Tuesday, November 29, 2011

Wayne T. Ward Invasive Species

Recently I read an article regarding the negative impacts of invasive species in lake ecosystems. Specifically, Vander sought deeper understanding of smallmouth and rock bass’s effect on native trout species. The author hypothesized that littoral fish prey abundance as well as diversity would be markedly lower in affected systems. In addition Vander believed that Trout diet would shift away from pelagic fish prey toward a more littoral diet. Data from this paper shows that introduction of prey species into non-native lakes will have negative ecological effect. It also, provides more incentive to the current angler to use non-live bait in order to avoid these costly consequences on the natural ecosystem.

The introduction of non native species should be discontinued as well as the use of live bait by anglers due to the potential strong top down effects that can occur as seen with bass on trout. Normally littoral and pelagic dynamics are not intimately associated, but the bass’s top-down effect, pressured the normally pelagic predators to obtain their energy from the littoral habitat. This was clearly demonstrated through Vanders clever use of isotopes to track energy flow within a system and should be considered by fisheries. What do you guys think? Could there  be potential benefits to such an introduction? If so, do you like Vanders use of isotope tracking as a means to study food web dynamics? http://limnology.wisc.edu/personnel/jakevz/pdf/1999_Nature_VZetal.pdf

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