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Evaluating the Coastal Environment for Marine Birds
in much of the Firth of Forth becoming much less suitable as a feeding habitat able to
support shags rearing a normal sized brood.
Discussion
Surveys 'At Sea' of fish and seabirds are difficult, expensive and often confined to
small areas. Our chapter illustrates how crucial ecological data on feeding behaviour
can be integrated with simple but extensive GIS data on the marine environment to
predict those areas most likely to be important for supporting shag populations. We
discuss elsewhere (Wanless et al., 1998) how these predictions could be checked
against seabird survey data, and the problems introduced by census counts that include
non-breeding shags that are not confined to colonies but can return elsewhere on the
coast after feeding.
We have used the shag to illustrate this approach, as its bottom-feeding habits
facilitate estimating the constraints on its feeding. However, collaborative work in
progress as part of a European Union funded study of the effects of large industrial
fisheries on non-target species aims to examine in detail the feeding behaviour of midwater and surface feeding seabirds (particularly the Common Guillemot (Uria aalge)
and Kittiwake (Rissa tridactyla)) as well as the spatio-temporal distribution (including
the diurnal vertical distribution in the water-column) of the fish shoals on which they
feed. Given such data, similar simple models may allow us to identify other areas of
the sea likely to be of particular importance to other top avian predators.
Acknowledgements
This work was funded partly by an award from the Leslie and Dorothy Blond Trust and
the European Commission study contract 95/c 76/15, 'Effects of large scale fisheries on
non-target species'. We thank the British Geological Survey for allowing a GIS
version of their data to be used in the project. Some data on bathymetry are reproduced
by permission of the Controller of Her Majesty's Stationery Office and the UK
Hydrographic Office.
References
British Geological Survey (1986). 1:250 000 series, sea bed sediments and quaternary
geology. Tay-Forth sheet. British Geological Survey, Keyworth.
Bryant, D.M., and Furness, R.W. (1995). Basal metabolic rates of North Atlantic
seabirds. Ibis 137: 219-226.
Carter, I.C., Williams, J.M., Webb, A., and Tasker, M.L. (1993). Seabird
Concentrations in the North Sea: An Atlas of Vulnerability to Surface
Pollutants. Joint Nature Conservation Committee, Aberdeen.
Dunn, E.H. (1975). Calorific intake of nestling double-crested cormorants. Auk 92:
553-565.
Evaluating the Coastal Environment for Marine Birds
in much of the Firth of Forth becoming much less suitable as a feeding habitat able to
support shags rearing a normal sized brood.
Discussion
Surveys 'At Sea' of fish and seabirds are difficult, expensive and often confined to
small areas. Our chapter illustrates how crucial ecological data on feeding behaviour
can be integrated with simple but extensive GIS data on the marine environment to
predict those areas most likely to be important for supporting shag populations. We
discuss elsewhere (Wanless et al., 1998) how these predictions could be checked
against seabird survey data, and the problems introduced by census counts that include
non-breeding shags that are not confined to colonies but can return elsewhere on the
coast after feeding.
We have used the shag to illustrate this approach, as its bottom-feeding habits
facilitate estimating the constraints on its feeding. However, collaborative work in
progress as part of a European Union funded study of the effects of large industrial
fisheries on non-target species aims to examine in detail the feeding behaviour of midwater and surface feeding seabirds (particularly the Common Guillemot (Uria aalge)
and Kittiwake (Rissa tridactyla)) as well as the spatio-temporal distribution (including
the diurnal vertical distribution in the water-column) of the fish shoals on which they
feed. Given such data, similar simple models may allow us to identify other areas of
the sea likely to be of particular importance to other top avian predators.
Acknowledgements
This work was funded partly by an award from the Leslie and Dorothy Blond Trust and
the European Commission study contract 95/c 76/15, 'Effects of large scale fisheries on
non-target species'. We thank the British Geological Survey for allowing a GIS
version of their data to be used in the project. Some data on bathymetry are reproduced
by permission of the Controller of Her Majesty's Stationery Office and the UK
Hydrographic Office.
References
British Geological Survey (1986). 1:250 000 series, sea bed sediments and quaternary
geology. Tay-Forth sheet. British Geological Survey, Keyworth.
Bryant, D.M., and Furness, R.W. (1995). Basal metabolic rates of North Atlantic
seabirds. Ibis 137: 219-226.
Carter, I.C., Williams, J.M., Webb, A., and Tasker, M.L. (1993). Seabird
Concentrations in the North Sea: An Atlas of Vulnerability to Surface
Pollutants. Joint Nature Conservation Committee, Aberdeen.
Dunn, E.H. (1975). Calorific intake of nestling double-crested cormorants. Auk 92:
553-565.