Oddly enough, the answer is usually "No." They didn't take it once they learned that they would have to dissect frogs. I had to dissect a cat in Physiology at my high school, and I understand that not everyone wants to be exposed to formaldehyde. I didn't like it all that well myself. But the knowledge from that course has come in handy in many ways.
Ecology is a science. Thre are things that you learn from studying it which can be experimentally validated. It requires physics, chemistry, zoology, and accurate observation, combined with statistical fluency, to come up with worthwhile results. That requirement is foreign to environmentalists, who generaly identify pollution with "something artificial" and "man-made". When you ask them to talk further about it, and whether sewage is pollution, they answer, "Yes, of course." It hasn't occured to them to look at other animals' contribution to public health, and they have confused their subjects. Yes, public health requires attention to water sources and problems. No, sewage is not a pollutant: it is a public health hazard. To solve this, we require "artificial" and "man-made" responses: pipes, ponds, burns, filters, and toilets are on the list: which should be cheered, not criticized.
Eventually, they will have to notice that human beings are part of nature, too. Our part includes stewardship, which leads to worthwhile discussions about use and advantage. It does not include saying, "Let's get rid of the people, that will solve our problem."