Fish Assemblages in Large Tropical Reservoirs: Overview of Fish Population Monitoring Methods

2016 ◽  
Vol 24 (2) ◽  
pp. 160-177 ◽  
Author(s):  
Anne Tessier ◽  
Stephane Descloux ◽  
Raymond Lae ◽  
Maud Cottet ◽  
Pierre Guedant ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Population Monitoring ◽  
Fish Population ◽  
Monitoring Methods ◽  
Tropical Reservoirs

scholarly journals Over 50 years of fish community monitoring in Illinois’ large rivers: The evolution of methods used by the Illinois Natural History Survey’s Long-term Survey and Assessment of Large-River Fishes in Illinois

2019 ◽  
Vol 41 (1) ◽  
Author(s):  
Mark W. Fritts ◽  
Jason A. DeBoer ◽  
Daniel K. Gibson-Reinemer ◽  
Benjamin J. Lubinski ◽  
Michael A. McClelland ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Monitoring Program ◽  
Population Monitoring ◽  
Fish Population ◽  
Large River ◽  
Large Rivers ◽  
Illinois River ◽  
Pulsed Dc ◽  
Community Monitoring

This document describes the methodological evolution of the Long-Term Illinois Rivers Fish Population Monitoring Program since its inception. The principal changes include a shift from fixed-site sampling to stratified random sampling at the reach scale to benefit statistical robustness and a concurrent shift from AC electrofishing to pulsed-DC electrofishing to increase the breadth of the diversity and size classes of fishes encountered. These changes in methodology were implemented during the 2016 field season and are based on quantitative assessments of program data and other results from recent peer-reviewed publications. These refinements will likely improve the program’s ability to detect and describe patterns and trends in the fish assemblages of the Illinois River and other large rivers of Illinois and the Midwest.

scholarly journals Benthic and fish population monitoring associated with a marine protected area in the nearshore waters of Grenada, Eastern Caribbean

2015 ◽  
Vol 60 ◽  
pp. 71 ◽  
Author(s):  
Robert Anderson ◽  
Clare Morrall ◽  
Steve Nimrod ◽  
Robert Balza ◽  
Craig Berg ◽  
...  
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Population Monitoring ◽  
Fish Population ◽  
Eastern Caribbean ◽  
Para Determinar ◽  
Los Grupos

<span>Un estudio sobre poblaciones bentónicas y de peces fue realizado en cinco localidades en la zona costera en el suroeste de Grenada entre 2008 y 2010. Dos sitios se ubicaron en una Área Marina Portegida (AMP) recientemente creada. Para determinar la cobertura se utilizaron foto-cuadrantes (FQ) y transectos de intersección de puntos (TIP). Las algas fueron el principal componente del bentos, aumentando significativamente de 45,9% en 2008 a 52,7% en 2010 (TIP). Las algas también fueron predominantes (61,9%-59,3) en los FQ, aunque las diferencias anuales no fueron significativas. La cobertura de corales pétreos tenía un ámbito de 16,5% a 15,4% (TIP) y de 11,4% a 12,0% (FQ), sin diferencias significativas entre años. Los corales ramificados e incrustantes fueron más frecuentes que los corales masivos. En los tres años no hubo diferencias significativas entre las AMPs y las áreas no protegidas. La abundancia relativa de peces a lo largo de un transecto de 30x2m no varió significativamente entre los años, sin embargo, la densidad de peces decreció significativamente a través de los años, para los grupos principales.<em> Chromis</em> spp. predominó con 65,2% en 2008 y 49,8% en 2012, seguido por damiselas territoriales, 11,1% y 15,5%, y los lábridos aumentaron de 7,3% a 15,5%. Tanto la coberura del sustrato como los datos de peces indican una comunidad estable pero degradada. Sondeos anuales están planeados para el futuro. Los datos existentes y futuros de este proyecto serán muy útiles para determinar la eficacia de la gestión de las AMPs y el estado de salud de los sistemas arrecifales de Grenada.</span>

scholarly journals Effects of enhanced hydrological connectivity on Mediterranean salt marsh fish assemblages with emphasis on the endangered Spanish toothcarp (Aphanius iberus)

2016 ◽  
Author(s):  
Patricia Prado ◽  
Carles Alcaraz ◽  
Lluis Jornet ◽  
Nuno Alberto Caiola ◽  
Carles Ibáñez
Keyword(s):  
Salt Marsh ◽  
Fish Community ◽  
Fish Assemblages ◽  
Fish Population ◽  
Important Variable ◽  
Hydrological Connectivity ◽  
Local Diversity ◽  
Large Numbers ◽  
Negative Effect ◽  
Migratory Movements

The hydrological connectivity between the salt marsh and the sea was partially restored in a Mediterranean wetland containing isolated ponds resulting from former salt extraction and aquaculture activities. A preliminary assessment provided evidence that ponds farther from the sea hosted very large numbers of the endangered Spanish toothcarp, Aphanius iberus, suggesting that individuals had been trapped and consequently reach unnaturally high densities. In order to achieve both habitat rehabilitation and toothcarp conservation, efforts were made to create a gradient of hydrologically connected areas, including isolated fish reservoirs, semi-isolated, and connected salt marsh–sea areas that could allow migratory movements of fish and provide some protection for A. iberus. The fish community was monitored prior to, and for three years after rehabilitation. Results showed an increase in the number of fish species within semi-isolated areas (Zone A), relative to connected areas (Zone B), while at the assemblage level, structural differences between zones were higher than interannual variability. GLMs evidenced that distance to the sea was the most important variable explaining the local diversity of the fish community after restoration, with occasional influence of other factors such as temperature, and depth. The abundance of A. iberus was consistently higher in semi-isolated areas at greater distances from the sea, but a decline occurred in both zones and in isolated reservoir ponds after restoration efforts, which may be attributable to dispersal to adjacent habitats, and to interannual differences in recruitment success. A negative effect of restoration works on fish population cannot be excluded, but the final outcome of the intervention likely needs a longer period .

Detecting, counting and following the giants of the sea: a review of monitoring methods for aquatic megavertebrates in the Caribbean

2019 ◽  
Vol 46 (7) ◽  
pp. 545
Author(s):  
D. N. Castelblanco-Martínez ◽  
M. P. Blanco-Parra ◽  
P. Charruau ◽  
B. Prezas ◽  
I. Zamora-Vilchis ◽  
...  
Keyword(s):  
Critical Role ◽  
Critical Evaluation ◽  
Population Monitoring ◽  
Tourism Industry ◽  
Caribbean Region ◽  
Monitoring Methods ◽  
Photo Identification ◽  
Important Region ◽  
The Caribbean ◽  
Marine Megafauna

Abstract The Caribbean is a mega-diverse and bio-geographically important region that consists of the Caribbean Sea, its islands, and surrounding coastlines. Among the billions of aquatic species inhabiting this region, the mega-vertebrates stand out for their social, economic and ecologic relevance. However, the Caribbean has been threatened by climate change, poverty, pollution, environmental degradation and intense growth of the tourism industry, affecting megafauna species directly and indirectly. Population monitoring plays a critical role in an informed conservation process and helps guide management decisions at several scales. The aim of the present review was to critically examine the methods employed for monitoring marine megafauna in the Caribbean, so as to create a framework for future monitoring efforts. In total, 235 documents describing protocols for the monitoring of sirenians, cetaceans, elasmobranchs, sea turtles and crocodilians in the Caribbean region, were reviewed. The methods included community-based monitoring (interviews, citizen science and fisheries monitoring), aerial surveys (by manned and unmanned aerial vehicles), boat-based surveys (including manta tow, and side-scan sonars), land-based surveys, acoustic monitoring, underwater surveys, baited remote underwater video, mark–recapture, photo-identification and telemetry. Monitoring efforts invested on aquatic megafauna in the Caribbean have been highly different, with some species and/or groups being prioritised over others. The present critical review provides a country-based overview of the current and emerging methods for monitoring marine megafauna and a critical evaluation of their known advantages, disadvantages and biases.

scholarly journals Effects of enhanced hydrological connectivity on Mediterranean salt marsh fish assemblages with emphasis on the endangered Spanish toothcarp (Aphanius iberus)

2016 ◽  
Author(s):  
Patricia Prado ◽  
Carles Alcaraz ◽  
Lluis Jornet ◽  
Nuno Alberto Caiola ◽  
Carles Ibáñez
Keyword(s):  
Salt Marsh ◽  
Fish Community ◽  
Fish Assemblages ◽  
Fish Population ◽  
Important Variable ◽  
Hydrological Connectivity ◽  
Local Diversity ◽  
Large Numbers ◽  
Negative Effect ◽  
Migratory Movements

The hydrological connectivity between the salt marsh and the sea was partially restored in a Mediterranean wetland containing isolated ponds resulting from former salt extraction and aquaculture activities. A preliminary assessment provided evidence that ponds farther from the sea hosted very large numbers of the endangered Spanish toothcarp, Aphanius iberus, suggesting that individuals had been trapped and consequently reach unnaturally high densities. In order to achieve both habitat rehabilitation and toothcarp conservation, efforts were made to create a gradient of hydrologically connected areas, including isolated fish reservoirs, semi-isolated, and connected salt marsh–sea areas that could allow migratory movements of fish and provide some protection for A. iberus. The fish community was monitored prior to, and for three years after rehabilitation. Results showed an increase in the number of fish species within semi-isolated areas (Zone A), relative to connected areas (Zone B), while at the assemblage level, structural differences between zones were higher than interannual variability. GLMs evidenced that distance to the sea was the most important variable explaining the local diversity of the fish community after restoration, with occasional influence of other factors such as temperature, and depth. The abundance of A. iberus was consistently higher in semi-isolated areas at greater distances from the sea, but a decline occurred in both zones and in isolated reservoir ponds after restoration efforts, which may be attributable to dispersal to adjacent habitats, and to interannual differences in recruitment success. A negative effect of restoration works on fish population cannot be excluded, but the final outcome of the intervention likely needs a longer period .

scholarly journals Estimating fish population abundance by integrating quantitative data on environmental DNA and hydrodynamic modelling

2018 ◽  
Author(s):  
Keiichi Fukaya ◽  
Hiroaki Murakami ◽  
Seokjin Yoon ◽  
Kenji Minami ◽  
Yutaka Osada ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Cost Effective ◽  
Population Monitoring ◽  
Fish Population ◽  
Abundance Estimation ◽  
Population Abundance ◽  
Jack Mackerel ◽  
Non Invasive ◽  
Quantitative Measurements ◽  
Japanese Jack Mackerel

AbstractWe propose a general framework of abundance estimation based on spatially replicated quantitative measurements of environmental DNA in which production, transport, and degradation of DNA are explicitly accounted for. Application to a Japanese jack mackerel (Trachurus japonicus) population in Maizuru Bay revealed that the method gives an estimate of population abundance comparable to that of a quantitative echo sounder method. These findings indicate the ability of environmental DNA to reliably reflect population abundance of aquatic macroorganisms and may offer a new avenue for population monitoring based on the fast, cost-effective, and non-invasive sampling of genetic information.

scholarly journals Learning to count: adapting population monitoring for Endangered huemul deer Hippocamelus bisulcus to meet conservation objectives

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
P Corti ◽  
C Saucedo ◽  
J Galaz
Keyword(s):  
Survey Data ◽  
Survey Methods ◽  
Cost Effective ◽  
Population Monitoring ◽  
Population Trends ◽  
Monitoring Methods ◽  
Monitoring Method ◽  
Hippocamelus Bisulcus ◽  
Detection Probabilities ◽  
Current Survey

Considerable efforts have been invested in recent years to improve methods for both data collection and analyses required for population monitoring. Where historical or current estimates of population size are not adjusted for detection probabilities they may be too inaccurate to provide meaningful estimates of trends and thus monitoring methods need to be adapted. Here, we use data from the Endangered huemul deer Hippocamelus bisulcus to outline a framework to develop accurate robust estimates of detection probabilities that can be incorporated into new surveys in a cost-effective way and applied to existing survey data sets. In particular, by retroactively estimating detection probabilities for surveys of huemul, we show that current survey methods for huemul are inadequate to determine population trends reliably. Based on these results we propose a new monitoring method for the huemul and discuss the importance of estimating accuracies of historical survey data to ensure that changes in the abundance of the species reflect real population trends and are not an artefact of variation over time in the accuracy of survey data. © 2010 Fauna & Flora International.

scholarly journals Learning to count: adapting population monitoring for Endangered huemul deer Hippocamelus bisulcus to meet conservation objectives

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
P Corti ◽  
C Saucedo ◽  
J Galaz
Keyword(s):  
Survey Data ◽  
Survey Methods ◽  
Cost Effective ◽  
Population Monitoring ◽  
Population Trends ◽  
Monitoring Methods ◽  
Monitoring Method ◽  
Hippocamelus Bisulcus ◽  
Detection Probabilities ◽  
Current Survey

Considerable efforts have been invested in recent years to improve methods for both data collection and analyses required for population monitoring. Where historical or current estimates of population size are not adjusted for detection probabilities they may be too inaccurate to provide meaningful estimates of trends and thus monitoring methods need to be adapted. Here, we use data from the Endangered huemul deer Hippocamelus bisulcus to outline a framework to develop accurate robust estimates of detection probabilities that can be incorporated into new surveys in a cost-effective way and applied to existing survey data sets. In particular, by retroactively estimating detection probabilities for surveys of huemul, we show that current survey methods for huemul are inadequate to determine population trends reliably. Based on these results we propose a new monitoring method for the huemul and discuss the importance of estimating accuracies of historical survey data to ensure that changes in the abundance of the species reflect real population trends and are not an artefact of variation over time in the accuracy of survey data. © 2010 Fauna & Flora International.

scholarly journals Multi-surveyor detection-mark-redetection as a powerful tool for butterfly population monitoring in the pre-imaginal stage

2022 ◽  
Author(s):  
Heiko Hinneberg ◽  
Jörg Döring ◽  
Gabriel Hermann ◽  
Gregor Markl ◽  
Jennifer Theobald ◽  
...  
Keyword(s):  
Population Monitoring ◽  
Population Estimates ◽  
Life Stages ◽  
Monitoring Methods ◽  
Model Assumption ◽  
Clear Cut ◽  
Detection Probabilities ◽  
Nymphalid Butterfly ◽  
Butterfly Population ◽  
Sessile Organisms

1. For many elusive insect species, which are difficult to cover by standard monitoring schemes, innovative monitoring methods are needed to gain robust data on population trends. We suggest a monitoring of overwintering larvae for the endangered nymphalid butterfly Limenitis reducta. 2. We tested one removal and three detection-mark-redetection (DMR) approaches in a field study in the “Alb-Donau” region, Germany. We replaced movement of the study organisms by random movement of multiple different surveyors, and we examined the model assumption of equal detectability using simulations. 3. Our results indicate that multi-surveyor removal/DMR techniques are suitable for estimating abundance of overwintering L. reducta larvae. Detection probabilities varied with surveyor experience and the uncertainty of population estimates increased with a decrease in personnel expenditure. Estimated larval densities on a spruce clear-cut ranged between one and three individuals per 100 m². 4. We suggest a detection-mark-redetection (DMR) approach with three trained surveyors for the monitoring of L. reducta populations in the pre-imaginal stage. Besides L. reducta, the proposed method is likely to be suitable for other insect taxa with specific immobile life-stages and some sessile organisms, e.g. corals, elusive plants, or fungi.

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