Recent changes in numbers of waders on the Clyde Estuary, and their significance for conservation
Synopsis The Clyde Estuary is recovering from gross pollution. In the early 1970s high densities of a small number of species of intertidal invertebrates tolerant of organic enrichment and low oxygen levels provided rich feeding for large numbers of dunlin, redshank, lapwing, oystercatcher and curle...
| Published in: | Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1986
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0269727000004978 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0269727000004978 |
| Summary: | Synopsis The Clyde Estuary is recovering from gross pollution. In the early 1970s high densities of a small number of species of intertidal invertebrates tolerant of organic enrichment and low oxygen levels provided rich feeding for large numbers of dunlin, redshank, lapwing, oystercatcher and curlew. Winter numbers of the first three species have now declined considerably. The declines cannot be attributed to national changes in wader numbers and are not due to changes in breeding habitats or lack of reproductive success in particular regions, since each species wintering on the Clyde Estuary breeds in a different area. The most likely explanation of the decline, which is most pronounced in the species highly dependent on Corophium volutator , is either that reduced organic pollution has reduced the densities of the main prey, or that higher oxygen levels over the mudflats have allowed fish, particularly flounders, to enter the estuary and compete with the waders for the available prey. Although there is evidence of some birds having moved to other wintering areas, the fate of most birds is unknown. |
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