Carping in the canal

Frightening Asian carp moving up the canal to the Great Lakes

http://www.bbc.co.uk/news/science-environment-26017956

The fish were deliberately introduced to control algal growth down south. Now they threaten all other fish species.

Let us eat carp!

There are three species of Asian carp poised to colonize the Great Lakes: Bighead Carp, Silver Carp (the one that jumps), and Grass Carp. The first two were imported by s US aquaculturists (e.g., Arkansas), as was Black Carp, which will likely soon follow Bighead and Silver Carp north. Grass Carp were stocked as supposedly sterile triploids in ponds in the Great Lakes area. A fifth species, Common Carp, was intentionally introduced to North America by early settlers (familiar food).

Invasive species move both ways between the Great Lakes and Mississippi River. For example, Zebra Mussels, introduced to the Great Lakes in ballast of oceangoing vessels accessed the interior of the US through the Mississippi River. Another Great Lakes ballast invader, a perch-like fish "Ruffe", will likely follow Zebra Mussels south. (Ruffe's proven a real problem in Scotland and other waters that it's invaded.)

Unfortunately, there don't appear to be failproof measures for containing aquatic invaders once they've established themselves. While reinstating separation between the Great Lakes and Mississippi R would be great, the carp eventually may access the Great Lakes via floodplains and intertwined Mississippi and Great Lakes tributaries in OH and MN. Southern aquaculturists raise carp with baitfish that they sell north. Commercial fisheries might depress populations if significant demand can be created, but range expansion won't be curtailed by fishing, which actually creates vested interest in wellbeing of the creatures. Currently, the biggest demand is in Asian fish markets, where live product is valued. Not only can these live fish escape, for example in truck spills into waterways (which happens, unfortunately), but cultural practices can result in release of individual live fish. (I understand there's actually a bow sports tournament planned for IL carp this year, which sounds dangerous to me!)

If only the efforts to contain carp could be directed to preventing future invasions by ballast, importation, etc. Prevention is much more cost-effective than the "rapid response" offered to placate a public worried about the most recent invader. Unfortunately, there are shippers and aquaculturists and hobbyists and other commercial interests who too often stand in the way of preventing access to the latest aquatic invader or pathogen.

Genetic modification has been proposed to contain exotic carp (and other pest species), e.g., daughterless carp. Thank goodness some scientists are calling for public discussion and regulation before loosing potentially helpful--but also potentially harmful--genes into the environment.

http://news.nationalgeographic.com/news/2014/07/140717-gene-drives-invasive-spec...

****************************************************

Kevin M Esvelt et al. 2014. Concerning RNA-guided gene drives for the alteration of wild populations. Published July 17, 2014. eLife 2014;10.7554/eLife.03401. Concerning RNA-guided gene drives for the alteration of wild populations | eLife

Abstract
Gene drives may be capable of addressing ecological problems by altering entire populations of wild organisms, ... The ability to edit populations of sexual species would offer substantial benefits to humanity and the environment. For example, RNA-guided gene drives could potentially prevent the spread of disease, support agriculture by reversing pesticide and herbicide resistance in insects and weeds, and control damaging invasive species. However, the possibility of unwanted ecological effects and near-certainty of spread across political borders demand careful assessment of each potential application. We call for thoughtful, inclusive, and well-informed public discussions to explore the responsible use of this currently theoretical technology.

****************************************************
Kenneth A oye et al. 2014. Regulating gene drives. Science DOI: 10.1126/science.1254287. Published Online July 17 2014. Regulating gene drives

Abstract
Regulatory gaps must be filled before gene drives could be used in the wild.

Yikes! Yet another bright idea to let loose before the full repercussions might be known.