Tuesday, January 24, 2012

Master Student First Impressions

The following are impressions and accomplishments of Masters Student, Zachary Siders, who spent his first field season in the Bay of Fundy off Grand Manan Island in August, 2011.  Zach is a Masters Student at the University of North Carolina, Wilmington.

As my first summer at the GMWSRS, I was unprepared for the extreme variation in the environment. Between tidal swings, fog banks, rolling swell, and varying chop the Bay of Fundy is always fluctuating.  Despite many days of rain, fog, swell, and chop we were able to survey for sharks, assist in whale poop collection, and help colleagues from Duke University deploy dive tags on fin whales. As part of the basking shark research group, my primary role was to help deploy seven satellite pop-up tags on adult sharks. With a cumulative of 255 hours of basking shark sightings we were fortunate to deploy six out of the seven pop-up satellite tags. These deployments are to provide information on migration out of the Bay of Fundy during the winter months. This effort was part of the station’s investigation of spatial and temporal patterns in basking shark movements.

Basking Shark, second largest shark and a filter feeder on zooplankton

As an active part of this investigation, I have been begun analyzing archival sighting data acquired by Laurie Murison, through Whales 'n Sails whale watching company. Fortunately, this dataset dates back 23 years and allows me to analyze how basking sharks spatial distribution has changed over time. Additionally, this dataset will be supplemented by a data request to the North Atlantic Right Whale Consortium. Together, this data will be used in habitat modeling the spatial distribution of basking sharks across the Bay of Fundy. Modeling this information will determine how basking shark critical habitat within the Bay of Fundy has changed across time. With the increasing prevalence of remote sensing data and detailed oceanographic information, the environment features defining this critical habitat can be elucidated. All of this information greatly increases our understanding where basking sharks occur in the Bay of Fundy, a critical habitat for these giant sharks.

Another aspect, I have begun analyzing is the dive profiling movements of basking sharks acquired through our Temperature-Depth Recording tagging efforts. These efforts have been ongoing since 2008 and have acquired 22 days of dive profiling data. This fine-scale diving information can help us understand how basking sharks utilize the extreme variations in the Bay of Fundy especially tidal fronts, temperature contours, and depth profiles. Unlike other basking shark habitats, the Bay of Fundy is extremely tidally driven as well as a protected body of water. Understanding how basking sharks utilized the unique dynamic oceanographic features can greatly enhance our understanding the ecological flexibility of these cosmopolitan creatures.
Basking shark just under the surface with only the large dorsal fin above the water surface.  Basking sharks received their name from this behaviour of coming to the surface.

Most importantly, understanding how basking sharks utilize critical habitat and where these habitats are in the Bay of Fundy can be used to further the conservation of this vulnerable species. In particular, I hope to spatial modeling and diving behavior analysis to determine the ship-strike risk to basking sharks in the bay. As these sharks spend up to 80% of their time within the 12 meter draft of cargo vessels, they are extremely vulnerable to cargo traffic travelling through the Bay of Fundy. Determining these ship-strike risks is essential for conserving basking sharks within the bay and more so, globally.

The field work this summer could not have been accomplished without the advisement of Dr. Andrew Westgate and the help of the rest of the GMWSRS senior scientists. Additionally, the help of Jared Juckiewicz, a summer research assistant, was considerable throughout the field season. The continued analysis could not be possible without Dr. Westgate, Dr. Heather Koopman, and Dr. David Johnston, and I would like to thank them for their ongoing support.

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