I've watched the movie and it is very depressing the statistics that are involved are we not supposed to fish the oceans dry by 2070 or something if we continue the trends, I watched the movie a few months ago on netflix. The whole situation really reminds me of the worlds oil market there was another documentary that I watched on netflix claiming that we have already reached peak oil production as a world wide market and are now on the decline much like our worldwide fisheries.
It all really stems from a growing population means more mouths to feed and this world is being tapped out of it's maximum production, something has to give and it isn't birth control in the local waters.
I believe the biggest factor to overfishing and the decline of stocks like salmon, tuna, predatory fish is that we fish out the bottom of the food chain such as herring, sardines etc the basic needs of the food chain for cheap food in third world markets, we use the fish eggs/roe (eggs that spawn new fish) for a very small and niche market such as the japanese/asian markets for sushi, dog foods, cat foods, those stupid pills of fish oil for people to take etc. We kill the food that predatory fish eat, they starve, populations drop add on humans chasing them down with space age technology pin pointing their location, depth, bio density, we know where they spawn and we know where to cut them off, we know they will be at X location during Y time.
Our worldwide fisheries have built huge massive fleets of destruction, you have boats that can catch, process, package and freeze their catch out in the ocean. They don't even have to come into a harbour for weeks or months they can just fish 24/7. Not to mention we have non selective methods to obtain said catches if it isn't dragging nets that are miles wide weighed down by massive weights that crush and destroy miles of habitat while targeting bottom fish that are slow growing high aged fish that arn't replenished very quickly. The ones that manage to escape the net have no home or food to eat while being a juvenile. The by-catch of said fleets are GROSS it should be illegal the way we fish some species while killing hundreds of thousands of millions of tonnes every year of fish that do not sell in markets. Perfect example is the pollock/haddock commercial catch in alaska and look how many juvenile halibut, migratory chinook are caught and crushed in those nets and then tossed overboard because they cannot sell those fish with their license.
Not to mention as previously mentioned the **** poor management we have not only in our waters but as a global fishery, the companies that sell and market these catches are basically the ones that control the industry with their power and wealth. Lean on some high end politics and work some under the table deals to shut them up and let them fish where and when they want and it leads to depressed stocks being targeted.
Lastly you have poaching, you have fleets, and ships from countries around the world that will go out to international waters or even waters of other countries (look at africa's coast right now) and they are moping up local fisheries with technology that is worlds above those of the locals and have no regards about catch limits or sustainable fishing methods they just want to catch as much as possible as fast as possible to make as much money as they can. In the movie they mention many of these illegal fishing ships will fly flags of other countries and often times unload their catch with legitimately caught catches.
To sum up what I am trying to say is there is simply way too much water and way too little enforcement, greed is always put ahead of sustainability. Remember that saying out of sight out of mind? Vast majority of people on this planet eating their grouper fillets in the middle of a state or country that is hundreds of miles away from any coast simply doesn't care or doesn't know the situation that is going on. Much like oil the people that are reaping the benefits now won't be around for when **** hits the fan and there is none left for anyone else or the next generation, same goes to our world wide fishery right now.
If there is money to be made rules will be broken and greed will ultimately control and manage said industry.
Sorry about the rant, sculpin asked for some discussion about the movie / topic.