In recent years a local experiential sport fishing industry, commonly known as Pesca Vivencial (P... more In recent years a local experiential sport fishing industry, commonly known as Pesca Vivencial (PV), has emerged as a new type of activity in the Galápagos Marine Reserve (GMR). We analyze this new industry, which incorporates a surprising multitude of styles, using a complex adaptive systems (CAS) framework. We use CAS (a) to trace feedbacks between the ecological changes and social processes involved and (b) to frame the driving factors behind PV as extending beyond the fishing sector, which makes its logic as a response to the declining profitability of commercial fisheries over recent decades more understandable. The birth of this industry is a “response” and a bottom-up adaptation by fishers to changes in fishing but also tourism and overall GMR management. Focusing on the island of San Cristobal, this chapter will include historical analyses of the development of PV through its initial proposals and its changing forms of uptake. This article contributes to a thin area of research in this new activity so far, understanding the contested politics and livelihood struggles of the local residents involved. More broadly, our use of CAS is novel in that power dynamics within human interactions are part of feedbacks, often underplayed when applied to fisheries change.
The importance of larval dispersal to the performance of marine reserve networks is widely recogn... more The importance of larval dispersal to the performance of marine reserve networks is widely recognized. We characterized patterns of passive dispersal in the eastern basin of the Strait of Juan, de Fuca, Washington, and interpreted the results in the context of marine reserve network connectivity. We used a surface current model to describe the dispersal of passive particles released from 16 sites over periods of 4 and 30 d in the spring of three consecutive years. We then used this approximation to infer the extent to which existing marine reseves and protected areas established on an ad hoc basis are likely to function as a network connected via larval exchange. Dispersal patterns varied substantially between release sites. Release site location accounted for the greatest amount of variation in dispersal distance, exceeding variation due to year, month, or tidal phase. After 30 d, dispersal distance and variance combined to describe three groups of release sites: those characterized by short distance, low variance dispersal; those characterized by long distance, low variance dispersal; and those characterized by intermediate to long distance, high variance dispersal. We suggest that sites within this third group are likely to make the strongest contributions to network connectivity in this system. Our findings underscore the importance of using both dispersal distance and variance estimates to model connectivity between sites and suggest that the performance of ad hoc collections of protected sites can be enhanced through the establishment of additional protected sites chosen to fill critical gaps in existing networks.
1. Conservation planning is often hampered by the lack of causal quantitative links between lands... more 1. Conservation planning is often hampered by the lack of causal quantitative links between landscape characteristics, restoration actions and habitat conditions that impact the status of imperilled species. Here we present a first step toward linking actions on the landscape to the population status of endangered stream-type Chinook salmon (Oncorhynchus tshawytscha).2. We developed relationships between land use, landscape characteristics and freshwater habitat of spring Chinook salmon in the Wenatchee River basin. Available data allowed us to find relationships that described water temperatures at several life stages (prespawning, egg incubation and summer rearing) and substratum characteristics, including fine sediments, cobble and embeddedness. Predictors included altitude, gradient, mean annual precipitation, total and riparian forest cover, road density, impervious surface and alluvium. We used a model averaging approach to account for parameter and model selection uncertainty. Key predictors were total forest cover and impervious surface area for prespawning and summer rearing temperatures; precipitation and stream gradients were important predictors of the percent of fine sediments in stream substrata.3. We estimated habitat conditions using these relationships in three alternative landscape scenarios: historical, no restoration and one that included a set of restoration actions from local conservation planning. We found that prespawning and summer temperatures were estimated to be slightly higher historically relative to current conditions in dry sparsely forested areas, but lower in some important Chinook salmon spawning and rearing areas and lower in those locations under the restoration scenario. Fine sediments were lower in the historical scenario and were reduced as a consequence of restoration actions in two areas currently unoccupied by Chinook salmon that contain reaches with some potential for high quality spawning and rearing. Cobble and embeddedness in general were predicted to be higher historically and changed little as a result of restoration actions relative to current conditions.4. This modelling framework converts suites of restoration actions into changes in habitat condition, thereby enabling restoration planners to evaluate alternative combinations of proposed actions. It also provides inputs to models linking habitat conditions to population status. This approach represents a first step in estimating impacts of restoration strategies, and can provide key information for conservation managers and planners.
1. A key element of conservation planning is the extremely challenging task of estimating the lik... more 1. A key element of conservation planning is the extremely challenging task of estimating the likely effect of restoration actions on population status. To compare the relative benefits of typical habitat restoration actions on Pacific salmon (Oncorhynchus spp.), we modelled the response of an endangered Columbia River Chinook salmon (O. tshawytscha) population to changes in habitat characteristics either targeted for restoration or with the potential to be degraded.2. We applied a spatially explicit, multiple life stage, Beverton-Holt model to evaluate how a set of habitat variables with an empirical influence on spring-run Chinook salmon survivorship influenced fish population abundance, productivity, spatial structure and diversity. Using habitat condition scenarios – historical conditions and future conditions with restoration, no restoration, and degradation – we asked the following questions: (i) how is population status affected by alternative scenarios of habitat change, (ii) which individual habitat characteristics have the potential to substantially influence population status and (iii) which life stages have the largest impact on population status?3. The difference in population abundance and productivities resulting from changes in modelled habitat variables from the ‘historical’ to ‘current’ scenarios suggests that there is substantial potential for improving population status. Planned restoration actions directed toward modelled variables, however, produced only modest improvements.4. The model predicted that population status could be improved by additional restoration efforts directed toward further reductions in the percentage of fine sediments in the streambed, a factor that has a large influence on egg survival. Actions reducing fines were predicted to be especially effective outside the national forest that covers most of the basin. Scenarios that increased capacity by opening access to habitat in good condition also had a positive but smaller effect on spawner numbers.5. Degradation in habitat quality, particularly in percent fine sediments, within stream reaches located in the national forest had great potential to further reduce this population’s viability. This finding supports current forest planning efforts to minimise road density and clear-cut harvests and to return forest stand structure in dry regions to the historical condition that promoted frequent low-intensity fires rather than catastrophic stand-replacing fires, as these landscape factors have been shown to influence percent fine sediment in streams.6. Together, these results suggest that planning focusing on protecting currently good habitat, reducing fine sediments to promote egg survival and increasing spawner capacity will be beneficial to endangered spring-run Chinook population status.
In recent years a local experiential sport fishing industry, commonly known as Pesca Vivencial (P... more In recent years a local experiential sport fishing industry, commonly known as Pesca Vivencial (PV), has emerged as a new type of activity in the Galápagos Marine Reserve (GMR). We analyze this new industry, which incorporates a surprising multitude of styles, using a complex adaptive systems (CAS) framework. We use CAS (a) to trace feedbacks between the ecological changes and social processes involved and (b) to frame the driving factors behind PV as extending beyond the fishing sector, which makes its logic as a response to the declining profitability of commercial fisheries over recent decades more understandable. The birth of this industry is a “response” and a bottom-up adaptation by fishers to changes in fishing but also tourism and overall GMR management. Focusing on the island of San Cristobal, this chapter will include historical analyses of the development of PV through its initial proposals and its changing forms of uptake. This article contributes to a thin area of research in this new activity so far, understanding the contested politics and livelihood struggles of the local residents involved. More broadly, our use of CAS is novel in that power dynamics within human interactions are part of feedbacks, often underplayed when applied to fisheries change.
The importance of larval dispersal to the performance of marine reserve networks is widely recogn... more The importance of larval dispersal to the performance of marine reserve networks is widely recognized. We characterized patterns of passive dispersal in the eastern basin of the Strait of Juan, de Fuca, Washington, and interpreted the results in the context of marine reserve network connectivity. We used a surface current model to describe the dispersal of passive particles released from 16 sites over periods of 4 and 30 d in the spring of three consecutive years. We then used this approximation to infer the extent to which existing marine reseves and protected areas established on an ad hoc basis are likely to function as a network connected via larval exchange. Dispersal patterns varied substantially between release sites. Release site location accounted for the greatest amount of variation in dispersal distance, exceeding variation due to year, month, or tidal phase. After 30 d, dispersal distance and variance combined to describe three groups of release sites: those characterized by short distance, low variance dispersal; those characterized by long distance, low variance dispersal; and those characterized by intermediate to long distance, high variance dispersal. We suggest that sites within this third group are likely to make the strongest contributions to network connectivity in this system. Our findings underscore the importance of using both dispersal distance and variance estimates to model connectivity between sites and suggest that the performance of ad hoc collections of protected sites can be enhanced through the establishment of additional protected sites chosen to fill critical gaps in existing networks.
1. Conservation planning is often hampered by the lack of causal quantitative links between lands... more 1. Conservation planning is often hampered by the lack of causal quantitative links between landscape characteristics, restoration actions and habitat conditions that impact the status of imperilled species. Here we present a first step toward linking actions on the landscape to the population status of endangered stream-type Chinook salmon (Oncorhynchus tshawytscha).2. We developed relationships between land use, landscape characteristics and freshwater habitat of spring Chinook salmon in the Wenatchee River basin. Available data allowed us to find relationships that described water temperatures at several life stages (prespawning, egg incubation and summer rearing) and substratum characteristics, including fine sediments, cobble and embeddedness. Predictors included altitude, gradient, mean annual precipitation, total and riparian forest cover, road density, impervious surface and alluvium. We used a model averaging approach to account for parameter and model selection uncertainty. Key predictors were total forest cover and impervious surface area for prespawning and summer rearing temperatures; precipitation and stream gradients were important predictors of the percent of fine sediments in stream substrata.3. We estimated habitat conditions using these relationships in three alternative landscape scenarios: historical, no restoration and one that included a set of restoration actions from local conservation planning. We found that prespawning and summer temperatures were estimated to be slightly higher historically relative to current conditions in dry sparsely forested areas, but lower in some important Chinook salmon spawning and rearing areas and lower in those locations under the restoration scenario. Fine sediments were lower in the historical scenario and were reduced as a consequence of restoration actions in two areas currently unoccupied by Chinook salmon that contain reaches with some potential for high quality spawning and rearing. Cobble and embeddedness in general were predicted to be higher historically and changed little as a result of restoration actions relative to current conditions.4. This modelling framework converts suites of restoration actions into changes in habitat condition, thereby enabling restoration planners to evaluate alternative combinations of proposed actions. It also provides inputs to models linking habitat conditions to population status. This approach represents a first step in estimating impacts of restoration strategies, and can provide key information for conservation managers and planners.
1. A key element of conservation planning is the extremely challenging task of estimating the lik... more 1. A key element of conservation planning is the extremely challenging task of estimating the likely effect of restoration actions on population status. To compare the relative benefits of typical habitat restoration actions on Pacific salmon (Oncorhynchus spp.), we modelled the response of an endangered Columbia River Chinook salmon (O. tshawytscha) population to changes in habitat characteristics either targeted for restoration or with the potential to be degraded.2. We applied a spatially explicit, multiple life stage, Beverton-Holt model to evaluate how a set of habitat variables with an empirical influence on spring-run Chinook salmon survivorship influenced fish population abundance, productivity, spatial structure and diversity. Using habitat condition scenarios – historical conditions and future conditions with restoration, no restoration, and degradation – we asked the following questions: (i) how is population status affected by alternative scenarios of habitat change, (ii) which individual habitat characteristics have the potential to substantially influence population status and (iii) which life stages have the largest impact on population status?3. The difference in population abundance and productivities resulting from changes in modelled habitat variables from the ‘historical’ to ‘current’ scenarios suggests that there is substantial potential for improving population status. Planned restoration actions directed toward modelled variables, however, produced only modest improvements.4. The model predicted that population status could be improved by additional restoration efforts directed toward further reductions in the percentage of fine sediments in the streambed, a factor that has a large influence on egg survival. Actions reducing fines were predicted to be especially effective outside the national forest that covers most of the basin. Scenarios that increased capacity by opening access to habitat in good condition also had a positive but smaller effect on spawner numbers.5. Degradation in habitat quality, particularly in percent fine sediments, within stream reaches located in the national forest had great potential to further reduce this population’s viability. This finding supports current forest planning efforts to minimise road density and clear-cut harvests and to return forest stand structure in dry regions to the historical condition that promoted frequent low-intensity fires rather than catastrophic stand-replacing fires, as these landscape factors have been shown to influence percent fine sediment in streams.6. Together, these results suggest that planning focusing on protecting currently good habitat, reducing fine sediments to promote egg survival and increasing spawner capacity will be beneficial to endangered spring-run Chinook population status.
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