A population of humpback whales in the South Atlantic has rebounded from the brink of extinction.

Intense pressure from the whaling industry in the 20^th century saw the western South Atlantic population of humpbacks diminish to only 450 whales. It is estimated that 25,000 whales were caught over approximately 12 years in the early 1900s.

Protections were put in place in the 1960s as scientists noticed worldwide that populations were declining. In the mid-1980s, the International Whaling Commission issued a moratorium on all commercial whaling, offering further safeguards for the struggling population.

A new study co-authored by , and from the 天美影视传媒鈥檚 School of Aquatic and Fishery Sciences shows the western South Atlantic humpback (Megaptera novaeangliae) population has grown to 25,000. Researchers believe this new estimate is now close to pre-whaling numbers.

The were published Oct. 16 in the journal Royal Society Open Science.

“We were surprised to learn that the population was recovering more quickly than past studies had suggested,” said Best, a UW doctoral student.

The study follows a previous assessment conducted by the International Whaling Commission between 2006 and 2015. Those findings indicated the population had only recovered to about 30% of its pre-exploitation numbers. Since that assessment was completed, new data has come to light, providing more accurate information on catches 鈥� including struck-and-lost rates 鈥� and genetics and life-history.

“Accounting for pre-modern whaling and struck-and-lost rates where whales were shot or harpooned but escaped and later died, made us realize the population was more productive than we previously believed,” said Adams, a UW doctoral student who helped construct the new model.

By incorporating detailed records from the whaling industry at the outset of commercial exploitation, researchers have a good idea of the size of the original population. Current population estimates are made from a combination of air- and ship-based surveys, along with advanced modeling techniques.

The model built for this study provides scientists with a more comprehensive look at the recovery and current status of the humpback population. The authors anticipate it can be used to determine population recovery in other species in more detail as well.

“We believe that transparency in science is important,鈥� said Adams. 鈥淭he software we wrote for this project is available to the public and anyone can reproduce our findings.”

Lead author of the UW’s Joint Institute for the Study of the Atmosphere and Ocean stressed the importance of incorporating complete and accurate information when conducting these assessments, and providing population assessments without biases. These findings come as good news, he said, providing an example of how an endangered species can come back from near extinction.

鈥淲ildlife populations can recover from exploitation if proper management is applied,鈥� said Zerbini, who completed this work at the NOAA Alaska Fisheries Science Center鈥檚 Marine Mammal Laboratory.

The study also looks at how the revival of South Atlantic humpbacks may have ecosystem-wide impacts. Whales compete with other predators, like penguins and seals, for krill as their primary food source. Krill populations may further be impacted by warming waters due to climate change, compressing their range closer to the poles.

鈥淟ong-term monitoring of populations is needed to understand how environmental changes affect animal populations,鈥� said Zerbini.

Other co-authors are of Alaska Fisheries Science Center and of the British Antarctic Survey.

This research was funded by the Pew Bertarelli Ocean Legacy Project, the U.S. National Marine Fisheries Service-National Oceanic and Atmospheric Administration, the British Antarctic Survey and the 天美影视传媒.

For more information, contact Zerbini at alex.zerbini@noaa.gov, Best at jkbest@uw.edu and Adams at adamsgd@uw.edu.

The , a collaboration between the at 天美影视传媒 and , is trying something very rare — bringing together multiple science models and people who care about a particular ocean resource or fishery to decide what’s most important for its vitality and the communities it serves.

“We’ve gotten to this point now where there’s an amazing amount of science, but it’s fragmented,” said , the Ocean Modeling Forum’s co-director and senior scientist with NOAA Fisheries. “We want to bring it together and exploit the strengths of all these different models and data streams and try to overcome the weaknesses.”

The Ocean Modeling Forum will address all ocean management issues, facilitating conversations among as many stakeholders as possible. Its first project, focused on the recently closed , will have its fourth and final meeting later this month in Seattle. The group will kick off its second project June 8-10 in Richmond, British Columbia, with a summit focusing on the .

The goals of the herring summit are to hear from tribes and First Nations peoples, social and natural scientists, the fishing industry, nonprofits, and federal and state wildlife managers about the role herring plays socially and ecologically, and to begin to develop a framework for how traditional ecological knowledge — in addition to scientific data — can be used in fisheries management practices.

“I think there is a lot to be gained in bringing together people who are working on common problems so we can use models in new ways,” said , director of the UW’s School of Aquatic and Fishery Sciences and co-director of the Ocean Modeling Forum.

The three-day summit in British Columbia comes at a time when many are questioning plans for the Pacific herring fishery. Some First Nations peoples protested and prevented commercial fishing by taking to the water last year and this spring, though Fisheries and Oceans Canada opened a commercial fishery. The First Nations have argued that the herring population, which holds deep cultural significance, hasn’t yet recovered to a sustainable level, and some scientists evaluating the fishery agree.

The first day of the summit is devoted to hearing stories about the significance of herring, and many tribes and First Nations peoples are expected to share. An artist will serve as a pictorial recorder, overlaying words, ideas and pictures from the stories into works of art that will remind participants of the discussions and themes throughout the conference.

The Ocean Modeling Forum’s approach for the summit 鈥� where the people who set fishing quotas, conduct the science, catch the fish and plan for the future are all brought to the discussion table 鈥� is the first of its kind worldwide for fisheries. The goal is to come up with a plan to sustainably manage a fishery in a way that’s more nimble to change, and sensitive to both ecological and social factors.

“The idea is to increase the breadth of the approach to address the complex questions that we’re facing right now,” said , managing director of the Ocean Modeling Forum and lead ecosystem ecologist with the at UW Tacoma. “Given the particularly knotty ocean management issues faced worldwide, our hope is to bring together all the existing models, with their modeling teams, to provide more reliable and clear advice.”

Some models combine a hypothesis and data to try to predict how healthy a fishery is ecologically, while others look at how well it’s performing from an economic standpoint. Nearly all involve complicated math, and scientists agree that all models are flawed in some way. So, by looking at every option on the table, organizers hope the best parts of each will rise to the surface.

The result is a way for managing a fishery that offers more than any single model could on its own.

Over the next year and a half, a smaller working group will take information from the herring summit and construct a framework that agencies can adopt when they are ready to incorporate human dimensions, such as the cultural significance of fishing, into fisheries management.

The sardine project launched with a similar meeting in March 2014, and its working group will wrap up this summer with a paper summarizing its findings and recommendations.

In the future, organizers say, the Ocean Modeling Forum could be used to address other fish and animal species, or issues such as how to manage resources affected by ocean acidification.

“I think the sky is the limit in terms of the sorts of issues we can address and the scope with which we can address them,” Levin said.

The Ocean Modeling Forum is funded by the David and Lucile Packard Foundation. The Pew Charitable Trusts is funding the summit in British Columbia, which brings together experts from the entire West Coast.

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For more information, contact Francis at tessa@uw.edu, Levin at phil.levin@noaa.gov and Punt at aepunt@uw.edu.

This is the only population of blue whales known to have recovered from whaling 鈥� blue whales as a species having been hunted nearly to extinction.

Blue whales 鈥� nearly 100 feet in length and weighing 190 tons as adults 鈥� are the largest animals on earth. And they are the heaviest ever, weighing more than twice as much as the largest known dinosaur, the Argentinosaurus. They are an icon of the conservation movement and many people want to minimize harm to them, according to , UW assistant professor of aquatic and fishery sciences.

聽聽聽聽聽聽聽聽聽聽聽 “The recovery of California blue whales from whaling demonstrates the ability of blue whale populations to rebuild under careful management and conservation measures,” said , a UW doctoral student in quantitative ecology and resource management and lead author of a on the subject posted online Sept. 5 by the journal Marine Mammal Science. Branch and , a UW professor of aquatic and fisheries sciences, are co-authors.

California blue whales 颅 are at their most visible while at feeding grounds 20 to 30 miles off the California coast, but are actually found along the eastern side of the Pacific Ocean from the equator up into the Gulf of Alaska.

Today they number about 2,200, according to monitoring by other research groups. That’s likely 97 percent of the historical level according to the model the co-authors used. That may seem to some a surprisingly low number of whales, Monnahan said, but not when considering how many California blue whales were caught. According to Monnahan, Branch and another set of co-authors published earlier this summer in PLOS ONE, approximately 3,400 California blue whales were caught between 1905 and 1971.

“Considering the 3,400 caught in comparison to the 346,000 caught near Antarctica gives an idea how much smaller the population of California blue whales was likely to have been,” Branch said.

The catches of blue whales from the North Pacific were unknown until scientists 鈥� in particular Yulia Ivashchenko of Southern Cross University in Australia 鈥� put on their detective caps and teased out numbers from Russian whaling archives that once were classified as secret but are now public. The numbers Russian whalers had publicly reported at one time were incomplete and inaccurate 颅鈥� something that was admitted in the late 1990s 鈥� but there wasn’t access to the real numbers until recently.

For the work published in PLOS ONE, the scientists then used acoustic calls produced by the whales to separate 鈥� for the first time 鈥� the catches taken from the California population from those whales taken in the western Northern Pacific near Japan and Russia. The two populations are generally accepted by the scientific community as being different. Places where acoustic data indicated one group or the other is present were matched with whaling catches.

In the subsequent Marine Mammal Science paper just out, the catches were among the key pieces of information used to model the size of the California blue whale population over time 鈥� a model previously used by other groups to estimate populations of hundreds of fish and various other whale species.

The population returning to near its historical level explains the slowdown in population growth, noted in recent years, better than the idea of ship strikes, the scientists said.

There are likely at least 11 blue whales struck a year along the U.S. West Coast, other groups have determined, which is above the “potential biological removal” of 3.1 whales per year allowed by the U.S. Marine Mammal Protection Act.

The new findings says there could be an 11-fold increase in vessels before there is a 50 percent chance that the population will drop below what is considered “depleted” by regulators.

“Even accepting our results that the current level of ship strikes is not going to cause overall population declines, there is still going to be ongoing concern that we don’t want these whales killed by ships,” Branch said.

Without ship strikes as a big factor holding the population back 鈥� and no other readily apparent human-caused reason (although noise, chemical pollution and interactions with fisheries may impact them) 鈥� it is even more likely that the population is growing more slowly because whale numbers are reaching the habitat limit, something called the carrying capacity.

“We think the California population has reached the capacity of what the system can take as far as blue whales,” Branch said.

“Our findings aren’t meant to deprive California blue whales of protections that they need going forward,” Monnahan said. “California blue whales are recovering because we took actions to stop catches and start monitoring. If we hadn’t, the population might have been pushed to near extinction 鈥� an unfortunate fate suffered by other blue whale populations.”

“It’s a conservation success story,” Monnahan said.

Funding for students working on the research in Branch’s lab comes through the Joint Institute for the Study of the Atmosphere and Ocean, a collaboration between the National Oceanic and Atmospheric Administration and UW.

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For more information:
–Branch, tbranch@uw.edu
–Monnahan, monnahc@uw.edu

(NOTE: Monnahan is traveling Sept. 6-20)

Blue Whale News,

Journal articles referenced in this release:
–“”
Marine Mammal Science
Co-authors: Cole Monnahan, Trevor Branch and Andr茅 Punt

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PLOS One
June 3, 2014
Co-authors: Cole Monnahan, Trevor Branch, Kathleen Stafford, Yulia Ivashchenko, Erin Oleson