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3549490 
Journal Article 
Is Recovery of Large-Bodied Zooplankton after Nutrient Loading Reduction Hampered by Climate Warming? A Long-Term Study of Shallow Hypertrophic Lake Sobygaard, Denmark 
Florencia Gutierrez, M; Devercelli, M; Brucet, S; Lauridsen, TL; Sondergaard, M; Jeppesen, E 
2016 
1 
Water
ISSN: 2073-4441 
8 
8 
WOS:000387675500006 
Nutrient fluctuations and climate warming can
synergistically affect trophic dynamics in lakes, resulting in enhanced symptoms of
eutrophication, thereby potentially counteracting restoration measures. We performed a long-term
study (23 years) of zooplankton in Danish Lake Sobygaard, which is in recovery after nutrient
loading reduction, but now faces the effects of climate warming. We hypothesized that the
recovery of large-bodied zooplankton after nutrient loading reduction would be hampered by
climate warming through indirect effects on fish size structure. We found a shift in
macrozooplankton from initial dominance of Daphnia spp. towards Bosmina spp. as well as a decline
in the body size of copepods and an increase in the abundance of nauplii. These changes coincided
with the increase in small sized fish as a result of rising water temperature. Despite a
reduction in body size, the total biomass of cladocerans increased coinciding with a diminished
fish catch per unit effort (CPUE), and likely then an overall reduction in the predation on
zooplankton. A cascading effect to phytoplankton was evidenced by enhanced zooplankton:
phytoplankton and cladoceran: phytoplankton ratios and a decrease in Chl-a: TP and Chl-a: TN
ratios. Our results indicate that climate warming, through changes in the size structure of fish
community, has major effects on zooplankton size structure. In Lake Sobygaard, the decline in
zooplankton size did not prevent, but modulated, the positive cascading effect on phytoplankton
through an expected diminished fish CPUE related to nutrient loading reduction. 
bottom-up control; cascading trophic interaction; fish; generalized linear mixed models; phytoplankton biomass; top-down control; zooplankton