Who cares about whales and fish, the loss of ocean plankton is the big scary trend that we should all be worried about.
Why is blogfish worried? Phytoplankton (microscopic floating ocean plants) are the foundation of ocean food webs and they make most of the oxygen we breathe. Not only that, but plankton also make about half of the organic matter made on earth. With an earth full of people, we can't afford to lose this productivity.
Hints of the plankton decline have been surfacing for years, and now the latest study shows a worldwide decline in phytoplankton.
The most likely cause of the plankton decline is warmer ocean waters. Phytoplankton need nutrients like nitrogen to grow, and warmer waters suppress the churning up process in ocean waters that brings plankton fertilizer up from nutrient-rich deep ocean waters.
How about the other (excess) nutrient problems that you've all heard about--eutrophication? Won't they just balance out, not enough nutrients here, too much there? Well it's sort of like people, you don't want the wrong thing in the wrong place. You may enjoy watching professional wrestling on TV, but would you invite the Undertaker and all his friends to your daughter's 16th birthday party?