Community structure in littoral, intertidal and subtidal habitats of a tropical bay — ASN Events

Community structure in littoral, intertidal and subtidal habitats of a tropical bay (#50)

Merritt E Adkins 1 , Colin A Simpfendorfer 1 , Andrew J Tobin 1
  1. Centre for Sustainable Tropical Fisheries and Aquaculture & School of Earth and Environmental Sciences , James Cook University, Townsville, QLD, Australia

Shallow coastal habitats are valuable for sustaining many fisheries yet are increasingly pressured by many anthropogenic impacts including fishing, coastal development and pollution.  Although historical research in shallow coastal waters suggested these habitats are most important for supporting and nurturing juvenile fishes, some contemporary research has indicated that many larger and mature fish also use these habitats.  Further few studies consider the contiguous nature of shallow coastal habitats and how these habitats may be preferentially used or avoided by fishes. To investigate the communities of large bodied fishes (> 200 mm) in the shallow coastal habitats of Cleveland Bay, a mosaic of littoral, intertidal and subtidal habitats were sampled across a 1 year period.  Seasonal sampling with a large mesh gill net yielded 1187 individuals from 28 families and 40 species.  Four families accounted for 74.6% of the total sample: namely Latidae, Polynemidae, Ariidae and Carcharhinidae.  The littoral and subtidal communities were distinctly different from each other with the intertidal community sharing some characteristics with both the littoral and subtidal communities. Teleosts were the dominate group in the littoral and intertidal habitats whereas sharks dominated the subtidal habitat.  Season did not influence the structure of the fish communities though some environmental factors (temperature, dissolved oxygen and salinity) did affect some species.  It is clear that most species have specific habitat requirements or limits while only some are evenly distributed among the shallow coastal habitat.  Why these patterns and preferences occur will be the focus of future research.

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