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Natural History of Sharks, Skates, and Rays Conservation & Management MARE 380 Dr. Turner. Fisheries Management. Involves regulating when, where, how, and how much people fish to ensure that people will be able to fish in the future
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Natural History of Sharks, Skates, and Rays Conservation & Management MARE 380 Dr. Turner
Fisheries Management Involves regulating when, where, how, and how much people fish to ensure that people will be able to fish in the future NOAA's National Marine Fisheries Service (also known as NMFS or NOAA Fisheries Service) is the Federal Government agency responsible for fisheries management in the United States
You Down With EEZ Law Of the Sea – established 200-mile-wide Exclusive Economic Zones (EEZ) – granting coastal nations exclusive rights with respect to natural resources
US EEZ Waters 3 to 200 miles offshore (or 9 to 200 miles offshore in western Florida and Texas)
US EEZ International shortages and disputes over fishing rights were solved the establishment of the Exclusive Economic Zone (EEZ), a 200-mile national fishing zone Actually led to overfishing by U.S. domestic fishing fleets
Fisheries Management Federal fisheries management in the United States is driven primarily by the Magnuson-Stevens Fishery Conservation and Management Act (MSA) - 1976 Set up a democratic form of fisheries management in which stakeholders of fisheries resources held important roles in their overall management
Magnuson-Stevens Governs the conservation and management of ocean fishing Establishes exclusive U.S. management authority over all fishing within the EEZ Foreign fishing within these areas prohibited unless permitted - only with reciprocity to U.S. fishing vessels Establishes 8 Regional Fishery Management Councils responsible for management plans
Magnuson-Stevens National Standards of the Magnuson-Stevens Act Conservation and management measures shall: (1) Prevent overfishing while achieving optimum yield (2) Be based upon the best scientific information available (3) Manage individual stocks as a unit throughout their range, to the extent practicable; interrelated stocks shall be managed as a unit or in close coordination (4) Not discriminate between residents of different states; any allocation of privileges must be fair and equitable (5) Where practicable, promote efficiency, except that no such measure shall have economic allocation as its sole purpose
Magnuson-Stevens (6) Take into account and allow for variations among and contingencies in fisheries, fishery resources, and catches (7) Minimize costs and avoid duplications, where practicable (8) Take into account the importance of fishery resources to fishing communities to provide for the sustained participation of, and minimize adverse impacts to, such communities (consistent with conservation requirements) (9) Minimize bycatch or mortality from bycatch (10) Promote safety of human life at sea
In Hawai‘i Western Pacific Regional Fishery Management Council – (WPRFMC) Decision-making body to develop and recommend specific management measures Fishery management plans (FMP), subject to approval and implementation by NOAA Fisheries
Shark Legislation Shark Finning Protection Act – 2002 - amendment to MSA to prohibit and person: 1) aboard a US vessel from finning a shark 2) possessing shark fins aboard a US vessel w/out the carcass 3) landing fins w/out carcass 4) from a foreign vessel w/in US EEZ from landing, possessing, or shipping fins w/out carcass 5) selling or purchasing shark fins taken in volation
Shark Finning Protection Act Aims are to: 1) prevent unsustainable levels of shark catch due to demand for shark fins 2) prevent waste of shark meat Led to localized regulations by states or Regional Fishery Councils
Shark Protection in Hawai‘i Observer program – both swordfish & tuna 100% coverage shallow-setting swordfish 20% coverage deep-setting tuna
Shark Protection in Hawai‘i To most fishermen in Hawai‘i – sharks are a nuisance/not desirable as they: 1) wreck gear 2) are not very marketable – only mako & thresher (meat or fins) 3) risk of injury 4) risk of overfishing 5) negative stigma 6) tainting of catch in hold - urea
Fishing Techniques Purse seine Bottom trawl Gill net Longline
Bycatches and Discards The aim of most fishers is to capture species that have financial or energetic value – target species Can become part of the catch known at incidental catch Target species are often associated with non-target species (organisms not intended catch of that fishery)
International Regulations Few countries (Canada, New Zealand, Australia, South Africa, United States) have fishery management plans for shark fisheries International cooperation and coordination of existing and development of new shark management plans are needed Wide range of shark distributions require cooperation, assessments, and agreements to understand and manage sharks sustainably
International Regulations No international management mechanisms effectively addressing the capture of sharks Number of international bodies: International Commission for the Conservation of Atlantic Tunas (ICCAT) Northwest Atlantic Fisheries Organization (NAFO), Inter-American Tropical Tuna Commission (IATTC) Initiated efforts to encourage member countries to collect information about shark catches
International Regulations International management initiatives: Guided by: Atlantic Tunas Convention Act Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks
International Regulations Ninth Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) adopted a Resolution on the Biological and Trade Status of Sharks, requesting that: (1) The United Nations Food and Agriculture Organization (FAO) and other international fisheries management organizations establish programs on shark species (2) all nations utilizing and trading specimens of shark species cooperate with FAO and other international fisheries management organizations
International Regulations FAO Committee on Fisheries: develop Guidelines for a Plan of Action for the improved conservation and management of sharks International Plan of Action for the Conservation and Management of Sharks (IPOA) Code of Conduct for Responsible Fisheries: encompasses all elasmobranch fisheries (commercial and recreational) - calls on all member nations to implement IPOA through own national plan
Got Sharks? Shark Catch from Hawai‘i Longline Data
Fisheries Models To produce a good fisheries model, we must account for all contributions to reproduction, growth, and mortality, throughout the life cycle of the fishery resource species Mortality Growth Recruitment Reproduction (Nursery Area)
Population Biomass Fisheries Models Similarly, population biomass depends upon growth, reproduction, natural mortality, but also includes the implications of fishing mortality Reproduction Growth Models! Natural mortality Fishing mortality
Constructing Fisheries Models Initial goal to to determine maximum sustainable yield (MSY) Surplus population models – used to search for the largest fishing mortality rates that can be offset by increased population growth, normally measured in changes in population biomass per unit time Complex calculations based upon several life history parameters, including: population density population biomass population growth rate *Equilibrium – point at which processes balance one another *
Bmax MSY Bmax Bmax Oh, I forgot to er, carry the one “I first observed this technology at the airport gift shop” – Professor John Frink Logistic population growth Populations grow most quickly at intermediate sizes up to a maximum total biomass Bmax MSY in biomass occurs at a level of fishing mortality that places the population at an intermediate size
Applying Fisheries Models Since MSY is a small target (an actual number) and is also a moving target (due to temporal changes in productivity), actual catch controls are first gauged by simulations of high and low quotas. If quota set too high: yield would exceed the surplus population so the population would be driven to extinction If quota set too low: if the population is larger than BMSY – will stabilize and yield lower than BMSY if population is smaller than BMSY – will become unstable and either increase to equilibrium at the higher population size or crash
A Evaluating Fisheries Models The choice of production quotas is minor compared to the procedure of fitting these models to real data to estimate MSY and the level of fishing effort at which it occurs Several to choose from: e.g., - delay-difference, virtual population, statistical catch-at-age Yield-per-recruit models–seek fishing mortality rates that achieve the best tradeoff between the sizes of the individual caught, and the number of individuals available for capture The logic of yield-per-recruit models is based upon the trade-off between growth and mortality of individuals A = optimal age at which to catch fish
Y/R Overfishing! B/R Fishing mortality -F Fisheries Models in Action If fishing mortality rates are set too high, too many individuals will be taken before they have had a chance to grow – growth overfishing If fishing mortality is too low, although individuals will be large when captured, the total yield will be low Yield per recruit (Y/R) and population biomass per recruit (B/R) for a single cohort of fish, for various potential fishing mortalities, F
Fisheries Management Fisheries are managed because the consequences of uncontrolled fishing are undesirable e.g., - fishery collapse, economic inefficiency, loss of employment, habitat loss, decreases in abundance of rare species Primary goal – maintain maximum biologically sustainable yield (MSY or BSY) Recently a mixture of biological, economic, social, and political objectives
Multiplicity Current thinking: - concept of MSY may not be useful in fisheries management since overfishing has caused major alterations in the trophic structure of marine food webs Individual species do not live in a vacuum – they eat each other and may compete for food and space Biological interactions – mean that population dynamics of different species are inevitably linked