Is seaweed in decline and how is it effecting marine life?

Question

is the seaweed in decline? what is the effects of this decline on marine life? and why is it in decline? (if it is)

Answer 1

I am unaware of any worldwide trend in seaweed decline.  Seaweed is part of the overall marine ecosytem chain so is very important to overall health.

For example, on the Pacific coast of Norht America, the otter population was decimated.  They ate a lot of sea urchins.  Sea urchins eat the kelp.  So when the population of otters was decimated, sea urchins became more prevalent and ate up the kelp, wiping out kelp forests on the coast.  Now the otters are back and the kelp forests are much more prevalent and healthy.

If seaweed went into decline, fish populations would fall and there would be less diversity in the ocean.  Like I said though, I don't know of any overall trend that puts seaweed in decline.  I expect there are spots where it is in decline and spots where it is booming.