Optimal gillnet sampling design for the estimation of fish community indicators in heterogeneous freshwater ecosystems

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F17%3A00479477" target="_blank" >RIV/60077344:_____/17:00479477 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60076658:12310/17:43895380

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.ecolind.2017.02.036" target="_blank" >http://dx.doi.org/10.1016/j.ecolind.2017.02.036</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ecolind.2017.02.036" target="_blank" >10.1016/j.ecolind.2017.02.036</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Optimal gillnet sampling design for the estimation of fish community indicators in heterogeneous freshwater ecosystems

Popis výsledku v původním jazyce

Monitoring of biota in heterogeneous ecosystems requires sampling in different habitats and across environmental gradients. The resulting multivariate community data are typically aggregated into one or several indicator values for the entire ecosystem, but the relationship between the robustness of such indicators and sampling effort, including the identification of minimum acceptable sampling designs, is not fully understood. nWe address this issue for multi-mesh gillnet sampling of freshwater fish communities in deep-valley reservoirs, using data from 29 detailed annual surveys in eight reservoirs in the Czech Republic that account for the inherent longitudinal and depth gradients and the qualitatively different benthic and pelagic habitats. We evaluate the performance of eight sampling scenarios, created by variously reducing the full dataset. To this end, we use 31 fish-based, community-, size- and species-level indicators calculated separately for benthic and pelagic habitats, and fit the relationships between the indicator values based on the reduced and full sampling design using Bayesian generalized linear models. nThe ability of reduced data to estimate the true indicator value across the entire dataset, expressed as the adjusted R-2 value of the best model for the given indicator, increased with sampling effort. However, the relationships differed between indicators: R-2 values were higher for abundance-based than for biomass-based indicators. We identified three suitable reduced sampling designs: (1) sampling the entire longitudinal profile in the epilimnion, (2) same as before but limited to one sampling layer closest to the surface, and (3) sampling all depth strata at the farthest points of the longitudinal gradient (i.e., dam and tributary). These results demonstrate that, in order to obtain robust estimates of fish community indicators, current gillnet sampling protocols can be optimized to reduce effort and minimize unwanted fish mortality.

Název v anglickém jazyce

Optimal gillnet sampling design for the estimation of fish community indicators in heterogeneous freshwater ecosystems

Popis výsledku anglicky

Monitoring of biota in heterogeneous ecosystems requires sampling in different habitats and across environmental gradients. The resulting multivariate community data are typically aggregated into one or several indicator values for the entire ecosystem, but the relationship between the robustness of such indicators and sampling effort, including the identification of minimum acceptable sampling designs, is not fully understood. nWe address this issue for multi-mesh gillnet sampling of freshwater fish communities in deep-valley reservoirs, using data from 29 detailed annual surveys in eight reservoirs in the Czech Republic that account for the inherent longitudinal and depth gradients and the qualitatively different benthic and pelagic habitats. We evaluate the performance of eight sampling scenarios, created by variously reducing the full dataset. To this end, we use 31 fish-based, community-, size- and species-level indicators calculated separately for benthic and pelagic habitats, and fit the relationships between the indicator values based on the reduced and full sampling design using Bayesian generalized linear models. nThe ability of reduced data to estimate the true indicator value across the entire dataset, expressed as the adjusted R-2 value of the best model for the given indicator, increased with sampling effort. However, the relationships differed between indicators: R-2 values were higher for abundance-based than for biomass-based indicators. We identified three suitable reduced sampling designs: (1) sampling the entire longitudinal profile in the epilimnion, (2) same as before but limited to one sampling layer closest to the surface, and (3) sampling all depth strata at the farthest points of the longitudinal gradient (i.e., dam and tributary). These results demonstrate that, in order to obtain robust estimates of fish community indicators, current gillnet sampling protocols can be optimized to reduce effort and minimize unwanted fish mortality.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10617 - Marine biology, freshwater biology, limnology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Ecological Indicators

ISSN

1470-160X

e-ISSN

—

Svazek periodika

77

Číslo periodika v rámci svazku

JUN

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

9

Strana od-do

368-376

Kód UT WoS článku

000406435800038

EID výsledku v databázi Scopus

2-s2.0-85014430867