LECTURE 1:

Evolution of Fish

  • Shift in trait for production and maintenance
  • Growth rate vs reproduction rate
  • Dependent on the existing selective pressure
  • Applies to current situations, can very in time
  • Example: Mesh nets
  • Selects for specific size in fish
  • Selection pressure for greater fish size at a younger age/ faster rate
  • Increases pressure for smaller fish who pass through these Mesh nets

Hypothesis: Increase in selective pressure of smaller fish over time

  • Multiple selective pressure used = fish size increases fitness
  • Example: Mesh nets that catcher larger fish = increase survival of smaller fish
  • Fisheries: Improve selective pressure of fish size
  • Selective pressure for slow growth rate, faster maturation
  • Pressure can ‘evolve’ fish populations through fishing
  • Commercial and recreational fisheries can be affected
  • Size and age of maturity has declined over time
  • Fisheries selective pressure for a specific size preference (Commercial and Recreational)
  • Resulted in a decrease in abundance for larger size individuals
  • Commercial and Recreational Fisheries has impacted natural selection of fish
  • Quantitative traits = most effective
  • Evolution = decrease harvest amount

LECTURE 2:

Marine Protected Areas (MPA), Sanctuaries and Conservation Reserves

  • MPA’s help in species preservation and protection of biodiversity
  • No protection = Environmental/ habitat degradation from human intervention
  • Large factor of anthropogenic actions such as commercial fisheries

Global Target:

  • 1992, Canada and other countries contributed to this
  • Goal of conservation of ~10% of marine life by 2020
  • Currently, we are at ~3%
  • MPA= Mostly USA water
  • Protection varies in both micro and macro scale
  • Exponential increase with rate of new MPA worldwild
  • Continuous effort in increase the amount of MPA’s for conservation efforts
  • Canada = 1% of oceans are protected
  • Only 0.10% are highly protected
  • Protection efforts of 5% by 2017, 10% by 2020 is the goal for Canada

Terrestrial Reserve:

  • Includes areas such as National Park
  • Areas prohibit buildings, large human intervention (degradation to land)
  • ‘Sanctuaries’ are another name or MPA
  • Protection usually involves rare or endangered organisms
  • Area promotes research!

Success of reserves:

  • Look at assess levels of traits within and without reserves
  • Usually greater within reserves
  • Includes survival and biodiversity of species in these areas
  • Success seen in many trophic levels

Mobility challenge:

  • MPA’s are hard to do with larger and more mobile species
  • Larger and mobile species are ‘non-enclosable’
  • Example: Swordfish
  • Minimum of 23-30% of Habitat for protection
  • Area may be more depending on species

Precautionary Principle:

  • Highlight uncertainty and risk
  • Stringent management actions taken first and relaxed later
  • Later comes with research that demonstrates it is not necessary
  • Reverses ‘burden of proof’ to industry or harvest
  • Scale of reserve = very large

LECTURE 3:

Sustaining Fish Biodiversity:

Types of Extinction:

  1. Local Extinction: Species is lost in a certain area it once inhabited. Species can still be found elsewhere
  2. Ecological Extinction:Reduction of species to the point where individuals can no longer contribute to biological communities
  3. Biological Extinction: Species is no longer existent on Earth

Extinction rates are 1000 to 10,000x times the rate before humans arrived

  • Rate of extinction of all species is 0.1 to 1.0% a year
  • Many causes to extinction include the following:
  • Habitat loss/ degradation
  • Invasive species (introduction of non-native species)
  • No natural predators to stop their spread, easier to outcompete local, native species