Seminar summary: Evaluating year-round seabird habitat needs in the Gulf of Mexico to improve oil pollution risk assessment and mitigation
By: Bobbi Carpenter
Dr. Juliet Lamb is a post-doctoral researcher at the University of Rhode Island and is adjunct faculty at Clemson University. Her focuses on has been on seabirds along the Atlantic for the decade. In 2010, the Deepwater Horizon drilling rig explosion lead to the release of 4.9 million barrels of oil in the Gulf of Mexico; inundating many sensitive coastal areas along coast. Many of these areas are undeveloped and difficult to access. This is part of the reason why these areas had little to no baseline information for the species of the region; particularly the Brown Pelican (Pelecanus occientalis). These birds were the most frequently observed victim of the spill. They were exposed to oil both when roosting/resting on shore and while foraging for fish in the ocean and ingesting it through preening and contaminated fish. With limited baseline information for habitat needs, diet, and distribution it was difficult to assess the damage following this disaster. Brown Pelicans being apex predators in coastal systems and their sensitivity to contaminants makes them a good species to assess risk factors in nearshore habitats.
Starting in 2013, Dr. Lamb started her research on Brown Pelican movement in relation to offshore development in the Gulf of Mexico funded by the Bureau of Ocean Energy Management. From 2013-2015 she deployed 90 remote-downloading GPS units all along the coastline of the Gulf of Mexico. The majority of previous studies have focused on the breeding population and the colonies, little was understood about the remaining portion of the annual cycle of these birds.
Since it is difficult to do direct studies of prey delivery and consumption she tested feather corticosterone to measure nutritional stress during chick development. Her findings agreed with previous studies that nutritional conditions are the main driver of reproductive success and recruitment. They differ in stating that the availability and the rate of delivery of prey (young being provided prey from adults) are more important to reproductive success than the nutritional value of the prey item that is consumed. So basically more prey available of lower quality that is close and easy to get is better than higher quality prey that is less common and takes longer to get and deliver to the young. She combined the location data with diet and reproduction data to better understand the relationships between reproductive success, risk exposure and spatial ecology. She found movement patterns were influenced by other competing species during both breeding and migration and there was a lot of individual variation in movement, and varying degrees of exposure to pollutants.
Recent publications from this work:
Lamb, J.S., Y.G. Satge and P.G.R. Jodice. 2017. Influence of density-dependent competition on foraging and migratory behavior of a subtropical colonial seabird. Ecology and Evolution 7(16): 6469‑6481.
Lamb, J.S., Y.G. Satge and P.G.R. Jodice. 2017. Diet composition and provisioning rates of nestlings determine reproductive success in a subtropical seabird. Marine Ecology Progress Series 581: 149-164.
Lamb, J.S., D.J. Newstead, L.M. Koczur, B.M. Ballard, M.C. Green and P.G.R. Jodice. 2017. A bridge between oceans: Overland migration of marine birds in a wind energy corridor. Journal of Avian Biology. available online, accepted articles.
0
