There is other changes that are going on in the tropical oceans then just heating up.  The Pacific Ocean has increased CO2 by 65% since 1998.  The Kelvin Wave is very acidic and will effect fishing along the California and Alaska coast.

This is a good article with easy to understand charts.

We have reached 400 p/mil of CO2 in the atmosphere in March.  That CO2 is being absorbed in the water. That absorption rate increase corresponds to the increase rate of CO2 in the atmosphere during the same time period. The small shell fish in the ocean admits 25% of the oxygen that goes into the atmosphere and they are in trouble with the increased acid in the ocean.  

Moreover, the oceans collectively are the largest carbon sink on the planet, absorbing more than 25 percent of fossil fuel emissions annually, NOAA points out. That varies regionally, however. The tropical Pacific, which is responsible for 70 percent of annual variability in global oceanic uptake of CO2, is actually emitting CO2 into the atmosphere at an increasing rate. Hence changes taking place there can affect the global carbon system.