Fishery Management

transcript

Fishery Management

• Fishing is extractive

– Removes choices organisms - “fine-ing”

– Changes food web structure

• The human condition provides little

incentive to maintain “sustainable

stocks”

• Need way to control ourselves…

Fisheries by Their Nature are Extractive; They Alter the Natural Environment

anthropogeniceffect

no fish no fishing

Maximum SustainableYield (MSY)

The objective of fisheries management is

to achieve a high level of sustainable yield

Under exploitation, natural populationsdecline in abundance to a new

equilibrium

no fish no fishing

Maximum SustainableYield (MSY)

The objective of fisheries management is

to achieve a high level of sustainable yield

A Bioeconomic MSY

• Considering costs lowers sustainable yields

• MEY < MSY

Fish Management

• Objectives are to maintain sustainable

maximum yields (or revenues)

• Harvest costs are sometimes considered (especially related to new regulation)

• Conservation is not (often) considered

• Nor are food webs (management is single species)

• Hard part is to figure out the proper harvest

effort that produces a MSY

The Magnuson-Stevens Fishery Conservation The Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) as Amended and Management Act (MSFCMA) as Amended

in 1996in 1996

“The policy of the Congress in this Act is to assure thatthe national fishery conservation and management

program utilizes, and is based upon, the best availablescientific information…”

16 U.S.C. 1801 M-S Act, Section 2, 101-627, 104-297

Recent Developments

• The Magnuson-Stevens Fishery Conservation and Management Act of 1976 was re-authorized by Congress in 1996 and was implemented nationally in 1997. Reauthorized this year.

• 2003 legislation requires Fishery Management Councils nationwide to establish biomass-based targets and thresholds for all actively managed stocks

Recent Developments

• On January 12, 2007, President Bush signed the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006.

• Mandates the use of annual catch limits & accountability measures to end overfishing

• Provides for market-based fishery management through limited access, bycatch restrictions, improved role of science & calls for increased international cooperation.

• http://www.nmfs.noaa.gov/msa2007/

What is the Pacific Fishery Management Council?

• Responsible for California, Oregon, and Washington EEZ waters (FEDERAL!!)

• Established with implementation of original MSFCMA of 1976

• Draft Fishery Management Plans including salmon, highly migratory, groundfish, and coastal pelagics.

• Nearshore species - State F&G

• All regulations are ultimately approved by National Marine Fisheries Service (NMFS)

PFMC Region

Who & Where of Fishery Management

State waters < 3 nmiFed waters > 3 but < 200 nmi (EEZ)

Final Network of MPAs, Oct 2007

Complete Marine Protected Area Network For the Channel Islands National Marine Sanctuary

StockAssessment

AllowableBiological

Catch (ABC)

HarvestPolicy

ExploitableBiomass

PromulgateRegulations

Socioeconomic,Allocation, andOther Issues

Optimum Yield (OY)OY < ABC

Pacific Fishery Management CouncilStock

AssessmentTeam

What is the process for What is the process for regulatingregulating

fishery harvests at the PFMC?fishery harvests at the PFMC?

“Wall ofScience”

This is now a three meeting

process, with a five month notice

and commentperiod, to be

conducted onceevery 2 years!!

sciencereview

Process must be transparent for all parties

Stock assessments form the basisStock assessments form the basisof all fishery managementof all fishery management

Stock Assessment(statistical model)

Landings by Gear Type 1. commercial 2. recreational

Fishery IndependentSurveys (shelf & slopetrawl surveys, etc.)

Age/Length Compositions 1. commercial 2. recreational

Life History Information growth, maturity, etc.

Fishery DependentInformation (logbookdata, discards, etc.)

Biomass and Recruitment

Science Review Harvest Policy

Allowable Biological Catch (ABC) Optimum Yield (OY)

Fish Management

• Instruments for setting Optimum Yield

Harvest quotas, trip limits, limited entry,

seasons, taxes on landings, ITQ’s, MPA’s, …

• Each has advantages

• Each requires knowledge of “excess”

fishery production

Fish Recruitment

• Recruits are fish at harvestable age/size

Reproductive

Adults

Juveniles

Eggs/Larvae

Immature Adults

HarvestableSize/Age

Recruitment

Curvature in the spawner-recruitcurve controls fishery productivity

Some Real “Data”

“Noise” makes “steepness” difficult

to measure

Fishery Management Plan for Pacific Sardine

• FMP needed to regulate all fisheries

• Gives the Allowable Biological Catch

• Components include:

stock biomass, recruitment, egg production,

size/age structure, spatial extent, SST, …

• Fishery dependent & independent data

• A coastal species that forms large schools

• Feed on zooplankton & large phytoplankton

• Oviparous, with pelagic eggs, and pelagic larvae

• Matures in ~2 years & Can live up to 25 years

• Population doubling time 1.4 to 4.4 years

• Up to 16” long (mature at ~9”)

• Northward migrations early in summer & south

in autumn

Chavez

• FMP needed to regulate all fisheries

• Gives the Allowable Biological Catch

• Fishery dependent & independent data

Pacific Sardine Egg Production

Relative abundance of sardine eggs in CalCoFI larval

Spawning Biomass from Egg Obs

Sardine Stock Area from Surveys

Abundance of Pre-Adults

Scripps Pier SST

Biomass of >1y Sardines

• These data were

used with an age-

structured stock

assessment model

to predict stock

biomass &

recruitment

Recruitment of Sardines

• These data were

used with an age-

structured stock

assessment model

to predict stock

biomass &

recruitment

Harvest Policy for Pacific Sardines

• U.S. harvest guideline for 2003

• Harvest = (TOTAL_STOCK_BIOMASS - CUTOFF) *

FRACTION * US_DISTRIBUTION

• CUTOFF = minimal allowable biomass with

harvest

• FRACTION = 5 to 15% depends on SST (f(PP)!!!)

• US_DISTRIBUTION = fraction total harvest in U.S.

Biomass of >1y Sardines

Pacific Sardine Quotas & Landings

Pacific Sardine Landings

• Harvest guidelines require estimates of

stock biomass & recruitment

• Fishery dependent & independent data are

Fishery Management

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