Sharks and rays, or elasmobranchs, are visitor favorites at the Aquarium, but wild populations are threatened by human activities, especially bycatch and shark finning. Elasmobranchs grow slowly, reproduce late in life and have small litters. With few predators of their own, this reproductive strategy has been successful for hundreds of thousands of years. However, under pressure from modern fishing practices, elasmobranch numbers are now dwindling. We still know little about their biology and ecology.
The Aquarium displays 13 species of sharks and rays. Collaborating with scientists worldwide, we're trying to better understand the biology and ecology of the species in our care, and to display new ones. In addition to our Project White Shark, research focuses on broadnose sevengill sharks, cookie cutter sharks and mobulid rays.
Broadnose sevengill sharks(Notorynchus cepedianus)
Broadnose sevengill sharks have been displayed in our Monterey Bay Habitats exhibit since we opened in 1984, yet scientists know little about their migrations and population structure. We're collaborating with scientists at the Moss Landing Marine Laboratories and the Seattle Aquarium to tag sharks in the San Francisco Bay, an important nursery area for sevengills, and to collect tissue samples for DNA analysis. Preliminary results indicate that sevengill sharks travel far. Sharks tagged and released in Willapa Bay, Washington, have been reported in San Diego—1,200 miles away. We think they return to the same coastal habitat often to mate and birth litters of live young.
Cookie cutter sharks(Isistius brasiliensis)
Cookie cutter sharks are among the strangest and most highly specialized sharks in the world, with a snout and mouth perfectly suited to take round chunks of blubber and flesh from marine mammals and fishes. These sharks are a mystery to biologists and have never been displayed by any aquarium. In collaboration with scientists at California State University, Long Beach, and the Hawaii Institute of Marine Biology at the University of Hawaii, we are researching their preferred habitats, seasonal movements and population structure. This research was started in 2008, and results will help us understand these mysterious sharks and develop the knowledge to display them.
Mobulid rays(Mantas and devil rays)
Some species of mobulid rays have wingspans of more than seven feet and are breathtaking in their grace and beauty. Mobulid rays are high-priority candidates for display in our Open Sea exhibit. While little is known about their lives in the wild, they have been the target of an intense artisanal fishery in the Gulf of California. Anecdotal reports suggest that populations there have declined dramatically over the last 20 years. Mobula japanica is a tropical species that appears seasonally in the Gulf of California and is listed as "near threatened" by the International Union for the Conservation of Nature. We're collaborating with scientists from the University of California, Santa Cruz, to better understand this threatened population. Thirteen of these rays received tags in the Gulf of California from 2004 to 2007, and results show they move out of the gulf and into the Pacific during late summer/early fall. Learning more about these movement patterns and where these rays congregate is key to their conservation.