Longlining, Overfishing & Atlantic Bluefin Tuna
Dr. Jane LubchencoProfessor, Marine Biology, Oregon State University
Two-thirds of the major marine fisheries of the world are currently fully exploited, over exploited, or depleted.
The reality is that there are multiple changes happening in oceans. If we look at all of those together, over-fishing is the biggest, single problem, but it's not the only one.
One example of a very large-scale disruption of ocean fisheries is the fact that the kind of fishes that we have been taking from the oceans has changed over time. Recently we have depleted the oceans of the very high trophic level or carnivorous species--the great big huge species that are very valuable and are at the top of the food web. And over time, we have been fishing down marine food webs and capturing lower trophic level species, that are smaller and less valuable.
This fishing down the food web has very serious ramifications for entire marine ecosystems with consequences to other wildlife as well as to fishing communities. When you remove the top predators of a system, there is a cascade of consequences that works its way down through the food web. In fact there are often very serious and abrupt changes at lower trophic levels that result.
Human activities have inadvertently modified ocean systems in ways that we didn't imagine would be possible. We are currently changing the chemistry, the physical structure and the biology of our oceans. It's time that we used a more cautious approach in making decisions about the oceans. The oceans and the life in them are too valuable to risk losing. Instead of assuming that there is no consequence or that things can always rebound, we need to be much more cautious in our activities and err on the side of protecting ocean resources for the future.
Takeharu JingujiRetired longline fisherman, Japan
The total number of fish has been decreasing a lot. So the biggest problem for me is that my income has been reduced.
I suspect we probably have no future if we keep doing this type of reckless fishing. In order to rebuild the tuna population, we have to control not only long-line fishing boats like ours, but also the net-fishing boats, since they catch even the small fish. Otherwise, I think the future of fishing is doomed.
Dr. Carl SafinaMarine biologist, author of Song for the Blue Ocean
When you look at the oceans, they seem so vast that you think to yourself, "how could people possibly fish out the oceans?" But the thing is, the fish in the ocean are concentrated only in the narrow margins along the continents--on the continental shelves, in some of the current systems, and in the borders along currents. They're not just spread evenly in between the continents. And there aren't more of them in deeper water the further out you go.
I think it's okay to use what's in the ocean. It's just not okay to use it up. So, the trick is simply when to know what is enough and what then becomes excessive.
We can use a lot of the modern stuff; reliable engines, radar, sonar, and all the things that make fishing a lot safer and a lot better. We just have to have an appropriate level of restraint and leave enough fish in the ocean to breed the next generation.