Pacific Pit Stops: Leveraging Genomics to Understand Scalloped Hammerhead Aggregations in the Galapagos Islands
Location
HCAS Guy Harvey Oceanographic Center, Nova Southeastern University
Start
2-14-2025 2:15 PM
End
2-14-2025 2:30 PM
Type of Presentation
Oral Presentation
Abstract
Authors:
Geoffrey Walker1,2, Andrea Bernard1, Pelayo Salinas-de-León1,3, Jennifer Suarez-Moncada4, Mahmood Shivji1,2
1. Save Our Seas Foundation Shark Research Center, HCAS, NSU
2. Guy Harvey Research Institute, HCAS, NSU
3. Charles Darwin Research Station, Charles Darwin Foundation, Galapagos Islands, Ecuador
4. Galapagos National Park Directorate, Galapagos Islands, Ecuador.
Scalloped hammerhead sharks (Sphyrna lewini; IUCN Red List: Critically Endangered) form iconic seasonal aggregations around Wolf and Darwin Islands in the Galápagos (Eastern Tropical Pacific). The genetic characteristics of these mainly adult aggregating sharks are unknown. Through collaboration with the Charles Darwin Foundation and Parque Nacional Galápagos, and as part of our satellite tag tracking studies on this species, we collected biopsy tissue samples from free-swimming sharks from 2016 to 2023 and are investigating the comparative genetic health and resilience of these aggregations. In this study, we employ a reduced representation genomic approach to obtain high-resolution single nucleotide polymorphism (SNP) genotype data from the Galápagos aggregating scalloped hammerheads, as well as non-aggregating adults of this species near Seychelles (Western Indian Ocean) and Florida (Western North Atlantic). Initial data analysis on population genetic differentiation and diversity shows clear genetic divergence among the three geographic groups, and much higher diversity in the sharks from Indo-Pacific (Seychelles and Galápagos) than Western North Atlantic (Florida). The genotype data are also being used to investigate whether genetic relatedness exists in the annually aggregating Galápagos sharks and if individuals sampled return to the aggregation over multiple years.
This project conducted under Permit MAE-DBI-CM-2021-0209 from the Ecuador Ministry of Environment.
Pacific Pit Stops: Leveraging Genomics to Understand Scalloped Hammerhead Aggregations in the Galapagos Islands
HCAS Guy Harvey Oceanographic Center, Nova Southeastern University
Authors:
Geoffrey Walker1,2, Andrea Bernard1, Pelayo Salinas-de-León1,3, Jennifer Suarez-Moncada4, Mahmood Shivji1,2
1. Save Our Seas Foundation Shark Research Center, HCAS, NSU
2. Guy Harvey Research Institute, HCAS, NSU
3. Charles Darwin Research Station, Charles Darwin Foundation, Galapagos Islands, Ecuador
4. Galapagos National Park Directorate, Galapagos Islands, Ecuador.
Scalloped hammerhead sharks (Sphyrna lewini; IUCN Red List: Critically Endangered) form iconic seasonal aggregations around Wolf and Darwin Islands in the Galápagos (Eastern Tropical Pacific). The genetic characteristics of these mainly adult aggregating sharks are unknown. Through collaboration with the Charles Darwin Foundation and Parque Nacional Galápagos, and as part of our satellite tag tracking studies on this species, we collected biopsy tissue samples from free-swimming sharks from 2016 to 2023 and are investigating the comparative genetic health and resilience of these aggregations. In this study, we employ a reduced representation genomic approach to obtain high-resolution single nucleotide polymorphism (SNP) genotype data from the Galápagos aggregating scalloped hammerheads, as well as non-aggregating adults of this species near Seychelles (Western Indian Ocean) and Florida (Western North Atlantic). Initial data analysis on population genetic differentiation and diversity shows clear genetic divergence among the three geographic groups, and much higher diversity in the sharks from Indo-Pacific (Seychelles and Galápagos) than Western North Atlantic (Florida). The genotype data are also being used to investigate whether genetic relatedness exists in the annually aggregating Galápagos sharks and if individuals sampled return to the aggregation over multiple years.
This project conducted under Permit MAE-DBI-CM-2021-0209 from the Ecuador Ministry of Environment.