Enviro Sci - Ch. 8.4

A fishery is an industry devoted to _________ fishing, or the places where fish are _______, _________, processed, and sold.

• commercial

• Caught

• Harvested

Why are fisheries so important? What percent of the world population relies on fish as main protein? Around ____ million people are involved in the industry and a revenue of $___ billion.

• humans rely on fish protein

• over 1/3

• 200 million

• 500 billion

A collapsed fishery happens when _______ catches fall too low - below __% of their historic high.

• annual

• 10%

Atlantic Cod:

• __________ fish

• Lives in north ________ waters

• 10-___ metres deep

• ________ species - live close to the sea floor

• Diverse ____ - fish, _______, squid, ____

• Depends on seabed for _____ and ______

• coldwater

• Atlantic

• 200m

• Demersal

• Diet, mussels, crabs

• Food, shelter

For ____ years, Atlantic cod supported an entire culture on the ____ coast of North America. In the 1800’s, upwards of ____ thousand metric tonnes were caught each year. After a peak in 1960’s the cod stock took a _______ ______.

• 400

• East

• 400,000

• dramatic crash

Because of the Atlantic cod crash, in Newfoundland over ___ thousand fisherman and plant workers became unemployed.

• 35,000

The ____ _____ is one of the most degraded areas of cod habitat. It previously supported a rich fishery because of ____ water and ____ water mixing together.

• Grand Banks

• Cold, warm

Due to the Atlantic cod crash, they put _____ in place so that fisherman would not catch too much. This did not work, and the Canadian government had to close the ___ _______.

• quotas

• Cod factory

What causes a fishery to collapse?

• ____________ advances

• Increasing ________ for fish

• ________ of the commons

• Discounting future _____

• technological

• Demand

• Tragedy

• Value

Technological advances:

• ______ engines

• _____ freezing (so it wouldn’t spoil)

• Trawler ships (dragging big ____)

All of these things enabled fishers to travel _____, catch more ____, to meet market demand.

• steam

• Flash

• Nets

• Further, fish

Increased fishing traffic causes more ________ in the waterways. Capturing non-target species can cause _______, which can be up to ___ to ___% of total catch!

• pollution

• bycatch

• 30-70%

Hook & Line methods:

• ____ and line (fishing poles)

• ___-____ (line with thousands of baited short lines)

• _____ (baited lines are pulled behind ship a specific speeds)

• pole and line

• Long-line

• Trolling

Net Methods:

• ______ (entrapping schools of fish)

• _______ (net pulled in open water or along seabed)

• ____ ____ (nets with weights on both sides)

• seines

• trawling

• Gill nets

Trawling is very damaging to ______, _______, and ______ grounds.

• seabed, ecosystems, spawning

The amount of fish that can be harvested with decreasing future yield, is known as?

• maximum sustainable yield (MSY)

Currently roughly ___% of global marine fisheries are ________ fished. The other ___% are _________ and this number has increased.

• 67%, sustainably

• 33%, overexploited

What is an overexploited fishery? What does this lead to?

• a fishery where more fish are harvested that what is sustainable

• Population decline and depleted fishery

What is a depleted fishery?

• when fish population is well below historic levels

• Reproductive capacity is low (slow recovery)

As we are unable to access the cod, we start fishing other things that are in the ___ _____. What do we use to measure the trophic level of fish?

• food chain

• Trophic level index

With the loss of higher-trophic-level species, fishers start pursuing things at _____ tropic levels. This is known as what? This depletes food sources that other _____ are reliant on.

• lower

• Fishing down the food chain

• Species

Protecting fisheries:

• exclusive ______ _____ (this gives any given nation exclusive rights over _____ ________)

• Marine ________ areas (MPAs) (protecting a specific species or its ______)

• marine _______ (absolutely no _______ disturbance is allowed)

• exclusive economic zones

• Marine resources

• Protected

• Habitat

• reserves

• Human

What is one way we can shop for more sustainable fishing products?

• looking for Marine Stewardship Council

Aquaculture is the _______ of aquatic species in tanks, ______, or ocean ___ ____.

• rearing

• Ponds

• Net pens

How much seafood consumed worldwide is produced by aquaculture?

• more than half

Aquaculture:

Problem - Density of organisms leads to high _______

Problem - greater use of _______ and ________

Problem - large amounts of ___ being released

Problem - habitat _________ (eg. Shrimp farms instead of mangrove habitats)

Solutions - decreasing ______, moving farms to be ___-_____, or _______ cages

Problem - fish feed is made from _____ fish

Problem - a lot of feed is needed to raise ____-______ level fish

Problem - escape of non-native or ____ fish

Solutions - feeding fish _______ food sources, raising _____ trophic level fish, raising ______ fish

• disease

• Antibiotics, pesticides

• Waste

• Displacement

• Density, land-based, robotic

• Wild

• High-trophic

• GMO

• Sustainable, lower, native

Indoor aquacultures use what type of system?

• recirculating aquaculture system (RAS)

Operation advantages of RAS:

• system can be _____ as needed

• Can raise any type of marine species, no matter the _______

• Tank conditions are controlled to _____ each species of fish

• sized

• Location

• Suit

Ecological advantages of RAS:

• reduce _____ loss

• System is ________, they can’t escape

• Fish require less food per ________

• Reduces distance between fishery and ________

• habitat

• Biosecure

• Kilogram

• Consumer

RAS uses ______ to produce _______. The bacteria convert about ___% of solid waste into fuel-grade _________.

• waste, energy

• 96%, methane

What is one unique challenge of marine aquacultures?

• most commercially important fish do not reproduce in captivity

• They have to be induced to do so by adding hormones