The effects of human activity on animal species
A recent JAVMA news article, “Endangered sea otters threatened by toxic algae,”1 described research suggesting that a rash of southern sea otter deaths off the coast of California in 2007 was caused by exposure to microcystin, a toxin produced by organisms typically found in warm, stagnant, nutrient-enriched freshwater. The article also reported that a recent survey of the sea otter population found that the number of sea otters had decreased for the second year in a row and quoted the lead scientist of the survey as saying, “A number of human and natural factors may be influencing this trend, and we are working to better understand what those are.”
Given that the survey estimated that only 2,711 sea otters are left in the wild, we need to expedite our understanding of how toxins such as microcystin end up in the ocean. With warming of the oceans secondary to climate change, the runoff of pesticides and nutrients used for industrial agriculture and residential applications, and the encroachment of domestic animals such as cats into the sea otter's habitat, it shouldn't be hard to understand what's happening. There's nothing natural about it. All of these activities are altering the ecology of the oceans and affecting plants and animals that have evolved over time to live in that environment.
The debate is no longer about whether climate change exists or even the role of humans in climate change but rather about what can be done at this stage to mitigate the consequences. Our profession needs to not only question current industrial agricultural and urban practices as they affect domestic animals, but also question how those practices are affecting all of the animal species on the planet. Our veterinarian's oath demands no less.
William C. Skaer, dvm, mses
Wichita, Kan
References
Nolen RS. Endangered sea otters threatened by toxic algae. J Am Vet Med Assoc 2010; 237:1116–1117.
