Recreational and Commercial Fisheries management Flashcards
(35 cards)
What is MSY? Understand the assumptions and problems associated with this approach?
Maximum Sustainable Yield (MSY) is the largest amount of fish that can be caught sustainably without depleting the population. It is based on maintaining the population size at half of its maximum capacity for optimal growth.
- Assumptions -
MSY assumes populations are renewable, carrying capacity is stable, and interactions between species or ecosystems don’t significantly affect outcomes. - Population is renewable, and will replace individuals taken
- Carrying capacity (population size) remains stable
- Species can be managed individually
- Problems -
MSY is risky as it can lead to overfishing, ignores ecosystem dynamics like food webs and species interactions, and relies on difficult-to-calculate data like carrying capacity and population variability. Modern fisheries management has largely moved toward ecosystem-based approaches.
How does evidence-based and ecosystem-based fisheries management differ?
- Evidence-Based Fisheries Management -
focuses on using scientific data and research to make decisions about managing fish stocks. It emphasizes single-species management, relying on biological and population data to ensure sustainable harvests. - Ecosystem-Based Fisheries Management -
considers the entire ecosystem, focusing on species interactions, habitats, and the impact of fishing on non-target species and overall ecosystem health.
It considers the entire ecosystem, including species interactions, food webs, and environmental factors, to maintain ecological balance while managing fisheries.
Why might some jurisdictions have more or less complex fisheries regulations than others?
Fisheries regulations vary in complexity based on biodiversity, economic importance, enforcement resources, local traditions, and international agreements.
What does broodstock mean?
Broodstock refers to a group of mature fish or aquatic animals kept for breeding purposes.
They are used in aquaculture to produce offspring, ensuring the sustainability and replenishment of fish populations.
How do biologists know what size = mature fish?
Biologists use the Length at Maturity Model to determine the size at which fish reach sexual maturity.
This involves studying the relationship between fish size and maturity stages, often identifying the size at which 50% of individuals in a population are mature.
Data is collected through observations, sampling, and statistical modeling to estimate this threshold accurately.
What is the difference between recreational and commercial fisheries?
Recreational fisheries : are focused on fishing for leisure, sport, or personal consumption, often using simple gear like rods and reels.
commercial fisheries: aim to catch large quantities of fish for profit, using advanced equipment like nets and trawlers to supply markets and industries.
Why might fishing seasons vary with latitude or region?
Fishing seasons vary due to differences in climate, water temperature, fish migration patterns, and spawning cycles.
Why does SK close most fisheries in the spring?
Saskatchewan closes most fisheries in the spring to protect fish during their spawning and incubation periods.
This ensures that fish populations can reproduce and replenish, maintaining healthy ecosystems and sustainable fishing opportunities
What gamefish have possession limits in SK?
Arctic grayling, burbot, channel catfish, lake trout, northern pike, perch, stocked trout (e.g., rainbow, brook, and tiger trout), walleye, sauger, and whitefish.
What is the primary reason that Walleye and Sauger co-regulated?
Walleye and Sauger are co-regulated because they share similar habitats and can hybridize, creating saugeye.
This makes it challenging to distinguish between the species, so managing them together ensures sustainable populations and simplifies enforcement.
What is the consequence of co-regulating different species?
Co-regulating species can overlook their unique needs and cause ecological issues.
However, it simplifies management when species share habitats or are hard to tell apart, like Walleye and Sauger.
which species are protected from angling in SK (possession limits = 0)
bigmouth buffalo, largemouth bass, smallmouth bass, and sturgeon
What is a “special regulation” and why do some waters have them?
A special regulation is a rule applied to specific waterbodies to manage fisheries more effectively. These regulations may include unique size limits, possession limits, or seasonal restrictions tailored to the needs of a particular ecosystem or fish population.
Some waters have special regulations to protect vulnerable species, maintain ecological balance, or address overfishing concerns. They ensure sustainable use while preserving the health of the aquatic environment.
What is the difference between a J-hook, Circle Hook, and treble ?
J-Hook: Shaped like the letter “J,” it’s versatile and commonly used for active fishing. It requires the angler to set the hook manually when a fish bites.
Circle Hook: Designed with a curved point that turns inward, it hooks fish in the corner of the mouth as they swim away, reducing injury and making it ideal for catch-and-release fishing.
Treble Hook: Features three hook points on a single shank, often used with lures to increase the chances of hooking fish during strikes
What is the difference between artificial, live and dead bait?
Dead Bait: Previously alive bait, such as frozen or cut fish, used for its scent and appearance to lure fish
Live Bait: Living organisms like worms or minnows used to attract fish, relying on their natural movement and scent.
Dead Bait: Previously alive bait, such as frozen or cut fish, used for its scent and appearance to lure fish
Why are there limitations to the types of live bait that can be used in SK?
Saskatchewan limits the types of live bait to prevent the spread of aquatic invasive species (AIS), diseases, and undesirable fish species.
These restrictions help protect native ecosystems, maintain biodiversity, and avoid ecological and economic harm caused by invasive organisms.
Discuss 3 reasons we stock fish
Create new opportunities
* New fisheries (self-sustaining)
* Artificial P-G-T fisheries (not self- sustaining)
Supplement natural populations
* Maintenance of genetic stocks
* Supplement natural reproduction
Recovery
* Rehabilitation (over-fishing, habitat loss)
* Re-introduction
What is meant by a “PGT” fishery?
A Put-Grow-Take (PGT) fishery involves stocking hatchery-raised fish into waterbodies to create fishing opportunities.
These fish grow in the wild but do not rely on natural reproduction, making PGT fisheries ideal for areas where natural populations are absent or need diversion from overfished lakes
Why is “supplemental stocking” becoming less common?
Supplemental stocking is becoming less common because fisheries management now prioritizes maintaining healthy, self-sustaining populations. Stocking can sometimes disrupt natural ecosystems, harm wild fish populations, or fail to achieve long-term benefits.
Modern approaches focus on habitat restoration and sustainable practices instead.
What exotic fish species are stocked in SK?
Rainbow Trout, Brown Trout, Brook Trout, Tiger Trout, and Splake
What native fish species are stocked in SK?
Walleye, Northern Pike, Yellow Perch, and occasionally Lake Sturgeon.
What major factors need to be considered when determining what fish species to stock?
When stocking fish, key factors include habitat suitability, ecosystem impact, fishing goals, growth potential, and preventing diseases or invasive species. These ensure sustainable and successful stocking programs.
How can stocking rate and stocking frequency impact the type of fishery created?
Stocking rate and frequency shape the type of fishery by influencing fish population density, growth rates, and sustainability.
High stocking rates and frequent stocking can create intensive fisheries with abundant catch opportunities, while lower rates and less frequent stocking support more natural, self-sustaining populations.
Balancing these factors ensures the desired fishery type and ecosystem health
Discuss 3 reasons we may decide to NOT stock fish in a particular system
Fish may not be stocked if the habitat is unsuitable, it could harm the ecosystem or native species, or if stocking isn’t sustainable for long-term benefits.
