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BC

Fish find bad news for the Fraser River

by Grant Scott - Story: 79641
Aug 25, 2012 / 12:00 pm

Fisheries and Oceans Canada (DFO) has issued an Invasive Species Alert after Asian Carp were found in the Fraser River near Lytton and Lillooet in early August.

There are also reports that eight carp were caught between Bridge River and Sawmill Creek during this years aboriginal fishery.

DFO officials are looking into confirming which Asian carp species were turned in, but one witness tells Castanet that one of specimens fisheries received is about two feet long.

The discovery has raised concerns for the ecology of the Fraser River and other waterways in the province.

The DFO reports Asian carp will compete for food with indigenous species and prey on their larvae. They can also cause significant habitat damage and ecological disruption.

Moreover, Asian Silver carp tend to jump out of the water and endanger recreational boaters and water skiers.

For over 30 years, four species of Asian Carp (grass carp, bighead carp, silver carp, and black carp) have been imported alive into Canada for the live fish food markets in urban centres, mainly Vancouver, Toronto and Montreal, or, in the case of grass carp, for control of aquatic vegetation.

Although reporting of live importation is mandatory, compliance is low, meaning DFO can not accurately calculate the total number or weight of live fish imported annually, however, they have determined that grass carp and bighead carp are the dominant species in recent years.

A recent DFO risk assessment concluded that it is 'reasonably certain' to 'very certain' that the ecological consequences of establishment of all four species would be high.

They say mitigation measures are available to reduce the risk posed by live importation of Asian carps, but those measures could result in fewer live carp available to the markets, which might lead sellers to seek other new, and perhaps even more invasive species.

DFO is also reluctant to completely ban the importation of live carp into Canada as this would remove live grass carp as a food product for which there is a substantial market in Canada that began in 1981.

Also, the carp have been introduced as a means of biological control of vegetation in ponds and water gardens.

Again, a ban would lead others to search for other species to do the job, which could also present a risk to Canadian biodiversity.

Ultimately, the DFO says the best approach for protecting Canadian waters from these invaders is to keep them out in the first place, and to do this, everybody's cooperation is essential.

If you suspect you have caught what might be an invasive species, the DFO asks that you do not throw them back in the river.

You're asked to note the location, (with GPS co-ordinates if possible) and then contact Fisheries and Oceans Canada.



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