29 April 2013

Fishing the little fish


What is forage fish? In the marine food and energy pyramid, they are the small to medium-sized schooling pelagic fish feeding on phytoplankton, i.e., primary consumers or grazers; or secondary consumers if they feed on zooplankton. Forage fish are prey to bigger fishes, like tuna and sharks; and marine mammals such as whales and sea birds. Because of the growing demand by fisheries, about 30% of the worldwide marine fish landings for aquaculture, livestock, human consumption and fish oil, forage fish are now in trouble of depletion [1]. The question now arises, what would be its ecological impact if this continues?


Over exploitation may result to decline in recruitment or reproductive success of both forage fish and its predators. As evidence, studies on large fish and marine mammals have shown decline, simply because of lower prey abundance [2]. In layman's term, if we continue to exploit the "little fish", sooner or later there will be no more "big fish" for us to catch and consume. So as early as today, we should push through ecosystem-based fishery management that will surely sustain the future generations of our kind.

Let us help spread the knowledge of conservation for a better future.

To know more about fishes, visit FishBase; and to know more about marine mammals, visit SeaLifeBase.

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[1] Alder, J., Campbell, B., Karpouzi, V., Kaschner, K., and Pauly, D. 2008. Forage Fish: From Ecosystems to Markets. Annu. Rev. Environ. Resour. 33:153-166.

[2] Pikitch, E., Boersma, P.D., Boyd, I.L., Conover, D.O., Cury, P., Essington, T., Heppell, S.S., Houde, E.D., Mangel, M., Pauly, D., Plagányi, É., Sainsbury, K., and Steneck, R.S. 2012. Little Fish, Big Impact: Managing a Crucial Link in Ocean Food Webs. Lenfest Ocean Program. Washington, DC. 108 pp. 

Note: Video and image credits to PEW.


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