Question: What is the most prominent change in underwater habitats over time?

Steve Thackeray answered on 19 Jun 2020:

Hi Tess! Great question! I bet a lot of people don’t think about this much, because underwater changes are hard to see without special equipment. For the lakes I look at, one of the biggest changes is that they have become more polluted with nutrients (from sewage and accidentally washed off of farmland). This has caused more algae to grow, and when those algae die they rot and cause oxygen to run out. In a lot of places, water treatment has been improved to reduce this problem. The other big change I’ve been looking at is climate change. We have seen lakes warming up, and that affects the way the water mixes, and how quickly underwater plants and animals grow and reproduce.