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. 

The dry northern reaches of Earth contain nearly half of all of the carbon originating in living matter, mostly stored in the frozen soils of the permafrost. It has been long thought that warming in the Arctic will result in this carbon being released from the soil and activated again, through the many lakes that are prominent features of the Arctic. 

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. 

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. 

Scientists trained in ecology and physiology are increasingly able to complement their work with the burgeoning field of “functional genomics”, i.e. the study of which parts of DNA (the “genome”) are actually expressed and used to make proteins under different conditions. A new guide is now provided for those from non-genetic fields to harness the power of fast computers and rapid technology in sequencing the letters in DNA, so that they can infer how animals respond to the environment. 

Reef fish species from waters deeper than 130 m are difficult to collect manually, because they are too deep for SCUBA divers. But now manned submersibles equipped with underwater vacuums are able to suck up new specimens with surprising alacrity. Among the specimens slurped up by one such submersible is brand new blue and gold species of basslet: the blue-backed basslet (Lipogramma adabeli), with distinct blue coloration, genetics, and habitat use distinguishing it from other similar species. 

The Columbia River used to host returns of nearly 9 million salmon every year, led by the largest returns in the world of Chinook salmon (4.4 million fish). But construction of multiple large dams on various tributaries and the Columbia River itself, eliminated salmon from vast tracts of rivers above impassable dams, and also had a serious effect on salmon survival in the remaining areas. 

This winter, Greg Jensen is releasing his follow-up book, Beneath Pacific Tides: Subtidal Invertebrates of the West Coast. Like the charismatic crustaceans featured in his debut publication, the colorful and bizarre invertebrates found along the Pacific Coast are explored in this new user-friendly guide, featuring Jensen’s underwater photography.

Male Pacific salmon usually compete aggressively with each other to gain access to spawning females, and are most successful when they are old and large. But a few males come back from the ocean early and small, and with less noticeable male traits. These small males are called “jacks” and cannot win battles of aggression but instead compete by sneaking into the spawning arena and fertilizing eggs on the sly. 

Genetic engineering is widely used in plants and animals to promote rapid growth and create resistance to common diseases. One genetic modification that has achieved prominence in fish is the insertion of growth hormone transgenes, which produce dramatically larger sizes and rapid growth rates. However, there is concern that escaped genetically modified fish might breed with their wild counterparts, passing on the genetic modification and changing the wild population.