Influence of tuna penning activities on soft bottom macrobenthic assemblages.

The influence of tuna penning on soft bottom habitat present in the vicinity of tuna pens and at distances 200 m and 1.5 km away, was assessed by comparing attributes of macroinvertebrate assemblages and sediment quality before (November 2000, March 2001) and after (November 2001, April 2002) initiation of the activity. Results from November 2001 indicated a significant increase in sediment organic carbon and organic nitrogen, and a non-significant increase in the abundance of Capitellidae in the vicinity of the cages.