Terrestrial support of zooplankton biomass in northern rivers (invited)

Research output: Contribution to conferenceAbstract

Abstract

The contribution of terrestrially-derived carbon to micro-crustacean zooplankton biomass (i.e. allochthony) has been previously studied in lakes and reservoirs, but little is known about allochthony in rivers. We hypothesized that restricted selective grazing in turbulent environments such as rivers would decouple zooplankton from specific microbial and algal food resources, such that their allochthony would mirror the allochthonous contribution to the bulk particle pool. Allochthony was analyzed in 13 widely distributed Swedish rivers, using a dual-isotope mixing model. Zooplankton biomasses were generally low, and allochthony in different micro-crustacean groups (Cladocera, Cyclopoida, Calanoida) varied from 2% to 77%. As predicted, there were no correlations between allochthony and variables such as Chlorophyll-a or bacterial production. Instead, allochthony was similar to the terrestrial contribution in the particulate organic matter, with relationships close to 1:1. The total zooplankton community allochthony was strongly related to the ecosystem metabolic balance between production and respiration, which in turn was dependent upon the ratio between total autochthonous organic carbon concentrations and water color. Our study suggests that micro-crustacean allochthony is regulated differently in rivers compared to in lacustrine systems.

Details

Authors
Organisations
External organisations
  • Umeå University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences
Original languageEnglish
Number of pages1
Publication statusPublished - 2018
Publication categoryResearch
Peer-reviewedNo
EventASLO Summer Meeting 2018 - Victoria, Canada
Duration: 2018 Jun 102018 Jun 15

Conference

ConferenceASLO Summer Meeting 2018
CountryCanada
CityVictoria
Period2018/06/102018/06/15