Predator control in marine tidal sediments
Reise, K. (1985). Predator control in marine tidal sediments, in: Gibbs, P.E. (Ed.) Proceedings of the 19th European Marine Biology Symposium, Plymouth, Devon, UK, 16-21 September 1984. pp. 311-321
In: Gibbs, P.E. (Ed.) (1985). Proceedings of the Nineteenth European Marine Biology Symposium, Plymouth, Devon, UK, 16-21 September 1984. Cambridge University Press: Cambridge. ISBN 0-521-30294-3. 541 pp., meer
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Documenttype: Congresbijdrage
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| Abstract |
The responses of prey populations to the experimental exclusion of predators from tidal flat sediments are reviewed. Artifacts of cage exclosures are serious only at sites exposed to strong wave surge or fast currents but do not modify the benthos at the more sheltered sites. Exclosures with a wide mesh size of 1 cm or more keep out birds, fish and large crabs, and in these only large individuals of the macrofauna gain in abundance relative to unprotected controls; this effect is most consistent in bivalves. Exclosures with narrow meshes (1-6mm) keep out also young fish, small crabs and shrimps, which are the nurselings of the tidal flat nursery areas. When these small epibenthic predators are removed, most macrofaunal species attain very high population densities (and biomass) because their early juveniles survive. The seasonally-intermittent predation by the nurselings severely reduces the tidal flat benthos to below carrying capacity. The effects of endobenthic carnivores apparently are continuous, more refined and less conspicuous. Occasional climatic or hydrographic disturbances interrupt the prevalent predation; and intraspecific competition then often limits population size. Some potential prey species avoid severe predation by taking refuge on then high tidal flats or they reproduce when the seasonal predators are absent. Multiple predation between the predators themselves and extensive overlap in the exploitation of prey species may also serve to balance prey and predator populations. |
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