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

Kód výsledku v 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>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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).

Název v anglickém jazyce

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

Popis výsledku anglicky

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).

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

10617 - Marine biology, freshwater biology, limnology

Projekt

<a href="/cs/project/LTC17017" target="_blank" >LTC17017: Validace bioindikačních metod jako nástrojů pro udržitelný management středoevropských vysychavých toků a přenos těchto metod do praxe</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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