The plight of bluefin tunas

by Kristen Weiss on 13 Mar 2016 Nearly 200 scientists, fisheries managers, policymakers, industry and non-governmental organization representatives and students gathered in Monterey from January 18-20 to discuss the plight of bluefin tunas, whose populations are struggling in many parts of the world. These global Olympian swimmers are found in the Pacific, Atlantic and Southern Oceans, and are some of the most biologically, economically and culturally significant apex predators in the ocean.

Hosted by Stanford University and the Monterey Bay Aquarium, the meeting’s focus was to assess the state of scientific knowledge and management of all three bluefin tuna species (Pacific, Atlantic, and southern) and to promote dialogue among researchers, management, industry and policy makers to ensure these ocean giants have a future. The Center for Ocean Solutions was proud to be a sponsor for this three day Bluefin Futures Symposium, which featured several Stanford and COS-affiliated speakers.

“Just as COP21 was a turning point for climate change, this symposium could be a turning point for bluefin tuna fisheries,” stated Julie Packard, executive director of the Monterey Bay Aquarium, during her keynote address. “We have some of the brightest minds in the field here in this room. We can learn from each other and identify new opportunities for collaboration to achieve sustainability for Bluefin fisheries.”

Woods Senior Fellow Barbara Block (Biology), professor of marine sciences at Stanford University’s Hopkins Marine Station and one of the catalysts for the symposium, shared her hope on the first day that the meeting’s participants could build a new roadmap for the future of bluefin tuna. Increasing the opportunity for productive interactions among the distinct bluefin tuna representatives at the meeting was key.

“There is the potential for a new path for creating a bluefin future that includes productive populations, protection of biodiversity, and economic vibrancy for aquaculture,” said Block in her opening address. “My dream is that we can forge this path together, to ensure these fish have a future in our global oceans. Science is the fundamental building block of rebuilding bluefin populations. We need to continue to find ways to develop the science and ensure it forms the basis for the management process.”

The symposium was in part a celebration of the 20 years of a successful research partnership between Stanford and the Monterey Bay Aquarium within a unique facility at Stanford called the Tuna Research and Conservation Center (TRCC). At the TRCC, over 40 bluefin and yellowfin tuna are held in captivity, creating the capacity for researchers to advance the knowledge of Pacific and Atlantic bluefin tunas. The scientific team at TRCC contributes to bio-logging, genomics, and the ecological physiology of bluefin tuna. TRCC has also placed over 2000 electronic tags on wild tunas – providing new information on their sojourns across the Atlantic and Pacific vital for understanding population movements and dynamics.

“Climate change is really about the resilience of species,” Block said. “Here at Stanford and the Monterey Bay Aquarium, we’re studying the basic physiology of how tunas cope with environmental change as well as answering critical questions about energetics and maturity, which are key for understanding these fish in the wild.”

Block expressed hope for bluefin tuna management based on novel technologies presented in Monterey that are helping to rebuild, monitor and characterize bluefin tuna populations, including novel gene tagging, advances in fisheries independent assessment tools, and advances in bluefin tuna aquaculture. These scientific advances are already informing tuna management in some regions. The symposium provided a forum for scientists and managers to share lessons learned from these technologies and how they can be better utilized in the future.

“I have been inspired by the symposium, particularly the open discussions and conversations, and the sense that everyone felt there was a need for such a forum that could build the trust required to work together- to rebuild all three species’ populations to healthy levels,” Block stated.

Meeting participants also considered the challenges that climate change may present for managing bluefin tunas in the coming decades. Keynote speaker Rob Dunbar, professor of earth science at Stanford University, summarized some of the ways climate change may affect tuna populations.

“Tuna are ice-age animals,” Dunbar explained. “They’ve already been through a lot of change, and now are having to deal with even faster temperature change, plus ocean acidification,” He said that we are likely to see as much change in climate over the next century as the earth has experienced over the last 10,000 years. Warmer oceans will hold less oxygen, causing changes all the way through the food web from primary producers up to large predators, including tuna.

The general tone throughout the symposium was one of cautious optimism. As Margaret Spring, vice president of conservation and science and chief conservation officer of the Monterey Bay Aquarium, reiterated in her closing remarks, “We need better communication between scientists and managers. This symposium filled a clear need for open dialogue and collaboration; now we need to keep the conversation going.”

Many participants seemed to agree, as discussions turned to next steps and hopes for another Bluefin Futures Symposium moving forward.