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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More sharks and manta rays in the CITES Appendices, please!

From the name itself, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) aims to ensure that the international trade of wild animals and plants will not cause their extinction. Only a handful out of the thousands of listed species in the CITES Appendices are marine species, and despite all efforts to include more, most proposals were rejected.

According to the Review of the State of World Marine Fisheries Resources published in 2005 by the Food and Agriculture Organization of the United Nations (FAO), more than 50% of marine fish stocks are fully exploited, 17% are overexploited and 7% are already depleted. The statistics are highly alarming and require immediate action.

As of this writing, the Sixteenth meeting of the Conference of the Parties (CoP16) is happening in Bangkok, Thailand. Today they will vote on the addition of five shark species and all manta rays to Appendix II. This newly published paper* from the Fish and Fisheries was written primarily to help the CoP in their discussions by providing information that can help address their concerns.

Hoping that they vote in favor of the sharks and manta rays!

* Executive summary can be found here (also available in French and Spanish).

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 UPDATE (as of 15 March 2013): All proposals were approved! More details here.

Awesome Non-fish in Trouble # 3: Loggerhead sea turtle, a survivor

Natural predation is the common cause of mortality of Caretta caretta, commonly called loggerhead sea turtle, as any other species. An example of which is the case of Yu Chan. She was caught in a Japanese fisherman's net and was brought in Suma Aqualife Park near Kobe, Japan in 2008. Her front flippers were torn off because of a shark attack, based on the teeth marks across her body. Fortunately, after many trials, she now has artificial limbs which she cannot take off easily and that she can swim with [1].

Disabled loggerhead turtle Yu Chan fitted with prosthetic flippers, photo by Toshifumi Kitamura, AFP.

Other major factors that resulted in their dramatic decline in number were incidental fishery catches, egg harvest and tourism developments [2]. Thus, they have been marked by the International Union for Conservation (IUCN) as threatened in 1978 and endangered since 1996 [3].

To know more about loggerhead sea turtles, visit SeaLifeBase.

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[1] Potter, N. Loggerhead sea turtle gets artificial flippers after shark attack. ABC News. Published online February 12, 2013.

[2] de Quevedo, I.A., L. Cardona, A. De Haro, E. Pubill, and A. Aguilar. 2010. Sources of bycatch of loggerhead sea turtles in the western Mediterranean other than drifting longlines. ICES J. Mar. Sci. 67(4):677-685.

[3] IUCN Red List of Threatened Species 2012.

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