scholarly journals Integrating ecological monitoring and local ecological knowledge to evaluate conservation outcomes

2021 ◽  
Author(s):  
Michelle-María Early-Capistrán ◽  
Elena Solana-Arellano ◽  
F. Alberto Abreu-Grobois ◽  
Gerardo Garibay-Melo ◽  
Jeffrey A. Seminoff ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Local Ecological Knowledge ◽  
Chelonia Mydas ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Ecological Knowledge ◽  
Population Declines ◽  
Conservation Actions ◽  
Ecological Science

Successful conservation of long-lived species requires reliable understanding of long-term trends and historical baselines. Using a green turtle (Chelonia mydas) foraging aggregation in the northern Gulf of California, Mexico as case study, we integrated scientific monitoring data with historic catch rate reconstructions derived from Local Ecological Knowledge (LEK). Models fit to LEK and monitoring data indicate that turtle abundance is increasing, but only after ~40 years of safeguarding the species' nesting and foraging habitats in Mexico. However, as population declines occurred 75% faster than increases, and current abundance is at ~60% of historical baseline levels, indicating the need for sustained, long-term conservation actions. This study demonstrates the potential of linking LEK and ecological science to provide critical information for conservation, by establishing reference baselines and gauging population status, while promoting equitable and sustainable futures for local communities.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2021 ◽  
Vol 19 (3) ◽  
Author(s):  
Vanessa Tobias ◽  
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are the result of changing water clarity affecting catchability.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2021 ◽  
Author(s):  
Vanessa Tobias
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

scholarly journals Overview on the distribution of gorgonian species in Tunisian marine coastal waters (central Mediterranean)

2018 ◽  
Vol 82 (1) ◽  
pp. 55 ◽  
Author(s):  
Raouia Ghanem ◽  
Emna Soufi Kechaou ◽  
Jamila Ben Souissi ◽  
Joaquim Garrabou
Keyword(s):  
Coastal Waters ◽  
Local Ecological Knowledge ◽  
Conservation Status ◽  
Ecological Knowledge ◽  
Central Mediterranean ◽  
Management Actions ◽  
Conservation Actions ◽  
Gorgonian Species ◽  
Species Richness And Abundance ◽  
And Function

Gorgonian species play an important ecological role in the structure and function of marine communities. Human activities are negatively affecting the conservation status of gorgonian populations in the Mediterranean. Acquiring knowledge of gorgonian distribution is therefore a key step required to promote efficient management and conservation actions. However, information on the distribution of gorgonian species is lacking in many Mediterranean areas. This study aimed to provide an overview of the geographic and bathymetric distributions of gorgonians in the coastal waters of the Tunisian coast (1136 km). The sampling design encompassed three sectors, 27 localities and 87 sites. Information was collected from scuba diving (26 sites) and local ecological knowledge surveys of fishermen and divers (132 interviews), as well as from a literature review. Overall, the occurrence of eight gorgonians was confirmed at 54 out of the 87 sites surveyed in Tunisian coastal waters (7-120 m depth). The species that were found were Eunicella singularis, Eunicella cavolini, Paramuricea clavata, Paramuricea macrospina, Leptogorgia sarmentosa, Eunicella verrucosa, Corallium rubrum and Ellisella paraplexauroides. The highest gorgonian species richness and abundance was recorded in northern, followed by eastern Tunisian waters. In the southern areas only one species was recorded. This pattern was related to the rocky substrate that characterizes the northern and eastern coasts of Tunisia. This study is the first to report the occurrence of E. singularis, E. cavolini, E. verrucosa and Leptogorgia sarmentosa in northern and eastern Tunisian waters. The results are discussed in the hope of guiding future conservation and management actions for gorgonian assemblages in Tunisia.

scholarly journals Population decline and range contraction of the Egyptian Vulture Neophron percnopterus in the Balkan Peninsula

2014 ◽  
Vol 25 (4) ◽  
pp. 440-450 ◽  
Author(s):  
METODIJA VELEVSKI ◽  
STOYAN C. NIKOLOV ◽  
BEN HALLMANN ◽  
VLADIMIR DOBREV ◽  
LAVRENTIS SIDIROPOULOS ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Population Decline ◽  
Balkan Peninsula ◽  
Population Declines ◽  
Egyptian Vulture ◽  
Breeding Grounds ◽  
Conservation Actions ◽  
Causes Of Mortality ◽  
Yugoslav Republic

SummaryThe Egyptian Vulture has been classified as ‘Endangered’ due to a rapid population decline in India and long term declines in Europe and Africa. Although the species has been reported to be declining in Eastern Europe, no quantitative assessment of the magnitude or the causes for population declines are available. We used monitoring data from the Balkan Peninsula to estimate changes in population size and extent of occurrence of Egyptian Vultures between 1980 and 2013. We quantified population trends in three countries (Bulgaria, Greece and the former Yugoslav Republic [FYR] of Macedonia) to assess whether population declines are similar within the Balkan range states. We found a rapid and consistent decline of the Egyptian Vulture population that was largely similar among the three countries (λ = 0.940 in FYR of Macedonia, 0.951 in Bulgaria, 0.920 in Greece). As a consequence of population declines, the breeding range of Egyptian Vultures has contracted and the population in the Balkan Peninsula has fragmented into six subpopulations separated by more than 80 km. Population declines may be driven by factors such as poisoning, electrocution, direct persecution and changes in food availability which operate at large spatial scales and affect birds both on breeding grounds as well as during migration and wintering. Because the relative importance of threats to the survival of Egyptian Vultures are poorly understood, there is a critical need for research into causes of mortality and potential conservation actions that may halt and reverse population declines.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2021 ◽  
Author(s):  
Vanessa Tobias
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

scholarly journals Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

2020 ◽  
Author(s):  
Vanessa Tobias
Keyword(s):  
San Francisco ◽  
Water Clarity ◽  
Ecological Monitoring ◽  
Monitoring Data ◽  
Delta Smelt ◽  
Individual Based Simulation ◽  
The Relationship ◽  
True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

scholarly journals Conserving Mekong Megafishes: Current Status and Critical Threats in Cambodia

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1820 ◽  
Author(s):  
Teresa Campbell ◽  
Kakada Pin ◽  
Peng Ngor ◽  
Zeb Hogan
Keyword(s):  
Body Size ◽  
Habitat Degradation ◽  
Local Ecological Knowledge ◽  
Conservation Status ◽  
Current Status ◽  
Conservation Strategies ◽  
Ecological Knowledge ◽  
Population Declines ◽  
Illegal Fishing ◽  
Maximum Body

Megafishes are important to people and ecosystems worldwide. These fishes attain a maximum body weight of ≥30 kg. Global population declines highlight the need for more information about megafishes’ conservation status to inform management and conservation. The northern Cambodian Mekong River and its major tributaries are considered one of the last refugia for Mekong megafishes. We collected data on population abundance and body size trends for eight megafishes in this region to better understand their conservation statuses. Data were collected in June 2018 using a local ecological knowledge survey of 96 fishers in 12 villages. Fishers reported that, over 20 years, most megafishes changed from common to uncommon, rare, or locally extirpated. The most common and rarest species had mean last capture dates of 4.5 and 95 months before the survey, respectively. All species had declined greatly in body size. Maximum body weights reported by fishers ranged from 11–88% of their recorded maxima. Fishers identified 10 threats to megafishes, seven of which were types of illegal fishing. Electrofishing was the most prevalent. Results confirm that Mekong megafishes are severely endangered. Species Conservation Strategies should be developed and must address pervasive illegal fishing activities, alongside habitat degradation and blocked migrations, to recover declining populations.

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