New Zealand hoki is a shining example of success or failure in fishery management, depending on who you ask. Mostly because of a decline in catch in the last decade.
There are other issues that matter, like bycatch of sharks and seabirds, and habitat impacts from trawling. But the most interesting part of the success/failure argument is the significance of the decline in hoki catch that happened in the last decade.
What does it mean when we see a decrease in the amount of a fish caught? Is this a sign of a collapsing fishery? Or is it a sign that managers are doing the right thing? People will claim both, and it's important to look at the details.
When a fishery is virtually unregulated, then declining catches are likely a sign of problems, such as a collapsing fish population. But when less fish are caught because managers reduce fishing limits, in response to scientific advice, then the shrinking catch may be a signal that sustainable management is responding to changing conditions.
A story in the New York Times presents a case for failure, but the Sustainable Fisheries Partnership presents a case for success. All based on the same set of facts about hoki.
Rather than speculate, I'll wait another year to see if hoki numbers increase or decrease. If the fishery is failing, then we should see further declines in the amount of fish. If management is sustainable, then the fishing decline should allow the fish to rebuild.
The latest sign is that managers claim hoki have already recovered to healthy levels. If that's true, then I lean more towards success as the correct story for hoki.