|Macrofaunal abundance analyses in the Ria de Foz (Lugo, Northwest Spain)|
Junoy, J.; Viéitez, J.M. (1992). Macrofaunal abundance analyses in the Ria de Foz (Lugo, Northwest Spain). Cah. Biol. Mar. 33(3): 331-345
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
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The abundance and dominance of the major taxonomic groups (polychaetes, molluscs, crustaceans and other groups) of the macrobenthic (> 1 mm) fauna of the intertidal soft-bottom in Ria de Foz (Galicia, NW Spain) was investigated. The estuary can be divided into five distinct habitats characterized by the nature of their sediments, tidal level, degree of exposure and presence or absence of seagrass meadows. The macrofauna increases in abundance towards the inner estuary. In sandy sediments, the macrofaunal abundance depends largely on the rate of exposure and the tidal level. In the exposed sandy beaches of the mouth of the estuary, the mean density was of exposure and the tidal level. In the exposed sandy beaches of the mouth of the estuary, the mean density was 192 individuals m super(-2), with the polychaetes and crustaceans dominating. In the sublittoral zone of the more sheltered sandy sites there was an increase in the mean macrofaunal density (855 individuals m super(-2)), with a notable enhancement of the quantitative importance of the molluscs. In the midlittoral zone of the sheltered sandy areas the mean density was 458 individuals m super(-2), with crustaceans the dominant group. In the muddy sand flats, the mean macro-faunal density was 3,499 individuals in these sites the polychaetes reached their highest abundance. The meadows of Zostera noltii of the inner ria support an abundance population of the mud-snail Peringia ulvae, with a mean macrofaunal density of 20,526 individual m super(-2).