Nutrient recycling by Daphnia reduces N2 fixation by cyanobacteria

N. A. Mackay, James Elser

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

A field experiment in an experimentally eutrophied lake (Lake 227) tested the hypothesis that differential recycling of nitrogen and phosphorus by Daphnia (a zooplankter with low body N:P ratio) affects the physiological status of cyanobacteria, including rates of N, fixation (stoichiometric recycling hypothesis). After a 5-d incubation in 2.4-liter bottles, Daphnia treatments had lower standing stocks of algae (based on particulate carbon or Chl a) and higher concentrations of dissolved nutrients than did Epischura (a high N:P ratio consumer) or control treatments lacking macrozooplankton, The N:P ratio of dissolved nutrients was higher in the Daphnia treatments than in control or Epischura treatments, consistent with the stoichiometric recycling hypothesis, and was associated with greater algal P deficiency. Measurements of absolute and C-specific N2 fixation rates following the incubation showed that Daphnia treatments experienced a 50% reduction in N2 fixation relative to Epischura and control treatments. This reduction is consistent with the higher N: P ratio of the dissolved pool in the Daphnia treatment, as NH4-N inhibits N2 fixation. Thus, by differentially recycling NH4-N relative to P, Daphnia reduce the advantage (N: fixation) cyanobacteria have over other phytoplankton. We suggest that this mechanism may be an important factor in the ability of Daphnia to reduce the incidence of cyanobacterial blooms in lakes with low N:P loading ratios.

Original languageEnglish (US)
Pages (from-to)347-354
Number of pages8
JournalLimnology and Oceanography
Volume43
Issue number2
StatePublished - 1998

Fingerprint

Daphnia
recycling
fixation
Cyanobacteria
cyanobacterium
nutrient
nutrients
lake
incubation
algae
lakes
algal bloom
alga
phytoplankton
physiological state
bottles
phosphorus
particulates
nitrogen
carbon

ASJC Scopus subject areas

  • Aquatic Science
  • Oceanography

Cite this

Nutrient recycling by Daphnia reduces N2 fixation by cyanobacteria. / Mackay, N. A.; Elser, James.

In: Limnology and Oceanography, Vol. 43, No. 2, 1998, p. 347-354.

Research output: Contribution to journalArticle

@article{bca9d297c33b411697419f986458a8e9,
title = "Nutrient recycling by Daphnia reduces N2 fixation by cyanobacteria",
abstract = "A field experiment in an experimentally eutrophied lake (Lake 227) tested the hypothesis that differential recycling of nitrogen and phosphorus by Daphnia (a zooplankter with low body N:P ratio) affects the physiological status of cyanobacteria, including rates of N, fixation (stoichiometric recycling hypothesis). After a 5-d incubation in 2.4-liter bottles, Daphnia treatments had lower standing stocks of algae (based on particulate carbon or Chl a) and higher concentrations of dissolved nutrients than did Epischura (a high N:P ratio consumer) or control treatments lacking macrozooplankton, The N:P ratio of dissolved nutrients was higher in the Daphnia treatments than in control or Epischura treatments, consistent with the stoichiometric recycling hypothesis, and was associated with greater algal P deficiency. Measurements of absolute and C-specific N2 fixation rates following the incubation showed that Daphnia treatments experienced a 50{\%} reduction in N2 fixation relative to Epischura and control treatments. This reduction is consistent with the higher N: P ratio of the dissolved pool in the Daphnia treatment, as NH4-N inhibits N2 fixation. Thus, by differentially recycling NH4-N relative to P, Daphnia reduce the advantage (N: fixation) cyanobacteria have over other phytoplankton. We suggest that this mechanism may be an important factor in the ability of Daphnia to reduce the incidence of cyanobacterial blooms in lakes with low N:P loading ratios.",
author = "Mackay, {N. A.} and James Elser",
year = "1998",
language = "English (US)",
volume = "43",
pages = "347--354",
journal = "Limnology and Oceanography",
issn = "0024-3590",
publisher = "American Society of Limnology and Oceanography Inc.",
number = "2",

}

TY - JOUR

T1 - Nutrient recycling by Daphnia reduces N2 fixation by cyanobacteria

AU - Mackay, N. A.

AU - Elser, James

PY - 1998

Y1 - 1998

N2 - A field experiment in an experimentally eutrophied lake (Lake 227) tested the hypothesis that differential recycling of nitrogen and phosphorus by Daphnia (a zooplankter with low body N:P ratio) affects the physiological status of cyanobacteria, including rates of N, fixation (stoichiometric recycling hypothesis). After a 5-d incubation in 2.4-liter bottles, Daphnia treatments had lower standing stocks of algae (based on particulate carbon or Chl a) and higher concentrations of dissolved nutrients than did Epischura (a high N:P ratio consumer) or control treatments lacking macrozooplankton, The N:P ratio of dissolved nutrients was higher in the Daphnia treatments than in control or Epischura treatments, consistent with the stoichiometric recycling hypothesis, and was associated with greater algal P deficiency. Measurements of absolute and C-specific N2 fixation rates following the incubation showed that Daphnia treatments experienced a 50% reduction in N2 fixation relative to Epischura and control treatments. This reduction is consistent with the higher N: P ratio of the dissolved pool in the Daphnia treatment, as NH4-N inhibits N2 fixation. Thus, by differentially recycling NH4-N relative to P, Daphnia reduce the advantage (N: fixation) cyanobacteria have over other phytoplankton. We suggest that this mechanism may be an important factor in the ability of Daphnia to reduce the incidence of cyanobacterial blooms in lakes with low N:P loading ratios.

AB - A field experiment in an experimentally eutrophied lake (Lake 227) tested the hypothesis that differential recycling of nitrogen and phosphorus by Daphnia (a zooplankter with low body N:P ratio) affects the physiological status of cyanobacteria, including rates of N, fixation (stoichiometric recycling hypothesis). After a 5-d incubation in 2.4-liter bottles, Daphnia treatments had lower standing stocks of algae (based on particulate carbon or Chl a) and higher concentrations of dissolved nutrients than did Epischura (a high N:P ratio consumer) or control treatments lacking macrozooplankton, The N:P ratio of dissolved nutrients was higher in the Daphnia treatments than in control or Epischura treatments, consistent with the stoichiometric recycling hypothesis, and was associated with greater algal P deficiency. Measurements of absolute and C-specific N2 fixation rates following the incubation showed that Daphnia treatments experienced a 50% reduction in N2 fixation relative to Epischura and control treatments. This reduction is consistent with the higher N: P ratio of the dissolved pool in the Daphnia treatment, as NH4-N inhibits N2 fixation. Thus, by differentially recycling NH4-N relative to P, Daphnia reduce the advantage (N: fixation) cyanobacteria have over other phytoplankton. We suggest that this mechanism may be an important factor in the ability of Daphnia to reduce the incidence of cyanobacterial blooms in lakes with low N:P loading ratios.

UR - http://www.scopus.com/inward/record.url?scp=0031810238&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031810238&partnerID=8YFLogxK

M3 - Article

VL - 43

SP - 347

EP - 354

JO - Limnology and Oceanography

JF - Limnology and Oceanography

SN - 0024-3590

IS - 2

ER -