Ecology in Fisheries

Minimum Size Limit

Prevents fishing of young individuals by making a limit as to the smallest fish you can catch

Challenges with Minimum Size Limits

Not effective for species that have poor survivorship (damaged when caught), Will not support reproduction if set below size at maturity

Maximum size limit

Limits the maximum size of fish you can catch in order to preserve older individuals who have more reproductive potential

Challenges for Maximum Size Limits

Needs to be set low enough for fish to reach safety, not effective for species that have poor survivorship, need to ensure that senescence is not an issue, need to ensure competition is not an issue

Prohibition on harvesting particular individuals

Prevents fishing of certain species/individuals to protect population size and ability to reproduce (Female Lobsters to protect reproductive capacity)

Challenges of Prohibitions on Harvesting Particular Individuals

Can cause a skewed sex ratio, not effective for species with poor survivorship

Gear Restrictions

Limits on the type of fishing and gear that can be used in a specific area

Challenges with Gear Restrictions

Narrowing down the specific gear that can and cannot be used, susceptible to effort creep, could restrictions have negative effects (preventing scuba equipment makes people less careful), economic efficiency, enforcement

Temporal closures

The temporary closure of a fishery preventing fishing activities

Challenges with temporal closures

Unlikely to reduce fishing effort unless paired with other tools, could shift fishing effort to other areas, how do you line up closures with multiple species

Spatial closure

Closure of a certain area or region from fishing activities

Challenges with spatial closures

Not effective for highly migratory species, determining where boundaries are placed, fishery displacement, removes access, enforcement

Licensing/Permitting Quota Systems

The designated quantity of a certain species that can be caught. Based on maximum sustainable yield, Split between commercial and recreational fishing

Is an ecosystem approach or a single species approach better

Whole ecosystem approach

What provisions does New Zealand have for protecting essential habitat

No provisions except benthic protection areas