Sentences with phrase «on juvenile salmon»

Based on the numbers of lice on juvenile salmon in 2015, researchers predicted an additional 9 — 39 per cent decline in returning pink salmon due to the outbreak.

Not exact matches

A biologist from the National Oceanic and Atmospheric Administration is working on a project to tag juvenile chinook salmon at Big Creek with microchips that are scanned like supermarket bar codes when the little fish pass detectors in the stream.

Because juvenile salmon, or smolt, leave their freshwater spawning grounds to spend an average of two to three years maturing at sea, the boom in 2001 was right on schedule.

Most salmon species feed heavily on copepods and euphausiids during their juvenile and adult life stages.

While juvenile coho salmon feed directly on spawning pink and chum salmon carcasses and eggs, even coho with no direct contact with spawning pink and chum benefit from their nutrient contributions to stream ecosystems.

Newly published research co-authored by scientists at Simon Fraser University and the Raincoast Conservation Foundation shows juvenile coho salmon benefit from dining on the distant remains of their spawning pink and chum cousins.

The sea lice spread to migrating juvenile wild salmon, resulting in the highest numbers of sea lice observed on wild salmon in a decade.

«Furthermore, during the juvenile wild salmon migration, farms are supposed to treat for sea lice within 15 days of when a threshold number of lice are found on adult farmed salmon,» says Peacock.

«These results are consistent with the idea that juvenile salmon imprint on (i.e. learn and remember) the magnetic signature of their home river, and then seek that same magnetic signature during their spawning migration,» said Nathan Putman, a post-doctoral researcher at Oregon State University and the lead author of the study.

Humpback whales feed on hatchery - released juvenile salmon.

On an adult fish this may be only a nuisance, but for small juvenile salmon (around the size of a finger), sea lice can be fatal.

For example, reductions in seasonal sea ice cover and higher surface temperatures may open up new habitat in polar regions for some important fish species, such as cod, herring, and pollock.128 However, continued presence of cold bottom - water temperatures on the Alaskan continental shelf could limit northward migration into the northern Bering Sea and Chukchi Sea off northwestern Alaska.129, 130 In addition, warming may cause reductions in the abundance of some species, such as pollock, in their current ranges in the Bering Sea131and reduce the health of juvenile sockeye salmon, potentially resulting in decreased overwinter survival.132 If ocean warming continues, it is unlikely that current fishing pressure on pollock can be sustained.133 Higher temperatures are also likely to increase the frequency of early Chinook salmon migrations, making management of the fishery by multiple user groups more challenging.134