Fish – Science Articles

As rivers along the Pacific coast get warmer, the survival rate of migrating sockeye salmon will plummet.

Half the culverts placed in creeks of Alberta's boreal forest hang in mid-air, preventing fish from travelling upstream.

One marine animal has quickly taken advantage of the recent rise in northern ocean temperatures.

The size of fish living near the ocean floor along the Pacific coast of the United States has declined dramatically in two decades.

Mercury concentrations are elevated in copper rockfish and quillback rockfish taken near salmon farms along British Columbia's coast.

Many of the larger fish in rivers of the western United States have mercury levels that exceed federal guidelines for safe human food.

Out of the 3072 reported incidents of fish getting loose into a foreign ecosystem, 60% have founded wild populations.

Data now confirm that walleye stocks plummet after rainbow smelt move into a lake.

Salmon

Marine biologists were surprised to find that the numbers of sea lice on juvenile salmon didn't climb when louse-infested wild adults swam by on their way to spawning.

It only takes a few sea lice to kill juvenile pink and chum salmon, and most louse-infested fish die.

A record 34% of pink salmon fry from rivers flowing into Kingcome and Knight Inlets in British Columbia survived at sea and returned to spawn in 2004.

Analyses of several sets of data finds mortality rates of 9 to 95% among various juvenile wild salmon populations as they migrate past salmon farms east of Vancouver Island.

Young chinook salmon fair poorly when competing with large numbers of pink salmon.

It's taken less than thirty years for chinook salmon that were let loose in South America to establish spawning runs along 1500 kilometres of the South Pacific coast.

Endangered Fish Species

Scientists conservatively estimate that well over one-quarter of native Pacific salmon populations spawning in rivers and lakes from California to southern British Columbia have gone extinct.

Lists of regional losses and population extinctions of native salmon in the western United States.

Thirteen species, subspecies and isolated populations of freshwater fish have vanished from Canada.

Non-native fish are already implicated in the extinctions of five fish species in Canada and they threaten the continued existence of many others.

Analysis of bull trout from British Columbia's coastal rivers finds that this species of special conservation concern comprises two genetically distinct groups.

Forecasts indicate that bull trout will become extirpated from many portions of Alberta's Kakwa watershed within the next 20 years.

Big fish have returned to California's southern coast following a 15-year ban on gill net fishing.