Structure and production of fish communities in tropical rain forest streams of northern Borneo

Abstract

1984. Structure and production of fish communities in tropical rain forest streams of northern Borneo. Can. J. Zool. 62: [927][928][929][930][931][932][933][934][935][936][937][938][939][940]. Tropical fish communities are often assumed to be more productive than temperate communities. To test this belief, fishes from tributaries of the tropical rain forest Baram River. Sarawak, Malaysia were quantitatively collected with a piscicide and production was calculated by the Ricker algebraic method. Temperature was not considered a ma-lor factor influencing production among different climatic regions since the average production in the Baram (76.7 kg-ha ' .year ' ) was less than in temperate Grand River, Ontario (279.4 kg ha ' . year ' ) and Nida River. Poland ( 121.0 kg. ha ' -year ' ) . Analysis of physical habitat characteristics, community-structure variables, and production estimates from Baram streams indicated production was controlled mainly by nutrient limitations ( P < 0.01) while close species packing maximized production by efficiently utilizing the limited resources available. In highly competitive and diverse communities, Baram fishes have probably developed specializations which make them particularly vulnerable to environmental perturbations or overexploitation. An estimated fish catch of 14.2-19.6 kg. h a ' . y e a r 1 by Baram subsistence fishermen was already within the estimated range for maximum sustainable yield (7.9-20.9 kg-ha-'-year ' ) . Therefore, it is recommended that research on community ecology should precede expansion of artisanal fisheries.WATSON, D. J., et E. K. BALON. 1984. Structure and production of fish communities in tropical rain forest streams of northern Borneo. Can. J. Zool. 62: 927-940. On croit generalement que les communautes tropicales de poissons sont plus productives que les communautks temperkes. Afin de mettre cette hypothese a I'kpreuve, des poissons provenant de tributaires du Baram, dans la foret tropicale ombrophile a Sarawak, en Malaysie, ont it6 echantillonnis quantitativement au moyen d'un piscicide et la production a kt6 calcul6e par la mithode algCbrique de Ricker. La temperature ne semble pas influencer fortement la production dans les differentes rkgions climatiques puisque la production moyenne du Baram (76,7 kg. ha ' . an ' ) est infirieure a celle de la riviere Grand en Ontario (279,4 kg h a ' -an-') et a celle de la Nida en Pologne (1 2 1,O kg. ha ' -an I ) . L'analyse des caractkristiques physiques de l'habitat, les variables de la communaute et I'estimation de la production dans les ruisseaux du Baram indiquent que la production est surtout fonction des ClCments nutritifs ( P < 0,01), alors que la presence d'un grand nombre d'especes voisines maximise la production en permettant l'utilisation des ressources disponibles limitees. Dans les communautks tres diversifiees oh il y a beaucoup de competition, les poissons du Baram ont probablement acquis des spkcialisations qui les rendent particulierement vulnkrables des perturbations ou la surexploitation d...

Growth, biomass, mortality, production and potential yield of the West African clam, Egeria radiata (Lamarck) (Lamellibranchia, Donacidae) in the Cross River system, Nigeria

“…(b) Length-frequency distribution (size structure) of E. radiata from commercial catch. (Waters, 1977;Chapman, 1978;Halyk & Balon, 1983;Watson & Balon, 1984) for both total and flesh production units, thus:…”

Produtividade de peixes em um riacho costeiro da bacia do Leste, Rio de Janeiro, Brasil

“…A estrutura geológica, com formações pré-cambrianas e corredeiras basálticas (PICCIRILLO et al, 1988), caracteriza os riachos neotropicais e determina ambientes pobres em nutrientes, livres de macrófitas e sujeitos a freqüentes chuvas torrenciais que agem na " lavagem" do ambiente. Tem-se ainda que a disponibilidade de alimento autóctone tornase limitada em função de seu carreamento rio abaixo (MARGALEF, 1983;WATSON & BALON, 1984;LOWE-MCCONNELL, 1987;PENCZAK & LASSO, 1991;MAZZONI & LOBÓ N-CERVIÁ 2000). As variações temporais do caudal da bacia de drenagem do rio Ubatiba são bastante elevadas durante os períodos de chuva, podendo sofrer variações de até 5 m na coluna d'água (MAZZONI & LOBÓ N-CERVIÁ , 2000), o que pode explicar as baixas taxas de produção para o ano chuvoso e, de maneira geral, as baixas taxas de produção do sistema como um todo.…”

“…A produção de peixes tem sido objeto de diversos estudos em lagos (RYDER, 1965;DIANA, 1983;KELSO, 1988;RANDAL et al, 1995) e riachos (HOPKINS, 1971;PENCZAK, 1981;NEVES & PARDUE, 1983;WATERS, 1983;WHITWORTH & STRANGE, 1983;PENCZAK et al, 1985;MANN & PENCZAK, 1986;O'HARA & PENCZAK, 1987;NEWMAN & WATERS, 1989;PENCZAK, 1992) de regiões temperadas, porém são poucos os estudos realizados em outras regiões (BISHOP, 1973;KAPETSKY, 1974;WATSON & BALON, 1984;PENCZAK & LASSO, 1991). Para peixes tropicais brasileiros, apenas dois trabalhos estão disponíveis na literatura (i.e.…”

Studies on Age and Growth of African Pike Hepsetus odoe in Ado Ekiti Reservoir

“…[34]Reported that age classes could be identified from length frequency histograms with sufficient accuracy. [16] Integrated Method expressed the length -at -age of the particular stock.…”