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Abstracts - Posters
P35. Is the foraging pattern of black guillemots linked to kelp forest depth
distribution?
Jannie Fries Linnebjerg, Susse Wegeberg & Morten Frederiksen
Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
jafl@dmu.dk
Black guillemots (Cepphus grylle) are well adapted to inshore benthic feeding and provide chicks
with benthic fish. Although foraging areas are often associated with a rocky seabed with dense
coverage of kelp reflecting the habitat preference of their prey, very little knowledge is available of
the importance of kelp associated habitats for this species. A known correlation between black
guillemots and their foraging habitats will be valuable in designating important and critical areas for
black guillemots. Black guillemots are very difficult to census due to concealed nest sites and rare
congregation in rafts on the water, and it is therefore difficult to identify the coasts with which they
are associated. Thus a correlation between foraging behaviour of black guillemots and
extent/density of macroalgae vegetation, as a measure for food availability, will provide a valuable
indicator of important areas for nesting and foraging of black guillemot.
We studied the association between black guillemot foraging and kelp forests at Kitsissut Avaliit,
Southwest Greenland, by deploying time-depth recorders on black guillemots to measure the
preferred dive depth, amount of time spent foraging, resting and flying. In addition, visual
observations were conducted to map the foraging locations in the vicinity of the breeding sites. To
map the depth extent and coverage of kelp forest, transects were conducted by ship where an
underwater video recorder was used to measure the distance from the coast as well as to determine
the depths limits of distinct vegetation communities, dominant species and their coverage.
Preliminary analyses of the results indicate that diving tracks of black guillemot are within the
depth extent of the kelp forest; average dive depth of approximately 30 m corresponds to the extent
of the 100 % kelp species coverage, and max dive depth of no more than 40 m corresponds to kelp
coverage of 10-50 %.
The poster will present results of these studies.
Program 17. danske havforskermøde, 153