Finally, the reading claims that environmental factors which led to different levels of pollution concentration perfectly explained the uneven pattern of the diminishing sea otter population.

最后，阅读文章称导致了不同水平的污染浓度的环境因素完美地解释了海獭数量减少分布不均。

In conclusion, although the reading and the lecture are both about hypotheses of the diminishing sea otter populations, the two or three main points made in the reading are effectively challenged by the lecturer.

总而言之，尽管阅读文章和演讲都是关于海獭数量减少的假设，阅读中提出的两三个主要观点都被演讲者很好地质疑了。