The peacock hind Cephalopholis argus (family Serranidae), locally known as 'roi', was introduced ... more The peacock hind Cephalopholis argus (family Serranidae), locally known as 'roi', was introduced from French Polynesia to Hawaii in the mid-twentieth century as a food fish. However, because of its association with ciguatera fish poisoning, it is rarely fished for food. Previous research indicates that roi could have a negative impact on native reef fish assemblages because of their high densities and prey consumption rates. However, it is unclear whether roi add to the cumulative mortality of prey (predation hypothesis), or whether predation is instead compensatory (doomed surplus hypothesis). This study experimentally assessed the effects of roi on reef fish populations through a long-term (5.5 year) predator removal experiment. A Before-After-Control-Impact study design was used to assess changes in fish assemblages following the removal of roi on 1.3 ha of patch reef. Increases in the density of prey-sized fish (<15 cm TL) were observed 18 months after roi removal. However, those effects did not translate into sustained increases in prey. While increases in potential competitors, wrasses (family Labridae), particularly the piscivorous ringtail wrasse Oxycheilinus unifasciatus, were observed on roi-free reefs, the fish assemblage did not diverge substantially in composition. Native reef fish appeared to resist the potential negative impacts of predation by roi, possibly through a refuge in size for some fish families. Management to protect intact fish assemblage size-structure could serve to bolster native resistance to invading species. In considering the threats facing coral reefs, and the possible solutions, roi removal alone will not likely replenish native fishery resources.
Species distribution models (SDMs) are used to interpret and map fish distributions based on habi... more Species distribution models (SDMs) are used to interpret and map fish distributions based on habitat variables and other drivers. Reef fish avoidance behavior has been shown to vary in the presence of divers and is primarily driven by spearfishing pressure. Diver avoidance behavior or fish wariness may spatially influence counts and other descriptive measures of fish assemblages. Because fish assemblage metrics are response variables for SDMs, measures of fish wariness may be useful as predictors in SDMs of fishes targeted by spearfishing. We used a diver operated stereo-video system to conduct fish surveys and record minimum approach distance (MAD) of targeted reef fishes inside and outside of two marine reserves on the island of O ' ahu in the main Hawaiian Islands. By comparing MAD between sites and management types we tested the assumption that it provides a proxy for fish wariness related to spearfishing pressure. We then compared the accuracy of SDMs which included MAD as a predictor with SDMs that did not. Individual measures of MAD differed between sites though not management types. When included as a predictor, MAD averaged at the transect level greatly improved the accuracy of SDMs of targeted fish biomass.
Behavioral changes due to human predation can affect the functional role of targeted fishes and h... more Behavioral changes due to human predation can affect the functional role of targeted fishes and has implications for ecosystem and fisheries management. Wariness of targeted fishes towards divers, often measured as flight initiation distance (FID), has been shown to increase in areas where spear fishing pressure is higher. Additional research is required to understand how these patterns vary among different species and places. To support such studies, there is a need to explore the relationship of approach starting distance (SD) and other variables that influence measures of fish wariness. We used stereo video to record FID, a new direct measure of minimum approach distance (dMAD), and escape responses of targeted reef fishes in a marine reserve and heavily fished area in Hawai'i. We investigated the role of SD and 15 other variables in influencing FID and dMAD and tested differences between the reserve and fished area. SD explained a large portion of the variability in FID and somewhat less variability in dMAD. FID and dMAD were higher when fishes were travelling (vs feeding), increased with fish body length, and decreased with depth. When including these co-variates in models of FID and dMAD of targeted reef fishes, we found significant differences between study sites for dMAD, though not for FID. We also found differences in escape responses between sites. Based on these results, we recommend using stereo video to conduct measures of dMAD as a complement or alternative to FID, while simultaneously measuring SD and collecting additional data such as escape response. Relative effect sizes of SD and, to a lesser extent, other covariates were large in comparison to site. Studies that use similar methods and do not control for or incorporate SD may produce biased results with regard to the effects of fishing pressure on flight behavior of targeted fishes.
We developed a linked land-sea modeling framework based on remote sensing and empirical data, whi... more We developed a linked land-sea modeling framework based on remote sensing and empirical data, which couples sediment export and coral reef models at fine spatial resolution. This spatially-explicit (60 × 60 m) framework simultaneously tracks changes in multiple benthic and fish indicators as a function of land-use and climate change scenarios. We applied this framework in Kubulau District, Fiji, to investigate the effects of logging, agriculture expansion, and restoration on coral reef resilience. Under the deforestation scenario, models projected a 4.5-fold sediment increase (>7,000 t. yr −1) coupled with a significant decrease in benthic habitat quality across 1,940 ha and a reef fish biomass loss of 60.6 t. Under the restoration scenario, models projected a small (<30 t. yr −1) decrease in exported sediments, resulting in a significant increase in benthic habitat quality across 577 ha and a fish biomass gain of 5.7 t. The decrease in benthic habitat quality and loss of fish biomass were greater when combining climate change and deforestation scenarios. We evaluated where land-use change and bleaching scenarios would impact sediment runoff and downstream coral reefs to identify priority areas on land, where conservation or restoration could promote coral reef resilience in the face of climate change.
The U.S. is adopting a Marine Spatial Planning (MSP) approach to address conflicting objectives o... more The U.S. is adopting a Marine Spatial Planning (MSP) approach to address conflicting objectives of conservation and resource development and usage in marine spaces. At this time MSP remains primarily as a concept rather than a well-defined framework, however expanding anthropogenic impacts on coastal and marine areas reinforce the need to adopt an MSP approach to manage societal demands while preserving the marine environment. The development of theory and methods to implement MSP are on the rise across the nation to address coastal and marine environmental challenges. Critical components of marine spatial planning are (1) spatial data collection, (2) data management, (3) data analysis, and (4) decision support systems. Advances in geotechnology have increased access to spatial data enabling the development of decision support tools to organize, analyze, and inform the MSP process by projecting future scenarios. A review of the current literature reveals the available technological and methodological tools that are best suited for marine spatial planning, as well as suggests areas for further research in order to better inform this process in the U.S.
Nearshore fish populations are in decline in the main Hawaiian Islands, and effective, sustainabl... more Nearshore fish populations are in decline in the main Hawaiian Islands, and effective, sustainable management is needed. There has been increasing emphasis on the value of ecosystem-based management and the conservation of essential fish habitat, but policy is encumbered by a lack of supporting information. This study uses science and technology to support traditional knowledge in identifying juvenile fish habitats, providing a basis for effective resource management in a rural Hawaiian community. Building on existing local knowledge of nearshore resources, we quantitatively assessed juvenile fish−habitat associations. We conducted fine-scale in situ ecological surveys of juvenile reef fishes and their habitats, and produced detailed benthic habitat maps using GIS and interpretation of satellite imagery, from which we extracted multiscale seascape variables. Canonical correspondence analysis was used to assess fish−habitat relationships at multiple scales. Depth, coral cover, structural complexity, scattered rock and coral habitat, and distance to shore emerged as primary factors associated with juvenile reef fish abundance. We identified the habitat associations of 2 important food resource species in the study area of Ha 2'ena, Kaua'i: the convict tang Acanthurus triostegus sandvicensis, an endemic subspecies, and the redlip parrotfish Scarus rubroviolaceus. Results from this study played an important role in the successful approval of the Ha 2'ena community-based fishery management plan by the state governing agency. We argue that an ecosystem-based co-management approach, informed by conventional survey methods, remote sensing technology, and traditional knowledge, can help to ensure the sustainability of fisheries worldwide.
Groundwater dependent ecosystems (GDE) are increasingly recognized as critical components of sust... more Groundwater dependent ecosystems (GDE) are increasingly recognized as critical components of sustainable groundwater management, but are threatened by multiple drivers of environmental change. Despite this importance, data that link drivers of hydrologic change to GDEs are scarce. This study adapts a land‐sea modeling framework by calibrating marine models with macroalgal experiments to quantitatively assess impacts of climate and land use change on submarine groundwater discharge (SGD) and subsequent habitat suitability for a native (Ulva lactuca) and an invasive (Hypnea musciformis) macroalgae in nearshore GDEs in Kona, Hawai'i. Lab analyses demonstrate that while U. lactuca grows optimally in low‐salinity, high‐nutrient waters, H. musciformis appears constrained to a salinity threshold and exhibits low growth in low salinity despite high nutrient concentrations. Land‐sea model results predict that while a dry future climate (Representative Concentration Pathway 8.5 mid‐century) coupled with increased urban development will likely reduce SGD, protecting native forests may prevent further loss of SGD quantity. This prevention thus partially mitigates the decline in habitat suitability of U. lactuca due to the combined effects of climate and land use change. Findings also suggest that, in contrast to the native U. lactuca, reductions in SGD may favor H. musciformis growth if introduced to Kona. Collectively, this study demonstrates the importance of considering multiple drivers of environmental change on GDEs. This study bridges experiments with models to spatially map changes in species abundance beyond their current habitat conditions, and thus informs management actions that can explicitly incorporate future human and climate‐related impacts.
Across the Pacific Islands, declining natural resources have contributed to a cultural renaissanc... more Across the Pacific Islands, declining natural resources have contributed to a cultural renaissance of customary ridge-to-reef management approaches. These indigenous and community conserved areas (ICCA) are initiated by local communities to protect natural resources through customary laws. To support these efforts, managers require scientific tools that track land-sea linkages and evaluate how local management scenarios affect coral reefs. We established an interdisciplinary process and modeling framework to inform ridge-to-reef management in Hawai'i, given increasing coastal development, fishing and climate change related impacts. We applied our framework at opposite ends of the Hawaiian Archipelago, in Hā'ena and Ka'ūpūlehu, where local communities have implemented customary resource management approaches through government-recognized processes to perpetuate traditional food systems and cultural practices. We identified coral reefs vulnerable to groundwater-based nutrients and linked them to areas on land, where appropriate management of human-derived nutrients could prevent increases in benthic algae and promote coral recovery from bleaching. Our results demonstrate the value of interdisciplinary collaborations among researchers, managers and community members. We discuss the lessons learned from our culturally-grounded, inclusive research process and highlight critical aspects of collaboration necessary to develop tools that can inform placed-based solutions to local environmental threats and foster coral reef resilience.
Coastal seascapes are productive and diverse land-sea systems that provide many valuable benefits... more Coastal seascapes are productive and diverse land-sea systems that provide many valuable benefits yet are increasingly threatened by human activity. Scaling up of nature-based solutions (NbS) to effectively protect, sustainably manage, and restore coastal seascapes is urgently required for mitigation of climate change and biodiversity loss while also providing socio-economic benefits. Evidence-based site selection is an important first step to improve the outcomes and avoid negative impacts when prioritizing NbS investments at national level. We developed a spatially explicit, integrative and culturally relevant ecosystem-based site selection process to identify a portfolio of seascapes for NbS consideration in the United Arab Emirates (UAE). The primary goal was to rank planning units based on potential for climate change mitigation action, positive impact to biodiversity and socio-economic benefits to people. The multi-criteria site-selection framework provided a rapid, transparen...
beach_seine_BACI.csv is a comma-separated file containing data from beach seine surveys of juveni... more beach_seine_BACI.csv is a comma-separated file containing data from beach seine surveys of juvenile fish populations from two sites on windward side of Oahu, Hawai
In 2007, due to growing concerns of declines in nearshore fisheries in Hawai‘i, a ban on gillnets... more In 2007, due to growing concerns of declines in nearshore fisheries in Hawai‘i, a ban on gillnets was implemented in designated areas around the island of O‘ahu in the main Hawaiian Islands. Utilizing a 17 year time-series of juvenile fish abundance beginning prior to the implementation of the gillnet ban, we examined the effects of the ban on the abundance of juveniles of soft-bottom associated fish species. Using a Before-After-Control-Impact (BACI) sampling design, we compared the abundance of targeted fishery species in a bay where gillnet fishing was banned (Kailua, O‘ahu), and an adjacent bay where fishing is still permitted (Waimānalo, O‘ahu). Our results show that when multiple juvenile fish species were combined, abundance declined over time in both locations, but the pattern varied for each of the four species groups examined. Bonefishes were the only species group with a significant BACI effect, with higher abundance in Kailua in the period after the gillnet ban. This study addressed a need for scientific assessment of a fisheries regulation that is rarely possible due to lack of quality data before enactment of such restrictions. Thus, we developed a baseline status of juveniles of an important fishery species, and found effects of a fishery management regulation in Hawai‘i
Hawaii_regime_drivers.csv is a comma-separated file containing data used to understand relationsh... more Hawaii_regime_drivers.csv is a comma-separated file containing data used to understand relationships between regime transitions and local and global drivers. The file includes data on human population density and degree heating weeks for each replicate found in Hawaii_regime_timeseries.csv. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan (donovan.maryk@gmail.com)
Hawaii_regime_timeseries.csv is a comma-separated file containing data used to investigate change... more Hawaii_regime_timeseries.csv is a comma-separated file containing data used to investigate changes in regimes over time. The file includes metadata for 1279 replicates across multiple years, 10 reef community metrics used to define regimes in a cluster analysis, and the geographic location of the replicate. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan (donovan.maryk@gmail.com)
Hawaii_regimes.csv is a comma-separated file containing data used to define reef regimes for the ... more Hawaii_regimes.csv is a comma-separated file containing data used to define reef regimes for the Hawaii Islands. The file includes metadata for 1027 replicates, 10 reef community metrics used to define regimes in a cluster analysis, and the resulting reef regime. Reef community metrics are averages of individual replicates grouped based on spatial proximity. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan (donovan.maryk@gmail.com)
The peacock hind Cephalopholis argus (family Serranidae), locally known as 'roi', was introduced ... more The peacock hind Cephalopholis argus (family Serranidae), locally known as 'roi', was introduced from French Polynesia to Hawaii in the mid-twentieth century as a food fish. However, because of its association with ciguatera fish poisoning, it is rarely fished for food. Previous research indicates that roi could have a negative impact on native reef fish assemblages because of their high densities and prey consumption rates. However, it is unclear whether roi add to the cumulative mortality of prey (predation hypothesis), or whether predation is instead compensatory (doomed surplus hypothesis). This study experimentally assessed the effects of roi on reef fish populations through a long-term (5.5 year) predator removal experiment. A Before-After-Control-Impact study design was used to assess changes in fish assemblages following the removal of roi on 1.3 ha of patch reef. Increases in the density of prey-sized fish (<15 cm TL) were observed 18 months after roi removal. However, those effects did not translate into sustained increases in prey. While increases in potential competitors, wrasses (family Labridae), particularly the piscivorous ringtail wrasse Oxycheilinus unifasciatus, were observed on roi-free reefs, the fish assemblage did not diverge substantially in composition. Native reef fish appeared to resist the potential negative impacts of predation by roi, possibly through a refuge in size for some fish families. Management to protect intact fish assemblage size-structure could serve to bolster native resistance to invading species. In considering the threats facing coral reefs, and the possible solutions, roi removal alone will not likely replenish native fishery resources.
Species distribution models (SDMs) are used to interpret and map fish distributions based on habi... more Species distribution models (SDMs) are used to interpret and map fish distributions based on habitat variables and other drivers. Reef fish avoidance behavior has been shown to vary in the presence of divers and is primarily driven by spearfishing pressure. Diver avoidance behavior or fish wariness may spatially influence counts and other descriptive measures of fish assemblages. Because fish assemblage metrics are response variables for SDMs, measures of fish wariness may be useful as predictors in SDMs of fishes targeted by spearfishing. We used a diver operated stereo-video system to conduct fish surveys and record minimum approach distance (MAD) of targeted reef fishes inside and outside of two marine reserves on the island of O ' ahu in the main Hawaiian Islands. By comparing MAD between sites and management types we tested the assumption that it provides a proxy for fish wariness related to spearfishing pressure. We then compared the accuracy of SDMs which included MAD as a predictor with SDMs that did not. Individual measures of MAD differed between sites though not management types. When included as a predictor, MAD averaged at the transect level greatly improved the accuracy of SDMs of targeted fish biomass.
Behavioral changes due to human predation can affect the functional role of targeted fishes and h... more Behavioral changes due to human predation can affect the functional role of targeted fishes and has implications for ecosystem and fisheries management. Wariness of targeted fishes towards divers, often measured as flight initiation distance (FID), has been shown to increase in areas where spear fishing pressure is higher. Additional research is required to understand how these patterns vary among different species and places. To support such studies, there is a need to explore the relationship of approach starting distance (SD) and other variables that influence measures of fish wariness. We used stereo video to record FID, a new direct measure of minimum approach distance (dMAD), and escape responses of targeted reef fishes in a marine reserve and heavily fished area in Hawai'i. We investigated the role of SD and 15 other variables in influencing FID and dMAD and tested differences between the reserve and fished area. SD explained a large portion of the variability in FID and somewhat less variability in dMAD. FID and dMAD were higher when fishes were travelling (vs feeding), increased with fish body length, and decreased with depth. When including these co-variates in models of FID and dMAD of targeted reef fishes, we found significant differences between study sites for dMAD, though not for FID. We also found differences in escape responses between sites. Based on these results, we recommend using stereo video to conduct measures of dMAD as a complement or alternative to FID, while simultaneously measuring SD and collecting additional data such as escape response. Relative effect sizes of SD and, to a lesser extent, other covariates were large in comparison to site. Studies that use similar methods and do not control for or incorporate SD may produce biased results with regard to the effects of fishing pressure on flight behavior of targeted fishes.
We developed a linked land-sea modeling framework based on remote sensing and empirical data, whi... more We developed a linked land-sea modeling framework based on remote sensing and empirical data, which couples sediment export and coral reef models at fine spatial resolution. This spatially-explicit (60 × 60 m) framework simultaneously tracks changes in multiple benthic and fish indicators as a function of land-use and climate change scenarios. We applied this framework in Kubulau District, Fiji, to investigate the effects of logging, agriculture expansion, and restoration on coral reef resilience. Under the deforestation scenario, models projected a 4.5-fold sediment increase (>7,000 t. yr −1) coupled with a significant decrease in benthic habitat quality across 1,940 ha and a reef fish biomass loss of 60.6 t. Under the restoration scenario, models projected a small (<30 t. yr −1) decrease in exported sediments, resulting in a significant increase in benthic habitat quality across 577 ha and a fish biomass gain of 5.7 t. The decrease in benthic habitat quality and loss of fish biomass were greater when combining climate change and deforestation scenarios. We evaluated where land-use change and bleaching scenarios would impact sediment runoff and downstream coral reefs to identify priority areas on land, where conservation or restoration could promote coral reef resilience in the face of climate change.
The U.S. is adopting a Marine Spatial Planning (MSP) approach to address conflicting objectives o... more The U.S. is adopting a Marine Spatial Planning (MSP) approach to address conflicting objectives of conservation and resource development and usage in marine spaces. At this time MSP remains primarily as a concept rather than a well-defined framework, however expanding anthropogenic impacts on coastal and marine areas reinforce the need to adopt an MSP approach to manage societal demands while preserving the marine environment. The development of theory and methods to implement MSP are on the rise across the nation to address coastal and marine environmental challenges. Critical components of marine spatial planning are (1) spatial data collection, (2) data management, (3) data analysis, and (4) decision support systems. Advances in geotechnology have increased access to spatial data enabling the development of decision support tools to organize, analyze, and inform the MSP process by projecting future scenarios. A review of the current literature reveals the available technological and methodological tools that are best suited for marine spatial planning, as well as suggests areas for further research in order to better inform this process in the U.S.
Nearshore fish populations are in decline in the main Hawaiian Islands, and effective, sustainabl... more Nearshore fish populations are in decline in the main Hawaiian Islands, and effective, sustainable management is needed. There has been increasing emphasis on the value of ecosystem-based management and the conservation of essential fish habitat, but policy is encumbered by a lack of supporting information. This study uses science and technology to support traditional knowledge in identifying juvenile fish habitats, providing a basis for effective resource management in a rural Hawaiian community. Building on existing local knowledge of nearshore resources, we quantitatively assessed juvenile fish−habitat associations. We conducted fine-scale in situ ecological surveys of juvenile reef fishes and their habitats, and produced detailed benthic habitat maps using GIS and interpretation of satellite imagery, from which we extracted multiscale seascape variables. Canonical correspondence analysis was used to assess fish−habitat relationships at multiple scales. Depth, coral cover, structural complexity, scattered rock and coral habitat, and distance to shore emerged as primary factors associated with juvenile reef fish abundance. We identified the habitat associations of 2 important food resource species in the study area of Ha 2'ena, Kaua'i: the convict tang Acanthurus triostegus sandvicensis, an endemic subspecies, and the redlip parrotfish Scarus rubroviolaceus. Results from this study played an important role in the successful approval of the Ha 2'ena community-based fishery management plan by the state governing agency. We argue that an ecosystem-based co-management approach, informed by conventional survey methods, remote sensing technology, and traditional knowledge, can help to ensure the sustainability of fisheries worldwide.
Groundwater dependent ecosystems (GDE) are increasingly recognized as critical components of sust... more Groundwater dependent ecosystems (GDE) are increasingly recognized as critical components of sustainable groundwater management, but are threatened by multiple drivers of environmental change. Despite this importance, data that link drivers of hydrologic change to GDEs are scarce. This study adapts a land‐sea modeling framework by calibrating marine models with macroalgal experiments to quantitatively assess impacts of climate and land use change on submarine groundwater discharge (SGD) and subsequent habitat suitability for a native (Ulva lactuca) and an invasive (Hypnea musciformis) macroalgae in nearshore GDEs in Kona, Hawai'i. Lab analyses demonstrate that while U. lactuca grows optimally in low‐salinity, high‐nutrient waters, H. musciformis appears constrained to a salinity threshold and exhibits low growth in low salinity despite high nutrient concentrations. Land‐sea model results predict that while a dry future climate (Representative Concentration Pathway 8.5 mid‐century) coupled with increased urban development will likely reduce SGD, protecting native forests may prevent further loss of SGD quantity. This prevention thus partially mitigates the decline in habitat suitability of U. lactuca due to the combined effects of climate and land use change. Findings also suggest that, in contrast to the native U. lactuca, reductions in SGD may favor H. musciformis growth if introduced to Kona. Collectively, this study demonstrates the importance of considering multiple drivers of environmental change on GDEs. This study bridges experiments with models to spatially map changes in species abundance beyond their current habitat conditions, and thus informs management actions that can explicitly incorporate future human and climate‐related impacts.
Across the Pacific Islands, declining natural resources have contributed to a cultural renaissanc... more Across the Pacific Islands, declining natural resources have contributed to a cultural renaissance of customary ridge-to-reef management approaches. These indigenous and community conserved areas (ICCA) are initiated by local communities to protect natural resources through customary laws. To support these efforts, managers require scientific tools that track land-sea linkages and evaluate how local management scenarios affect coral reefs. We established an interdisciplinary process and modeling framework to inform ridge-to-reef management in Hawai'i, given increasing coastal development, fishing and climate change related impacts. We applied our framework at opposite ends of the Hawaiian Archipelago, in Hā'ena and Ka'ūpūlehu, where local communities have implemented customary resource management approaches through government-recognized processes to perpetuate traditional food systems and cultural practices. We identified coral reefs vulnerable to groundwater-based nutrients and linked them to areas on land, where appropriate management of human-derived nutrients could prevent increases in benthic algae and promote coral recovery from bleaching. Our results demonstrate the value of interdisciplinary collaborations among researchers, managers and community members. We discuss the lessons learned from our culturally-grounded, inclusive research process and highlight critical aspects of collaboration necessary to develop tools that can inform placed-based solutions to local environmental threats and foster coral reef resilience.
Coastal seascapes are productive and diverse land-sea systems that provide many valuable benefits... more Coastal seascapes are productive and diverse land-sea systems that provide many valuable benefits yet are increasingly threatened by human activity. Scaling up of nature-based solutions (NbS) to effectively protect, sustainably manage, and restore coastal seascapes is urgently required for mitigation of climate change and biodiversity loss while also providing socio-economic benefits. Evidence-based site selection is an important first step to improve the outcomes and avoid negative impacts when prioritizing NbS investments at national level. We developed a spatially explicit, integrative and culturally relevant ecosystem-based site selection process to identify a portfolio of seascapes for NbS consideration in the United Arab Emirates (UAE). The primary goal was to rank planning units based on potential for climate change mitigation action, positive impact to biodiversity and socio-economic benefits to people. The multi-criteria site-selection framework provided a rapid, transparen...
beach_seine_BACI.csv is a comma-separated file containing data from beach seine surveys of juveni... more beach_seine_BACI.csv is a comma-separated file containing data from beach seine surveys of juvenile fish populations from two sites on windward side of Oahu, Hawai
In 2007, due to growing concerns of declines in nearshore fisheries in Hawai‘i, a ban on gillnets... more In 2007, due to growing concerns of declines in nearshore fisheries in Hawai‘i, a ban on gillnets was implemented in designated areas around the island of O‘ahu in the main Hawaiian Islands. Utilizing a 17 year time-series of juvenile fish abundance beginning prior to the implementation of the gillnet ban, we examined the effects of the ban on the abundance of juveniles of soft-bottom associated fish species. Using a Before-After-Control-Impact (BACI) sampling design, we compared the abundance of targeted fishery species in a bay where gillnet fishing was banned (Kailua, O‘ahu), and an adjacent bay where fishing is still permitted (Waimānalo, O‘ahu). Our results show that when multiple juvenile fish species were combined, abundance declined over time in both locations, but the pattern varied for each of the four species groups examined. Bonefishes were the only species group with a significant BACI effect, with higher abundance in Kailua in the period after the gillnet ban. This study addressed a need for scientific assessment of a fisheries regulation that is rarely possible due to lack of quality data before enactment of such restrictions. Thus, we developed a baseline status of juveniles of an important fishery species, and found effects of a fishery management regulation in Hawai‘i
Hawaii_regime_drivers.csv is a comma-separated file containing data used to understand relationsh... more Hawaii_regime_drivers.csv is a comma-separated file containing data used to understand relationships between regime transitions and local and global drivers. The file includes data on human population density and degree heating weeks for each replicate found in Hawaii_regime_timeseries.csv. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan (donovan.maryk@gmail.com)
Hawaii_regime_timeseries.csv is a comma-separated file containing data used to investigate change... more Hawaii_regime_timeseries.csv is a comma-separated file containing data used to investigate changes in regimes over time. The file includes metadata for 1279 replicates across multiple years, 10 reef community metrics used to define regimes in a cluster analysis, and the geographic location of the replicate. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan (donovan.maryk@gmail.com)
Hawaii_regimes.csv is a comma-separated file containing data used to define reef regimes for the ... more Hawaii_regimes.csv is a comma-separated file containing data used to define reef regimes for the Hawaii Islands. The file includes metadata for 1027 replicates, 10 reef community metrics used to define regimes in a cluster analysis, and the resulting reef regime. Reef community metrics are averages of individual replicates grouped based on spatial proximity. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan (donovan.maryk@gmail.com)
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Papers by Kostantinos A Stamoulis