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Fish Conservation and Management

CONS 486

Aquaculture IssuesFeeding the world, but at what cost?

Chapter 8 Ross

Major theme: Linking science to conservation & management

• Harvest regulations

• Managing fisheries & habitats

• Protecting populations & habitats

• Restoring populations & habitats

• Fisheries exploitation data

• Applied life history data

• Human dimensions: socio-economic data

• Physiology

• Behaviour

• Population ecology

• Ecosystem ecology

• Habitat data (limnology, oceanography)

• Life historyBasic science

Applied science

ManagementConservation

Fish production

1. Aquaculture: goal to produce and consume

2. Hatcheries: goal to produce and release

Aquaculture: Background• Aquaculture: growing of aquatic animals & plants

• Began 1000s of years ago!

– Rearing fish in freshwater ponds in Asia and Europe

– Over time: providing food, modifying habitats & fish communities to enhance productivity

• Recent decades, shift towards more controlled environments

– Closed systems: recirculating indoor or outdoor pools/tanks for rearing and development (typically on land)

– Open systems: net pens or other containment structures in open water, ranching

• Less control over abiotic conditions but cost effective

Aquaculture: Types

FAO

Annual revenue: $838.4 million (2011) - Mostly finfish sales

Statistics Canada

Aquaculture production in Canada

Statistics Canada

Aquaculture production in Canada

Statistics Canada

Aquaculture production in Canada

Aquaculture production in Canada

B.C. AQUACULTURE SPECIES

Finfish Shellfish Plant

Atlantic SalmonChinook SalmonCoho SalmonSturgeonRainbow TroutTilapiaSablefish

Pacific OystersManila ClamsVarnish/Savory ClamsBlue MusselsMediterranean MusselsJapanese Scallops

Seaweed

Sablefish

Atlantic salmon

Tilapia Japanese scallop aquaculture

Salmon farming accounted for $653M in Canada in 2009

Atlantic salmon aquaculture

Sea Louse Infection of Juvenile Sockeye Salmon inRelation to Marine Salmon Farms on Canada’s West

Coast

• Rapid growth of marine salmon farms over the past two decades has increased host abundance for natural pathogenic sea lice and other pathogens in coastal waters

– Wild juvenile salmon swimming past farms are frequently infected with lice.

• Downstream boundary encircles all sockeye collection sites situated downstream of at least one salmon farm given the direction of prevailing oceanic flow and migration direction

• All other collection sites are considered upstream

• In 2007 lice abundances on juvenile sockeye in the salmon farm region were substantially higher downstream of farms (maximum infection intensity highest 28 lice per fish) compared to upstream sites (16 lice per fish)

• Demonstrates potential role of salmon farms in sea lice transmission to juvenile sockeye salmon during their critical early marine migration

– Is this a concern for wild salmon stocks?

– Is swim performance affected ? (maybe)

– Is survival of smolts affected? (hard to know)

– Lice mature in < 2 weeks and fall off host

– Studies to date incomplete

– Bigger concerns are likely the viruses that could be spread between cultured and wild (and vice versa)

– Cohen Commission recognized this and recommended more research before expanding seapen aquaculture.

Nendick et al 2011 CJFAS

Another approach - closed, recirculating land-based systems- Less risk to environment but much more costly to operate

Swift Aquaculture in Agassiz, B.C. uses strictly land based infrastructure to culture coho salmon

Vancouver Sun