If there is one thing that nuclear testing sites, meltdowns, and DMZ thats mined all show is that animals tend to reclaim territory quite fast. Unless nearby areas are still heavily fished I doubt this place is the result of learned behavior.

In order to explain it I would instead look at reason why this place has stayed strong while other places has not. At that depth the ocean might not have been effected as much by changing temperatures, and there might be a better sustained eco balance.

Don’t understand why you are being downvoted. Chernobyl is a good example what happens when humans leave.

http://www.telegraph.co.uk/news/2016/04/23/wildlife-returns-...

Exactly what I thinking of. There is also a interesting episode from Discovery Channel Shark Week 2016’s “Nuclear Sharks", which describe the massive number of sharks at Bikini Atoll. To quote "Its nicely how things can recover so quickly. I think this is the last eden.".