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Environmentally controlled Daphnia spring increase with implications for sockeye salmon fry in Lake Washington, USA

Hampton, SE; Romare, Pia LU and Seiler, DE (2006) In Journal of Plankton Research 28(4). p.399-406
Abstract
In Lake Washington, juvenile sockeye salmon (Oncorhynchus nerka) strongly prefer Daphnia over other prey, switching uniformly to Daphnia when the threshold abundance of 0.4 Daphnia L-1 is achieved. Using long-term Lake Washington data (1978-2001) and fry trap data (1992-2001) from a major tributary, we examined the following: (i) factors that predict Daphnia pulicaria and Daphnia thorata increase to this threshold "switching" abundance, (ii) trends in Daphnia dynamics that may affect sockeye foraging and (iii) temporal correspondence of Daphnia increase and fry arrival. The winter abundance of D. pulicaria, in combination with basic parameters of spring conditions, was an important predictor of the date of D. pulicaria spring increase,... (More)
In Lake Washington, juvenile sockeye salmon (Oncorhynchus nerka) strongly prefer Daphnia over other prey, switching uniformly to Daphnia when the threshold abundance of 0.4 Daphnia L-1 is achieved. Using long-term Lake Washington data (1978-2001) and fry trap data (1992-2001) from a major tributary, we examined the following: (i) factors that predict Daphnia pulicaria and Daphnia thorata increase to this threshold "switching" abundance, (ii) trends in Daphnia dynamics that may affect sockeye foraging and (iii) temporal correspondence of Daphnia increase and fry arrival. The winter abundance of D. pulicaria, in combination with basic parameters of spring conditions, was an important predictor of the date of D. pulicaria spring increase, indicating greater reliance on pelagic population dynamics (versus diapause hatch) than D. thorata exhibited. In addition, D. pulicaria was a more consistent prey than D. thorata, the latter exhibiting larger population fluctuations. Thus, recently increasing D. thorata prominence could decrease diet consistency for sockeye fry. Additionally, the timing of sockeye arrival to Lake Washington and Daphnia's increase to the switching threshold has become less concordant, so that fry in recent years have had to rely upon less profitable prey for longer periods. Long-term trends and species-specific differences in Daphnia phenology may affect fry through altering diet composition, with additional implications for other zooplankton withstanding greater predation pressure in Daphnia's absence. Recent decades of warming in Lake Washington are consistent with the warming of lakes worldwide, and complex phenological responses such as those reported here may be common as the climate continues to change. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Plankton Research
volume
28
issue
4
pages
399 - 406
publisher
Oxford University Press
external identifiers
  • wos:000236254200005
  • scopus:33645310166
ISSN
0142-7873
DOI
10.1093/plankt/fbi125
language
English
LU publication?
yes
id
e2cd8547-3a03-4f44-8aa2-142fb50899a5 (old id 415130)
date added to LUP
2007-10-03 17:44:45
date last changed
2019-02-20 07:43:56
@article{e2cd8547-3a03-4f44-8aa2-142fb50899a5,
  abstract     = {In Lake Washington, juvenile sockeye salmon (Oncorhynchus nerka) strongly prefer Daphnia over other prey, switching uniformly to Daphnia when the threshold abundance of 0.4 Daphnia L-1 is achieved. Using long-term Lake Washington data (1978-2001) and fry trap data (1992-2001) from a major tributary, we examined the following: (i) factors that predict Daphnia pulicaria and Daphnia thorata increase to this threshold "switching" abundance, (ii) trends in Daphnia dynamics that may affect sockeye foraging and (iii) temporal correspondence of Daphnia increase and fry arrival. The winter abundance of D. pulicaria, in combination with basic parameters of spring conditions, was an important predictor of the date of D. pulicaria spring increase, indicating greater reliance on pelagic population dynamics (versus diapause hatch) than D. thorata exhibited. In addition, D. pulicaria was a more consistent prey than D. thorata, the latter exhibiting larger population fluctuations. Thus, recently increasing D. thorata prominence could decrease diet consistency for sockeye fry. Additionally, the timing of sockeye arrival to Lake Washington and Daphnia's increase to the switching threshold has become less concordant, so that fry in recent years have had to rely upon less profitable prey for longer periods. Long-term trends and species-specific differences in Daphnia phenology may affect fry through altering diet composition, with additional implications for other zooplankton withstanding greater predation pressure in Daphnia's absence. Recent decades of warming in Lake Washington are consistent with the warming of lakes worldwide, and complex phenological responses such as those reported here may be common as the climate continues to change.},
  author       = {Hampton, SE and Romare, Pia and Seiler, DE},
  issn         = {0142-7873},
  language     = {eng},
  number       = {4},
  pages        = {399--406},
  publisher    = {Oxford University Press},
  series       = {Journal of Plankton Research},
  title        = {Environmentally controlled Daphnia spring increase with implications for sockeye salmon fry in Lake Washington, USA},
  url          = {http://dx.doi.org/10.1093/plankt/fbi125},
  volume       = {28},
  year         = {2006},
}