Bertarelli-Annual-Report-2024-LR - Flipbook - Page 21
Projects
Building Genomic Seascapes
to Enable Genetic surveillance
of Illegally Fished Sharks
Lead Investigator: Prof. Barbara Block, Stanford University
The objective for this project is to develop the genomic
tools for creating an ocean traceability system which
will enable assessments of the genetic diversity and
stability in reef shark populations. Genomics can be
a powerful tool for creating a robust framework to
track illegal bycatch of sharks in fisheries and provide
a comprehensive method for measuring conservation
efficacy in the Chagos Archipelago and across fisheries
in the rest of the Indian Ocean (IO).
Marine Science 2023
19
procured samples for local species populations and
at markets/landing sites in ten nations including 15
locations across the Indian Ocean and three sites in the
Pacific. Through one of these field sampling efforts, they
have discovered a population of silvertip shark once
thought to be extinct in the Lakshadweep Archipelago in
southwest India.
Large scale sequencing of samples has been intensive
across the region with approximately 300 samples
sequenced including a subset of the samples from local
species populations collected across the IO. All samples
from the Chagos Archipelago that were collected
during previous Bertarelli Foundation funded electronic
tagging expeditions have also been sequenced. These
shark genomes have then been aligned to the reference
genomes, enabling the team to discover population
structure and connectivity across the IO.
The team have made good progress building two
chromosome level reference shark genomes, one each
for our study species grey reef shark Carcharhinus
amblyrhynchos and silvertip shark Carcharhinus
albimarginatus. They have conducted sampling or have
Nurse shark, Chagos © Marleen Stuhr
