ON THE SETTLEMENT AND GROWTH OF MARINE BIO-FOULING ORGANISMS

The effects of wood preservatives on settlement, abundance, growth and biomass development of fouling organisms (Non-target organisms) was studied on treated panels exposed at an Indian harbour, Krishnapatnam (Lat.13028 ’ to13059 ’ N; Long: 800 10 ’ to 800 16’E). Panels of Bombax ceiba treated with copper chrome arsenic (CCA), copper chrome boric acid (CCB), ammoniacal copper zinc arsenate (ACZA), ammoniacal copper quaternary (ACQ), or ammoniacal copper citrate (CC) and hem-fir panels treated with copper dimethyldithiocarbamate (CDDC) were exposed over a 24 month period. There was considerable variation in abundance and biomass of fouling organisms among the preservatives. Algal and bryozoan settlement was common on all the treated and untreated panels during the initial stages (up to one month), but these communities were replaced due to heavy settlement of calcareous organisms such as barnacles, oysters and serpulids. A greater variety of fouling assemblages were recorded on control, CCB and CCA treated panels compared to CDDC, ACZA, CC and ACQ treated panels. CCA treated panels had heavier settlement of barnacles followed by oysters and bryozoans, while CCB treate