Evaluating the physical removal of ruffe (Gymnocephalus cernuus) with bottom trawling
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چکیده
منابع مشابه
Competition between perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus) : the advantage of turning night into day
1. The outcome of interspecific competition for food resources depends both on the competitors’ sensory abilities and on environmental conditions. In laboratory experiments we tested the influence of daylight and darkness on feeding behaviour and specific growth rate (SGR) of two species with different sensory abilities. 2. We used perch (Perca fluviatilis) as a visually orientated, and ruffe (...
متن کاملRisk analysis for species introductions: forecasting population growth of Eurasian ruffe (Gymnocephalus cernuus)
The North American distribution of the Eurasian ruffe (Gymnocephalus cernuus), an ecologically important and costly invasive fish, is presently limited to the Laurentian Great Lakes. Risk analyses for accidental introductions of ruffe to inland lakes should focus on the chance of establishment for small introductions such as those that would result from transporting ruffe as bait. Here I use Ak...
متن کاملCompetition for food between perch (Perca fluviatilis L.) and invasive ruffe (Gymnocephalus cernuus (L.)) in re-oligotrophic Lake Constance
The effect of group size on routine metabolic rate (RMR) and activity of the two shoaling percids Eurasian perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus) was studied using twin flow intermittent respirometry and time-lapse video techniques. In both species, we found a clear group effect. In isolated fish, oxygen consumption was up to two times as high as in groups of eight fish, wi...
متن کاملOverwinter changes in mass and lipid content of Perca fluviatilis and Gymnocephalus cernuus
The body condition, lipid reserves and mortality of 0 and 1 year-old perch Perca fluviatilis and ruffe Gymnocephalus cernuus, sampled during the winter in Lake Constance, Germany, were compared. Length-frequency analyses did not provide evidence for overwinter mortality in either species. The fresh and dry mass of perch as well as their lipid contents decreased during winter, while ruffe were h...
متن کاملInfluence of Bottom Trawling on the Normal- Incidence Reflection Coefficient
A North Sea area characterized by muddy, sandy, and gravelly sediments is surveyed with a single-beam echo sounder operating at 12, 38, and 200 kHz. Closely spaced survey legs and a high repetition rate of five sounder pings per second allow the production of echo energy maps with a high spatial resolution. These energy maps reveal a series of string-like features, which are believed to be due ...
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ژورنال
عنوان ژورنال: Journal of Freshwater Ecology
سال: 2011
ISSN: 0270-5060,2156-6941
DOI: 10.1080/02705060.2011.569336