English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The Columbia River in the Pacific Northwest has been the site of the world’s most expensive effort in ecological management and restoration. Primarily using revenues from the hydroelectric system, roughly $400 million have been spent annually on the fish and wildlife program in the Columbia Basin, most of it on salmon. Much of this funding goes to operate hatcheries and modify the operation of dams, but also to a research program that, over the last four decades, has funded thousands of scientists and supported a number of technical advances, including three tagging techniques that have revolutionized our ability to understand the freshwater and marine life of salmon. One of these techniques is the use of acoustic tags on juvenile salmon. In PNAS, the article by Rechisky et al. (1) reports how these acoustic tags are used to measure survival of juvenile salmon in their early ocean life. The tags are implanted in thousands of juvenile salmon and arrays of acoustic listening devices detect their passage down the Columbia River and their northward ocean migration. Before the development of acoustic tags, the ocean was essentially a black box. Using earlier tagging techniques, individual fish were marked and nothing was known of them until they returned from the ocean, when the small stainless steel tags, known as coded wire tags, were either seen by physical inspection for a missing adipose fin, or passively interrogated tags were electronically detected at a range of a meter or two as the fish pass up fish ladders. The ocean distribution of fish could be inferred when coded wire tag-marked fish were caught, but the timing and location of ocean mortality remained unknown. The decline of Columbia River salmon is a well-documented story of the conflict between industrial-scale human activity and wild resources (2). A combination of …

Ocean and dam influences on salmon survival