Due to the number of shell fish the green crab eats, and the rate at which it is done, the green crab is seen as a large threat to the many of the nations commercial shellfisheries. It is estimated that millions of dollars could be spent and are spent each year to try and thwart the green crabs from destroying a very important industry, and helping to maintain biodiversity in areas poplutlated by the green crab. The green crab also carries a parasitic worm that can infect birds that prey on the crabs. This can have a potentially devastating effect by throwing off the food chain, and on the ecosystem as a whole in these areas. (Washington Sea 1998, Washington Dept.1997, Jaquette 1998, Holden 1997)