Can Overfished Tuna be Saved?
We love Tuna! We love to eat Tuna! And the great Tuna are being seriously overfished. Attempts to remedy this situation have not been effective to date.
Now the University of Hawaii has come up with a new approach that holds promise.
A fish modelling study has found that marine zoning in the Pacific Ocean, in combination with other measures, could significantly improve numbers of heavily overfished bigeye tuna and improve local economies.
Scientists working at the University of Hawai'i at Mānoa, the Secretariat of the Pacific Community (SPC, Noumea, New Caledonia) and Collecte Localisation Satellites (CLS, Toulouse, France), have found that a network of marine zones in the Pacific Ocean could be a more effective conservation measure than simply closing relatively small areas to some types of fishing. These marine zones, where different fishing activities are allowed in different areas, may have significant and widespread benefits for bigeye tuna numbers.
After testing the effectiveness of a range of conservation measures with an ecosystem and fish population model, Sibert says the team found that the most effective measures were to:
- restrict longline fishing in tuna-spawning areas
- manage the use of fish-aggregating devices (e.g. moored or drifting buoys which attract fish) in purse-seine areas.
"We found that simply closing areas off to fishing doesn't work, because the boats just move their operations to neighbouring zones and fish even harder. It’s going to need a combination of approaches," said Sibert. "The model will help people evaluate alternative policies to manage tropical tuna fisheries. Our predictions can help countries estimate how effective conservation measures might be, relative to any economic effects, and tailor measures to suit their goals. The advantage of this approach is that effects can be estimated locally, as well as for the stock as a whole."
Tuna school via Shutterstock.
Read more at University of Hawaii.