Seasonality, depth and habitat distribution of breeding males of Oreochromis spp., 'chambo', in Lake Malawi National Park

The temporal pattern of breeding by chambo, Oreochromis spp., and the vertical and horizontal distribution of territorial males at the Golden Sands-Chembe beach were examined in the Cape Maclear region of Lake Malawi National Park. The breeding season began in September and ended in April, and the number of breeding males between 3 and 15 m was approximately 25 ha. Along the beach studied, the highest concentrations of nests were found at the ends of the beach near rocks, and the lowest number of breeding males occurred in front of Chembe village
Results from experimental gill netting demonstrated that the catches of chambo within the 100-m Lake Malawi National Park 'no fishing zone' were identical to those outside the 100-m zone, suggesting that fishermen would suffer little or no loss in catch by being encouraged to fish more than 100 m from the shore. Such a reduction in fishing and disturbance of the shallow water breeding grounds would probably enhance the chambo fishery. Preliminary data are provided on the chambo nest forms found in the Cape Maclear region, and further research is suggested to resolve the question of how many species comprise the genus Oreochromis in Lake Malawi.