Flashcards in Fisheries and conservation - part 1 Deck (55)
Where is most of the money spent regarding fish?
Conservation or research
Terrestrial ecosystems starting getting negatively impacted after the _______ ______.
There used to be no negative impacts on fisheries up until the last ___ years or so where we got more _______ at ________ fish.
What is the FAO?
Food and Agriculture organization of the UN
How is the FAO pertinent to fish?
FAO is a group of the UN whose job it is to track all the food uses around the world.
A special fisheries section publishes the state of the worlds fisheries.
Currently, according to the FAO, we are _______ our harvest of fishes worldwide.
Total harvest is ______.
Capture is _________.
Aquaculture is _______.
_________ is more important now in feeding the world population.
The FAO is completely ________ and thus they cannot impose fines.
The stuff they publish is based on ____-______ from different countries and thus is an ___________ at best.
_______ numbers are often underreported to avoid bad publicity.
What are the main fishing areas based on current data?
1 - NW Pacific
2 - Central Pacific
3 - Northeast Pacific
4 - Indian Ocean
For the fishing areas including __________, ________ and ________, one reason for them being so good of a fishing spot is due to what?
NW Pacific, Central pacific, northeast pacific
One reason is due to coldwater which tends to drive productivity,
Related to upwelling events.
What is upwelling?
This is when warm water is replaced by deeper, colder water with nutriens which rises to the surface.
Many productive fisheries are ________ zones.
In the Pacific, that upwelling is caused by _____ _____ which blow from the _____ to the _____.
right to left
In the Northern pacific, upwelling is due to patterns of _____ ______ but the result is the same.
Why is the Indian Ocean a productive fishery then?
Does get some upwelling from Antarctic currents.
One reason for it being a hotspot is because other areas have been fished out.
The Indian Ocean is a productive fishery currently but will probably not last because?
It has less upwelling
Describe the Northwest Atlantic fishery.
Canada used to sit on it
Historically one of the most productive zones
Collapsed, fished out.
Describe the Mediterranean fishery
Used to be hugely productive.
Small and warm-ish but had lots of new water come in.
Has seriously been crashing in the last couple of years.
No longer productive due to overfishing and pollution.
What is an economic exclusion zone?
Each country has its own EEZ in which they can set regulations on who can fish, how many fish can be caught and what gear can be used.
Extends from coast line to 200 miles off shore generally.
What is one issue with EEZs?
Outside the zones, its lawless.
- Fishing companies can bribe smaller countries
- dont have to declare catches offshore
Sometimes EEZs conflict and can be a major source of international tension.
According to the latest data, what is being caught the most?
Most common fish is Alaskan Pollock.
Second most common is Anchovida.
Anchovida is usually the most common, why wasnt it this year?
Partly due to overfishing but mainly due to El Nino.
Most Anchovida is caught off the coast of Peru but, during El Nino, trade winds die off reducing upwelling events and causing population crashes.
Describe the largehead hairtail.
Relatively new fish that is deep living and starting to be caught more and more globally.
Issue is that we know nothing of its life history traits.
Describe the common practice of fisheries once a certain species is "fished out".
Fisheries start to catch less desirable fish over the common ones.
Start exploiting deeper living species.
However, the issue is we know nothing of their population sizes, how sustainable they are or on life history traits.
What are the different uses of fish?
Food - fresh or frozen
- feeding livestock
What is the majority of fish used for?
Fish can be used for straight up cash, what type of countries would do this?
Major exploit in developing countries.
What is the reason that Canada support fish research?
We are a major exporter of fish globally. Huge source of jobs.
Sometimes, it is easy to scientifically determine how many fish to keep constant catch rates but, ________ pressures trump this.
Canada remains a major exporter of fish. ________ export in millions of tonnes from 2000 to 2010.
Most fish are _______.
Officially, ________ is defined as catching more fish than they can be naturally replaced.
When catchrates exceeds natural replacement rates.
Over __% of fisheries are fully exploited. About __% are recovering from overfishing.
What are the 3 population characteristics that make it more likely to be overfished?
Relatively few offspring each time they spawn
Is the Great White susceptible to overfishing?
Grow slowly, late maturity (babies at age 10) and have few offspring.
Slow replacement rate!
Describe a fish species that should be exploited.
Fast growing fish
Mature within a year
Have lots of offspring
Of the 129 species of fish in Lake Huron, ___ are extirpated or imperiled.
What is/are the causes of this?
- Habitat degradation
- Invasive species
What are the causes for extirpation in lake Huron?
One study predicted the collapse of global fisheries by ______.
What is a fishery collapse?
Means the fishery no longer has enough fish to be viable commercially. There are still fish there bu they aren't worth the company's money.
When there is ____ species richness, there is a _____ likelihood of fishery collapse.
Describe how increasing the number of species caught can lead to a stable fishery.
By increasing the number of species that are considered viable, this takes pressure off of some of the commonly fished species.
The same tonnage can be caught but there will be more variety, increasing the likelihood of rebound in fish populations.
Competing demands drive fisheries management.
What is the goal?
What is easier to sell to voters?
The goal is to fish at MMSY - multiple species maximum sustainable yield.
What is easier to sell to voters?
- Maintaining high employment
What are the competing demands that drive fisheries?
1 - Maintaining biodiversity
2 - Maintaining high catches
3 - Maintaining high employment
How do the competing demands conflict?
What is the best solution?
Politicians want high employment which means that they want a high catch rate initially but, that will lead to a decline.
If maintaining biodiversity is the goal, thats fine but it will have a negative economic impact in most cases.
Aim for MMSY.
Highest possible sustainable exploitation rate.
Government regulators aim for a high catch rate in a sustainable way to prevent overfishing.
MMSY is generally what percentage of exploitation rate?
What occurs as exploitation rate is increased?
Number of collapsed species increases.
What occurs when fishing rates increases?
total biomass caught tends to decrease
As overfishing is approached, what happens to the size of fish?
Mean length, max size all decrase.
See a decrease in size of fish.
As overfishing is approached, what exarcerbates the problem?
As overfishing begins to become more and more of a problem, the fish caught become smaller and smaller and have not reached reproductive age, furthering the issue.
Globally, what is the trend leaning towards for the competing demands?