Revista de Gestão Costeira Integrada
Volume 15, Número 4, Dezembro 2015, Páginas 443-451

DOI: 10.5894/rgci600
* Submission: 27 MAR 2015; Peer review: 24 APR 2015; Revised: 8 MAY 2015; Accepted: 2 JUN 2015; Available on-line: 29 JUN 2015  

The influence of the river runoff in the artisanal fisheries catches in tropical coastal waters – The case of the Zambezi River and the fisheries catches in the northern Sofala Bank, Mozambique *  

Antonio Mubango Hoguane^@,1; Elisa Vasco Armando^b

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@ - Corresponding author to whom correspondence should be addressed.
a - School of Marine and Coastal Sciences, Eduardo Mondlane University, PO Box 128, Quelimane, Mozambique. e-mail: [email protected].
b - Ministry of Science and Technology, Zambézia Office. e-mail: [email protected].     

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ABSTRACT
The artisanal catches contributes significantly in the overall annual fish production in Mozambique, estimated to 115,000 - 140,000 tones, and thus of significant importance to livelihood of the coastal communities. However, the variation in fish production depends on several factors, among which the climatic factors, that need to be understood for sustainable fisheries management.
The present study analyses the influence of the river runoff in coastal fisheries production, using the Zambezi Runoff (1996-2014) as a climatic indicator and the artisanal fisheries catches (2000-2014) as the indicator of fisheries production. The results obtained indicated that the artisanal catches in Sofala Bank were dominated by resident species in the region of fresh water influence (Engraulidae (53%), Clupeídea (10%), Sciaenidae (8%) and Sergestidae (7%)), by species that inhabit these regions at their earlier stage of life (Penaeidae (4%)) and by species that inhabit the vicinity and move to the region of fresh water influence for feeding (Trichiuridae (6%), Ariidae (4%), Carangidae (4%) and Hemulidae (2%)); The total annual catches were positively-linearly correlated with the total annual runoff (slope = 0.343, r2 = 0.500, p = 0.005, n = 14). Further, the catches correlated better with both the wet season runoff (slope = 0.534, r2 = 0.369, p = 0.021, n = 14) and the dry season runoff (slope = 0.773, r2 = 0.389, p = 0.013, n = 15). The result is justified by the fact that most of the species caught (Engraulidae, Clupeídea, Sergestidae and Penaeidae) live in the region of freshwater influence, with one to two years life span and recruited to fisheries within the first year of their life. The present study emphasises the importance of the environmental/ climatic factors such as river runoff in the fish production, and hence, on the need for the inclusion of the runoff variability in the fisheries management strategies.

Keywords: River runoff, climatic factors, fisheries production, sustainable fisheries.   

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RESUMO
Influência do escoamento de rios nas capturas de pescarias artesanais nas águas costeiras tropicais – o caso do Rio Zambeze e as capturas na zona norte do Banco de Sofala, Moçambique As pescarias artesanais contribuem de uma forma significativa na produção pesqueira total de Moçambique, estimada em cerca de 115 000 -140 000 toneladas por ano, e por isso com impacto positivo na economia das comunidades costeiras. No entanto, a variação da produção pesqueira depende de muitos fatores, de entre eles os fatores climáticos, que devem ser comInfluência do escoamento de rios nas capturas de pescarias artesanais nas águas costeiras tropicais – o caso do Rio Zambeze e as capturas na zona norte do Banco de Sofala, Moçambique As pescarias artesanais contribuem de uma forma significativa na produção pesqueira total de Moçambique, estimada em cerca de 115 000 -140 000 toneladas por ano, e por isso com impacto positivo na economia das comunidades costeiras. No entanto, a variação da produção pesqueira depende de muitos fatores, de entre eles os fatores climáticos, que devem ser compreendidos para uma gestão sustentável das pescarias. No presente trabalho analisou-se a influência da descarga dos rios na produção pesqueira tomando como base o escoamento do Rio Zambeze (1996-2014), como variável climática e as capturas dos pescadores artesanais no Banco de Sofala (2000-2014), como indicador da produção pesqueira. Os resultados indicaram que a composição especifica das capturas artesanais no Banco de Sofala eram dominadas por espécies residentes nas zonas de influência de água doce (Engraulidae (53%), Clupeídea (10%), Sciaenidae (8%) e Sergestidae (7%)), por espécies que passam a parte inicial de sua vida em zonas de influência de água doce (Penaeidae (4%)) e por espécies que habitam na vizinhança de zonas de influencia de água doce e que se deslocam para estas zonas para se alimentar (Trichiuridae (6%), Ariidae (4%), Carangidae (4%) e Hemulidae (2%)); as capturas correlacionaram-se positivamente e significativamente com o escoamento total anual (tangente = 0,343, r2 = 0,500, p = 0,005, n = 14). O escoamento da época chuvosa correlacionou se melhor com as capturas (tangente = 0,534, r2 = 0,369, p = 0,021, n = 14) do que o escoamento da época seca (tangente = 0,773, r2 = 0,389, p = 0,013, n = 15). Este resultado se justifica pelo facto de a maioria das espécies nas capturas (Engraulidae, Clupeídea, Sergestidae e Penaeidae) habitarem zonas de influencia de água doce, com um ciclo de vida de um a dois anos, e serem recrutados para a pesca dentro do seu primeiro ano de vida. O presente estudo enfatiza a importância dos fatores ambientais/climáticos tais como escoamento dos rios na produção pesqueiras e daí a necessidade de sua inclusão nas estratégias de gestão das pescarias.

Palavras-chave: Escoamento do rio, fatores climáticos, produção pesqueira, gestão sustentável das pescarias

 

Arceo, Ayub, Z. (2010) – Effect of Temperature and Rainfall as a
Component of Climate Change on Fish and Shrimp Catch in Pakistan. The Journal of Transdisciplinary Environmental Studies
(ISSN: 1602-2297), 9(1):1-9, Roskilde, Denmark. Available on-line at http://www.journaltes.dk/vol_9_no_1__page_15/no%203%20%20
Edinger%20og%20Martin%20%28high%29.pdf.

Bardin, O.; Pont, D. (2002) – Environmental factors controlling the spring immigration of two estuarine fishes Atherinaboyeri and Pomatoschistus spp. into a Mediterranean lagoon. Journal of Fish Biology, 61(3):560–578. DOI: 10.1111/j.1095-8649.2002.tb00896.x.

Binet, D.; Le Reste, L.; Diouf, P.S. (1994) – The influence of runoff and fluvial outflow on the ecosystems and living resources of West African coastal waters. In: Effects of Riverine Inputs on Coastal Ecosystems and Fisheries Resources, pp. 89-118, FAO Fisheries Technical Paper No.349, FAO - Food and Agriculture Organization of the United Nations, Rome, Italy. ISBN: 978-9251036341. Available on-line at
http://www.fao.org/docrep/003/v4890e/V4890E04.htm#ch4.

Cisneros-Mata, M. A.; Montemayor-Lopez, G.; Roman-Rodriguez, M.J. (1994) – Life history and conservation of Totoabamacdonaldi.
Conservation Biology, 9(4):806-814.
DOI: 10.1046/j.1523-1739.1995.09040806.x.

Conway, D.; Allison, E.; Felstead, R.; Goulden, M. (2005) – Rainfall
variability in East Africa: implications for natural resources management and livelihoods. Philosophical Transactions of the Royal Society, A363:49-54. DOI: 10.1098/rsta.2004.1475.

Dolbeth, M.; Martinho, F.; Leitão, R.; Cabral, H.; Pardal, M.A. (2007) – Strategies of Pomatoschistus minutus and Pomatoschistus microps to cope with environmental instability. Estuarine, Coastal and Shelf Science, 74(1–2):263-273. DOI: 10.1016/j.ecss.2007.04.016.

Froese, R.; Pauly, D. (eds.) (2000) - FishBase 2000: concepts, design and data sources. 344p., ICLARM, Los Baños, Laguna, Philippines. ISBN 971-971-8709-99-1.

Gammelsrød, T. (1992) – Variation in shrimp abundance on the Sofala
Bank, Mozambique, and its relation to the Zambezi River runoff. Estuarine, Coastal and Shelf Science, 35(1):91-103.
DOI: 10.1016/S0272-7714(05)80058-7.

Garcia, S.M.; Zerbi, A.; Aliaume, C.; Do Chi; T.’Lasserre, G. (2003) – The ecosystem approach to fisheries. In: terminology, principles, institutional foundations, implementation and outlook, pp.1-71p., FAO Fisheries Technical Paper No.443, FAO - Food and Agriculture Organization of the United Nations, Rome, Italy. ISBN: 9251049602. Available on-line at
http://ocean.floridamarine.org/efh_coral/pdfs/Ecosystem_Approaches_
to_Fisheries_FAO.pdf.

Hoguane, A.M.; Cuamba, E.L.; Gammelsrød, T. (2012) – Influence of rainfall on tropical coastal artisanal fisheries – a case study of Northern Mozambique. Journal of Integrated Coastal Zone Management / Revista de Gestão Costeira Integrada, 12(4):477-482. DOI: 10.5894/rgci338.

Hoguane, A.M.; Motta, H.; Lopes, S.; Menete, Z. (2002) – Mozambique
National Report on integrated problem analysis – Development and protection of the coastal and marine environment in sub-Saharan Africa. 125p, GEF MSP Sub-Saharan Africa Project (GF/6010-0016), Maputo, Mozambique. Unpublished.

Hossain, M.S.; Das, N.G.; Sarker, S.; Rahaman, M.Z. (2012) – Fish
diversity and habitat relationship with environmental variables at Meghna river estuary, Bangladesh. The Egyptian Journal of Aquatic Research, 38(3):213–226. DOI: 10.1016/j.ejar.2012.12.006.

Instituto nacional de Investigação Pesqueira (2007-2011) – Relatórios
anuais de 2007 a 2011. Instituto Nacional de Investigação Pesqueira, Maputo, Moçambique. In: http://www.moziip.org.

Jacquet, J.L.; Zeller, D. (2007) – National conflict and fisheries:
Reconstructing marine fisheries catches for Mozambique. In: D. Zeller & D. Pauly (eds.), Reconstruction of marine fisheries catches for key countries and regions (1950-2005). Fisheries Centre Research Reports (ISSN: 1198-6727) 15(2):35-47, Fisheries Centre, University of British Columbia, Vancouver, Canada. Available on-line:
http://www.seaaroundus.org/researcher/dpauly/PDF/2007/
Books&Chapters/.

Johnson, G.D.; Gill, A.C. (1998) – Perches and their allies. In: J. R. Paxton & W. N. Eschmeyer (eds.), Encyclopedia of Fishes. 2nd ed., pp.181-194, Academic Press, San Diego, CA, USA. ISBN: 978-0125476652.

Larkin, P.A. (1996) – Concepts and issues in marine ecosystem
management. Reviews in Fish Biology and Fisheries, 6(2):139-164.
DOI: 10.1007/BF00182341.

Loneragan, N.R. (1999) – River flows and estuarine ecosystems:
Implications for coastal fisheries from a review and a case study of the Logan River, southeast Queensland. Australian Journal of Ecology, 24:431–440. DOI: 10.1046/j.1442-9993.1999.00975.x.

Meynecke, J.-O.; Lee, S.Y.; Duke, N.C.; Warnken, J. (2006) – Effect of rainfall as a component of climate change on estuarine fish production in Queensland, Australia. Estuarine, Coastal and Shelf Science, 69(3-4):491-504. DOI: 10.1016/j.ecss.2006.05.011.

Nehama, F.P.J.; Reason, C.J.C. (in press) - Morphology of the Zambezi
River plume in the Sofala Bank, Mozambique. Western Indian Ocean Journal of Marine Sciences, in press.

Nelson, G. (1998) - Clupeidae: Wikis. In: J. R. Paxton & W. N. Eschmeyer (eds.), Encyclopedia of Fishes. 2nd ed., pp.91-92. Academic Press, San Diego, CA, USA. ISBN 0125476655.

Ramos, S.; Cowen, R.K.; Paris, C.; Ré, P.; Bordalo, A.A. (2005) –
Environmental forcing and larval fish assemblage dynamics in the Lima River estuary (northwest Portugal). Journal of Plankton Researh, 28(3):275-286. DOI: 10.1093/plankt/fbi104.

Sætre, R.; Jorge da Silva, A. (1984) – The Circulation of the Mozambique
Channel. Deep-Sea Research, 31(5):485-508.
DOI: 10.1016/0198-0149(84)90098-0.

Siddorn, J.R.; Bowers, D.G.; Hoguane, A.M. (2001) – Detecting the
Zambezi River Plume Using Observed Optical Properties. Marine
Pollution Bulletinn, 42:942-950. DOI: 10.1016/S0025-326X(01)00053-4.

Simões, S.M.; D’Incao, F.; Fransozo, A.; Castilho, A.L.; da Costa, R.C. (2013) – Sex ratio, growth and recruitment of the pelagic shrimp Acetesamericanus on the southeastern coast of Brazil. Journal of Crustacean Biology (E-ISSN: 1937-240X), 33(1):1-9.
DOI: 10.1163/1937240X-00002108; ISSN: 0278-0372.

Steen, J.-E. And Hoguane, A.M. (1990) - Oceanographic results on
expedition carried out by R/V Dr. Fridjof Nansen in Mozambique waters during April-May 1990. 35p., Relatório No. 13. Maputo, Mozambique. Unpublished.

 

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