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Outline for the Day. Lingering Questions? Reading Quiz 2 and Announcement of Other Quiz Discussion of Worm et al. 2006 Fisheries Crisis Lecture Break Foraging Behavior and Diets Lecture Diet Analysis Lab. Reading Quiz 2. Discussion Topics. Are MPA’s the Answer? WTF Mate?.

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Outline for the Day

  • Lingering Questions?
  • Reading Quiz 2 and Announcement of Other Quiz
  • Discussion of Worm et al. 2006
  • Fisheries Crisis Lecture
  • Break
  • Foraging Behavior and Diets Lecture
  • Diet Analysis Lab

Ecology and Fisheries

  • “Ecological training places a high value on intact ecosystesm, which leads to the push by ecologists for marine protected areas. The fisheries community has traditionally been legislated to use MSY as an objective, though political pressure often pushes fishing efforts higher than MSY to preserve and create jobs” – Ray Hillborn
  • What should the primary goal/goals be for the world’s fisheries?
  • How can we mediate conflicting objectives?

Scientists as Advocates

  • Is it possible to be both a good scientist and a good advocate?
  • How has advocacy hindered scientific advancement?
  • How has advocacy helped science?


  • Global Trends in Fisheries
  • Maximum Sustainable Yield
  • Examples of Collapsed Fisheries
  • Management Goals for Fisheries

Agriculture Term



Population Size

Population Growth


Population Size



Logistic Growth Equation






Maximum Sustainable Yield



Catch exceeds recruitment

Recruitment Rate

Population Size


Population Size

Populations influenced by other forces


MSY is "perfect condition"


California Sardine Fishery

  • Sardine demand increased when use shifted from human consumption to fishmeal and oil circa 1920
  • No catch limits: State scientists issue warning that draining supplies should be avoided until research can detect overfishing
  • 1930s: catch no longer increases in proportion to increases in effort. California state scientists recommend a limit
  • US Bureau of Fisheries, hesitant to limit a successful economic enterprise during the Depression, deemed limits unnecessary b/c evidence of sardine depletion, while strong, was not “clear-cut”.
  • 1939: CA state experts replaced with “emergency appointees” and state opinion mysteriously changes from “fishery is depleted” to “all is well”.
  • 1942: Sardine fishery collapses. Only began to recover in 1980s.

North Atlantic Cod

  • Optimism in 1970s that past mistakes (sardine) could be avoided
  • Fishing intensity grew in 1960s with peak catch in 1968
  • Canada extends jurisdiction from 12 to 200 nautical miles offshore in the late 1970s
  • Allowed the setting of conservative restrictions on catches to 20% of the total stock to promote rebuilding
  • 1988 the Dept. of Fisheries and Oceans claimed a 5x increase in Northern Cod since 1976; tooted horn as a shining example of what cautious, science driven management could do for fisheries
  • 1992: No cod left to catch; loss of fishery cost several billion $
  • Science drastically underestimated stock size, resulting in much more than 20% being harvested – for any year, data from 5 subsequent years was needed to estimate stock. Shorter time periods simply returned the assumed mortality rate

Bluefin and other tuna species were relatively unregulated until the 1980s, in part due to it being an international fishery

  • 1981 recommendation from international commission recommended reducing tuna fishing to as near to 0 as possible

Lobbyists convince commission to reduce fishing by 55% instead of a ban

  • Continuing trend of reducing fishing by less then recommended
  • Total collapse still feared, total ban still considered, Japan working on artificially raising young tuna

Management Goals

  • Biological: MSY
  • Economic
  • Social

Economic Incentives

Protected Areas

Precautionary Regulation

Dedicated Access

Rest of CFL


Kornis Weidel

Management Strategies for Sustainable Fisheries


Good Governance

Dedicated Access


Characteristics of Sustainable Fisheries

Appropriate Incentive

Open Access

  • Lowered demand for fish
  • Wealth
  • Knowledge of complex ecosystems
  • Cooperation between fisheries and other governmental agencies

US Fisheries Policy

Magnuson - WA

Stevens - AK

Fishery Conservation & Management Act 1976 – Known as Magnuson-Stevens Act

- mandated a national program for the conservation and management of fishery resources

- exercise sovereign rights and exclusive fishery management authority over all fish and Continental Shelf fishery resources within the Exclusive Economic Zone (EEZ) (200 miles)

- no foreign fishing is authorized within the EEZ

1996 amendments focused rebuilding overfished fisheries, protecting essential fish habitat, and reducing bycatch.

2006 Ocean Action Plan : the President called for a hard deadline to end overfishing, increased use of market-based management tools, creation of a national saltwater angler registry, and an emphasis on ecosystem approaches to management


2006: Worm et al.

= 0 trained fisheries stock assessors (I think)


response 2006 : Worm et al.

Catch ≠ Abundance

NMFS reported in 2004 26% of stocks were overfished, in 2005 24% of stocks

....shall we extrapolate to show that US fisheries will be fine by 2018, no !

if you do the same thing with German unemployment it says no one in Germany will be working by 2056 (100% unemployment)