Shockingly good news

Maryland officials are declaring the eradication program for the snakehead fish (Channa spp.) a success, according to this article from SunSpot.net. A recent survey of the affected ponds (by electroshock) indicated that there were no more snakeheads, the evidence being that no fish floated to the pond surface after the shock was applied. The article concludes that quick action has prevented the snakeheads from spreading to the nearby Little Patuxent River, but there is no mention of any surveys done there, so I'm not sure how they can know this for sure. While it is estimated to have cost Maryland about $50,000 to remove the snakeheads, it is possible that this came with a greater ecological cost, since all the fish life was eradicated, and probably some aquatic invertebrate species as well. Apparently the rotenone application was a bit too effective, and back in September Maryland wildlife officials, worried that the piscicide would spread, added a neutralizer to the pond