14. Spatial Fisheries Management Flashcards
(38 cards)
What is the main objective of spatial fisheries management?
regulate where, when, and how fishing activities can take place to ensure the sustainability of
1) fish populations
2) fishing activities
In specific areas
What are the three main types of spatial management tools in fisheries?
1) Marine Protected Areas (MPAs)
2) Spatial closures
3) Gear restrictions.
What is a Marine Protected Area (MPA)?
An MPA is a designated area of the ocean that restricts human activities to protect marine ecosystems and promote biodiversity.
What is the purpose of time-area closures in spatial fisheries management?
Time-area closures aim to protect specific fish stocks or habitats during critical periods, such as
a) breeding
b) migration
c) Spawning
seasons.
How do gear restrictions contribute to spatial fisheries management?
Gear restrictions regulate the types of fishing equipment allowed in certain areas to minimize the impact on fish populations and habitats.
What is the role of zoning in spatial fisheries management?
Zoning divides an area into smaller regions with specific management measures to address
a) local ecological and
b) socio-economic needs.
Name three benefits of implementing spatial fisheries management.
a) Improving fish stock sustainability
b) protecting critical habitats
c) supporting ecosystem-based management approaches.
What is the main challenge in implementing spatial fisheries management?
Making sure rules are followed
Making sure that regulations are being followed and enforced effectively.
: What is the role of stakeholder involvement in spatial fisheries management?
Stakeholder involvement is crucial for gathering local knowledge, building support for management measures, and promoting compliance.
: How can technology aid in spatial fisheries management?
Technology, such as
a) satellite monitoring
b) electronic reporting systems
can help improve data collection
-> compliance, and enforcement.
How has spatial fisheries management been thought of traditionally?
Traditionally, fisheries have been thought of in a very stylized way, with one homogeneous population that grows until it converges towards a theoretical carrying capacity. This is captured by a growth model that uses the variables S and K to represent the stock and carrying capacity, respectively. However, the real world is far from being homogeneous, and fisheries management needs to account for this heterogeneity.
why is it complicated to measure fish stocks
Heterogenity -> The spatial distribution of fish stocks.
Living creatures in the ocean have complex life cycles:
* Migration pattern
* Spawning behavior
Can be affected by
* weather patterns
* inner population dynamics.
Simple models are insufficient to capture these spatial dynamics, and more complex models are needed to represent the behavior of fish populations over space and time.
Two sources of complexity in spatial fisheries management that we need to understand
a) Spatial distribution of fish stocks
- Can capture the dynamics of fish populations over space and time
b) Heterogeneity of fishers
- Understanding the behavior and characteristics of individual fishers, such as their home port, vessel size, and captain experience.
Sanchirico and Wilen 1999 – Patchiness – Easy explanation.
Why is it important to know the patchiness
- fish is not evenly spread out, but are patched together in certain areas. this is “patches”
- By knowing, studying patchiness, and how the fishermen move between them, we can develop better ways to manage fish poopulations. gain knowledge
Sanchirico and Wilen 1999 – Patchiness – Professional Explanation
• Spatial bioeconomics model
• Reflects modern ideas about population structure
• How fishermen move from patch to patch to catch fish, and how it affects the fish population
- How the patches are connected; and how fishes can move between them
• Give us a better understanding of fish stock (sustainability)
Sanchirico and Wilen 1999 – Patchiness – Show the different Spatial characteristics of patch populations
We have four different patches
a) Fully integrated: Every patch is related to the others
b) Closed patches: None of the patches are related
c) Sink Source: Patch 1 is a source to patch 2, 3 and 4. But from 2, 3 and 4, fishes do not go to another (closed)
d) Multiple sources: They vary: 1 can go to 2, 3 and 4. 2 can be closed. 3 can go back to 1, and 4 can be closed.
e) Spatially Linear: 1 to and back from 2. From 2 they can go to 1 and 3. From 3 they can go to 2 and 4. From 4 they can go to 3.
Three different patches example
- prices p, catchability coefficients q, intrinsic growth rates and opportunity costs equal across patches
- Costs are assumed greater in patch 3 than in patches 1 and 2
- because of strong currents, or other oceanographic conditions
a) Closed patches:
Because of this, fishermen will prefer to fish in patch 1 and 2. This makes the effort:
* Effort: E1 = E2 > E3.
Because patch 3 has larger fishing costs, fewr fishermen will target this area. This allows the fish population to grow to higher levels, leading to higher biomass levels in patch 3.
* Biomass: x1 = x2 < x3
b) Three fully integrated patches
* Fish will now become more evenly distributed across the three patches. The increased biomass levels in patches 1 and 2 makes them more attractive for fishing, while the decrease in patch 3 makes it less attractive. We get:
- E1 = E2»_space; E3
c) The sink-source case
* When the biomass flows out of patch 1 (biological dispersal), it is distributed equally in patches 2 and 3. This results in an increase in the biomass levels in patches 2 and 3, which makes these patches more attractive for fishing. As a result, the fishing effort in patches 2 and 3 increases, while the fishing effort in patch 1 decreases.
- E1 goes down
- E2 and E3 goes up.
* Spatial distribution of profitability: lower cost at 1 and 2
* Biological dispersal: higher biomass at 2 and 3.
Explain biological dispersal versus spatial distribution of profitability in the sink-source case, where the costs in patch 3 are higher.
- “biological dispersal” refers to the movement of fish between different patches in the system,
- “spatial distribution of profitability” refers to the relative economic cost of fishing in different patches. In this case, patches 1 and 2 have lower economic costs than patch 3, which makes them more attractive locations for fishing.
- The statement “biological dispersal vs spatial distribution of profitability” suggests that these two factors can have different impacts on the distribution of biomass and fishing effort in the system. Specifically, while the spatial distribution of profitability makes patches 1 and 2 more attractive for fishing, the biological dispersal of fish can result in higher biomass levels in patches 2 and 3.
- So, in this case, the biological dispersal of fish leads to higher biomass levels in patches 2 and 3, despite the fact that patches 1 and 2 have lower economic costs and are more attractive locations for fishing.
What was Sanchirico and Wilen 1999 investigating?
Spatial dynamics of fisheries
* Spatial dynamics of fish stocks
* Spatial dynamics of fishing activities
What is the fishery production function?
Explain it
- To describe the relationship between the amount of fish harvested (i.e. the “harvest”) and the level of fishing effort applied to catch them.
- It is typically represented as a Schaefer-type harvest function:
Harvest = q * Effort * Biomass
where “Harvest” is the amount of fish caught, “Effort” is the level of fishing effort (e.g. number of boats), “Biomass” is the size of the fish stock, and “q” is a catchability coefficient that represents how efficiently the fishing effort translates into harvest.
- Highlights how EFFORT is related to HARVEST
- As well as the importance of the SIZE of the FISH STOCK (biomass) as a limiting factor on the amount of fish that can be caught sustainably.
- Often used as a starting point (for modeling the impact of various management policies on the fishery, such as restrictions on fishing effort or quotas on the amount of fish that can be caught.)
Give an interpretation of effort in the fishery production function.
Refers to the number of inputs by fishermen to catch fish. Many variables, which make it very complex
* Number of boats
* Fishing trips taken
* Vessel size
* Crew size
* Working hours
* Target spieces
* Spatial: fishing locations (like hunting)
It is an important variable in the production process because the amount of effort used by fishermen can impact the amount of fish caught and ultimately their profits. However, when too many fishermen try to catch a limited number of fish, their profits may decrease. This is because they have to spend more money and effort to catch the same amount of fish, and they may have to sell their catch at a lower price.
Explain the product funtion
Production is a function of capital and labor
Production = f(Capital, Labor)
* In the short run, labor variable, capital fixed
* In the long run, both labor and capital variable
What can happen by limiting one dimension of effort?
One dimension of effort down (number of boats, fishing trips) might lead to fishermen responding by increasing other levels of effort (gear, fishing in different locations).
Can lead to unintended consequences such as increased competition and ultimately resulting in lower profits for the fishermen
What is the short- and long-run goal for a fishing vessel?
Short run goal: maximize profits by using the inputs of labor and capital as efficient as possible.
• Capital inputs such as vessel length, tonnage, engine size and gear type are fixed
• Labor inputs such as crew size and working hours are variable
Long run goal: both labor and capital inputs are variable. Want to optimize these to maximize profits
• Ultimately, the long-run goal is to achieve sustainable fishing practices that ensure the continued availability of fish populations for future generations while still generating profits for fishing vessels.