Provision of food and nutrients

Sheltered shores in general provide a higher yield of net production, as they tend to be dominated by macro algae, which are consumed by a large variety of herbivores and grazers that in turn are preyed upon by predators, such as crabs and dog whelks. Fish and coastal birds take the place of top predators, although carnivorous fish are more prominent during high tides, while birds such as gulls and sandpipers prefer to hunt during low tide, and are more prominent during winter season. The high production rates also generate a significant level of detritus that in turn is exported to other systems by coastal currents.

Main producers on exposed shores are microalgae, therefore abundant levels of smaller grazers, for example, Littorinidae snails and limpets, can be found on them. Exposed shore ecosystems in general have higher levels of energy consumption than shelter ones as they are home of various suspension feeder species that feed on phytoplankton and detritus that are imported in the system by wave forces. On the other hand, these filter feeders are in turn an important part of the diet for various carnivorous invertebrates and birds.

In both shelter and exposed shores subtidal communities create a significant level of organic detritus, which in turn is consumed by such invertebrates as sea urchins, brittle stars or mussels. Major predators found there are starfish, lobsters, crabs and various fish species (Little et al., 2010).

Referenties

The Biology of Rocky Shores. 2nd Edition, Little, Colin, Williams, Gray A. and Trowbridge, Cynthia D., 28 april 2010.

Provision of food and nutrients

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