Two studies of amphibians in Xanadu National Park confirm a significant decline in the numbers of amphibians In 1975 there were seven species of amphibians in the park and there were abundant numbers of each species However in 2002 only four species of am

A letter is sent to an editor of an environmental magazine refering to amphibians in Xanadu National park and their decline since 1975. The author concludes that trouts which introduced to the park at 1975 are responsible for this decline. He bases this to knowledge from the two surveys and another unmentioned sources. However, some errors the author is making can lead to alternative explanations regarding the conclusion. I found three of them and prioritzed them in the following paragraphs.

In his letter the author bases his conclusion that trout are responsible for the decline in the amphibians species and numbers in two surveys. However, more information is needed in order for these surveys to be creditable. For example, who conducted the surveys, did the same person who conducted the survey in 1975 conducted the survey in 2002? and if yes with the same equipment? Another survey should be conducted now in 2015 in order to find whether this declination continued or not. The factor of time between the two surveys is a factor that need to be taken into much consideration because if the surveys were not conducted under the same circumstances then it would significantly alter their outcome and therefore have a very different explanation for the numbers of aphibians.

The author of the letter is also falling to the post hoc fallacy as he misinterprets the data from the surveys about the decline of aphibians' species and numbers and the introduction of trouts into the water parks which as mentioned began the same period back in the 75s. These two events happening together does not necessarily mean that they are linked to each other with cause-effect connection. For example, if the trouts indeed eat eggs but not amphibian ones, only eggs from species that are known to counteract with aphibians then the proposed explanation will not be valid.

Another culprit in which the author falls is that he assumes that trouts are solely responsible (or if not solely at a large percentage) for the decline in amphibians species and numbers. There could be number of other more plausible explanations such us the pollution in the waters of the Park. Since, 1975 the development of companies and factories, some of them nearby the park or near under earth rivers and streams could seriously lead in an increase in the pollution of water and therefore to the decline in the amphibians. Therefore, more explanation is needed in terms of pollution of waters, a survey perhaps, in order to find out if trout are solely responsible for this decline.

All in all, in this essay the fallacies in which the author fell are demonstrated and a series of alternative explanations that these could lead on were indicated. The editor of the magazine should try to find more data in order to support this article because if published this could lead to a series of measures against trouts that maybe are not responsible for this decline.