Lisa Webb

 

Before joining the Vertebrate Ecology Lab in 2005, I received my B.A. in Marine Biology from the University of California, Santa Cruz and held a variety of fisheries management positions at California Department of Fish and Game. My primary research interests are foraging ecology and movements of marine mamals, seabirds, and sea turtles. During my time at Moss Landing Marine Laboratories I have been involved in a variety of field projects including aerial and boat-based surveys to determine distribution, abundance, and movements of marine mammals and sea turtles along the central California coast, as well as two land-based monitoring programs that collect baseline data such as the location, species, age class, and sex of beach cast marine mammals and seabirds.

For my thesis project I am studying the foraging ecology of Brandt’s Cormorants in the Monterey Bay area during the nonbreeding season. Brandt’s Cormorants are one of the few seabirds that are year-round residents in Monterey Bay and their population is increasing in abundance. They are relatively large-bodied, foot-propelled pursuit divers with a long, hooked bill. The diet during the breeding season (April through September) has been described as diverse, primarily composed of fishes with smaller numbers of invertebrates. There have been very few diet studies during the nonbreeding season (September through March).

I am using a noninvasive technique to determine the diet of Brandt’s Cormorants. Adult and sub-adult cormorants regurgitate pellets at roosting sites. These pellets contain remnants of their prey such as bones of fishes, beaks of cephalopods, shell and carapace fragments of crustaceans, and soft tissues of other invertebrates. These remnants can be used to identify prey to family, genus, or species level based on unique morphologies of the structures. In addition, the ear bones of fishes (called otoliths) can be used to estimate the number of fishes eaten because they are paired structures, and otolith length is related to fish length so I can also estimate the size of fishes consumed.

For the past two nonbreeding seasons I collected pellets from three roosting sites: Año Nuevo Island, Moss Landing harbor, and the Monterey harbor. My research objectives are to determine if diet composition differs among these sites and if diet composition varies within the nonbreeding season.