Wednesday, May 27, 2009

Spring Research

We have four of our researchers here at the moment. Heather Koopman and Andrew Westgate (and Arran, Skye and Nevis) are on Grand Manan for a couple of weeks to sample lobster eggs from berried females, arriving May 21. Berried females are individuals who are brooding their eggs externally on the underside of their tail. Heather is looking at energy content of the eggs and comparing this to the various sizes of the females to determine if there are particular size ranges where energy stores are better than others. Heather goes out lobster fishing with local fishermen to measure the size of the females and to collect small samples of eggs from different sized females. Heather is also sampling at different times of the year, her last sampling period was in December.

Heather and Andrew are offshore today in our research boat, "Phocoena", collecting zooplankton as part of monitoring zooplankton in the Grand Manan Basin. This monitoring was re-initiated in 2006 after a long lapse when Zach Swaim began his Master's thesis looking at lipids or fats in right whale faeces and comparing these to what is found in their favourite prey, calanoid copepods, a small zooplankton that can occur in huge concentrations, attracting filter feeders such as right whales, herring and basking sharks. Zach's research discovered that right whales can metabolize or break down waxes found in the copepods. Most mammals are not capable of this although the mechanism in right whale digestion that breaks down waxes into a usable energy source is not known at this time.

Heather's Masters student Caitlin McKinstry, began a study of basking sharks last summer, successfully attaching a data logger to one basking shark which recorded dive patterns. She will be returning this summer to try to tag additional sharks and will be interested in looking at zooplankton concentrations as well. An interesting study of satellite tracked basking sharks was recently aired on CBC radio:

"The basking shark is the world's second largest fish, and during summers, it lives a peaceful life sifting plankton from temperate ocean waters. It leads a mysterious double life, however, as during the winter, it simply disappears. Dr. Greg Skomal, a marine biologist with the Massachusetts Division of Marine Fisheries in Oak Bluffs on Martha's Vineyard, used special tags to track the sharks' movements during the winter. He discovered that these huge animals were sneaking off for southern vacations, travelling thousands of kilometers to tropical waters in which they'd never been seen before. He suspects these trips are to the secret nursery where the basking sharks bear and raise their young."

Rob Ronconi and Sarah Wong arrived on Monday, May 25 and immediately headed for Kent Island and the Bowdoin Research Station. Rob is working on a comparative study in habitat use of greater shearwaters and herring gulls to confirm feeding "hot spots" in the Bay of Fundy for seabirds. He hopes to attach solar powered satellite tags to three herrring gulls that may operate for more than a year. Herring gulls are nesting this time of year and it is easier to catch the gulls on their nesting islands than at sea.

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