Impact of drying up of streams on population structure and fecundity of freshwater gammarid Gammarus fossarum

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F18%3A00103322" target="_blank" >RIV/00216224:14310/18:00103322 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Impact of drying up of streams on population structure and fecundity of freshwater gammarid Gammarus fossarum

Original language description

Ongoing climate change alters stream flow regime and leads to increasing stream intermittency. Frequent drying up also affects populations of aquatic organisms. One of the strongly impacted species of streams up to 4th Strahler order is crustacean Gammarus fossarum, whose populations inhabit such streams in high densities, but do not produce any dry resistant stages. Gammarids can survive on dry streambed only a few hours, and therefore must recolonize the stream mostly from nearest perennial reaches, or from residual pools. The comparison of 12 pairs of intermittent and perennial streams in years 2012-16 shows, that autumn samples from recolonized intermittent sites have a higher proportion of larger males and a lower proportion of juveniles, comparing to perennial sites. Different population structure in intermittent reaches can be explained by better recolonization abilities of bigger individuals (more efficient migrators) in comparison to not so mobile juveniles. Fecundity analyses of gammarids in residual pools in 2017 shows a lower proportion of small breeding females with eggs in comparison to females on perennial sites. This difference can be explained e.g. by an increase of predation in overcrowded refuge pools with possible cannibalism or by overall stress in these shrinking habitats that leads to egg loss. Our results demonstrate substantial impact of longer dry episodes on populations of very important ecosystem engineer of small streams. A gradual decline in reproduction abilities of this key species (leaves shredder and important predator in fishless streams) could have a fundamental impact on the whole community of intermittent streams. This study is supported by INTER-COST (LTC17017) project and utilizes data from project BIODROUGHT (www.biodrought.eu).

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10617 - Marine biology, freshwater biology, limnology

Project

<a href="/en/project/LTC17017" target="_blank" >LTC17017: Validation of bioindication methods as tools for sustainable management of intermittent streams in Central European region, their transfer into the practice</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Publication year

2018

Confidentiality

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