Food Webs and Fish Size Patterns in Insular Lakes Partially Support Climate-Related Features in Continental Lakes

Disentangling the effects of climate change on nature is one of the main challenges facing ecologists nowadays. Warmer climates forces strong effects on lake biota for fish, leading to a reduction in size, changes in diet, more frequent reproduction, and stronger cascading effects. Space-for-time substitution studies (SFTS) are often used to unravel climate effects on lakes biota; however, results from continental lakes are potentially confounded by biogeographical and evolutionary differences, also leading to an overall higher fish species richness in warm lakes. Such differences may not be found in lakes on remote islands, where natural fish free lakes have been subjected to stocking only during the past few hundred years. We studied 20 species-poor lakes located in two remote island groups with contrasting climates, but similar seasonality: the Faroe Islands (cold; 6.5 ± 2.8 °C annual average (SD) and the Azores Islands (warm; 17.3 ± 2.9 °C)). As for mainland lakes, mean body size of fish in the warmer lakes were smaller overall, and phytoplankton per unit of phosphorus higher. The δ13C carbon range for basal organisms, and for the whole food web, appeared wider in colder lakes. In contrast to previous works in continental fresh waters, Layman metrics of the fish food web were similar between the two climatic regions. Our results from insular systems provide further evidence that ambient temperatures, at least partially, drive the changes in fish size structure and the cascading effects found along latitude gradients in lakes.

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AN EXPERIMENTAL DISTURBANCE ALTERS FISH SIZE STRUCTURE BUT NOT FOOD CHAIN LENGTH IN STREAMS

Ecology ◽

10.1890/08-0273.1 ◽

2008 ◽

Vol 89 (12) ◽

pp. 3261-3267 ◽

Cited By ~ 55

Author(s):

Annika W. Walters ◽

David M. Post

Keyword(s):

Chain Length ◽

Food Chain ◽

Size Structure ◽

Fish Size ◽

Food Chain Length ◽

Experimental Disturbance

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Surface water connectivity controls fish food web structure and complexity across local- and meta-food webs in Arctic Coastal Plain lakes

Food Webs ◽

10.1016/j.fooweb.2019.e00123 ◽

2019 ◽

Vol 21 ◽

pp. e00123 ◽

Cited By ~ 1

Author(s):

Sarah M. Laske ◽

Amanda E. Rosenberger ◽

Mark S. Wipfli ◽

Christian E. Zimmerman

Keyword(s):

Surface Water ◽

Food Web ◽

Food Webs ◽

Coastal Plain ◽

Food Web Structure ◽

Fish Food ◽

Web Structure ◽

Arctic Coastal Plain

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Predator size-structure and species identity determine cascading effects in a coastal ecosystem

Ecology and Evolution ◽

10.1002/ece3.4571 ◽

2018 ◽

Vol 8 (24) ◽

pp. 12435-12442 ◽

Cited By ~ 1

Author(s):

John N. Griffin ◽

Brian R. Silliman

Keyword(s):

Size Structure ◽

Coastal Ecosystem ◽

Species Identity ◽

Cascading Effects ◽

Predator Size

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Cascading Effects on Microbial Food Web Structure in a Dense Macrophyte Bed

The Structuring Role of Submerged Macrophytes in Lakes - Ecological Studies ◽

10.1007/978-1-4612-0695-8_16 ◽

1998 ◽

pp. 262-273 ◽

Cited By ~ 10

Author(s):

Klaus Jürgens ◽

Erik Jeppesen

Keyword(s):

Food Web ◽

Microbial Food Web ◽

Food Web Structure ◽

Cascading Effects ◽

Web Structure

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Trophic Relationships in Freshwater Pelagic Ecosystems

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-195 ◽

1986 ◽

Vol 43 (8) ◽

pp. 1571-1581 ◽

Cited By ~ 572

Author(s):

Donald J. McQueen ◽

John R. Post ◽

Edward L. Mills

Keyword(s):

Food Web ◽

Trophic Status ◽

Size Structure ◽

Trophic Relationships ◽

Top Down ◽

Eutrophic Lakes ◽

Bottom Up ◽

Coefficients Of Variation ◽

Step Down ◽

Pelagic Ecosystems

Relative impacts of bottom-up (producer controlled) and top-down (consumer controlled) forces on the biomass and size structure of five major components of freshwater pelagic systems (piscivores, planktivores, zooplankton, phytoplankton, and total phosphorus availability) were estimated. Predictions that emerge are (1) maximum biomass at each trophic level is controlled from below (bottom-up) by nutrient availability, (2) this bottom-up regulation is strongest at the bottom of the food web (i.e. phosphorus → phytoplankton) and weakens by a factor of 2 with each succeeding step up the food web, (3) as energy moves up a food web, the predictability of bottom-up interactions decreases, (4) near the top of the food web, top-down (predator mediated) interactions are strong and have low coefficients of variation, but weaken with every step down the food web, (5) variability around the bottom-up regressions can always be explained by top-down forces, and (6) interplay between top-down and bottom-up effects changes with the trophic status of lakes. In eutrophic lakes, top-down effects are strong for piscivore → zooplankton, weaker for planktivore → zooplankton, and have little impact for zooplankton → phytoplankton. For oligotrophic lakes, the model predicts that top-down effects are not strongly buffered, so that zooplankton → phytoplankton interactions are significant.

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Temporal trends of polychlorinated biphenyls (PCBs) in Lake Ontario fish and invertebrates

Environmental Reviews ◽

10.1139/a99-013 ◽

1999 ◽

Vol 7 (4) ◽

pp. 203-223 ◽

Cited By ~ 7

Author(s):

E Bentzen ◽

D Mackay ◽

B E Hickie ◽

D RS Lean

Keyword(s):

Food Web ◽

Lake Trout ◽

Temporal Trends ◽

Lake Ontario ◽

Fish Food ◽

International Joint Commission ◽

Analytical Protocol ◽

Fish Lipid ◽

Key Species ◽

Aquatic Food

A comprehensive review is presented of changes of PCB concentrations in aquatic biota collected from Lake Ontario between 1977 and 1993, with emphasis on data for lake trout. Results of three major lake trout surveys from Canadian and United States agencies indicate lake trout PCBs have declined from the early 1980s, but changes in recent years are masked by interannual variability. These results also apply to other biota in the aquatic food web. PCB concentrations were consistent among the surveys after consideration of fish lipid content, age or size and analytical protocol. Variability of 20 to 30% in annual average estimates is attributed to both analytical and in situ sources. Current levels of PCBs in many salmonids exceed PCB consumption and wildlife protection advisories. The average half-life for PCBs in Lake Ontario biota is about 12 years and it will take three to four times that to reach the International Joint Commission target of 100 ng/g (ww) for protection of wildlife. It is essential that the design of monitoring programs ensures consistent, coordinated sampling and analysis. A monitoring strategy of annual sampling of key species supplemented with periodic intensive sampling of the entire food web (e.g., every 5 years) is suggested as more effective than current practices. There is a frequently neglected need for fuller interpretation of contaminant dynamics based on complementary research on the nature of the changing biotic and abiotic environments in a complex aquatic ecosystem like Lake Ontario. Key words: Lake Ontario, PCBs, fish, food webs, monitoring data, bioaccumulation.

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Effects of experimental warming, litter species, and presence of macroinvertebrates on litter decomposition and associated decomposers in a temperate mountain stream

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2014-0119 ◽

2015 ◽

Vol 72 (2) ◽

pp. 206-216 ◽

Cited By ~ 23

Author(s):

Verónica Ferreira ◽

Eric Chauvet ◽

Cristina Canhoto

Keyword(s):

Food Web ◽

Food Webs ◽

Litter Decomposition ◽

Castanea Sativa ◽

Mountain Stream ◽

Ambient Temperatures ◽

C Cycle ◽

Detrital Food Web ◽

Water Courses ◽

Aquatic Food

Small woodland streams make the majority of water courses in most watersheds. Litter decomposition is a key ecosystem process in these shaded streams, and its response to warming can have profound consequences for food webs and the carbon (C) cycle. However, these responses can be modulated by litter identity and the structure of the detrital food web. Here we report on a manipulative study aiming at evaluating the effects of warming (+2.8 °C), litter identity (chestnut (Castanea sativa) or oak (Quercus robur) litter), and the structure of the detrital food web (presence or absence of macroinvertebrates) on litter decomposition and decomposers in a small, temperate woodland stream. Warming significantly stimulated overall (microbial- + macroinvertebrate-driven) decomposition of oak and microbial-driven decomposition of chestnut. The similar shredder densities at elevated and ambient temperatures suggest that stimulated overall decomposition of oak resulted from increased activity of macroinvertebrate individuals. Stimulated microbial-driven decomposition of chestnut resulted from higher fungal activity with warming. Stimulation of litter decomposition by warming can lead to increases in the amount of C returned to the atmosphere and to a faster disappearance of litter from the benthos, with consequences to the C cycle and aquatic food webs.

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Occurrence and trophic transfer of nanoparticulate Ag and Ti in the natural aquatic food web of Taihu Lake, China

Environmental Science Nano ◽

10.1039/c9en00797k ◽

2019 ◽

Vol 6 (11) ◽

pp. 3431-3441 ◽

Cited By ~ 3

Author(s):

Bowen Xiao ◽

Yinqing Zhang ◽

Xiaolei Wang ◽

Meng Chen ◽

Binbin Sun ◽

...

Keyword(s):

Food Web ◽

Taihu Lake ◽

Trophic Transfer ◽

Aquatic Food Web ◽

Fish Food ◽

Aquatic Food

Nanoparticulate Ti was biodiluted while nanoparticulate Ag was biomagnified in the fish food web in Taihu Lake, China.

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Calanoid copepod grazing affects plankton size structure and composition in a deep, large lake

Journal of Plankton Research ◽

10.1093/plankt/fbz067 ◽

2019 ◽

Vol 41 (6) ◽

pp. 955-966

Author(s):

Alessandra Janina Kunzmann ◽

Harald Ehret ◽

Elizabeth Yohannes ◽

Dietmar Straile ◽

Karl-Otto Rothhaupt

Keyword(s):

Food Web ◽

Cell Size ◽

Size Structure ◽

Disruptive Selection ◽

Significant Shift ◽

Calanoid Copepods ◽

Planktonic Food ◽

In Situ Incubation ◽

Copepod Grazing ◽

Phytoplankton Cell

Abstract Cultural oligotrophication is expected to shift lake zooplankton to become dominated by calanoid copepods. Hence, understanding the influence of calanoids on the taxonomic and size structure of the lower plankton food web is crucial for predicting the effects of oligotrophication on energy fluxes in these systems. We studied the effect of an omnivorous calanoid, Eudiaptomus gracilis, on the lower planktonic food web using an in situ incubation approach in large and deep Lake Constance. We show that E. gracilis significantly reduced ciliate, phytoplankton, rotifer, but increased bacteria biovolume. Highest clearance rates were observed for ciliates whose biovolume declines may have caused a release of predation pressure on bacteria. E. gracilis grazing shifted the size structure of the phytoplankton community by reducing mean phytoplankton cell size (directional selection) and simultaneously increasing cell size variance (disruptive selection). Ciliate cell sizes experienced a similar selective regime in one of the experiments, whereas in the other two experiments, no change of size structure was detected. Results suggest strong influences of E. gracilis grazing on the lower plankton food web and a significant shift in phytoplankton size structure. For evaluating detailed effects of omnivorous consumers on plankton size structure, cascading interactions need to be considered.

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