This is a good documentary about the problems are oceans are facing. It isn't just about over fishing. Warming ocean temps due to Climate Change and pollution are also huge factors.

https://vimeo.com/ondemand/theendoftheline2

As for the IPCC, while I respect some of what they say, ,I also feel that they often purposely underestimate how damaging Climate Change really is.

Also, how do you argue for increased abundance when the population will continue to increase? Possibly as high as 9 billion by 2050. Even if mass starvation doesn't result from the disasters we are already experiencing due to Climate Change where are you going to get the raw materials to provide this "increased abundance"? Mining them from has been suggested, but I think we are still a very long way away from being able to do that.