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71 posts in Research

New tool for the safe passage of fish through hydroelectric dams

More than 80% of the world’s renewable electricity comes from hydropower generated from dams, but these dams impede upriver passage of fish, and potentially damage fish migrating downstream that pass through turbines or over slipways. A new toolset has now been developed that can better estimate injury and death rates from fish passing downstream, using the data from artificial “sensor fish” that mimic the passage of fish through turbines and slipways while collecting high-resolution data. 

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Timing of sea-ice retreat affects where birds are found

The Bering Sea has highly variable sea ice extent in winter, which can be used to tease out the effects of future climate change on marine animals such as seabirds. In a new study, SAFS professor George Hunt and coauthors examined how seabirds change location in years when sea ice melts earlier in the year. In these years, seabirds that feed far from land tend to come closer inshore, while seabirds that feed closer to shore move further offshore. 

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Massive death wave of sea birds was caused by a marine heat wave

A marine heat wave called The Warm Blob parked itself over the North Pacific Ocean in 2014-15, and has now been determined to be responsible for an unusually large mass mortality of Cassin’s Auklets. Volunteers involved in three citizen science projects (COASST, BeachWatch, BeachCOMBERS) scour beaches from California to British Columbia, and reported thousands of dead Cassin’s Auklets at the same time that the Blob was present. 

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Better measures of citizen science

Science can often benefit from broad participation in data collection by the public. For example, people recording their bird sightings in the eBird app has led to multiple scientific papers. Now a new paper provides valuable advice on how to set up and run such citizen science projects, including how to start a citizen science project, how to better collect data, and how to measure the impact of such projects. 

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Moving from single-species management to ecosystem management

Ecosystem-based fisheries management (EBFM) has become popular in recent years, but there is broad debate about what it means and how to implement it. At its simplest level, EBFM involves improving fisheries management by moving beyond management designed for single species, towards considering interactions that are important for entire ecosystems. Part if the reason this is difficult, says a new paper, is that perceptions of what counts as EBFM differ among stock assessment scientists, conservationists, ecologists, and managers. 

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Combining trawl and acoustic surveys to assess the status of the largest U.S. fishery

Many species of fish spend some of the time on the ocean bottom, and some of their time far off the bottom, which makes them hard to survey. Acoustic surveys (that bounce sound off fish schools), can estimate the midwater component of so-called “semipelagic” fish, while trawl surveys can measure the portion on the bottom. Now a new method has been developed that combines data from both types of surveys into a single estimate using information about the environment (bottom light, temperature, sand type, and fish size). 

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A whole new ocean zone is needed for these fish species

Scientists currently classify groups of reef species by the depths at which they occur, with the so-called “mesophotic” species living at depths of 40-150 meters. Now, though, new data suggests that an additional depth zone is needed for reef species living in the coral reef twilight zone, to be called the “rariphotic” zone, covering the depths of 130-310 meters (400-1000 ft). 

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Stunning footage of bizarre mating anglerfish with glowing cat’s-whiskers fin rays

In a world’s first, a mating pair of anglerfish is observed in the wild, evoking awe in SAFS professor Ted Pietsch, who comments in UW Today on the video footage by researchers Kirsten and Joachim Jakobsen aboard a submersible run by the Rebikoff-Nigeler Foundation. Only 14 females (and no males) of this species have ever been recorded, all collected in jars and none observed alive in the ocean. 

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Why do some species associate together? Habitat is the key, not randomness

The species found in a particular place (“species assemblages”) differ from those found in other places, and figuring out why this is so has occupied the minds of ecologists since the mid-20th century. Currently two theories dominate: the niche theory, and the neutral theory. The niche theory holds that species assemblages result from species migrating into a particular place, and then either thriving or leaving based on how good of a match they are to the habitat and other living organisms (the “niche”) in that place. 

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To reduce human infections, control the snails

Schistosomiasis (also known as billharzia) is a parasitic flatworm that infects a quarter of a billion people worldwide, mostly in tropical countries. If left untreated, it causes chronic pain and diseases of the liver and kidney, and kills up to 200,000 people annually. In recent years, control of the disease has focused on mass-treating humans with a drug called praziquantel, instead of reducing the prevalence of snails that are a required part of the parasite’s life cycle. 

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