Ecology of fishing on the Grande River (Brazil): technology and territorial rights

Abstract

On the Grande River (Rio Grande, Brazil), fishermen from two communities use different fishing gear (cast nets, longlines, gillnets or fishing rods) in different seasons, marked by the river water level. This study is an ecological analysis of fishing strategies at Grande River, downstream of a hydroelectric plant. Procedures included interviews and systematic observations of fishing trips. Corimba ( Prochilodus lineatus) is caught especially in the wet season (November–March), barbado ( Pinirampus pirinampu) is caught in the transitional months between seasons (April and October) and a relatively high diversity of fish is caught in the dry season (May–September). Cast nets are used especially in the wet season, longlines in the transition period, and gillnets and fishing rods in the dry season. In the wet season, P. lineatus is abundant and fishermen concentrate on fishing, whereas in the dry season some fishermen look for other jobs in construction, agriculture and local distilleries, and fishing is almost for subsistence. In the transition period, only fishermen who have rights on fishing grounds, used for longlines to catch P. pirinampu, continue to fish commercially. Predictability of fish migrations, fish abundance and market value of fish species are factors determining gears used, territorial rights and shift of economic activities at Grande River.