites, as well as how they move around different areas and habitats.
The key objective of this project is met by several specific study objectives:
– To mark and recapture juvenile rays of all three species, collecting tissue samples and data on their size and sex.
– To develop a drone survey protocol to estimate ray abundance, distribution and movements within the study site.
– To map each species’ core areas of use and investigate which habitat features and/or environmental conditions correlate with this.
Nico is using acoustic telemetry and BRUVs around Seychelles to explore how reef sharks are using their reef homes. What are they eating? What prey is available? His project aims to explore what factors influence ideal habitats for sharks and will combine information from both pristine and degraded reefs to create a model to test this suitability. The point? To build on work by the Marine Futures Lab across the Indian Ocean and the Indo-Pacific and to help identify priority shark conservation areas.
Jeremy wants to understand when blue whales and other whales and dolphins visit Seychelles, and how many visit when they do. He investigates which factors, such as ocean currents and noise pollution, affect their presence and behaviour in these waters. To do this, he spends hours observing whales and dolphins from a boat, documenting their behaviour, where they move and what they do. He also uses their calls to determine when they arrive, whether they’re feeding or mating, and where they come from. This information can help identify new behaviours and important areas that need protection.
This study uses long-term reef fish survey data, by underwater visual census, from 2011 – 2017. Sarah will use the dataset to investigate differences in the reef fish community at different sites around the islands and assess annual changes in patterns of abundance at the site, considering which factors are causing these variations, with particular consideration of extreme climate events (ocean warming event in 2016).