Chinook salmon (king salmon) are the most prized salmon in the Pacific because of their large size. But now an analysis shows that the oldest Chinook salmon are disappearing, and their size is also declining, and these patterns are seen from California to western Alaska and in both wild and hatchery Chinook salmon. The research by SAFS researchers Jan Ohlberger and Daniel Schindler, and their coauthors Eric Ward and Bert Lewis, appears in the journal Fish and Fisheries, and was highlighted in UW News. 

By Ben Miller, SAFS student
When you first arrive at the community of Kampong Phluk, your neck cranes up bamboo stilts to meet the chatter of families in houses high above. From the top of what guidebooks call “bamboo skyscrapers,” locals gaze over the tops of submerged trees, a glittering, island Buddhist temple, and clusters of floating fishing villages in the distance. 

The Bevan Series is the premier seminar series at SAFS, bringing 10 speakers each year from around the globe to discuss, debate, and challenge our community to listen to different perspectives. This year, the associated undergraduate class has been writing a series of blogs, one for each speaker. In the most recent post, undergraduates Carter Johnson, Ethan Seay, and Max Urbanek highlight for Valentine’s Day the relationship tips needed for science and policy. 

SAFS Professor Chelsea Wood was awarded a Sloan Fellowship, awarded to early-career researchers in recognition of distinguished performance and a unique potential to make substantial contributions to their field. Prof. Wood is a prolific researcher who uses parasites and pathogens (both human and fish-based) to uncover fundamental ecological truths about the natural world. She will receive $65,000 to further her research initiatives, which includes using museum fish specimens as “parasite time capsules”, as reported in UW News. 

Salmon are capable of using the Earth’s magnetic field as a part of their built-in navigating skills to home back to their streams of birth. Now it has been discovered that young salmon emerging from the gravel also use the Earth’s magnetic field to figure out which way is up. Salmon eggs are laid in gravel nests, and the young salmon remain in the gravel until all of the attached yolk reserves are finished, then they emerge to live out in the open water. 

Satellite tracking devices on beluga whales in the Arctic show how they reacted to far lower sea ice concentrations in recent years. Instead of shifting where they feed, as might have been expected, beluga whales continued to feed in similar (but now largely ice-free) places. However, where dive data were available, their dives were significantly longer and deeper than in years with higher ice concentrations. 

Combining data from glaciers with tracking devices on narwhals, reveals that these elusive marine mammals prefer glaciers that calve infrequently over active calving glaciers. The research, to be presented by SAFS professor Kristin Laidre at the Ocean Sciences Meeting next week, shows narwhals congregating at the outlets of serene glaciers in Greenland’s Melville Bay. Prof. Laidre speculates that the cold fresh water melting off the glacier may stun fish, making them easy prey for the hunting narwhals, while active glaciers produce more silt-filled waters that are harder to hunt in. 

The intent of ecosystem-based fisheries management is to move beyond managing each species separately, and to also consider interactions with other species and ecosystem functioning, as well as human benefits such as food, revenue and recreation. A new paper shows that, in practice, people have very different opinions about which management actions could be classed as ecosystem-based. Furthermore, it is highly unlikely that any particular fishery would be able to meet all of the items on a checklist of possible ecosystem-based actions. 

Nearly all fisheries management is based on assessing one species at a time, ignoring any interactions with other species. Many have claimed that including these interactions will improve management and lead to greater fisheries profits. A new paper tests whether precise information on species interactions improves economic performance in fisheries. Somewhat reassuringly, economic value was not markedly lower if managers assumed that an incorrect type of interaction was true. 

Millions of tons of plastics enter the ocean each year, and many of these end up entangling on coral reefs. Microbes that live on the plastic can then cause coral diseases. A new study appearing in Science today examined more than 100,000 individual corals, finding that only 4% of corals have disease when they are plastic free, but a staggering 89% of corals that are in contact with plastics are diseased.