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.
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.
University of Hawaii ‑ SOEST:
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Algorithms developed by Google designed to encode thoughts, could lead to computers with ‘common sense’ within a decade, says leading AI scientist
New fossil evidence suggests dogs emerged as a separate species from wolves far earlier than scientists previously believed
Researchers discover the 425-million-year-old remains of a new species of parasite - still clamped to the host animal it invaded.
It should be raptor egg blue instead of robin egg blue. Some modern birds lay colourful eggs, but now we know it's a trick their dinosaur ancestors used too
WASHINGTON (Reuters) - Scientists on Thursday unveiled the most comprehensive analysis ever undertaken of the world's ocean plankton, the tiny organisms that serve as food for marine creatures such as the blue whale, but also provide half the oxygen we breathe.
Scientists on Thursday unveiled the most comprehensive analysis ever undertaken of the world's ocean plankton, the tiny organisms that serve as food for marine creatures such as the blue whale, but also provide half the oxygen we breathe.
Researchers say they're excited about a new brain implant that allowed a paralyzed patient to control a robotic arm with his mind. Erik Sorto is the first in the world to have this new neural prosthetic device. Elaine Quijano reports.
Genetically, at least, not that much has changed in the billion years since you two last shared a relative. Roughly half the 500 genes yeast need for life are interchangeable with the human versions.
What controls aging? Biochemist Cynthia Kenyon has found a genetic mutation that can more than double the lifespan of a tiny worm, which points to how we might one day significantly extend human life.
Java sparrows amp up their tunes with acoustic beak taps synchronized with chirps