Tuesday, January 24, 2012

Continued Work on Leach's Storm Petrels

Sandy Camilleri is a graduate student of Dr. Heather Koopman at the University of North Carolina, Wilmington.  She has been studying Leach's Storm Petrels for her Masters thesis on Kent Island, part of the Bowdoin Scientific Station, in the Grand Manan archipelago.  Sandy hopes to defend her thesis this spring.

Most seabirds provision their chicks with whole or partially digested prey items whereas tube-nosed seabirds (albatrosses, shearwaters, fulmars and petrels) concentrate their prey into a lipid rich oil, called stomach oil. For her master’s thesis research she is investigating this unique strategy used by tube-nosed seabirds by comparing the lipid composition, energy content, and the contaminant levels of the stomach oil to prey items that would be fed to other species.

Leach's Storm Petrel chick.  Note the tube-nose on the bill.

The tube-nosed species chosen for this study was the Leach’s storm-petrel, which has a large population that nests on Kent Island and has been studied since the 1930s by Bowdoin College. I spent a couple of weeks learning how to properly handle petrels and how to collect stomach oil in 2009, then developing the laboratory analyses of the stomach oil. In the summer of 2010, I spent a total of 8 weeks on Kent Island monitoring and collecting stomach oil samples from petrels. A total of 83 samples were collected in 2010, 49 from adults and 34 from chicks.
Sandy Camilleri with a Leach's Storm Petrel adult on Kent Island.

In the summer of 2011, Ispent a total of 8 weeks on Kent Island, again monitoring and collecting stomach oil samples from petrels. The field season was split into two parts, the first was 2 weeks in June which was used to set up the field site, called the Ditch, monitor the burrows and collect adult stomach oil samples. The second part started in mid-July and lasted for 6 weeks. During this time, I finished sampling adults and monitored the nests daily waiting for chicks to hatch. The first chick to hatch for the summer was found in the Ditch on July 14! Once the chicks hatched, they were weighed daily and measurements of wing length and tarsus (foot bone) length were recorded as growth indicators. Once chicks were 2 weeks old, those that gained more than 10g overnight were sampled, indicating that mom and/or dad had fed it that night. A second sample from the chicks was collected at least one week after the first.
Some of the buildings on Kent Island, part of the Bowdoin Scientific Station

A total of 147 samples were collected in 2011, 72 from adults, 45 from chicks sampled once, and 30 from chicks sampled twice. All samples were brought back to UNCW where lipid analysis and energy content will take place in Dr. Heather Koopman’s lab. Contaminant analysis will be completed in Dr. John Kucklick’s lab at the National Institute of Standards and Technology in Charleston, SC.

This project will provide insights to the costs and benefits to the unique provisioning strategy used by tube-nosed seabirds. Leach’s storm-petrels are ideal for monitoring environmental health and can be used as a model for other tube-nosed seabirds that have more remote nesting locations, those that are experiencing population declines, and those that live in known contaminated areas.

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.

Tracking Greater Black-backed Gulls from Sable Island

Here is an open letter from one of our researchers who has been working on a Post-Doctoral study on Sable Island, requesting your help:

Dear gull enthusiasts,

On an icy, wintery trip to Sable Island this month, I was able to capture and deploy wing-tags on a dozen Great Black-backed Gulls that were happily gorging themselves on the carcasses of seal pups that didn't make it. There are far too many Black-backs on the island in the winter for them to be loafers sticking around from the summer breeding season. So...they are likely traveling here from other colonies (Maine? New Brunswick? Newfoundland?) to indulge on the ill fated seals.

Greater Black-backed Gull
This summer while you're in the field, keep your eyes open for these birds so that we might document their movements (tracking the old fashioned way). Please forward this email to colleagues, students, and volunteers that might be working around or in Great Black-backed colonies this summer.

Check out my latest blog entry for details and pictures of these blue/turquoise wing-tags on the birds.


Rob Ronconi
Postdoctoral Researcher
Dept. of Biology, Acadia University