Pacific Tuna Alliance

Marine Mammal Protection

One of the areas of our fishery of most interest to global NGOs is our efforts to protect marine mammals.  NGOs are seeking more investment to protect marine mammals and to learn more about them. The Alliance has committed to an ambitious Sustainability Action Plan to protect dolphins and marine mammals as part of meeting the MSC conditions. This article gives background on our fishing technique and interactions with marine mammals for stakeholders that are new to our fishery.

Overview of Commercial Tuna Fishing Methods
Commercial fishers utilize five primary techniques for fishing tuna – longline, gillnet, pole and line, purse seine, and troll. Our members fish with purse seine vessels which is the most common commercial technique used around the world. The International Sustainable Seafood Foundation states that purse seine fishing is responsible for about 63 percent of tuna caught globally every year. Of course, each technique has advantages for the environment and areas of opportunity for improving environmental performance.

More about Our Purse Seine Fishing Method
Purse seine vessels fish by spotting free-swimming schools of tuna, by spotting tuna swimming in association with dolphins, or by fishing the schools that congregate under natural floating objects (i.e. drifting logs, dead floating animals, kelp beds, floating debris) or man-made objects (floating devices made by man) also known as fish aggregating devices (FADs).

Our members fish free-school tuna and dolphin-associated tuna. Fishing tuna found swimming in association with dolphins is our primary method of fishing.  In this blog, we outline in more detail about our fishing practices.

Both free school fishing and fishing in association with dolphins are environmentally desirable fishing techniques due to low levels of bycatch: the International Sustainable Seafood Foundation finds that when fishing on free-swimming schools, purse seine fishing has an average bycatch rate of less than 1 percent.  Free school is the method that is most protective of bycatch; and fishing in association with dolphins is the method most protective of both bycatch and tuna stocks.

What are dolphin-associated schools?
In the Eastern Tropical Pacific Ocean (ETPO) and other oceans – like in the Indian Ocean – dolphins swim in association with mature tuna. This behavior is believed to be due to predator avoidance – and is hypothesized to be more prevalent in the ETPO than in other oceans due to water temperatures, but contrary to common beliefs, this associative swimming is found in many other oceans.  Fishing tuna that are swimming in association with dolphins requires particular care to ensure that dolphins are not harmed during the fishing process – and that they are able to swim free from the net, before the net is closed.

How can you protect dolphins while fishing tuna that swim with them?
The right technologies must be used so that dolphins are not entangled in nets; nets must be aligned so that dolphins can swim over the nets; and captain and crews must ensure that dolphins are not entangled in nets. These practices have been refined and regulated by the Agreement on International Dolphin Conservation Program (AIDCP).

What is the current performance on marine mammal protection?As a result of the AIDCP regulation, over 95% of dolphin-associated sets in the Eastern Tropical Pacific Ocean have no dolphin mortality and dolphin mortalities have been reduced to fewer than 1,000 mortalities* per year from all nations fishing in association with dolphins (Colombia, Ecuador, Mexico and Venezuela amongst them) in this regional fishery – as compared with over 95,000 cetacean mortalities from the global tuna industry each year from other regional tuna fisheries from around the world. We believe in continuous improvement across our operations and believe that there is still room to improve on dolphin protection.

*The IATTC limits dolphin mortality in the ocean at 5,000 per year, at which point all vessels would be required to stop fishing until the following fishing season.

What are the top areas for improvement in marine mammal protection?

The Alliance will continue our goal of zero mortality of marine mammals with:

  • Further dolphin protection measures including investments in net alignment and in improving the observer program and training in best practices across the fleet.
  • External audits of the on-board observer program (in place on 100% of our vessels).
  • New investments in training and technology to protect shark, rays, and dolphins.
  • Continuing technological improvements that could lead to lower dolphin mortalities.

(The Alliance will continue strive for zero mortality of all non-target species – from dolphins to sharks to rays: our perspective is that sustainability requires these ambitious goals for all species.)

The Alliance will seek to collaborate to build further global understanding of dolphin populations – catalyzing a multi-lateral effort to assess the status of dolphin populations in the ocean including:

  • Funding for workshops and expert scientists to establish methodologies and approaches for a multi-lateral project to assess the current status of dolphin populations in the Eastern Tropical Pacific Ocean.
  • Significant financial investment to assess dolphin populations in this ocean region.

We invite all stakeholders to participate in our dolphin conservation programs.

How does fishing in association with dolphins protect tuna stocks?
Dolphins associate and swim with mature tuna, adult tuna that have reproduced time and again and added to the genetic diversity of the ocean and population. Fishing the mature tuna that swim with dolphins is the best method for managing tuna stocks because the technique protects juvenile and breeding tuna stocks. For this reason and the fact that fishing in association with dolphins has such a low rate of by-catch compared to other commercial fishing techniques, many fisheries scientists and NGOs agree that fishing in association with dolphins is an ecologically sound fishing technique.

More Questions?  You can read all of the data on the fishery here in SCS Global Services’ Public Comment Draft Report for their evaluation of the fishery.