A PRELIMINARY ICHTHYOPLANKTON SURVEY OF THE TSITSIKAMMA NATIONAL-PARK

An ichthyoplankton survey using bongo nets was conducted within the Ts itsikamma National Park over an 18-month period between January 1991 a nd July 1992. Four sampling stations along the coast were chosen, appr oximately 5 km apart. At each station four samples were taken along a transect perpendicular to the coast, between 0,35 km and 3,8 km offsho re. Horizontal tows were taken at three and 15 m below the surface ove r reef and sand substrata respectively. Larvae belonging to 24 of the 35 families and 55 of the 97 species known to occur in the area were c aptured. Engraulid larvae completely dominated the catches while among st the reef-associated taxa sparids and blenniids were prominent. Seas onally occurring cold upwelling events impacted negatively on egg and larval abundance. Mean values for egg and larval abundances were 1207 and 282 per 100 m(3) respectively. A relationship between larval numbe r and plankton volume was revealed. Most larvae captured were between 2,0 and 20,3 mm (SL), and in the preflexion condition. The absence of larger size classes in samples was attributed to net avoidance.