Hypoxia kills dozens of crabs off the Oregon coast

Photo by Elizabeth Gates, courtesy of Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO).

These Dungeness crabs washed up along Cape Perpetua off the Oregon coast after being exposed to low-oxygen levels and experiencing hypoxia due to a dead zone in 2004. Although more mobile animals--such as mature fish--can usually swim away from dead zones and avoid hypoxia, less mature or mobile creatures like crabs, mussels and other slow moving crustaceans are more vulnerable and usually succumb to hypoxia more often than not. This phenomenon creates a dearth of those creatures most affected by hypoxia in the given environment and causes a problematic alteration in the food chain. Animals that rely on those creatures most affected by dead zones are, in turn, forced to find other food sources--which may be and often are, few and far between.

Through the reduction and elimination of excess nutrients (e.g. phosphorous and nitrogen) that are dumped or exposed to coastal waters, less animals will be effected by or die from hypoxia due to eutrophication (i.e. excess nutrients). Raising awareness about the ramifications of dead zones and hypoxia is key to advancing towards the reduction and eventual elimination of these deadly occurrences.

Posted by Jesse John