Shark Savers Gets the Latest on Ground-Breaking Shark Science

Posted on August 21, 2012
Written by: Shark Savers

This August, Shark Savers joined scientists and researchers from around the world as one of the few non-profit conservation groups at this year’s conference of the American Elasmobranch Society.

Elasmobranchs are sharks, skates and rays, and this annual conference, held in Vancouver over an intense four days, is the first time that the public can hear about the newest ground-breaking research being done to help understand and conserve these amazing marine animals.

At Shark Savers, we recognize that strong and sustainable conservation measures are based on the best available science, so we were happy to have our Outreach Manager Hannah Medd attending meetings, creating new relationships and collaborating on these important issues.

Elasmobranchs have a lot to teach us. Studying sharks and rays has helped us better understand evolution, inspired new biomaterials, and some have even become symbols for larger conservation issues, such as overfishing and pollution. We are excited to share some of the newest research that we learned about elasmobranchs:

NEW Discoveries About Shark Biology & Behavior

• Tag data from Blue and Mako Sharks in the Atlantic Ocean showed they shared 75% of the space they use with the GPS location of European longliners.

• A Blue Shark has been recorded as diving more than 1,400 meters deep, with a Longfin Mako shark diving more than 1,700 meters. Temperature changes in the ocean may be driving the shark’s prey movement, which may be why these sharks are making these dives.

• The bioaccumulation of DDT, PCBs and Mercury in Great White Sharks along the coast of California seems to occur as legacy contamination: the fetus receives the highest levels of the contaminants through connection with the mother, not just from the environment. The oldest pups tend to accumulate the most.

NEW Recommendations for Managing Fisheries

• Targeting the males of a population instead of females might not be the best management technique, because in Nurse Sharks, cooperative mating behavior amongst males may mean that several males are required for a successful mating.

• There has been a lot of interest in the use of rare Earth elements, like lanthanide, to deter capture of sharks on longlines but these elements are extremely expensive and dissolve in salt water. A positive but unexpected outcome of the research was that the combination of zinc and graphite (basically a battery) is much cheaper, doesn’t dissolve and works better!

• Spiny Dogfish Sharks are currently managed as one population along the entire east coast of the United States, but research has found that it may be two different populations that spend more time in the water column, making them more vulnerable to certain fishing methods.

NEW Shark Research Studies

• Deep sea surveys are expensive, requiring lots of specialized equipment and extensive travel time, but in the Bahamas the deep drop off is close to land so researchers are able to deploy new equipment, such as Medusa from Orca (an US $80,000 piece of equipment that gets tossed overboard) to record never-before seen species and behaviors at depth.

• The impact of the Deep Horizon Oil spill is still a cause of much concern for many research groups throughout the Gulf of Mexico. Surveys indicate the uptake of the nastiest compounds has occurred in some species of sharks but the methods to detect levels are being modified because sharks seem to metabolize the toxins differently than other species.

• There were several calls for cooperation among researchers in the field of taxonomy, which is dynamic, to avoid misinformation that can hinder conservation efforts.