Pacific fishing zones -- lifeline for overfished tuna?

November 13, 2012

Marine zoning in the Pacific Ocean, in combination with other measures, could significantly improve numbers of heavily overfished bigeye tuna and improve local economies, a fish modelling study has found.

Scientists working at the University of Hawaii at Manoa (Honolulu, HI), 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. Dr John Sibert of the University of Hawaii Joint Institute of Marine and Atmospheric Research is one of four scientists leading the study. After testing the effectiveness of a range of conservation measures with an ecosystem and fish population model, Dr Sibert says the team found that the most effective measures were to:"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," he says.

"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."

Half the current bigeye tuna catch is by longline, which targets high-value tuna sold as fresh fish. These fish command a market premium and sell for over $10 per kilogram.

The other half is caught in purse-seine nets as incidental bycatch when aiming to catch skipjack tuna. These juvenile bigeye tuna are sold to the canning industry for $1.70 per kilogram.

Dr Sibert says the study calls for a complete economic valuation of the Western Central Pacific Ocean (WCPO) tuna fishery.

He says the most effective conservation measures are those "which protect fish throughout their lifetime."

Rebuilding the bigeye-tuna stock will take at least 15 years, and will be affected by any climate changes the ecosystems experience.
-end-
The Spatial Ecosystem and Population Dynamics Model (SEAPODYM) used in the analysis was developed with support from a series of European Union-funded projects implemented by the Oceanic Fisheries Programme of the SPC, the NOAA-funded Pelagic Fisheries Research Program at the University of Hawaii and CLS.

Sibert, J., I. Senina, P. Lehodey, and J. Hampton. 2012. Shifting from marine reserves to maritime zoning for conservation of Pacific bigeye tuna (Thunnus obesus). PNAS 109(44): 18221.

For more information:

Pelagic Fisheries Research Program (PFRP): http://www.soest.hawaii.edu/PFRP/

The Secretariat of the Pacific Community (SPC): http://www.spc.int/en/

Collecte Localisation Satellites (CLS), a subsidiary of CNES (French Space Agency) and IFREMER (French Research Institute for exploration of the sea): http://www.cls.fr/welcome_en.html

The Spatial Ecosystem and Population Dynamics Model (SEAPODYM) model: http://www.spc.int/OceanFish/en/ofpsection/ema/ecosystem-a-multispecies-modelling/seapodym/148-seapodym

University of Hawaii ‑ SOEST

Related Fishing Articles from Brightsurf:

Waste fishing gear threatens Ganges wildlife
Waste fishing gear in the River Ganges poses a threat to wildlife including otters, turtles and dolphins, new research shows.

How smart, ultrathin nanosheets go fishing for proteins
An interdisciplinary team from Frankfurt and Jena has developed a kind of bait with which to fish protein complexes out of mixtures.

Fishing less could be a win for both lobstermen and endangered whales
A new study by researchers at Woods Hole Oceanographic Institution (WHOI) found that New England's historic lobster fishery may turn a higher profit by operating with less gear in the water and a shorter season.

'Pingers' could save porpoises from fishing nets
Underwater sound devices called 'pingers' could be an effective, long-term way to prevent porpoises getting caught in fishing nets with no negative behavioural effects, newly published research suggests.

Fishing can disrupt mating systems
In many fish species body size plays an important role in sexual selection.

Oversight of fishing vessels lacking, new analysis shows
Policies regulating fishing in international waters do not sufficiently protect officials who monitor illegal fishing, the prohibited dumping of equipment, or human trafficking or other human rights abuses, finds a new analysis by a team of environmental researchers.

Microplastics from ocean fishing can 'hide' in deep sediments
Microplastic pollution in the world's oceans is a growing problem, and most studies of the issue have focused on land-based sources, such as discarded plastic bags or water bottles.

Neither fishing tales nor sailor's yarn
An international team led by Robert Arlinghaus from the Leibniz Institute of Freshwater Ecology and Inland Fisheries and the Humboldt-Universit├Ąt zu Berlin have developed a method for combining the empirical knowledge of fishery stakeholders in such a way that the result corresponds to the best scientific understanding.

Lights on fishing nets save turtles and dolphins
Placing lights on fishing nets reduces the chances of sea turtles and dolphins being caught by accident, new research shows.

Another casualty of climate change? Recreational fishing
Another casualty of climate change will likely be shoreline recreational fishing, according to new research.

Read More: Fishing News and Fishing Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.