What's killing the reefs and diminishing our fish?

[Guest]

I Recently took a trip to the kona side to do a little fishing and snorkeling. The ocean was calm and the wind was down which usually makes for good fishing. Unfortunately we saw very little fish in the murky ocean water and we caught only two rock fish between the four of us. We saw no hermit crabs, sea slugs, or yellow tang, all of which use to be very common in these places we visited.
So I have to ask here on PWeb, seriously what is happening to our coral reefs in Hawaii?
Where have all the reef fish gone, why?
What causes the fish kills like the ones we see in kapoho?

Pretty sure there is no one reason for these noticeable reef changes so hoping for a wide range of opinions or answers.

I found a couple articles that were interesting.
http://www.cnbc.com/2015/07/18/hawaiis-c...ching.html

http://news.nationalgeographic.com/2016/...ral-reefs/

http://www.hawaiibusiness.com/whats-hawa...ent-worth/