Journal of Natural Environment

Evaluation of Nitrogen, Phosphorus and Carbon Loadings from Rainbow Trout (Oncorhynchus mykiss) Marine Cage Farms in Mazandaran Province

Document Type : Research Paper

Authors

Agricultural economics department, University of Tehran

Abstract

Being an essentially open system, cages are usually characterized by a high degree of interaction with environment and cage systems are highly likely to produce large bulk of wastes that are released directly into the aquatic ecosystem if optimal use of inputs, especially fish food, is not available. Nevertheless, measurement of side effects of fish cage culture, along with providing solutions for the optimal use of fish food, can be used as an effective tool to reduce the side effects of this system. So the purpose of this study is to quantify nutrient loadings in rainbow trout (Oncorhynchus mykiss) marine cage farms as the most important nutrients released to the marine and near-shore ecosystem and to make suggestions for reducing the emissions of these nutrients in Mazandaran province. In the production cycle of 2017-18, there were 9 active fish cage farms which the nutrient loadings from each farm were calculated based on an indirect method. According to the results, the environmental loss amounted to 73.979 kg N t-1, 13.893 kg P t-1, and 488.353 kg C t-1 of fish produced. Feed conversion ratio (FCR = feed supplied/ body weight gained) varied between 0.897- 4 with an average of 1.249 representing severe inefficiencies of feeding. Based on study findings, weak technical knowledge of farmers, especially in choosing the right time for start and the end of production cycles, and feeding mismanagement will increase the amount of nutrients released into the environment.

Keywords

Aşır, U., Pulatsü, S., 2008. Estimation of the Nitrogen-Phosphorus Load Caused by Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792) Cage-Culture Farms in Kesikköprü Dam Lake: A Comparison of Pelleted and Extruded Feed. Available from from  http://www.fao.org. Accessed   25th October 2018.
Ballester-Moltó, M., Sanchez-Jerez, P., Cerezo Valverde, J., Aguado-Giménez, F., 2017. Particulate waste outflow from fish-farming cages. How much is uneaten feed?. Marine Pollution Bulletin, 119(1): 23-30.
Brooks, K.M., Mahnken, C., Nash, C., 2002. Environmental effects associated with marine net pen waste with emphasis on salmon farming in the Pacific Northwest. In: Stickney, R.R., McVey, J.P. (Eds.), Responsible Marine Aquaculture. CAB International, Cambridge, pp. 149–203.
Bureau, D.P., Gunther, S.J., Cho, C.Y., 2003. Chemical Composition and Preliminary Theoretical Estimates of Waste Outputs of Rainbow Trout Reared in Commercial Cage Culture Operations in Ontario. North American Journal of Aquaculture, 65: 33-38.
Chen, J., Guang, C., Xu, H., Chen, Z., Xu, P., Yan, X., Wang, Y., Liu, J., 2007. A review of cage and pen aquaculture: China. In M. Halwart, D. Soto, and J.R. Arthur (eds). Cage aquaculture – regional reviews and global overview. Fisheries Technical Paper 498, FAO, Rome.
Cloern, J.E., 2001. Our evolving conceptual model of the coastal eutrophication problem. Marine Ecology Progress Series, 210: 223–253.
Croomey, C.J., Nickell, T.D., Black, K.D., 2000. DEPOMOD— modeling the deposition and biological effects of waste solids from marine cage farms. Aquaculture, 214: 211–239.
FAO. 2018. FAO aquaculture newsletter. Available at www.fao.org/ag/ca/.
Gondwe, J., Guildford, S.J., Hecky, R.E., 2011. Carbon, nitrogen and phosphorus loadings from tilapia fish cages in Lake Malawi and factors influencing their magnitude. Great Lakes Research, 37:93-101.
Hall, P.O.J., Anderson, L.G., Holby, O., Kollberg, S., Samuelsson, M.O., 1990. Chemical fluxes and mass balances in a marine fish cage farm. I. Carbon. . Marine Ecology Progress Series, 61: 61–73.
Hall, P.O.J., Holby, O., Kollberg, S., Samuelsson, M.O., 1992. Chemical fluxes and mass balances in a marine fish cage farm. IV. Nitrogen. Marine Ecology Progress Series, 89: 81–91.
Holby, O., Hall, P.O.J., 1991. Chemical fluxes and mass balances in a marine fish cage farm. II. Phosphorus. . Marine Ecology Progress Series, 70: 263–272.
Iliyasu, A., Mohamed, Z. A., Ismail, M. M., Amin, A. M., Mazuki, H., 2016. Technical efficiency of cage fish farming in Peninsular Malaysia: a stochastic frontier production approach. Aquaculture Research, 47: 101-113.
Islam, M.S., Tanaka, M., 2004. Impacts of pollution on coastal and marine ecosystems including coastal and marine fisheries and approach for management: a review and synthesis. Marine Pollution Bulletin, 48 (7-8): 624–649.
Islam, S.M., 2005. Nitrogen and phosphorus budget in coastal and marine cage aquaculture and impacts of effluent loading on ecosystem: review and analysis towards model development. Marine Pollution Bulletin, 50: 48-61.
Izadi, A., Seyedi Ghomi, M.K. and Haghighi, S., 2016. Investment opportunities in marine fish cage culture. Iran Fisheries Organization. (in Persian).
Luo, Z., Hu, S., Chen, D., 2018. The trends of aquacultural nitrogen budget and its environmental implications in China. Scientific Reports 8, 10877.
Mbowa, S., Odokonyero, T., Munyaho, A.T., 2017. Harnessing floating cage technology to increase fish production in Uganda. Economy policy research centre.
McIver, R., Milewski, I., Loucks, R., Smith, R., 2018. Estimating nitrogen loading and far-field dispersal potential from background sources and coastal finfish aquaculture: A simple framework and case study in Atlantic Canada. Estuarine, Coastal and Shelf Science, 205: 46-57.
Pearson, T.H., Black, K.D., 2001. The environmental impacts of marine fish cage culture. In: Black, K.D. (Ed.), Environmental Impacts of Aquaculture. Sheffield Academic Press, pp. 1–30.
Persson, G., 1986. Kassodling av regnb8ge; Narsaltemissioner och miljo vid tre odlingslagen langs Smalandskusten. Report 3215. Nat. Swed. Envlron Prot. Bd., Solna, p. 1-42.
Price, S.C., Morris, J., 2013. Marine Cage Culture and the Environment, first ed. National oceanic and atmospheric administration, United States, 172 p.
Schmittou, H.R., 2006. Cage culture. In: Lim, C., Webster, C.D. (Eds.), Tilapia: Biology, Culture and Nutrition. Haworth Press. Binghamton, New York, pp. 313–342.
Verdegem, M.C.J., 2013. Nutrient discharge from aquaculture operations in function
of system design and production environment. Reviews in Aquaculture, 5: 158–171.
Journal of Natural Environment
Volume 73, Issue 1
April 2020
Pages 185-197