Nutrient dynamics, Egestion, Ecological stoichiometry, Excretion, Metabolic Theory of Ecology


Peixes podem contribuir direta e indiretamente na reciclagem de nutrientes em ambientes aquáticos, afetando a estrutura das comunidades e processos ecossistêmicos. Através da excreção de resíduos metabólicos, os peixes redisponibilizam no ambiente nutrientes inorgânicos que podem ser utilizados por algas e bactérias. O nitrogênio e o fósforo são, frequentemente, nutrientes limitantes em riachos, portanto peixes podem representar uma fonte relevante destes nutrientes. Muitos fatores podem influenciar as taxas de excreção, incluindo a dieta, a demanda de nutrientes do organismo (para reprodução e crescimento), a ontogenia, o tamanho do corpo, a temperatura e outros fatores abióticos. Atualmente, duas teorias se propõem a explicar quais fatores controlam as taxas de excreção: 1) a Teoria da Estequiometria Ecológica se baseia nos modelos de balanço de massa e utiliza a quantidade de nutrientes da dieta e a demanda de nutrientes do peixe como preditores das taxas de excreção; e 2) a Teoria Metabólica da Ecologia que se baseia no tamanho do corpo e na temperatura como fatores que regulam as taxas metabólicas de um organismo e, assim, suas taxas de excreção. A importância relativa dos peixes como recicladores de nutrientes em riachos varia dependendo de fatores intrínsecos das espécies e características do ambiente. Isto inclui a magnitude das taxas de excreção da comunidade inteira de peixes, a concentração e entrada de nutrientes no riacho, a demanda de nutrientes do sistema e o período de atividade e comportamento dos peixes. Por exemplo, espécies abundantes em riachos oligotróficos têm potencial de representar uma importante fonte de nutrientes. Mas outras peculiaridades, como a dieta, demanda de nutrientes específicas, ou comportamentos migratórios, podem torná-los importantes fontes ou sumidouros de nutrientes num riacho.  Neste artigo são revisados estudos que tratam o papel dos peixes como recicladores de nutrientes e são explicadas as técnicas mais comuns utilizadas neste tipo de estudos.

THE ROLE OF FISH IN THE RECYCLING OF NUTRIENTS IN TROPICAL STREAMS: Fish can contribute directly and indirectly to nutrient recycling in aquatic environments, affecting community structure and ecosystem processes. Through the excretion of metabolic waste, fish make inorganic nutrients available in the environment that can be used by algae and bacteria. Nitrogen and phosphorus are often limiting nutrients in streams, so fish can be a relevant source of these nutrients. Many factors can influence excretion rates, including diet, body nutrient demand (for reproduction and growth), ontogeny, body size, temperature and other abiotic factors. Currently, two theories propose to explain which factors control excretion rates: 1) The Theory of Ecological Stoichiometry is based on mass balance models and uses the amount of nutrients in the diet and the fish nutrient demand as predictors of excretion rates; and 2) the Metabolic Theory of Ecology that uses body size and temperature as factors that regulate an organism metabolic rates and, thus, its excretion rates. The relative importance of fish as nutrient recyclers in streams varies depending on species intrinsic characteristics and environmental factors. This includes the magnitude of excretion rates from the entire fish community, the nutrient concentration and nutrient input into the stream, the stream nutrient demand and the period of activity and behavior of the fish. For example, species that are abundant in oligotrophic streams have the potential to represent an important source of nutrients. But other peculiarities, such as diet, specific nutrient demands, or migratory behaviors, can make them important sources or sinks of nutrients in a stream. This article reviews studies that address the role of fish as nutrient recyclers and explains the most common techniques used in this type of studies.


Allgeier, J. E., Wenger, S. J., Rosemond, A. D., Schindler, D. E., & Layman, C. A. 2015. Metabolic theory and taxonomic identity predict nutrient recycling in a diverse food web. Proceedings of the National Academy of Sciences of the United States of America, 112(20), E2640–E2647. DOI: 10.1073/pnas.1420819112

Alves, J. M., Caliman, A., Guariento, R. D., Figueiredo-Barros, M. P., Carneiro, L. S., Farjalla, V., Bozelli, R. L., & Esteves, F. A. 2010. Stoichiometry of benthic invertebrate nutrient recycling: interspecific variation and the role of body mass. Aquatic Ecology, 44(2), 421–430. DOI: 10.1007/s10452-009-9302-3

Atkinson, C. L., Capps, K. A., Rugenski, A. T., & Vanni, M. J. 2017. Consumer-driven nutrient dynamics in freshwater ecosystems: from individuals to ecosystems. Biological Reviews, 92(4), 2003–2023. DOI: 10.1111/brv.12318

Benstead, J P, Cross, W. F., March, J. G., McDowell, W. H., Ramirez, A., & Covich, A. P. 2010. Biotic and abiotic controls on the ecosystem significance of consumer excretion in two contrasting tropical streams. Freshwater Biology, 55(10), 2047–2061. DOI: 10.1111/j.1365-2427.2010.02461.x

Benstead, Jonathan P., Evans-White, M. A., Gibson, C. A., & Hood, J. M. 2017. Elemental Content of Stream Biota. In: Methods in Stream Ecology: Third Edition. Vol. 2, pp. 255–273. Elsevier Inc.

Brown, J. H., Gillooly, J. F., Allen, A. P., Savage, V. M., & West, G. B. 2004. Toward a Metabolic Theory of Ecology. Ecology, 85(7), 1771–1789. DOI: 10.1890/03-9000

Capps, K. A., & Flecker, A. S. 2013a. Invasive aquarium fish transform ecosystem nutrient dynamics. Proceedings of the Royal Society B-Biological Sciences, 280(1769), 7. DOI: 10.1098/rspb.2013.1520

Capps, K. A., & Flecker, A. S. 2013b. Invasive Fishes Generate Biogeochemical Hotspots in a Nutrient-Limited System. PLoS ONE, 8(1). DOI: 10.1371/journal.pone.0054093

Childress, E. S., Allan, J. D., & McIntyre, P. B. 2015. Nutrient Subsidies from Iteroparous Fish Migrations Can Enhance Stream Productivity. Ecosystems, 17(3), 522–534. DOI: 10.1007/s10021-013-9739-z

Clarke, A., & Fraser, K. P. P. 2004. Why does metabolism scale with temperature? Functional Ecology, 18, 243–251. DOI: 10.1111/j.0269-8463.2004.00841.x

Covino, T. P., McGlynn, B. L., & McNamara, R. A. 2010. Tracer additions for spiraling curve characterization (TASCC): Quantifying stream nutrient uptake kinetics from ambient to saturation. Limnology and Oceanography: Methods, 8(SEPT), 484–498. DOI: 10.4319/lom.2010.8.484

Dolan, C. R., & Miranda, L. E. 2003. Immobilization Thresholds of Electrofishing Relative to Fish Size. Transactions of the American Fisheries Society, 132(5), 969–976. DOI: 10.1577/t02-055

El-Sabaawi, R. W., Warbanski, M. L., Rudman, S. M., Hovel, R., & Matthews, B. 2016. Investment in boney defensive traits alters organismal stoichiometry and excretion in fish. Oecologia, 181(4), 1209–1220. DOI: 10.1007/s00442-016-3599-0

Elser, J. J., Dobberfubl, D. R., Mackay, N. A., & Schampel, J. H. 1996. Organism Size, Life History, and N:P Stoichiometry Toward a unified view of cellular and ecosystem processes. BioScience, 46(9), 674–684. DOI: 10.2307/1312897

Evans-White, M. A., & Lamberti, G. A. 2006. Stoichiometry of consumer-driven nutrient recycling across nutrient regimes in streams. Ecology Letters, 9(11), 1186–1197. DOI: 10.1111/j.1461-0248.2006.00971.x

Finney, B. P., Gregory-Eaves, I., Sweetman, J., Douglas, M. S., & Smol, J. P. 2000. Impacts of climatic change and fishing on Pacific salmon abundance over the past 300 years. Science, 290(5492), 795–799. DOI: 10.1126/science.290.5492.795

Flecker, A. S., Mcintyre, P. B., Moore, J. W., Anderson, J. T., Taylor, B. W., & Hall, R. O. 2010. Migratory Fishes as Material and Process Subsidies in Riverine Ecosystems. American Fisheries Society Symposium, 73(2), 559–592.

Galtherman, H. L. 1978. Methods for physical and chemical analysis of fresh water. IBP Handbook, 8, 213.

Grimm, N. B. 1988. Feeding dynamics, nitrogen budgets, and ecosystem role of a desert stream omnivore, Agosia chrysogaster (Pisces: Cyprinidae). Environmental Biology of Fishes, 21(2), 143–152. DOI: 10.1007/BF00004849

Hall, R., Koch, B., Marshall, M., Taylor, B. W., & Tronstad, L. M. 2007. How body size mediates the role of animals in nutrient cycling in aquatic ecosystems. Body Size: The Structure and Function of Aquatic Ecosystems, 286–305.

Halvorson, H M, Hall, D. J., & Evans-White, M. A. 2017. Long-term stoichiometry and fates highlight animal egestion as nutrient repackaging, not recycling, in aquatic ecosystems. Functional Ecology, 31(9), 1802–1812. DOI: 10.1111/1365-2435.12875

Halvorson, Halvor M., Fuller, C., Entrekin, S. A., & Evans-White, M. A. 2015. Dietary influences on production, stoichiometry and decomposition of particulate wastes from shredders. Freshwater Biology, 60(3), 466–478. DOI: 10.1111/fwb.12462

Halvorson, Halvor M, & Atkinson, C. L. 2019. Egestion Versus Excretion: A Meta-Analysis Examining Nutrient Release Rates and Ratios across Freshwater Fauna. Diversity, 11(10), 189. DOI: 10.3390/d11100189

Holmes, R. M., Aminot, A., Kérouel, R., Hooker, B. A., & Peterson, B. J. 1999. A simple and precise method for measuring ammonium in marine and freshwater ecosystems. Canadian Journal of Fisheries and Aquatic Sciences, 56(10), 1801–1808. DOI: 10.1139/f99-128

Huxley, J., & Teissier, G. 1936. Terminology of relative growth. Nature, 137(3471), 780–781. DOI: 10.1038/137780b0

Kennard, M. J., Pusey, B. J., Harch, B. D., Dore, E., & Arthington, A. H. 2006. Estimating local stream fish assemblage attributes: Sampling effort and efficiency at two spatial scales. Marine and Freshwater Research, 57(6), 635–653. DOI: 10.1071/MF06062

Kosten, S., Huszar, V. L. M., Mazzeo, N., Scheffer, M., Sternberg, L. da S. L., & Jeppesen, E. 2009. Lake and watershed characteristics rather than climate influence nutrient limitation in shallow lakes. Ecological Applications, 19(7), 1791–1804. DOI: 10.1890/08-0906.1

Lall, S. P. 1991. Digestibility, metabolism and excretion of dietary phosphorus in fish. Nutritional Strategies and Aquaculture Waste. First International Symposium on Nutritional Strategies in Management of Aquatic Wastes. University of Guelph, Guelph, Ontario. 1991.

McGarvey, D. J., Falke, J. A., Li, H. W., & Li, J. L. 2017. Fish Assemblages. Methods in Stream Ecology: Third Edition. Vol. 1Elsevier Inc.: p. 321–353. DOI: 10.1016/B978-0-12-416558-8.00016-0

Mcintyre, P. B., Jones, L. E., Flecker, A. S., & Vanni, M. J. 2007. Fish extinctions alter nutrient recycling in tropical freshwaters. Proceedings of the National Academy of Sciences, 104(11), 4461–4466. DOI: 10.1073/pnas.0608148104

McIntyre, P B, Flecker, A. S., Vanni, M. J., Hood, J. M., Taylor, B. W., & Thomas, S. A. 2008. Fish distributions and nutrient cycling in streams: Can fish create biogeochemical hotspots? Ecology, 89(8), 2335–2346. DOI: 10.1890/07-1552.1

McIntyre, Peter B., & Flecker, A. S. 2010. Ecological Stoichiometry as an Integrative Framework in Stream Fish Ecology. American Fisheries Society Symposium, 73, 539–558.

McIntyre, Peter B., Flecker, A. S., Vanni, M. J., Hood, J. M., Taylor, B. W., & Thomas, S. A. 2008. Fish distributions and nutrient cycling in streams: Can fish create biogeochemical hotspots? Ecology, 89(8), 2335–2346. DOI: 10.1890/07-1552.1

Moody, E. K., Corman, J. R., Elser, J. J., & Sabo, J. L. 2015. Diet composition affects the rate and N:P ratio of fish excretion. Freshwater Biology, 60(3), 456–465. DOI: 10.1111/fwb.12500

Moreira-Ferreira, B. 2019. O efeito da cobertura vegetal na contribuição de um consumidor aquático na ciclagem de nutrientes. Master thesis. Departamento de Ecologia da Universidade do Estado do Rio de Janeiro. p. 52.

Newbold, J. D., Elwood, J. W., O’Neill, R. V., & Winkle, W. Van. 1981. Measuring Nutrient Spiralling in Streams. Canadian Journal of Fisheries and Aquatic Sciences, 38(7), 860–863. DOI: 10.1139/f81-114

Oliveira-Cunha, P., Capps, K. A., Neres-Lima, V., Lourenço-Amorim, C., Tromboni, F., Moulton, T. P., & Zandonà, E. 2018. Effects of incubation conditions on nutrient mineralisation rates in fish and shrimp. Freshwater Biology, 63(9), 1107–1117. DOI: 10.1111/fwb.13120

Randall, D. J., & Tsui, T. K. N. 2002. Ammonia toxicity in fish. Marine Pollution Bulletin, 45(2), 17–23.

Schindler, D. E., & Eby, L. A. 1997. Stoichiometry of Fishes and Their Prey : Implications for Nutrient Recycling Author. Ecology, 78(6), 1816–1831. DOI: 10.1890/0012-9658(1997)078[1816:SOFATP]2.0.CO;2

Small, G. E., Pringle, C. M., Pyron, M., & Duff, J. H. 2011. Role of the fish Astyanax aeneus (Characidae) as a keystone nutrient recycler in low-nutrient Neotropical streams. Ecology, 92(2), 386–397. DOI: 10.1890/10-0081.1

Sterner, R., & Elser, J. 2002. Ecological stoichiometry: the biology of elements from molecules to the biosphere.Princeton University press.

Strayer, D. L., & Dudgeon, D. 2010. Freshwater biodiversity conservation: Recent progress and future challenges. Journal of the North American Benthological Society, 29(1), 344–358. DOI: 10.1899/08-171.1

Taylor, B. W., Keep, C. F., Hall, R. O., Koch, B. J., Tronstad, L. M., Flecker, A. S., & Ulseth, A. J. 2007. Improving the fluorometric ammonium method: matrix effects, background fluorescence, and standard additions. Journal of the North American Benthological Society, 26(2), 167–177. DOI: 10.1899/0887-3593(2007)26[167:itfamm]2.0.co;2

Vanni, M. J., Flecker, A. S., Hood, J. M., & Headworth, J. L. 2002. Stoichiometry of nutrient recycling by vertebrates in a tropical stream: linking species identity and ecosystem processes. Ecology Letters, 5(2), 285–293. DOI: 10.1046/j.1461-0248.2002.00314.x

Vanni, M.J. 2002. Nutrient cycling by animals in freshwater ecosystems. Annual Review of Ecology and Systematics, 33, 341–370. DOI: 10.1146/annurev.ecolsys.33.010802.150519

Vanni, Michael J., & McIntyre, P. B. 2016. Predicting nutrient excretion of aquatic animals with metabolic ecology and ecological stoichiometry: A global synthesis. Ecology, 97(12), 3460–3471. DOI: 10.1002/ecy.1582

Webster, J. 2007. Solute dynamics. Methods in Stream Ecology: Second Edition.Elsevier Inc.

West, G. B., Brown, J. H., & Enquist, B. J. 1997. A general model for the origin of allometric scaling laws in biology. Science, 276(5309), 122–126. DOI: 10.1126/science.276.5309.122

Wheeler, K., Miller, S. W., & Crowl, T. A. 2015. Migratory fish excretion as a nutrient subsidy to recipient stream ecosystems. Freshwater Biology, 60(3), 537–550. DOI: 10.1111/fwb.12495

Whiles, M. R., Huryn, A. D., Taylor, B. W., & Reeve, J. D. 2009. Influence of handling stress and fasting on estimates of ammonium excretion by tadpoles and fish: recommendations for designing excretion experiments. Limnology and Oceanography: Methods, 7(1), 1–7. DOI: 10.4319/lom.2009.7.1

Wilson, H. F., & Xenopoulos, M. A. 2011. Nutrient recycling by fish in streams along a gradient of agricultural land use. Global Change Biology, 17(1), 130–139. DOI: 10.1111/j.1365-2486.2010.02284.x

Zandonà, E., Moraes, M., Neres-Lima, V., Dalton, C. M., Flecker, A. F., & Mazzoni, R. 2021. Differences in nutrient mineralization between native and invasive grazing catfish during the invasion process. Austral Ecology. DOI: 10.1111/aec.12978

Zandonà, E., Oliveira-Cunha, P., Tromboni, F., Neres-Lima, V., Moraes, M., & Moulton, T. P. 2021. Do body elemental content and diet predict excretion rates of fish and shrimp? Fundamental and Applied Limnology, 194(3), 271-283. DOI: 10.1127/fal/2020/1329