Leopard Sharks Might Not Be Marine Mammals ~ But The Marine Mammal Center Helps to Solve a Mystery!
The Marine Mammal Center Blog is written by Dina N. Warren, Communications & Harbor Seal Crew volunteer.
A leopard Shark washes ashore, in distress and dying, on Ocean Beach in San Francisco.
Dr. Bill Van Bonn and Dr. Martha Delaney, work quickly to sample blood from the still living shark, to help current, scientific research on recent mass die-off of this important marine fish.
The leopard shark is a common sight along the California coastal shelf and within our own local waters. At this time of year, it is typical to find larger than normal numbers of these fish congregating in and around the San Francisco Bay, to breed and give birth. Lately, these particular sharks have been in the news because of large numbers reportedly washing ashore sick, dying or dead.
Just recently, The Marine Mammal Center’s Stranding Department received a call from a concerned citizen in Tiburon, describing a large, 10 to 12 foot leopard shark struggling near shore in the town’s small marina. The Center’s chief veterinary scientist, Dr. Bill Van Bonn, decided they had a rare free moment from caring for the Center’s primary pinniped patients, and responded to the call. (Prior to joining the Center, Dr. Van Bonn was senior director for animal care, at Shedd Aquarium, Chicago.) Once the team arrived, the shark had already disappeared back into the Bay.
Then, on Friday, June 10, 2011, the Center’s Stranding Department received yet another leopard shark call, this time sighted near Ocean Beach, on the Peninsula. In addition, The California Department of Fish & Game had asked if the Center could lend support to their leopard shark mortality study. Again, Dr. Van Bonn was pleased to help by collecting blood samples from the still-living leopard shark. Working together with one of the Center’s residents-in-training, Dr. Martha Delaney, whose specialty is part of the University of Illinois Zoo Pathology program; the veterinarians reached the struggling yet still-living shark, successfully collecting nearly 10 vials of blood. “Unfortunately, this shark was close to death when we arrived and expired moments after we completed our work,” explained Dr. Van Bonn. “We were also asked to conduct some scientific studies using the Center’s Laboratory and Necropsy Departments; so we collected the deceased shark and performed a post mortem dissection,” added Dr. Van Bonn.
Of course, we all know the Center specializes in marine mammals, and last time anyone checked, sharks are not mammals — though some species do bare live young, just like mammals! However, the health of all marine creatures is key to the Center’s work, and crucial to marine mammals and fish — and humans, alike! The Center’s Necropsy Department will share comprehensive post mortem results, including; internal measurements, observational data, and multiple tissue samples. These data will be crucial to the California Department of Fish and Game’s task of solving this mysterious die-off on one particular species.
Note: Sharks are an important indicator species of our ocean’s health. Some scientists believe that Bay’s reduced salinity, from heavy spring rains, may be a factor. This and other hypotheses are still under investigation.
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