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421 posts in Research

How many beluga whales are there in that school? A new method.

Smaller species of swimming marine mammals are often hard to count because they might be present in ones or twos or in groups of hundreds of individuals. Typical survey methods face multiple types of bias when trying to count total numbers because some individuals are missed. For aerial surveys, this is particularly problematic: individuals in a school can be missed because they are diving, too close to other individuals to be seen, or too far away to be detected in photographs or videos. 

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Sea otters diversify their diets as their numbers grow

Due to hunting, sea otters were extirpated from most of their former range, including all of Washington state. In 1969 and 1970 a small group of 59 sea otters from Amchitka Island, Alaska, were reintroduced to the outer coast of Washington state, where they have since flourished to more than 2000 individuals. As their numbers have increased, they have expanded along the coast, resulting in a patchwork of locations containing sea otters that have been present in each location for differing lengths of time and at a range of densities. 

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Protected by Prawns

In rural communities across the tropics, a parasitic disease called schistosomiasis that is carried by freshwater snails currently infects more than 220 million people, rivaling malaria in its prevalence. Capable of residing in an infected human for more than 30 years, the Schistosoma parasite can cause debilitating and often-fatal health complications, including liver failure, bladder cancer, and an increased risk of AIDS. An estimated 280,000 people in Africa alone die each year from the disease. Despite 50 years of medical intervention and the availability of a relatively inexpensive and effective drug, the disease has stubbornly resisted eradication efforts, largely due to the ease with which the parasite reinfects its human hosts.

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The Ocean Modeling Forum presents Pacific herring research in Haida Gwaii, British Columbia

The Ocean Modeling Forum (OMF) is a University of Washington program run through the School of Aquatic and Fishery Sciences that aims to bring together interdisciplinary scientists, modeling experts, decision makers, and other people invested in ocean resources. The OMF helps managers frame questions, understand the strengths and limitations of different models, and learn how to incorporate models in their work. 

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Testing the impact of dam passage on homing success in salmon

Snake River salmonids are federally protected, but face a succession of dams to navigate from the ocean to the spawning grounds. The final dam in the sequence is the Lower Granite Dam. Ascending salmonids (sockeye salmon, steelhead, and Chinook salmon) all enter the fish ladders on the side of the dam, but some pass straight through and exit above the dam, while others are shunted off to one side and either released after a longer pathway, or held in tanks and sampled before being released to continue up the fish ladders. 

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Wisdom of Crowds: A Conversation with Andrew Berdahl

School of salmon staging at mouth of Sam Creek.

In 1906 while attending a livestock fair in Plymouth England, Sir Francis Galton witnessed an interesting contest where locals were trying to guess the correct weight of a slaughtered and dressed ox (think jellybeans in a jar, but for butchers). He examined all 800 guesses and calculated the median calling it the vox populi, or “voice of the people,” reasoning that this would cancel out outliers on either side of the true answer. Astonishingly, the median guess was extremely close–within .8%–of the weight measured by the judges and closer than any individual guess. “This started the idea of the wisdom of crowds, where if you have a whole bunch of independent guesses you can average them, cast off the errant guess on either side and hone in on the right answer,” said Dr. Andrew Berdahl one of the University of Washington School of Aquatic and Fishery Sciences’ newest faculty members.

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Shifting newspaper headlines on what makes for a ginormous fish

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Shifting baselines is the concept that each human generation thinks “normal” conditions are those when they were growing up, and therefore only takes into account declines during their lifetime, instead of over multiple generations. A new paper now examines newspaper headlines over time to see whether declining fish size is detectable in fish described as superlatively enormous (e.g. “giant”, “huge”, or “monster”), finding declines in reports of lengths. 

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Helping bird science while walking along the beach: lessons from 17 years of the COASST project

Citizen science, where the nonexpert public joins in freely to produce useful science, has grown to more than 2100 projects on the SciStarter website alone. These projects range from online identification of astronomical objects, to gaming-like projects predicting how proteins will fold (Foldit), to seasonal bird counts. One long-running project is COASST (Coastal Observation and Seabird Survey Team) where members of the public conduct monthly surveys of beach areas from California to Alaska looking for bird carcasses. 

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Variability in body growth is an important part of variability in fish populations

It has long been established, indeed it is almost axiomatic, that annual variability in births of new fish (“recruitment”) is the most important reason why the total mass of fish populations varies from year to year. The rate of which individual fish grow (“body growth”) is also known to vary from year to year, but is generally considered to be fairly unimportant in explaining population variability. 

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