Search results for "Fish"

Early-season river entry of adult Atlantic salmon: its dependency on environmental factors

2003

River entry of adult Atlantic salmon Salmo salar into the River Tornionjoki, monitored during three migration seasons (1997–1999) by horizontal split-beam hydroacoustics, started early in June when water temperature was c. 9° C and when the discharge varied between 1700 and 2000 m3 s−1. In 1997 and 1999, migration peaked during the latter half of June, 17 days after the peak flood, at water temperatures ranging from 11· 5 to 18·2° C. Few statistically significant correlations were observed between river entry and six measured environmental factors and those that were significant were not persistent over the years. The strongest correlation ( r = −0·60) was between the number of upstream mig…

Vegetation Types Mapping Using Multi-Temporal Landsat Images in the Google Earth Engine Platform

2021

Vegetation Types (VTs) are important managerial units, and their identification serves as essential tools for the conservation of land covers. Despite a long history of Earth observation applications to assess and monitor land covers, the quantitative detection of sparse VTs remains problematic, especially in arid and semiarid areas. This research aimed to identify appropriate multi-temporal datasets to improve the accuracy of VTs classification in a heterogeneous landscape in Central Zagros, Iran. To do so, first the Normalized Difference Vegetation Index (NDVI) temporal profile of each VT was identified in the study area for the period of 2018, 2019, and 2020. This data revealed strong se…

Effect of cobalt and silver nanoparticles and ions on Lumbricus rubellus health and on microbial community of earthworm faeces and soil

2016

The aim of this study was to investigate the impact of silver and cobalt, supplied both as ions and nanoparticles (Ag+, Co2+, AgNPs, CoNPs) through contaminated food to earthworms (Lumbricus rubellus), on their health as well as on microbial community of both soil and earthworm faeces. Earthworms and microbes were exposed to the contaminants in laboratory microcosms with artificial soil. Contaminants were supplied once a week for 5 weeks by spiking them on horse manure. The accumulation of CoNPs and Co2+ in earthworm tissues was two and three times greater than AgNPs and Ag+, respectively. Except for AgNPs, contaminants significantly affected microbial community structure of earthworm faece…

Correction: Size does matter—the eco-evolutionary effects of changing body size in fish

2021

Are people willing to pay for eco-labeled wild seafood? An overview

2017

In the last two decades, eco-labeled seafood has been becoming an instrument of sustainability directed towards consumers, addressing a market-based incentive for better management of fisheries. In this context, several studies across the countries have been conducted about how much consumers are willing to pay for fish caught by certifiably sustainable fishing activities. In this direction, the aim of this study was to systematize the available information about the willingness-topay (WTP) more for eco-labeled wild seafood. Therefore, only papers published on ISI journals were searched on “Web of Knowledge” and “SciVerse Scopus” platforms, using the combinations of the following key words:…

Invasion biology in non‐free‐living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in …

2013

In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entoc…

Status, distribution and conservation of Kentish plover <em>Charadrius alexandrinus</em> (Aves, Charadriiformes) in Sicily

2021

The Kentish Plover Charadrius alexandrinus is a sensitive species whose national breeding population has been undergoing a sharp decrease, up to 50%, in 2010 compared to the previous decade. Due to the lack of updated data and fragmented knowledge about its current status and distribution in Sicily, a specific and accurate monitoring of this species was carried out during the years 2018 and 2019. About 230 km of coastline and 64 UTM squares 10x10 km were investigated during the breeding seasons, and a total of 205-287 pairs have been estimated for the whole region, distributed in 41 UTM squares (including the island of Favignana). Pairs are mainly concentrated in the complex of “Saline di T…

Dietary plasticity of Arctic charr (Salvelinus alpinus) facilitates coexistence with competitively superior European whitefish (Coregonus lavaretus)

2011

–  Habitat use and diet of Arctic charr (Salvelinus alpinus) coexisting with European whitefish (Coregonus lavaretus) and grayling (Thymallus thymallus) were studied in one deep and two relatively shallow subarctic lakes in northern Norway. Stomach content and stable isotope analyses revealed clear and temporally stable resource partitioning between the species in all three lakes. Arctic charr had a wide and flexible trophic niche and was the only piscivorous species. In contrast, whitefish and grayling had remarkably stable planktivorous and benthivorous niches, respectively. In the deepest lake, Arctic charr together with grayling mainly utilised littoral benthos, while piscivory was more…

Predicting future thermal habitat suitability of competing native and invasive fish species: From metabolic scope to oceanographic modelling

2015

Global increase in sea temperatures has been suggested to facilitate the incoming and spread of tropical invaders. Here, we determined the effect of temperature on the aerobic metabolic scope of two competing fish species, one native and one invasive, and we predicted their future thermal habitat suitability.

Challenging fear: chemical alarm signals are not causing morphology changes in crucian carp (Carassius carassius)

2010

Published version of an article in the journal: Environmental Biology of Fishes. Also available at SpringerLink: http://dx.doi.org/10.1007/s10641-010-9707-9 Crucian carp develops a deep body in the presence of chemical cues from predators, which makes the fish less vulnerable to gape-limited predators. The active components originate in conspecifics eaten by predators, and are found in the filtrate of homogenised conspecific skin. Chemical alarm signals, causing fright reactions, have been the suspected inducers of such morphological changes. We improved the extraction procedure of alarm signals by collecting the supernatant after centrifugation of skin homogenates. This removes the minute …