FISHING AT RIO-GRANDE (BRAZIL) - ECOLOGICAL NICHE AND COMPETITION

This study is an ecological analysis of the use of resources by two po tentially competitive groups, the commercial and recreational fisherme n of Rio Grande, located on the border of the States of Sao Paulo and Minas Gerais. Tourism at Rio Grande was intensified after the construc tion of the hydroelectric plant of Marimbondo in 1974, and local fishe rmen have complained about its interference. Values of niche dimension s, such as fishing periods, grounds, and prey caught were obtained thr ough data gathered at landing points. Local and recreational fishermen usually fish in different parts of the river and catch different fish , because they use different gear However in transition months between the wet and dry seasons, when fish ave less abundant, there is confli ct or competition related to fishing grounds, reinforced by the territ orial fishing rights of local longline fishermen in this period We sho w how ecological concepts, such as niche and competition, may help to understand strategies of exploitation by human groups, fundamental inf ormation for the management of tropical areas.