Patterns of dark respiration in aquatic systems


Mantikci M., Staehr P. A., Hansen J. L. S., Markager S.

MARINE AND FRESHWATER RESEARCH, no.4, pp.432-442, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2020
  • Doi Number: 10.1071/mf18221
  • Journal Name: MARINE AND FRESHWATER RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Animal Behavior Abstracts, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Communication Abstracts, Environment Index, Geobase, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Page Numbers: pp.432-442
  • Keywords: bacteria, coastal ecosystems, lake, optode, phytoplankton, PLANKTON COMMUNITY RESPIRATION, DISSOLVED ORGANIC-MATTER, TEMPERATURE SENSITIVITY, BACTERIAL RESPIRATION, METABOLISM, LIGHT, GROWTH, BACTERIOPLANKTON, PHOTOSYNTHESIS, VARIABILITY
  • Middle East Technical University Affiliated: Yes

Abstract

We used continuous measurements of dissolved oxygen (DO) in dark bottles to characterise patterns of the dark respiration rate (R-dark) for three marine phytoplankton monocultures and in natural-water samples from two marine coastal systems. Furthermore, patterns of ecosystem community respiration rate were determined from open-water changes in DO in a fjord and in a lake. We considered two models of R-dark to describe temporal changes in DO: constant R-dark and decreasing R-dark; increasing R-dark. In addition, the effect of incubation time on R-dark was investigated in bottle incubations. Constant R-dark was observed in short-term (12-h) bottle incubations in natural-water samples from two marine coastal systems. Declining R-dark was observed in marine phytoplankton cultures and open-water measurements in a lake. Increasing R-dark was observed in open-water measurements in a fjord, particularly during summer. Long-term (120-h) bottle incubations in natural-water samples showed an increase in R-dark after 48 and 72 h. We show that the conventional expectation of constant rates of respiration in darkness is far from typical, because non-linear changes are common under both controlled experimental conditions, as well as for open-water measurements of ecosystem respiration.