Spatial Protection for Porbeagle Sharks, Lamna nasus, in the Northwest Atlantic: The Road to Recovery? [graduate project].
Abstract
Sharks have dominated the seas as apex predators for more than 400 million years, but today they are being fished by humans at an unprecedented rate. Many of the biological characteristics of sharks make them particularly vulnerable to overfishing. Conservation of sharks is critical, not only because they are a commercially valued species that are threatened with extinction, but also because sharks are keystone species and play an important ecological role in marine ecosystems. One common mechanism being used around the world to conserve marine biodiversity is the implementation of marine protected areas (MPAs). The traditional design of an MPA is limited in its capacity to protect mobile and migratory species that travel outside the boundaries of the MPA. However, the potential value that protected areas can have for pelagic conservation is becoming more widely discussed and explored. There is currently a lack of research on the relationship between mobile species and MPA networks internationally as well as in Nova Scotia, so studying the movements and migrations of these species can allow managers to better design connected areas which would have ecological, social, and economic benefits. This project examines a depleted population of endangered porbeagle sharks, Lamna nasus, off the Atlantic coast of Canada and evaluates the effectiveness of incorporating sharks into the Maritimes network of MPAs to assist in the recovery of this mobile predator in the temperate Northwest Atlantic. A spatial analysis of fisheries landings data using ArcGIS identified several potential sites of interest throughout the Maritimes region. Recommendations for future work include obtaining fisheries independent data on porbeagle movements and distribution, further studying the identified sites of interest, and studying how the changing climate may affect shark distributions.