Investigation into Silky Shark Population Provides Insights for Preservation Measures
In a groundbreaking study, researchers have successfully mapped the population structure of silky sharks (Carcharhinus falciformis) across the Eastern Pacific Ocean, providing significant new insights that can inform conservation efforts. The study, led by UC San Diego's The Nature Conservancy and the Inter-American Tropical Tuna Commission (IATTC), was co-authored by a team of scientists from both organisations and Scripps Oceanography.
The research, published in Reviews in Fish Biology and Fisheries, reveals a surprising amount of structure in the population that was previously thought to be well mixed across the Eastern Pacific Ocean. This achievement is crucial for understanding the genetic and spatial distribution of silky sharks in this region.
The study proposed a new approach to conducting population assessments for silky sharks. This method could lead to more accurate management strategies and improved conservation outcomes, as it accounts for the spatial distribution and genetic diversity of the species.
The research highlights the urgent need for shark conservation efforts. Silky sharks are the second most commonly caught oceanic shark species worldwide, and their populations have been declining due to overfishing and bycatch. Juveniles account for 81% of the silky sharks caught by purse seines set on floating objects, and 45% of those caught by longline fisheries.
The study sheds light on the whereabouts of juvenile silky sharks in the Eastern Pacific, revealing potential evidence of pupping or nursery grounds. The authors propose a preliminary three-stock model for silky sharks in the region, identifying core populations in the northern, central, and southern regions.
Lyall Bellquist, an independent fisheries scientist and Scripps Oceanography alumnus, emphasised the importance of the study in advancing conservation of a highly vulnerable species. The collaborative approach of the study offers a model for studying other vulnerable species in similar regions or elsewhere.
The IATTC Ecosystem and Bycatch Working Group has issued a formal recommendation to fund similar studies focused on three species of critically endangered hammerhead sharks in 2024. The study was funded by The Nature Conservancy and Scripps Oceanography in support of Talwar's postdoctoral research.
Building on the success of this effort, the study demonstrates that multi-institutional support from key organisations and agencies can enable cost-effective, impactful science that will advance conservation of highly vulnerable species. The University of California San Diego (UC San Diego), where the study was conducted, embraces a culture of exploration and experimentation, being one of the top 15 research universities in the world. Scripps Oceanography, a part of UC San Diego, is one of the world's most important centers for global earth science research and education, offering unparalleled education and training for the next generation of scientific and environmental leaders. Scripps Oceanography operates a fleet of four oceanographic research vessels and is home to Birch Aquarium at Scripps, which welcomes 500,000 visitors each year.
In conclusion, these findings underscore the importance of continued research into shark biology and ecology to support effective conservation strategies. The study offers a blueprint for future research into the conservation of other vulnerable marine species.
Science, spearheaded by Scripps Oceanography at UC San Diego and in partnership with The Nature Conservancy and the Inter-American Tropical Tuna Commission (IATTC), has paved the way for health-and-wellness strategies aimed at preserving the critically endangered hammerhead sharks. This research, similar to the recent oceanographic study on silky sharks, could contribute to the fitness-and-exercise sector by providing insights that can inform sustainable fishing practices and conservation efforts. The new approach to conducting population assessments, as demonstrated in the research, could lead to more accurate management strategies and improved health outcomes for marine species, mirroring the importance of exercise and nutrition in human well-being.
