Participants:
Mark Carr, Chair (University of California, Santa Cruz)
Lisa Ziobro, Rapporteur (Monterey Bay National Marine Sanctuary)
Tom Hourigan (NMFS, Office of Protected Resources)
Dan Ito (NMFS, Alaska Fisheries Science Center)
Deborah McArdle (UC Sea Grant Marine Extension Program)
Lance Morgan (University of California, Davis and Bodega Laboratory)
Wayne Palsson (Washington Department of Fisheries)
Richard Parrish (NMFS, Pacific Fisheries Environmental Laboratory)
Steve Ralston (NMFS, Tiburon Laboratory)
Paul Reilly (California Department of Fish and Game)
Josh Sladek Nowlis (NMFS, Northeast Fisheries Science Center)
Rick Starr (UC Sea Grant Marine Extension Program)

The design working group recommended three different scenarios in which marine harvest refugia could be developed for rockfish populations, based largely on the goals and objectives for establishing the refugia. The three scenarios range from small no-take areas used for research and to protect key habitats and species to large harvest refugia used to enhance fisheries. Each scenario includes different design characteristics and subsequent levels of protection. It is important to understand that the three distinct scenarios provide greatly different benefits, and that a system of marine refugia could include all three levels of resource protection.


Scenario I. Harvest Refugia as an Alternative Strategy For Sustainable Fishery Management

Goal

In this scenario, marine harvest refugia collectively comprise an area that is sufficient to sustain fisheries in adjacent fished areas. Refugia at this level of protection are designed from an ecosystem approach, whereby specific requirements for targeted species are considered along with more general objectives.

Objectives

1. Protect and maintain spawning biomass
2. Select for larval dispersal over adult spillover
3. Establish and maintain natural size and age structure of a population
4. Preserve essential fish habitats and increase habitat diversity
5. Enhance and protect biological diversity (i.e., species, community and genetic diversity)
6. Provide control communities, that is "pristine" communities that can be used as benchmarks for comparison with unprotected areas to estimate the effects of exploitation

Design Considerations

Size. Refugia are established on the largest scale, protecting from 20 to 50% of (1) the total area of habitat for multi-species, or (2) the spawning potential for targeted species. Size of individual refugia should be based on the extent of rockfish movements and on the pristine size structure of the population.

Number. The number of refugia will be based on the size of individual refugia and on the collective or total area of protection.

Shape. The shape of each refuge is region-specific, encompassing an onshore-offshore swath for increased protection of both shallow and deepwater rockfishes and of the whole ecosystem. Additionally, a contiguous swath of protected area, rather than patches, offers logistical advantages in terms of effective enforcement.

Location. Refugia would be established within a minimum of three bioregions along the west coast, considering the following criteria:

1. Sites should be located with consideration to ocean current regimes (i.e., as a bet-hedging tactic, select multiple sites in regions of both high and low upwelling).
2. Sites should include both heavily and less exploited populations. Heavily exploited populations are more likely to exhibit a greater, although lagged, response to protection. Areas of heavy exploitation most likely indicate sites of historically large populations. Less exploited populations may provide immediate response to protection by maintaining existing spawning biomass.
3. Sites should meet habitat diversity and depth requirements for multi-species assemblages.
4. Sites should have sufficient resources to support spawning biomass.
5. Sites should be distributed in a network that guarantees replenishment of one another and increases the likelihood of sustainability.

Restrictions. These refugia would prohibit directed fisheries for rockfish species of concern. They also would prohibit those gear types that adversely affect these species and that adversely disturb or destroy essential habitats. One consequence of such restrictions would be to allow exploitation of non-demersal transient species (e.g., salmon, tuna). Within this scenario, there may be a range of restrictions in different areas, including a core zone that would prohibit all fishing.

Primary Information Needs For Effective Design

1. Current regimes
2. Spatial structure of populations
3. Demographics of exploited and unexploited populations, especially size and age structure
4. Regional-scale habitat maps
5. Habitat associations, depths, movements
6. Stock assessments for targeted species
7. Distribution of fishing effort

Research Goals

1. Explore methods to quantitatively or qualitatively describe larval dispersal
2. Describe mechanisms that influence larval dispersal and recruitment
3. Conduct adaptive management, using the information gleaned from established refugia (e.g., the effects of various design criteria) to improve the design and management of existing and future refugia


Scenario II. Harvest Refugia as a Buffer or Insurance Against Overfishing

Goal

In this scenario, marine harvest refugia supplement fishery management practices, thereby providing a buffer against fishery collapse caused by environmental change, failed fishery management plans, or unexpected natural or anthropogenic events. Refugia created under this scenario also serve as a benchmark for management trials or experiments.

Objectives

1. Provide a buffer against uncertainty associated with environmental change and deficiencies in fishery management strategies
2. Preserve essential fish habitats and increase habitat diversity
3. Enhance and protect biological diversity (i.e., species, community and genetic diversity)
4. Provide control communities, that is "pristine" communities that can be used as benchmarks for comparison with unprotected areas to estimate the effects of exploitation

Design Considerations

Size. Refugia are established on an intermediate scale, protecting from 5 to 20% of a species' essential habitat. The smallest possible size (e. g., 5%) should encompass the typical movements of individuals of a targeted species.

Number. The number of refugia will be based on the size of individual refugia and on the collective or total area of protection. A suggested minimum number of refugia would be one per upwelling region.

Shape: The shape of each refuge is region-specific, encompassing an onshore-offshore wedge for increased protection of the whole ecosystem and to accommodate the larger home ranges of deeper dwelling species. Additionally, a contiguous swath of protected area, rather than patches, offers logistical advantages in terms of effective enforcement. The exact shape of the swath would be dependent on the distribution of species and habitats to be protected, and be designed to maximize the diversity of species and habitats.
Location. The refugia need to encompass the essential fish habitats of the species and/or species complex. The criteria listed for large scale refugia need even more emphasis and consideration here. Refugia in this scenario would be established within a minimum of three bioregions along the west coast, and placed in upwelling cells with careful consideration of the following criteria:

1. Sites should be located with consideration to ocean current regimes (i.e., areas of high and low upwelling as a bet-hedging tactic).
2. Sites should include both heavily and less exploited populations. Heavily exploited populations are more likely to exhibit a greater, although lagged, response to protection. Areas of heavy exploitation most likely indicate sites of historically large populations. Less exploited populations may provide immediate response to protection by maintaining existing spawning biomass.
3. Sites should meet habitat diversity and depth requirements for multi-species assemblages.
4. Sites should have sufficient resources to support spawning biomass.
5. Sites should be distributed in a network that guarantees replenishment of one another and increases the likelihood of sustainability.

Restrictions. These refugia would prohibit directed fisheries for rockfish species of concern. They also would prohibit those gear types that adversely affect these species and that adversely disturb or destroy essential habitats. One consequence of such restrictions would be to allow exploitation of non-demersal transient species (e.g., salmon, tuna).

Primary Information Needs For Effective Design

1. Demographics of exploited and unexploited populations, especially size and age structure
2. Regional-scale habitat maps
3. Habitat associations, depths, movements
4. Stock assessments for targeted species
5. Distribution of fishing effort
6. Current regimes

Note: Although comprehensive information for the above listed items generally is unavailable, effective refugia implementation can occur using existing data.

Research Goals

1. Evaluate response of populations to protection (BACI [Before After Control Impact] monitoring designs)
2. Explore response of stock in terms of 1) spawning potential, 2) change in size and age distribution, 3) yield and catch per unit effort at different spatial scales
3. Experiment with management strategies on exploited population
4. Monitor the response of the fishery to harvest refugia
5. Improve the design and management of existing and future refugia using the information gleaned from established refugia

Scenario III. Harvest Refugia as Heritage Sites And Areas For Fisheries Research
Goal

In this scenario, marine harvest refugia protect representative essential fish habitats and key associated species. Refugia at this smallest level of protection are not intended as an alternative or supplement to traditional fisheries management. These areas may be quite small, but focus critical protection on ecologically valuable areas and highly sedentary species. Refugia created under this scenario also may serve as important control sites for research.

Objectives

1. Preserve essential fish habitats and increase habitat diversity
2. Enhance and protect biological diversity (i.e., species, community and genetic diversity)
3. Provide control communities, that is "pristine" communities that can be used as benchmarks for comparison with unprotected areas to estimate the effects of exploitation

Design Considerations

Size. Refugia are established on the smallest acceptable scale, protecting less than 5% of the population.

Number. The number of refugia will be based on the size of individual refugia, the collective or total area of protection, and on the distribution of essential fish habitats.

Shape. The shape of each refuge is region-specific. Shape is a function of the distribution of key habitats and species, and of the need for habitat and ecosystem protection. Where possible, an onshore-offshore wedge should be considered to protect all portions of the local ecosystem. This shape also has logistical advantages, in terms of effective enforcement, as compared to patches of protection.

Location. Refugia would be established by bioregion, considering the following criteria:
1. Large enough to incorporate home ranges of species and to minimize edge effects
2. Include representative essential fish habitats (not just unique habitats) of both exploited and unexploited populations
3. Areas that maximize habitat diversity
4. Provide coupling with natural refugia to increase overall protection
5. Complementary to and integrated with protected areas under other management jurisdictions
6. Located in deep water near existing nearshore refugia
7. Contiguous across depths allowing onshore-offshore movement

Restrictions. These refugia are no-take areas, allowing fisheries research by permit.

Primary Information Needs For Effective Design

1. Regional-scale habitat maps identifying essential fish habitats
2. Detailed fish habitat maps and descriptions of proposed refugia
3. Descriptions of fish-habitat associations, depth distributions, movements of key species
4. Identify levels of exploitation in and around selected areas of protection

Note: Although available information is sufficient to proceed with establishment of harvest refugia at this level of protection, a thorough review and identification of information gaps is needed.

Research Goals

1. Evaluate the response of the communities to protection (BACI monitoring designs)
2. Quantify fish home ranges and movements
3. Conduct experiments to separate fisheries effects from environmental variables
4. Compare health (e.g., quality and quantity) of fish habitats inside and outside refuge