A comparative study of three fishery methods for sampling the invasive topmouth gudgeon (Pseudorasbora parva) in ponds

Journal of Fish Biology, Год журнала: 2023, Номер 102(5), С. 1121 - 1128

Опубликована: Март 1, 2023

Abstract Invasive fish threaten ponds' ecological status and their ecosystem services, therefore obtaining a representative sample of community composition is fundamental to fishery management, research nature conservation. Estimates the size distribution, density biomass topmouth gudgeon ( Pseudorasbora parva ) model species invasive in three ponds were compared among sampling methods: electrofishing, fish‐trapping throw‐netting. The study illustrates that fish, P. , can be detected by all tested fishing methods, yet our results clearly showed there are pronounced differences methods population characteristic estimates. Electrofishing throw‐netting gave biased information on distribution . Fish‐trapping reasonable estimates, while electrofishing underestimated it. All body increment between summer autumn sessions, neither nor recorded an its density. Our most reliable affordable method estimate characteristics despite more time‐demanding sampling. success depends mesh gear, operator skill habitat structure. cost‐effectiveness selected importance monitoring discussed. gear must considered carefully according aim monitoring.

Язык: Английский

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Making waves: The sensitivity of lakes to brownification and issues of concern in ecological status assessment

Water Research, Год журнала: 2023, Номер 249, С. 120964 - 120964

Опубликована: Дек. 6, 2023

Brownification or increasing water colour is a common problem in aquatic ecosystems. It affects both physico-chemical properties and biotic communities of the impacted waters. A view that lakes having low background are most sensitive to brownification. In this article, we show although low-colour high-colour respond differently brownification, effects on can be strong irrespective colour. For phytoplankton production, effect brownification positive at negative high colour, relative being strongest fish foraging, disturbance per unit may also highest conditions. Additionally, presently used classification systems mostly describe eutrophication do not account for Studies whole range needed indicators ecological status assessment must developed reveal Indicators distinguishing from those especially needed.

Язык: Английский

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Long-term monitoring of fish in a freshwater reservoir: Different ways of weighting complex spatial samples

Frontiers in Environmental Science, Год журнала: 2022, Номер 10

Опубликована: Дек. 13, 2022

Anthropogenic activities continue to pose the greatest challenges freshwater ecosystems. Therefore, long-term monitoring is essential for management and conservation of these resources. Monitoring programs bodies often use a range indicators, including biological elements such as fish. Existing European standard provides depth-stratified gillnet sampling approach mainly in benthic habitats at deepest part lakes account uneven distribution However, commonly used CEN (European Committee Standardization) protocol does not weight sufficiently habitat volumes underrepresent pelagic calculate whole-lake catch biomass per unit effort (CPUE BPUE, respectively). Extended (4 larger mesh-sizes added geometric series) data collected over 18 years (2004–2021) Římov Reservoir (Czech Republic) were method comparison on indices relative abundance fish: without volume-weighting two volume-weighted approaches. We also evaluated changes species composition trends fish population time. Results indicated interannual composition, abundance, community. The tended put greater emphasis which generally have CPUE BPUE. Consequently, approaches produced lower estimates parameters, with exception most dominant bleak Alburnus alburnus (L.). All consistently showed an increasing trend whole-reservoir decreasing study period. Following our assessment, we forward that considers Volume depth Stratum (VOST) weighting realistic approximation populations therefore recommend its use.

Язык: Английский

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An integrative approach to assess the impact of disturbance on native fish in lakes

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2023, Номер 99(1), С. 85 - 109

Опубликована: Авг. 24, 2023

ABSTRACT Freshwater fish are in a perilous state with more than 30% of species considered critically endangered. Yet significant ecological and methodological complexities constrain our ability to determine how disturbances impacting native communities. We review current methods used assess the responses communities, especially fish, disturbances, focus on lakes. These include contemporary population surveys, manipulative experimental approaches, paleolimnological approaches Indigenous Knowledge social histories. identify knowledge gaps, such as lack baseline data for an inability impact historical stressor response dynamics multi‐stressor environments, natural disturbance regimes. Our assessment highlights challenges filling these gaps using reviewed methods. advocate strongly implementation integrative approach that combines emerging technologies (i.e. molecular‐based techniques surveys paleolimnology) underutilised streams histories) which should be concert conventional This will allow researchers key drivers decline degree change, enable informed successful management actions.

Язык: Английский

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Environmental DNA in different media reveals distribution characteristics and assembly mechanisms of fish assemblages in a complex river–lake system

Web Ecology, Год журнала: 2024, Номер 24(2), С. 59 - 70

Опубликована: Авг. 2, 2024

Abstract. Capture-based methods are commonly used for biomonitoring fish assemblages in freshwater. The recent advancement environmental DNA (eDNA) metabarcoding provides a sensitive, cost-effective, and non-intrusive alternative to traditional methods. Nevertheless, the effectiveness of this approach river–lake systems has yet be assessed, there is ongoing debate regarding selection sampling media. In study, we investigated based on approaches eDNA method by analyzing water sediment from 30 locations along Baiyang Lake its inflow rivers (China). results showed that 21 species were identified methods, total 29 detected using eDNA, with 22 found river 25 lake 27 surface samples. Nine benthic exclusively sediment. community composition lakes revealed similar, reflecting biotic homogenization system. A neutral model (NCM) analysis not dominated random processes (5.3 % 2.7 concordance model, respectively), while more support (50.2 %). Temperature was main factor correlated NH3–N TP factors correlating eDNA.

Язык: Английский

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Pelagic niche shift by fishes following restorations of a eutrophic lake

Hydrobiologia, Год журнала: 2024, Номер 852(2), С. 289 - 303

Опубликована: Май 30, 2024

Abstract Lake restoration by biomanipulation or phosphorus fixation has been commonly applied methods to improve the ecological status of lakes. However, effects lake on food-web dynamics are still poorly understood, especially when and nutrient used simultaneously. This study investigated combined a 70% fish removal (mainly roach ( Rutilus rutilus Linnaeus, 1758) bream Abramis brama Phoslock® treatment trophic ecology in Lyngsø (area: 9.6 ha, mean depth: 2.6 m), Denmark. The resulted decreased levels, increased water clarity, coverage more structurally complex submerged macrophytes. Following restoration, significant changes diets dominant species were observed. Stomach content analyses perch Perca fluviatilis revealed significantly reduced detritus utilization foraging macrophytes macrophyte living invertebrates. Results from stable isotope mixing models indicated shift littoral benthic pelagic food resources species. Our findings provide further evidence that restorations can lead substantial webs communities, thereby potentially facilitating toward an state resembling pristine reference state, less influenced anthropogenic factors.

Язык: Английский

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Are perch (Perca fluviatilis L.) getting larger or smaller in Swedish lakes?

Ecology Of Freshwater Fish, Год журнала: 2023, Номер 32(4), С. 735 - 749

Опубликована: Март 30, 2023

Abstract Space‐for‐time approaches are often used to indicate current or future changes over time. A European gillnet standard facilitates spatial‐scale comparisons of fish communities in lakes. Fish size was generally lower and densities higher warmer lakes, but less is known about trends decadal time scales. We analysed the perch ( Perca fluviatilis L.) 2121 Swedish lakes sampled during 1996–2021. The aim test whether changed time, were similar southern northern regions. mean length occurrence relative abundance classes from smallest (<100 mm) largest individuals (≥350 mm), at 1 5 years. large data set find general within regions, within‐lake tested for 40 time‐series decreased increased region. proportion southern, not most trend an increasing largest‐sized both regions dataset. average region dataset also appeared as predominant although opposite occurred some each This study revealed that age while more variable found 5. duration growth season has frame present study, other may differ between same recommend studies based on series monitoring, including possible reasons very

Язык: Английский

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Ecological implications of fish removal: Insights from gut‐content analysis of roach (Rutilus rutilus) and European perch (Perca fluviatilis) in a eutrophic shallow lake

Journal of Fish Biology, Год журнала: 2023, Номер 103(6), С. 1321 - 1334

Опубликована: Авг. 22, 2023

Abstract Large reductions in fish biomass are common both as a method of managing lake ecosystems by removals (biomanipulation) and naturally occurring kills. To further understand how change feeding patterns fish, we studied the diets small‐ to medium‐sized roach ( Rutilus rutilus ) European perch Perca fluviatilis on monthly basis using gut‐content analysis during an 18‐month period before after whole‐lake removal eutrophic shallow lake. Further, performed in‐depth analyses zoobenthos communities profundal littoral zones, well analysed zooplankton community pelagic parts estimate abundance potential diet items. We found that, general, there was trend toward increased zoobenthivory species among all‐sized removal, regardless prior preference. Reduced piscivory larger (>150 mm) reduced zooplanktivory smaller (<150 were also observed. Moreover, short high (all sizes) shifted their daphnids, which likely caused decrease daphnid population. suggest that such periodical across size groups may lead unexpectedly top‐down control restoration removal.

Язык: Английский

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Fish scale stable isotopes as potential indicators of nutrient pollution: Exploring the response of roach (Rutilus rutilus) scale δ15N and δ13C to a gradient of land use disturbance

The Science of The Total Environment, Год журнала: 2022, Номер 865, С. 161198 - 161198

Опубликована: Дек. 30, 2022

Язык: Английский

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Reconstructing the response of native fish in lakes to historical anthropogenic disturbances

Опубликована: Фев. 26, 2024

<p><strong>There is a well-documented decline in the native fish of Aotearoa New Zealand, with 74% species currently categorised as at risk or threatened. There an urgent need for more data on how communities respond to complex and synergistic drivers that are causing their biodiversity loss lakes. Paleolimnological studies overcome limitation short monitoring records allow research which explores impact disturbances wider ecosystem. Until recently ability detect changes historical has been limited by lack fossil remains left behind fish. This thesis explored use sedimentary DNA (sedDNA) track sediment cores. I began reviewing available methods used measure infer disturbance. These included contemporary population surveys, manipulative experimental methods, paleolimnological approaches, Indigenous Knowledge social histories. The benefits limitations these approaches were identified discussed within context eutrophication, land change introduced highlighted value environmental based histories different can compensate inherent other methodologies. demonstrated application integrative methodological approach could greatly advance knowledge freshwater lakes anthropogenic disturbances. sedDNA emerging tool paleolimnology but ongoing method development. Secondly, tested five various modifications establish desorb extracellular from aquatic sediments. characterised recovery sediments using droplet digital PCR (ddPCR) assays targeting eel (Anguilla australis, Anguilla dieffenbachii) perch (Perca fluviatilis). A range masses (0.25–20 g) assessed optimal amount required accurately assess sedDNA. An optimised extraction was developed my subsequent chapters. effect core location (nearshore verses depocentre), mussel molecular (ddPCR versus metabarcoding) detection cores small eutrophic lake Wairarapa region (Aotearoa Zealand). higher detections nearshore compared depocenter most likely related locality target species. Differential caused ecology biomass. ddPCR sensitive than metabarcoding approach. Target negatively impacted reduction total concentration older results current techniques result inconsistent temporal spatial species, especially sediments.</strong></p><p>I reconstructed abundance diversity community over 1390 years Gisborne Zealand) specific suite traditional e.g., pollen analysis, X-ray fluorescence hyperspectral scanning, trace metal analysis explore communities. Generalised additive mixed models distinct shifts composition, notably Galaxias concomitant early starting around 1350 CE. significant 1950 CE aligned agricultural intensification both phytoplankton zooplankton suggested major mostly external (i.e., intensification) correlated internal productivity eutrophication) food web composition dietary shifts). study emphasised potential (with appropriate considerations) investigate disturbance will assist future management conservation lakes.</p>

Язык: Английский

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