FISH FINAL

the end?

objective and goal for Lake Trout in the US

Objective → enhance control efforts for ANS in 5 years

Goal → Healthy Aquatic Ecosystems and Sustainable Lake Trout Populations

Which commandment resonated with Lake Trout?

Commandment 8 (account for ecosystem change through time)→ balance of population with the invasive species removal taken into consideration of the change of introduced species. IT is now working on creating balance of the fish and parasite since it cannot be removed 100%

Why can community sampling be difficult?

Biased through size, shape, location and identification of the fishery

How to fix community sample bias?

Community Monitoring Program → local stakeholders, fishermen, and citizens in collecting data on fish populations, catch, and environmental health, often utilizing both traditional surveys and electronic technology

Richness

# of species/families → more richness = better quality

Eveness

abundance of each species (dont want too high or two low)

Diversity

combines richness & evenness → more diversity = better

Dominance

how dominant the most abundant species is (dont want too high too low)

Shannon-Wiener Diversity Index

Sensitive to rare species

Simpson’s Diversity

influenced by high abundant species

How are fisheries implemented?

The public (fishers/nonfishers), Management agencies, and legislation

4 types of regulation

Input controls, Output controls, Closures, & Species and sizes caught

Input Controls? WHy>?

License sale (recreational and commercial), Regulation of gear (nets, hooks, lines) → bycatch decline, overfishing control

Output Controls? Why?

Commercial Harvest Limits (Total allowable catch, Shared Based), Recreational Harvest limits (Bag/creel/posession limit)

Closures? Why which one?

Short time (spawning season), recovery (long-term), spatial closure (protected areas), catch and release?

Species and sizes caught? Why which one?

Minimize size limits → most common, to ensure spawners remain

Maximum size limits → less common, protect bigger fish for reproduction

protected slot limit → protects spawners but harvest young/older, reduce competition

Inverse slot limit → reduce competition at moderate size by harvesting spawners, C&R trophy

Why is fishery management required?

TO prevent overfishing, protect marine habitats, and ensure long-term stability of fish stocks for food

Goals vs objectives

goals are broader statements and long term focus where objectives are measurable outcomes usually short term and more specific

Common types of goals

1. Maximum sustainable yields

2. Maximize economic yields

3. Perserve ecosystem function

4. Manage for fishing opportunities

5. Manage for desired size structure

Common objectives

1. PSD of x

2. x% of trophy sized fishes

3. Increase mean size by x cm

4. Maintain CPUE of X

Management challeneges

Natural Variation, Uncertainty, Manage humans, fish and habitat, Broad Space and time scales

How to resolve situations when stakeholders have conflicting goals/objectives

SOUND, evidence-BASED management plan with stakeholder engagement, allows resolving any issues

Commandments

1.     Keep a perspective that is holistic, risk-averse and adaptive

2.     Question key assumptions, no matter how basic

3.     Maintain old-growth age structure in fish populations.

4.     Characterize and maintain the natural spatial structure of fish stock.

5.     Characterize and maintain viable fish habitats.

6.     Characterize and maintain ecosystem resilience.

7.     Identify and maintain critical food web connections.

8.     Account for ecosystem change through time

9.     Account for evolutionary change caused by fishing

10.  Implement an approach that is integrated, interdisciplinary, and inclusive

How to dress management challenges

idk you tell me