Because when the planet gets hotter that leads to ice melting, and if a lot of ice melts, sea levels rise and the biomes are effected. Also, a lot of aquatic biomes have a regulated temperature and lower or higher temperatures result in the death of plants/animals in that biome. My friend's dad had a Koi pond in their front yard. With the bad winter the North East saw, the pond froze over and it killed all the Koi. He had the pond for about 5 years before it froze over so it was not normal for his area, but the huge winter storms got it too cold.

Terrestrial species have evolved tricks such as internal fertilization, placentas and eggshells to isolate their gametes and embryos from a hostile environment. Most aquatic species have no such defenses and have bred for millions of generations in a relatively unchanging environment. If temperature and pH vary outside the narrow ranges they've been in for the last few million years, reproductive failure becomes very likely. An example is oyster spat in commercial farms in Oregon and Washington.

They are not, temperatures are not rising and hav'nt for 18yrs now, global sea ice is above normal, so I see no reasons for aquatic biomes to be affected.

Because of the climatic changes taking places in and around the world,.... The biomass is changing its properties whic are not apt for the aquatic plants and animals.... To change is very difficult.

It's one giant stretch of Al Gore's imagination that there is a relation between temperature variations and activities of men.

http://www.teachoceanscience.net/teachin...

And it's not just coral that is in trouble.

Many other species spawn around coral reefs, and then expand to the open ocean.