Lecture 1:

Managing the Fishery:

Currently, Newfoundland is the last spot for Salmon farms

  • qXN= Fishing Mortality from fishing (F)
  • q*N=F
  • Catchability = q
  • Effort = x
  • N = Population size

This value is dependent on Total Allowed Catch (TAC), Unit usually set in Tonnes

  • Harvest ‘stops’ when value is reached
  • For safe harvest, ~30-40% of Adult should fall under TAC
  • Recreational fishery does not need to report the number of catch per day
  • No accurate number of participants and catch number
  • Use of relative abundance data on assessment to find data
  • KNOW ABUNDANCE VS TIME GRAPH
  • Reg. Change and Target model

Licences: Different between commercial and recreational Fisheries

  • Commercial: Tight regulation and is in limited numbers
  • Recreational: Open to anyone who wants to buy

Recreational Fishery: qXN= f

  • q can be further broken down
  • Catchability = q =c * h
  • c = Catch rate of angling gear
  • h = HARVEST
  • F can change by altering x, c, and h values
  • Recreational regulation usually changes these 3 values

Catch and Release Regulation (C&R)

  • Effects harvest (h)
  • C&R may be specific with size and weight of catch
  • Balance of conservation efforts
  • Protects brood stock until they reach mature age/ reproductive age
  • Source of management tool

Creel and Possession Limit

  • Creed Limit: Limit to number of catch per dayperindividual
  • Possession Limit: Number of catch at any one time is limited
  • Effects h, harvest

Length (slot) Limits:

  • Specifies what length can be allowed to be taken away from environment
  • Minimum length, conserves reproductive age fish
  • Intermediate stage
  • Allows adult brood stock to ‘replenish’ population
  • Effects h, harvest

Season:

  • Effects x, effort
  • Protection of specific fish during spawning season
  • Cannot fish during specific time of year
  • Allows for recruitment and ‘replenishment’ of population

Gear restriction:

  • Effects x, effort
  • Effects c, catch rate of gear
  • Specific type of gear can only be used in certain areas
  • Example: Only 1 rod per individual vs 2 rods per individual
  • Specific type of techniques are restricted

Tags:

  • Set number of tags per angler
  • Application process
  • Allows a certain number of fish to be taken
  • Effects h, harvest

Model impact with regulation changes

  • Model accounts for an average level of recreational fishery
  • Estimated level
  • Adaptive Management: Sets goals and objectives
  • Set strategy to get
  • Assess strategy with regulation to get goals

Lecture 2:

Habitat:

  • Eutrophic habitat = less vision and clarity in water
  • Changing habitats results in changing populations
  • Affected by urbanization
  • Habitat alteration = 1 of the biggest impacts on Fishery
  • Many variables change or causes habitat loss (Eutrophication / toxicity)
  • Destroyed/ homogenized via structural damage or removal to ecosystem

5 Major declines in native fish species:

  1. Physical alterations
  2. Competition/ predation of invasive species
  3. Hybridization
  4. Chemical change (pollution)
  5. Overharvesting

Habitat Issues – Lakes:

  • Increase in turbidity, temperature, organic input (runoff)
  • Mostly due to deforestation
  • Draining of harbors/ channels
  • All factors result in compounding effect from each other

Riparian Zones:

  • Terrestrial borders immediately adjacent to rivers/ streams
  • Filters sediment coming in and provides nutrients
  • Provides protection to water by decreasing erosion, controlling range elevation of streams
  • Provides habitat (Tree roots = stability)
  • Grazing within Riparian Zones results in damage to vegetation (trampled)

Increase turbidity and sediment

  • Changed by Riparian zones, agriculture
  • Change Fish spawning rate -> deoxygenated and buried eggs
  • Salmonids, destroy spawning eggs

Channelization:

  • Change in water ‘craft’
  • Uniform of water types (clarity, sediment, nutrients, ph…etc)
  • Decrease refuge for fish

Road construction:

  • Alters water flow and temperature
  • Decrease flow with increased temperatures
  • Kills many fish in local/ surrounding areas
  • Attributes to fragmentation of path of migration

Habitat Fragmentation:

  • Trawling: Biggest/ Important influence on sea bed destruction
  • Destroys and displaces sediment on sea bed
  • Projects on Dam removal, stream restoration in act now

Lecture 3:

Final paper discussion