Fisheries Vocab

Fishery

The industry or occupation devoted to catching, processing, or selling aquatic animals

Subsistence fishing

Fishing for yourself or family, for food

Regionally specific

Fishing practices that are tailored to local environments and cultures

Commercial fishing

Fishing for trade or money. Fishing for economic purposes

Recreational fishing

Fishing for recreation rather than subsistence. Fish do not necessarily have to be kept (catch and release)

Catch and release fishing

Recreational fishing in which fish are caught and then released rather than kept

Demersal

Living on or near the seafloor

Salt cod

Cod preserved by drying and salting. Also called bacalao

Inlanders

People living 10 miles away from a coast, where historically fish were unable to be transported to

Exclusive Economic Zones

EEZ. 200 mile limits around country land mass where fishing rights are exclusive to that country. It gives coastal nations control over fisheries within 200 nautical miles and encompasses 90% of global fisheries. Reduced conflicts over fishing grounds.

Stock

A group of organisms of the same species that live in the same area and interbreed

Catch

All organisms caught during a fishing or harvesting event, including organisms that may later be discarded at sea

Landings

All organisms brought back to shore

Discards

Organisms that are caught but not landed and are discarded at sea, whether dead or alive

Bycatch

Organisms that are caught unintentionally because they are not the target of the fishery

Artisanal fishers

Mom and pop small scale local/regional fisheries

Food and Agriculture Organization

FAO, an agency of the United Nations (UN) whos goal is to defeat hunger and improve nutrition and food security. They monitor global fish stocks

Underexploited fishery

An underdeveloped or new fishery believed to have significant potential for expansion in total production

Moderately exploited fishery

A fishery exploited with a low level of fishing effort and believed to have some limited potential for expansion in total production

Fully exploited fishery

A fishery operating at or close to an optimal yeild level with no expected room for further expansion. It does not necessarily mean a fishery has collapsed, just that it cant expand and is at optimal yeild.

Overexploited fishery

A fishery exploited at or above a level believed to be sustainable in the long term, with no potential room for further expansion and increased risk of stock depletion or collapse

Depleated fishery

A fishery where catches are well below historical levels regardless of the amout of fishing effort exerted

Recovering fishery

A depleated fishery in which catches are increasing again

Fisheries ecology

A newer field that combines ecological sciences and fisheries sciences

Gross growth efficiency

The amount of prey carbon converted to predator carbon

Trophic transfer efficiency

The ratio of predator efficiency to proportion of prey production taken by predator

Carrying capacity

The maximum amout of organisms an ecosystem is able to support without environmental degradation

Production

Results from growth. The organic material made by an organism

Surface mixing

The mixing of surface layers by tides, currents, upwellings, and winds.

New production

Made during photosynthesis

Regenerated production

Recycling of nutrients in the photic zone

Primary production is quantified as…

The mass of C/area/time

Net primary production

The carbon that remains AFTER respiration

Gross primary production

Total amount of fixed carbon

Marine orgaism primary production

Produce 3-60×10^9 tons of organic carbon annually, about 40% of global production

What are the three basic frameworks for life history strategies?

r-K theory, bet-hedging theory, age-specific models based on optimal reproductive effort

Where does almost all of primary production in the ocena happen?

The first 200 meters of the water column

What is the r-K theory?

If a population is under stable conditions, nearing carrying capacity, with strong intraspecific competition, then natural selection will favor K-selection resulting in delayed reproduction, resulting in higher longevity.

What is r in the r-K theory?

Producing many many offspring, having reduced longevity

What is K in the r-K theory?

Producing fewer offspring, having higher longevity

Bet-hedging theory

Predicts that environmental variability will cause high and variable juvenile mortality. Results in K-selection, unless environmental conditions are stable and juvenile mortality is constant, under which r-selection is favored

What are age specific models?

Specific models based on distinct age classes, that require specific information, and predict r-K selection based on each specific age class.

What does production result from?

Growth

Indeterminant growth

Never really stop growing, just slows way down
Fish and some molluscs

Determinate growth

Grow fast at a young age, then slow down to a stop at a certain age
crustaceans, birds, mammals

What indeterminate growth curve is commonly used?

Bertalanffy growth curve

In a Bertalanffy growth curve, what does L_t represent?

Predicted length at time t

In a Bertalanffy growth curve, what does L∞ represent?

Maximum length predicted

In a Bertalanffy growth curve, what does K represent?

Growth coefficient

In a Bertalanffy growth curve, what does t₀ represent?

Theoretical birth size

What are some ways to measure growth?

Molecular tools, Energetic approaches, Captive studies, Mark and recapture, Length-frequency analysis, Radiocarbon uptake, RNA/DNA analysis, Back calculation

In what oceanic sites/conditions is production expected to be highest?

Upwelling sites

What does upwelling intensity depend on?

Wind strength and seasons

Spatial scales in movement patterns

Individual to population. Patrolling/ranging to migration

Temporal scales in movement patterns

Diel to interannual. ontogenic.

What is the most abundant source of information for movement patterns of fish?

Catch or landing data

In situ monitoring

Direct observation methods such as snorkeling, scuba, ROVs, ect.

Remote sensing

Sonar systems, Lindar, and Telemetry

Lindar

Light detection and ranging systems that shine a beam of light into the water and measure the spectral characteristic and intensity of the light that is reflected back

Telemetry

Satelite and acoustic. Allow remote estimation or calculation of location and possibly other abiotic information

Genetics and natural tags

Uses parasites and trace elements, as they are site specific.

Home ranging

Area a fish uses on a regular bases. Governed by resource availability, predation pressure, and conspecific density

What are the two phases of development

Growth and ontogeny

Growth

Leads to changes in size or abundance of existing features

Ontogeny

Leads to the appearance of new features and reorganization

What is the relationship between survivorship and development?

Survivorship increases as larvae move through each stage of development successfully

What is larval starvation threshold?

The point where larvae are capable of eating on their own and no longer relying on nutrient reserves. They have to eat, or die. Most vulnerable stage.

Ocean stability hypothesis

When the ocean is calm, you get patches of high food concentration, which supports larval survival. Rough waters disperse prey and densities become too low to support larvae. Dense patches are more important thatn evenly distributed prey.

Match-mismatch hypothesis

Interannual variation in larval survivorship would be due to a mismatching in hatching time and peak primary production cycle. Spawning peaks should be juuuuust in front of primary production peaks so there is enough food to sustain everyone. Cycles must be matched up for larvae to find food.

Member-vagrant hypothesis

Physical factors are predominantly stressed rather than biotic. The relationship between spawning time and stable ocean conditions that retain larvae is an important predictor of recruitment.

Where in the ocean do planktonic larvae settle the most

Inside gyres

Bigger is better hypothesis

The faster a larvae grows, the quier mortality rates decrease

What oceanographic features can affect recruitment?

Upwelling, large scale atmospheric events like ENSO and PDO, current patterns, water temperatures,

Compensation

Regulatory mechanism that allows stock to withstand additional fishing mortality and to recover from low spawner abundances

Allee Effect

Lower than expected recruitment at low population levels

Depensation

Caused by reductions in proportional mortality of larvae
If spawning females cannot find mates when stock is too low
If fertilization rates of broadcast spawners are dependent upon sperm concentration

Hyperstability

When catch rates overestimate actual abundance. Main cause of unexpected stock crashes

What drives fluctuations in population size

Processes that affect production and survival of eggs and larvae
growth of mortality during the juvenile and adult stage
behavioral processes such as migration or density dependent habitat use

Demographics

structures of population such as age, fecundity, recruitment, ect

Fecundity

reproductive capacity

Recruitment ecologically

Number of individuals that reach a specific life stage, usually when they metamorphosis from larval stage

Recruitment fisheries

Number of individuals that reach a size where they enter the fishery

What factors affect recruitment

Abundance and distribution of mature adult population (spawning biomass)

Number and viability of eggs produced

Subsequent survival of eggs and larvae

Autocorrelation

Where one thing is dependent on the other and so on so forth. In recruitment relationships, year 2 is dependent on year 1 for example. The more years you have the better.

What are the three spawner-recruit models

Beverton and Holt, Ricker, and Shepherd

What type of recruitment model does this look like?

Beverton and Holt model

In recruitment models, what does R S a b stand for

R= mean recruitment
S= spawner abundance or biomass
a= recruits per unit spawner at low stocks
b= density dependence of relationship

What does the Beverton and Holt model describe

an asymptotic curve with consistently high mean recruitment at high spawner abundance

What does the Ricker model describe

A parabolic shaped curve and is based on increasing density dependent mortality at higher spawner abundance

What type of recruitment model does this look like

Ricker

What describes the Shepherd model

Uses 3 parameters so the curves can be more complex
c= determines shape of the curve

What model does this look like

Shepherd

Ovipary

External eggs and fertilization

Aplacental vivipary

Internal fertilization, live birth with maternal input (matrotrophy)

Oophagy

Mom ovulated eggs which embryos eat in utero

Histotrophy

Glycoprotein secreted by uterine vili (uterine milk)

Adelphophagy

Larger embryos eat the smaller ones

Pseudo-placenta

Umbilicus connection from mom to embryo

What is different about male and female gonad mass by body size?

Males increase linearly, females increase exponentially

What is the relationship between fecundity and body size?

Fecundity (# eggs) increase exponentially with body size