Logo: to the web site of Uppsala University

uu.sePublikasjoner fra Uppsala universitet
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Responses in zooplankton populations to food quality and quantity changes after whole lake nutrient enrichment of an oligotrophic sub-alpine reservoir
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
2008 (engelsk)Inngår i: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 70, nr 2, s. 142-155Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

To sustain production of higher trophic levels in oligotrophic systems it is important that the trophic transfer of energy and nutrients is efficient. The phytoplankton-zooplankton interface is of specific interest since nutritional constraints can decouple energy flow in this step. Increased nutrient loading to oligotrophic systems with initially low abundance of high quality phytoplankton could induce changes in seston composition that reduces the nutritional value for zooplankton. We carried out a whole lake enrichment experiment for five years in two ultraoligotrophic subalpine hydroelectric power reservoirs in Sweden. The first year was an untreated reference year. Phosphorus and nitrogen were added to Lake Stora Mjolkvattnet during the following four years, and upstream Lake Burvattnet was used as an untreated reference lake. The phosphorus content of seston in the experimental lake increased in the years of fertilization and seston phosphorus to carbon ratios (atomic) were non-limiting for zooplankton growth. Decreasing concentrations of phosphorus in the reference lake lead to low phosphorus to carbon ratios that probably affected zooplankton growth negatively. The seston fatty acid concentrations and phytoplankton composition indicated good food quality in both lakes. The phytoplankton increased in the experimental lake despite an increase in zooplankton biomass. Some changes in the relative contributions of plankton species occurred but the same species were present. The crustacean zooplankton community composition shifted towards smaller species during the latter years in the experimental lake, indicating increased predation pressure from fish. A major result of this whole-lake ecosystem fertilization experiment is that gentle fertilization can significantly boost phytoplankton production while food quality remains high, and plankton community composition is not substantially altered.

sted, utgiver, år, opplag, sider
2008. Vol. 70, nr 2, s. 142-155
Emneord [en]
elemental stoichiometry, essential fatty acids, Cladocera, Holopedium, Bosmina, trophic transfer efficiency
HSV kategori
Identifikatorer
URN: urn:nbn:se:uu:diva-95735DOI: 10.1007/s00027-007-7013-1ISI: 000256426400005OAI: oai:DiVA.org:uu-95735DiVA, id: diva2:170060
Tilgjengelig fra: 2007-04-11 Laget: 2007-04-11 Sist oppdatert: 2017-12-14bibliografisk kontrollert
Inngår i avhandling
1. Food Quality Effects on Zooplankton Growth and Energy Transfer in Pelagic Freshwater Food Webs
Åpne denne publikasjonen i ny fane eller vindu >>Food Quality Effects on Zooplankton Growth and Energy Transfer in Pelagic Freshwater Food Webs
2007 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Alternativ tittel[sv]
Effekter av födokvalitet på djurplanktons tillväxt och på energiöverföringen i födovävar i sjöar
Abstract [en]

Poor food quality can have large negative effects on zooplankton growth and this can also affect food web interactions. The main aims of this thesis were to study the importance of different food quality aspects in Daphnia, to identify potentially important differences among zooplankton taxa, and to put food quality research into a natural context by identifying the importance of food quality and quantity in lakes of different nutrient content.

In the first experiment, the RNA:DNA ratio was positively related to the somatic growth rate of Daphnia, supporting a connection between P content, RNA content, and growth rate. The second experiment showed that EPA was important for Daphnia somatic growth, and 0.9 µg EPA mg C-1 was identified as the threshold below which negative effects on Daphnia growth occurred.

A field survey identified patterns in the PUFA content of zooplankton that could be explained by taxonomy and trophic position. Cladocera enriched EPA and ARA relative to seston, and Copepoda primarily enriched DHA. In a whole-lake experiment, gentle fertilization of an oligotrophicated reservoir increased the seston P content and the biomass of high quality phytoplankton (Cryptophyceae, high EPA content). This was followed by increases in zooplankton and fish biomasses.

An empirical model based on data from a literature survey predicted that food quantity is most important for zooplankton growth in oligotrophic lakes, and that food quality factors are more important in eutrophic lakes. Thus, zooplankton growth, and energy transfer efficiency in the food web, is predicted to be highest in mesotrophic lakes. The results predict that the strength and nature of food quantity and quality limitation of Daphnia growth varies with lake trophic state, and that some combination of food quantity and/or quality limitation should be expected in nearly all lakes.

sted, utgiver, år, opplag, sider
Uppsala: Acta Universitatis Upsaliensis, 2007. s. 43
Serie
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 292
Emneord
Ecology, elemental stoichiometry, phosphorus, polyunsaturated fatty acids, EPA, oligotrophic lakes, empirical modelling, Daphnia, Cladocera, Copepoda, Ekologi
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-7811 (URN)978-91-554-6859-0 (ISBN)
Disputas
2007-05-04, Zootissalen, Gamla Zoologen, Norbyvägen 18, Uppsala, 10:00
Opponent
Veileder
Tilgjengelig fra: 2007-04-11 Laget: 2007-04-11 Sist oppdatert: 2016-04-28bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekst
Av organisasjonen
I samme tidsskrift
Aquatic Sciences

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 1265 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf