Translation of Umweltschützer

Hi Christin, how are you? I am on vacation right now, but you can call me if there are any problems. I am planning to meet my students in the end of next week. I will deliver the message anyway.
The belief of somebody that a race or a group of people to which he belongs is superior to another. Even though the word itself stems from the word 'race', its meaning must be generalized.
We had to be careful of not falling into the water. We rowed for about an hour and we got tired pretty easily. Especially the other man and woman looked devastated, at the limit of their physical capabilities.