Short Project: Little is known about the diversity and abundance of elasmobranch species around Fregate Island, Seychelles. The images captured during a previous assessment revealed an array of species including critically endangered species such as the guitarfish.

Juvenile Tiger Shark at BRUV

Photo © Masha Lourie

Background

From the 2019-2021 marine biodiversity assessment report around around Fregate Island, Seychelles, elasmobranchs were marked as “incidentals” and were excluded from further statistical analysis. However, the images captured during this previous assessment revealed an array of species including critically endangered species such as the guitarfish.

The aim of this study is to further assess the abundance and diversity of elasmobranch species around Fregate Island during different seasons and see if there are any significant changes in diversity within each season.

Objectives

Baited Remote Underwater Video (BRUV) will be deployed around 22 different sites that were included in the previous census; 11 shallow and 11 deep. Each BRUV will be deployed for 1 hour at each site. For the bait we will be using Bonito as it is the best bait used for elasmobranch studies.
Additionally, important environmental variables to be collected at each site e.g. location, temperature (air and water), depth, bottom type, visibility, air pressure, wind speed, dissolved Oxygen and salinity (if possible to obtain a measure device).
The data obtained will then be analyzed and compared with previous data taken in 2019 and 2020.

Project Status

Data have been obtained and are now being analyzed.

Administrative Details

Project Status:   in progress since 2022
Project leader: Masha Lourie, University of Lisbon
Funding since 2022: approx. CHF 2,700