Notes on the Fishery Potential and Fish Fauna of the Brokopondo Reservoir (Surinam)
ABSTRACT The Brokopondo reservoir is situated in north-east Surinam and has a surface area of 150,000 ha. The dam was completed in 1964 for providing hydroelectric power. During the filling stage of the reservoir. 1964–1967, the composition of the fish fauna was studied. From 1967 to the present, no fishery research has been carried out in the reservoir. The aim of a mission, which was conducted in December 1978, was to obtain fundamental information on the fishery potential and fish fauna. Thirty-seven species have been collected with various fishing techniques; of these the characid Serrasalmus rhambeus (Linnaeus, 1766) and the cichlid Cichla ocellaris Block & Schneider, 1801 are possibly exploitable. The potential yeild of the reservoir is estimated at 3500 tonne yr-1. Gill nets with large mesh sizes proved to give the best results of the different fishery techniques tried. A comparison of the recent ichthyofauna with the fish species composition during 1966–1967 is provided and discussed.
- SourceAvailable from: scielo.br[Show abstract] [Hide abstract]
ABSTRACT: We investigated long-term changes in the fish fauna of Brokopondo Reservoir, Suriname, the first large reservoir (1560 km2) that was created in tropical rainforest. Before closure of the dam in 1964, the fish fauna of Suriname River had 172 species, high diversity and high evenness. The riverine fauna was dominated by small-sized species, but no single species was dominant in numbers. Large catfishes were dominant in biomass. Species were evenly distributed over riverine habitats: rapids, tributaries and main channel. Four years after closure of the dam, only 62 fish species were collected from Brokopondo Reservoir, but the composition of the fish fauna was still changing. The reservoir fauna in 1978 was very similar to the reservoir fauna in 2005, indicating that a stable equilibrium had been reached 14 years after closure of the dam. The reservoir fauna had 41 species, low diversity and low evenness. Most species of Suriname River and its tributaries with strict habitat requirements did not survive in Brokopondo Reservoir. Fish community structure was different among four habitats of Brokopondo Reservoir. The open-water habitat (10 species) was dominated by the piscivores Serrasalmus rhombeus, Acestrorhynchus microlepis and Cichla ocellaris and their prey Bryconops melanurus and two Hemiodus species. B. melanurus fed on zooplankton, Culicinae pupae and terrestrial invertebrates. Hemiodus fed on fine flocculent detritus, demonstrating that the detritus-based food chain was still important in late stages of reservoir development. Serrasalmus rhombeus also fed on peccaries that drowned when swimming across the large reservoir in rough weather. The shore community (27 species) was dominated by seven cichlids, but early stages and juveniles of the open-water species S. rhombeus and B. melanurus also occurred in the shore habitat. Fish biomass in the shore habitat was 66.5±59.9 kg ha-1. The cichlid Geophagus surinamensis and the characid B. melanurus had a lower biomass in Brokopondo Reservoir than in Suriname River. Serrasalmus rhombeus showed reduced body length in Brokopondo Reservoir as compared to riverine populations.Neotropical Ichthyology 01/2007; 5(3). · 1.05 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: This study investigated the role of predators in preventing competitive exclusion among three closely related armoured catfishes (Callichthys callichthys, Hoplosternum littorale and H. thoracatum) that occur synthopically in multi-predator freshwater swamps of Suriname, South America. The potential impact of predation on armoured catfish was determined by combining laboratory measurements of predation rates on five early developmental stages of the armoured catfish H. thoracatum for 24 aquatic predators with field studies of the density of the predators in the swamps. The contribution of a particular predator to the total predation pressure on its prey was determined to a large extent by the density of the predator in the swamp. Seemingly innocuous predators with low or moderate predation rates in the laboratory may be extremely important in the swamps due to their high abundance. Small-sized omnivorous fishes and aquatic invertebrates were major predators of early developmental stages of armoured catfish. Both qualitative and quantitative ontogenetic changes in the predation pressure on armoured catfish were observed. Major predation on eggs, larvae and juveniles of H. thoracatum resulted from a different set of predators in each developmental stage of the prey. In all developmental stages of H. thoracatum the predation pressure involved several predator species and not a single, dominant predator. The potential predation pressure of the 24 predators taken together and the number of predators that were able to prey on H. thoracatum decreased sharply with increasing age (size) of the prey. Even if egg (nest) predation is prevented by the guarding male, the potential impact of the 24 predators on the populations of armoured catfish is large. Predation may account for the high mortality of H. thoracatum observed in the swamps. The high predation pressure on callichthyid catfishes may help to explain the coexistence of three closely related and morphologically quite similar armoured catfishes in Surinamese swamps.Oecologia 07/1996; 107(3):395-410. · 3.01 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Piranhas have a reputation of being man‐eating fishes, notwithstanding the absence of well‐documented records of piranha attacks on human beings. Three sites in Suriname where piranha attacks on bathers have taken place are discussed. In two isolated villages on the Wayombo River, most victims were children. In one village, 30 piranha attacks occurred in a period of 12 years, bites were mostly on the feet, and injuries were relatively harmless. In the second village, attacks occurred in a period of 7 years, and injuries were more serious, including the loss of digits and large and deep wounds in legs, arms and trunk. Two victims were attacked by several piranhas simultaneously. At the third site, a recreation park on the Suriname River, most attacks involved a single bite on the feet and victims were able to walk back to the beach without being attacked by other piranhas. Piranha attacks on humans did not result in deaths. The recovery of a toe phalange (Wayombo River) and a piece of flesh including a nail (Suriname River) from the stomach of two piranhas identified the fish responsible for the attacks as Serrasalmus rhombeus. Attacks on humans by S. rhombeus were associated with high age 0+ piranha densities in the dry season, high human prey densities, commotion in the water by humans, and spillage of food, fish offal or blood in the water.Studies on Neotropical Fauna and Environment - STUD NEOTROP FAUNA ENVIRON. 01/2006; 41(3):189-195.