While they’re mollusks, there’re not brainless. In fact, most of their brain is spread throughout their 8 arms. They like puzzles, make friends, and remember people. Sadly, they have short lives and can’t pass on their knowledge to their offspring because they die soon after reproducing.
Dead Zones are areas in the oceans that have very little oxygen. They don’t have enough oxygen to support most marine life. We’ve known about them for a long time, but now the number of them are increasing rapidly. This threatens populations of large fish, including tuna.
This is tied in with climate change, because warmer water can’t hold as much oxygen as colder water. Over time, this will have profound effects on many marine populations.