Wednesday, September 23, 2009

Fisheries in Peril: The Evolution of Exploitation

What happens when the commercial fishing industry and recreational fishers target certain species for size? Do these practices of selective harvest equate to active artificial selection for smaller fish? Do these practices reverberate in the fish DNA in such a way that humans can be said to be manipulating the evolutionary trajectory of marine life? Thanks to the journal of Evolutionary Applications, here’s your chance to find out!

A few weeks back Loren McClenachan of the Scripps Institution of Oceanography provided an overview of her recent work to the folks at Florida State University - where she’s currently doing some post doc stuff. The bulk of her research centers on the impact that historic human activities have on the populations of fish and marine mammal species. More specifically, using contemporary and historical records such as ship logs, archived photographs, newspaper articles, documented personal accounts, and similar sources, she examines the quantity, geographic distribution and individual sizes of harvested species.

For example, to look at the toll humans have taken on populations of the goliath grouper (Epinephelus itajara) in south Florida, McClenachan ventured to Key West and collected photographs from resident fishing charter services, and historical newspaper articles from the archives at the local county library. Through analyzing the information, she was able to statistically demonstrate (and pictorially illustrate) the change in species composition and individual size of fish harvested recreationally in the Florida Keys. More to the point, she was able to show that between the 1920s and 1970s the maximum size of harvested trophy fish decreased while at the same time the total number of caught fish plummeted.

Photo from McClenachanlen's below cited paper; Grouper Catch Dated 04/14/57

If interested, McClenachan’s grouper paper can be found here:
McClenachan, L. (2009). Historical declines of goliath grouper populations in South Florida, USA Endangered Species Research, 7, 175-181 DOI: 10.3354/esr00167

One has to wonder (i.e. worry) what impact humans are having on fisheries worldwide. Rather it is for recreational or commercial purposes, our fishing actively is reducing the abundance of many marine species, and one can argue that we’re even aggressively and proactively engaging in an artificial selection practice that seems to be in pursuit of smaller fish and reduced species diversity…

I’m reminded of McClenachan’s talk because the journal Evolutionary Applications has just published a special edition which makes available (FREE!) research presented during the 2008 American Fisheries Society Annual Meeting. Anyone with an interest in fisheries, oceanography, ecology, evolution or conservation should take a look – there’s something for everyone!

Included papers (All of which are free - HERE):

Life history change in commercially exploited fish stocks: an analysis of trends across studies (p 260-275)Diana M. T. Sharpe, Andrew P. Hendry

The role of experiments in understanding fishery-induced evolution (p 276-290)David O. Conover, Hannes Baumann

Comparison of demographic and direct methods to calculate probabilistic maturation reaction norms for Flemish Cap cod (Gadus morhua) (p 291-298)Alfonso Pérez-Rodríguez, Marie Joanne Morgan, Fran Saborido-Rey

Is fishing selective for physiological and energetic characteristics in migratory adult sockeye salmon? (p 299-311)Steven J. Cooke, Michael R. Donaldson, Scott G. Hinch, Glenn T. Crossin, David A. Patterson, Kyle C. Hanson, Karl K. English, J. Mark Shrimpton, Anthony P. Farrell

Life-history traits and energetic status in relation to vulnerability to angling in an experimentally selected teleost fish (p 312-323)Tara D. Redpath, Steven J. Cooke, Robert Arlinghaus, David H. Wahl, David P. Philipp

Avoidance of fisheries-induced evolution: management implications for catch selectivity and limit reference points (p 324-334)Jeffrey A. Hutchings

Quantifying selection differentials caused by recreational fishing: development of modeling framework and application to reproductive investment in pike (Esox lucius) (p 335-355)Robert Arlinghaus, Shuichi Matsumura, Ulf Dieckmann

Size-selective fishing gear and life history evolution in the Northeast Arctic cod (p 356-370)Christian Jørgensen, Bruno Ernande, Øyvind Fiksen

Propensity of marine reserves to reduce the evolutionary effects of fishing in a migratory species (p 371-393)Erin S. Dunlop, Marissa L. Baskett, Mikko Heino, Ulf Dieckmann

Implications of fisheries-induced evolution for stock rebuilding and recovery (p 394-414)Katja Enberg, Christian Jørgensen, Erin S. Dunlop, Mikko Heino, Ulf Dieckmann

Mitigating fisheries-induced evolution in lacustrine brook charr (Salvelinus fontinalis) in southern Quebec, Canada (p 415-437)Kenichi W. Okamoto, Rebecca Whitlock, Pierre Magnan, Ulf Dieckmann

Eco-genetic model to explore fishing-induced ecological and evolutionary effects on growth and maturation schedules (p 438-455)Hui-Yu Wang, Tomas O. Höök

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