Area utilisation and activity patterns of roman Chrysoblephus laticeps (Sparidae) in a small marine protected area

• Published in: African journal of marine science 2007-08, Vol.29 (2), p.259-270
• Main Authors: Kerwath, SE, Götz, A, Attwood, CG, Sauer, WHH, Wilke, CG
• Format: Article
• Language: English
• Subjects: CHRYSOBLEPHUS LATICEPS; FISH MOVEMENT; HOME RANGE; Marine; MARINE PROTECTED AREAS; ROMAN; SOUTH AFRICA; Sparidae; SPILL OVER; TELEMETRY
• ISSN: 1814-232X; 1814-2338
• DOI: 10.2989/AJMS.2007.29.2.10.193

Information on the movement of fish is vital to determine the effectiveness of marine protected areas (MPAs) for fish conservation and fisheries management. This study investigates area utilisation and activity patterns of 13 adult roman Chrysoblephus laticeps (Sparidae) using telemetry and underwater observations. Acoustic transmitters implanted into C. laticeps in tanks had no apparent effects on growth and mobility. Natural behaviour of the treated fish in the field was verified by SCUBA divers. Manual boat- and diver-based tracking was carried out inside the Castle Rock MPA, False Bay, South Africa, over a 17-month period. A radio acoustic positioning system (VRAP, VEMCO Ltd) was used to record automatically fish positions over two 1-month periods during and after the spawning season of roman. Manually recorded fish positions and VRAP positions inside the triangle of buoys within the system were accurate within 10m; deviations increased with increased distance of the fish from the centre of the system and during unfavourable sea conditions. Analysis of movement data using a 95% fixed kernel algorithm suggests that roman occupy small home ranges of between 1 000m 2 and 3 000m 2 , which shows that this species is well suited for protection in small MPAs. Interestingly, the home range size did not seem to be related to fish size or habitat quality. Swimming activity decreased at night. During periods of cold-water upwelling, fish retreated into caves. During the spawning season, females extended their home ranges, which result in a 'spill over' effect of adult fish into fishing areas.