NOAA Fisheries Works with International Partners to Better Understand Shark Behavior

Silently patrolling the ocean depths for the last 400 million years, sharks are some of the oldest creatures on the planet … and some of the most elusive. However, that’s changing a bit now that NOAA scientists are working collaboratively with Uruguay’s fisheries agency to research blue sharks in the southwestern Atlantic Ocean using state-of-the-art tagging techniques and satellite monitoring. In this project, which is partially funded by NOAA Fisheries, scientists from Uruguay and the United States have been working together to tag blue and other pelagic sharks since 2007 to determine their movement patterns and interactions with Atlantic pelagic longline fisheries. Like the global positioning systems (GPS) we have in cars and smart phones, the satellite tags used in the study supply invaluable data on the sharks’ long-distance migratory routes, areas of abundance, and mating or pupping areas. Experts believe that this research could lead to better conservation of sharks, by informing sustainable fishing practices and reducing unnecessary bycatch. 

International Collaboration

Through this international research project and the information it generates, NOAA Fisheries and Uruguay’s fisheries agency hope to better inform the management process under which sharks in the southwestern Atlantic are managed, facilitate more effective enforcement and compliance with the conservation measures already in existence, and provide enhanced understanding that can benefit shark conservation efforts throughout the ocean. For additional information on NOAA Fisheries’ international stewardship and science activities, please visit ourInternational Science page and our Office of International Affairs. To view the tracks of several blue sharks tagged to-date as part of this project, visit the project website.

Unique Life History Characteristics

It’s not unusual for sharks to be the focus of scientific research. As top predators, sharks are often used by scientists as indicators of the ocean’s health. Some sharks, like many other types of fish, are ‘pelagic’ which means they live in the open ocean and all parts of the water column and are also highly migratory, referring to the fact that they swim long distances and move in and out of national and international waters. While the United States has some of the strictest conservation and fisheries management measures in place, enforcing such practices in international waters is a real challenge. For this reason, it is crucial for the United States to work with international partners and conduct research to improve our understanding of fish and the role they play in the marine ecosystem. The current decline in many global shark populations due to unsustainable fishing practices and catch levels, and changes in the ocean environment, could greatly affect ocean ecosystems and biodiversity. 

Pelagic Shark 101

The open ocean is home to many species of pelagic sharks. These species range widely in their diversity and distribution - occurring throughout the ocean.  In common with other shark species, pelagic sharks generally mature late (around 11 years) and can have long life spans, with some species living up to 65 years. After a long gestation period (typically 9 to 18 months) they give live birth to a few well-developed offspring, which typically have a high probability of surviving to adulthood. It is this slow life-history and low population growth rate that render sharks particularly vulnerable to high levels of fishing mortality. Due to their wide distribution across the ocean and its many jurisdictions, pelagic sharks are subject to fishing pressures from many sources – including commercial, recreational and artisanal fisheries. Many shark populations are in decline and being overfished.

Hammerhead shark tagged during research cruise.

Researchers measure a large tiger shark alongside research vessel. 

Satellite tag applied to bull shark by NOAA researcher.