School of Aquatic and Fishery Sciences

A new study uses two decades of tagging data on beluga whales to identify habitats that they prefer. In the eastern Chukchi and eastern Beaufort Seas, belugas preferred places with particular depth features, like canyons and continental slopes, instead of preferring places based on sea ice characteristics. Thus while reduced sea ice in this region may indirectly affect belugas through ecosystem changes, they did not rely on sea ice features to find places with good food availability. The research was by former SAFS PhD student Donna Hauser, SAFS Prof. Kristin Laidre, and others, and appeared in PLoS ONE.

Seafood consumers are increasingly interested in buying seafood that has a sustainable ecolabel certification by companies such as the Marine Stewardship Council. A new study identifies a key reason why it is so difficult for retailers to get a price premium for ecolabeled seafood: people differ widely in their willingness to pay more for ecolabels. In particular, those who might be happy to pay a lot more for sustainably labeled seafood, may not be willing to pay a lot for seafood relative to other protein such as chicken, pork, or beef. This presents a serious challenge to retailers who have to set a single price for each product, and thus can’t easily capture the extra value from consumers willing to pay a lot more for certified seafood. The new research was based on an auction experiment in Japan, was coauthored by SAFS professor Chris Anderson, and appears in Marine Resource Economics.

Salmon have complicated DNA that, at some point in the past, was completely duplicated. These duplicated genomes are hard to sequence because every gene has multiple copies, and in the past, duplicated genes were filtered out before studies were conducted on how salmon adapted to different environments. But new work on humans, yeast and rats shows that duplicated genes are often responsible for important adaptations. Now, geneticists at SAFS have developed a new method that enables study of gene duplicates in Pacific salmon, and have found that variation within these formerly unstudied genes is responsible for when salmon return from the sea, differences in body shape and size, and even whether individuals from the same species choose to migrate to the sea (sockeye salmon) or not (kokanee). These approaches will unleash a new wave of important studies to better inform fisheries and hatchery managers of genetic variation important for response to climate change, response to pollution, or disease resistance. The new research was authored by SAFS postdoc Morten Limborg, Wesley Larson, and SAFS professors Lisa Seeb and Jim Seeb, and appears in Molecular Ecology.

Smaller tags are needed to eliminate tagging effects in fish survival studies. Now a new miniaturized acoustic tag is small enough to be injected by syringe. The injectable transmitter, engineered by Pacific Northwest National Laboratory, is just 15 mm in length, 3.35 mm in diameter, and weighs 0.216 g. The research team tested the new tag over a 500-km reach in the Columbia/Snake River using young Chinook salmon. Survival was significantly higher for fish injected with this tag compared to those fish with surgically implanted tags, and thus we can track smaller fish with less fear of impacting their survival or behavior. The research was coauthored by SAFS professor John Skalski and research consultant Richard Townsend and appears in the journal Scientific Reports.

Redfish (North Atlantic fish in the genus Sebastes) are highly diverse and notoriously hard to identify. Now, new research shows that the problem is even worse than was thought. The new genetic analysis of microsatellites in rose fish (Sebastes norvegicus) showed that what is currently thought to be a single species, is actually three separate species. One of the new species, the giant version, is larger and has some biological features that can be used to distinguish it; but the other two new species are currently impossible to distinguish by external appearance. The new finding complicates management of redfish in the North Atlantic, because extra care needs to be taken to avoid overexploitation of each of the three species. The research was coauthored by SAFS professor Lorenz Hauser and appears in the ICES Journal of Marine Science.

New research shows that the oldest fish can decline dramatically in fished populations, even when fisheries are sustainable. Old fish declined in 97% of populations when compared to an unfished state, and in about a third of populations, old fish declined by more than 90%. These changes reduce the diversity of fished populations, which can lead to lower stability. Reducing the impact of fishing on old fish would require marine reserves, rotational harvesting, or slot limits that prohibit fishing on all but a narrow range of fish ages. The work by SAFS postdoc Lewis Barnett and professors Trevor Branch and Timothy Essington, together with Anthony Ranasinghe, appeared in Current Biology. and was featured in National Geographic News.

Infectious diseases reduce human health both through death and disability, with the total disease burden being lower in wealthy and more urban countries, but higher in countries with more biodiversity. Contrary to expectations, increases in biodiversity over time did not result in better human health, and in fact higher disease burdens resulted when forest cover increased over time. Thus the key reason why infectious disease burdens have declined in recent decades is a shift towards urbanization and greater wealth, immediately suggesting levers for improving global human health. This research by SAFS professor Chelsea Wood and colleagues appeared in Philosophical Transactions B  and prominently covered in a recent report by The Atlantic.

New research on Alaskan fishing communities shows the crucial importance of fishing portfolios and turnover. In 1989, when there were both major ocean and market regime shifts, most communities lost fishing revenue. But those with the greatest diversity of fished species, and those that were most able to switch from one group of species to another, had little lost revenue, or even experienced increased revenue. The new research by SAFS graduate student Timothy Cline and Profs Daniel Schindler and Ray Hilborn, appears in Nature Communications.

Animal populations are endangered when they face multiple human-caused pressures at the same time, especially if those pressures interact to worsen depletion. A new study shows that whether pressures interact to worsen overall pressure, or interact to reduce overall pressure, depends on how animal populations behave at low versus high densities. If the number of offspring that survive for each adult drops off slowly as populations increase, this can unexpectedly lead to trouble, since it is more likely that individual pressures will interact to make things worse. The research in Ecology was authored by SAFS PhD student Emma Hodgson, SAFS professor Timothy Essington, and Ben Halpern of UCSB.