October Research Cruise Targets Swordfish, Albacore, Opah and Sharks

Scientists from the Southwest Fisheries Science Center and Monterey Bay Aquarium and crew of the Ventura II set out for an 18-day research cruise to discover new information about swordfish, albacore, shark and opah biology, especially what habitat swordfish use and to determine if there are depths at which swordfish swim that do not overlap with endangered sea turtle habitat. The cruise is part of an effort to examine the feasibility of a deepest longline fishery for swordfish, characterize large fish in the California Current and it allows scientists to collect hard-to-obtain, but necessary-to-science, biological samples. The Ventura II will fish along the California coast between Mexico and San Francisco using longline and trolling gear to collect fish samples. Once collected, scientists will implant satellite tags on healthy swordfish, sharks and opah. By transmitting geographic location, temperature and depth information to satellites, which transmit the information back to the scientists’ computers, the tags will help us understand where the fish travel and what kind of habitats they prefer – information critical to understanding the health of these populations and sustainable management. After a predetermined amount of time, the tags used on swordfish and opah pop off whereas the tags attached to the sharks transmit its information to satellites each time the shark's fin breaks the ocean's surface. Scientists will also collect biological samples, like otoliths, tissues and stomach contents to learn about age and growth, how populations are structured, genetics and diet preferences, information critical to sustainable management.

Thresher Shark with tag