scholarly journals Effects of the introduction of an omnivorous fish on the biodiversity and functioning of an upland Amazonian lake

2019 ◽  
Vol 49 (3) ◽  
pp. 221-231
Author(s):  
Regina L. G. NOBRE ◽  
Adriano CALIMAN ◽  
Rafael D. GUARIENTO ◽  
Reinaldo L. BOZELLI ◽  
Luciana S. CARNEIRO
Keyword(s):  
Food Web ◽  
Phosphorus Limitation ◽  
Freshwater Ecosystems ◽  
Data Series ◽  
Macroinvertebrate Communities ◽  
Introduced Fish ◽  
Fish Introduction ◽  
Omnivorous Fish ◽  
Fishless Lakes ◽  
Food Web Theory

ABSTRACT The introduction of nonnative species is one of the main threats to freshwater ecosystems. Although omnivory and intraguild predation are common in those systems, little is known about the effects of introduced omnivorous fish on pelagic and littoral communities. This study tested predictions of food-web theory regarding the effects of omnivorous fish introduction on previously fishless lakes in the Amazonian uplands of Serra dos Carajás, Pará, Brazil. The trophic structure of two similar lakes, one with and the other without the introduced omnivorous fish Astyanax bimaculatus, was compared using a data series of biotic variables collected from both lakes twice a year from 2010 to 2013. Zooplankton was more abundant in the lake with fish, and the zooplankton composition differed between lakes. Phytoplankton richness and chlorophyll-a were higher in the lake with the introduced fish than in the fishless lake regardless of phosphorus limitation. For the benthic macroinvertebrate communities, species richness and biomass were higher in the fishless lake. Our results also indicate that A. bimaculatus has the potential to link pelagic and littoral habitats through nutrient cycling. The differences observed between the studied lakes are consistent with predictions from food-web theory regarding the effects of multichain omnivorous fish on trophic dynamics. Despite limitations regarding replication at the ecosystem level, it is possible to infer from our findings that the introduction of an omnivorous fish might have changed lake overall functioning.

Food Web Interactions in Freshwater Ecosystems

2017 ◽  
Author(s):  
Christer Brönmark ◽  
Lars-Anders Hansson
Keyword(s):  
Food Web ◽  
Alternative Stable States ◽  
Ecosystem Approach ◽  
Freshwater Ecosystems ◽  
Stable States ◽  
Food Web Interactions ◽  
Spatial Changes ◽  
Temporal And Spatial ◽  
Cascading Trophic Interactions ◽  
Food Web Theory

This chapter on food web interactions connects the organisms and their interactions with the abiotic frame and provides a helicopter perspective on the function of freshwater ecosystems. Initially, the theoretical basis for an ecosystem approach is outlined, including food web theory, the bottom-up and top-down concepts and how these have evolved in concert with empirical advances. Specifically, the concepts of cascading trophic interactions and alternative stable states are discussed both from a theoretical and empirical viewpoint, as well as in both benthic and pelagic habitats. This chapter links all components, from microbes to vertebrates, to temporal and spatial changes in abiotic features leading to successional patterns in populations and communities.

scholarly journals The more food webs change, the more they stay the same

2009 ◽  
Vol 364 (1524) ◽  
pp. 1789-1801 ◽  
Author(s):  
Kevin Shear McCann ◽  
Neil Rooney
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Temporal Variability ◽  
Spatial And Temporal Variability ◽  
Scale Invariant ◽  
Food Web Structure ◽  
Behavioural Responses ◽  
Web Structure ◽  
Food Web Ecology ◽  
Food Web Theory

Here, we synthesize a number of recent empirical and theoretical papers to argue that food-web dynamics are characterized by high amounts of spatial and temporal variability and that organisms respond predictably, via behaviour, to these changing conditions. Such behavioural responses on the landscape drive a highly adaptive food-web structure in space and time. Empirical evidence suggests that underlying attributes of food webs are potentially scale-invariant such that food webs are characterized by hump-shaped trophic structures with fast and slow pathways that repeat at different resolutions within the food web. We place these empirical patterns within the context of recent food-web theory to show that adaptable food-web structure confers stability to an assemblage of interacting organisms in a variable world. Finally, we show that recent food-web analyses agree with two of the major predictions of this theory. We argue that the next major frontier in food-web theory and applied food-web ecology must consider the influence of variability on food-web structure.

scholarly journals Do alpine macroinvertebrates recover differently in lakes and rivers after alien fish eradication?

2019 ◽  
pp. 37
Author(s):  
Rocco Tiberti ◽  
Stefano Brighenti
Keyword(s):  
Fish Populations ◽  
Mountain Lake ◽  
Macroinvertebrate Communities ◽  
Italian Alps ◽  
Introduced Fish ◽  
Habitat Features ◽  
Stream Communities ◽  
Mechanical Methods ◽  
Eradication Campaign ◽  
Alien Fish

Introduced fish can have detrimental effects on native biota inhabiting alpine freshwaters with the extent of their impact depending on variables such as habitat features. The present study aims to compare the recovery of macroinvertebrate communities following a fish eradication campaign in a mountain lake (Lake Dres, 2087 m a.s.l., Western Italian Alps) and its inflowing and outflowing streams. All fish were removed using mechanical methods, not producing side-effects for macroinvertebrates. During eradication, the lake community, which had previously been greatly affected, rapidly recovered to levels typical of never-stocked lakes. Stream communities, however, were apparently not impacted by fish populations and remained relatively stable, proving their greater capacity to withstand fish presence. The abundance of spatial refugia and invertebrate recruitment (via birth or immigration) can explain the observed stability in stream communities. Drifting macroinvertebrates are often called into question to explain the resistance of stream communities as they can partially offset predation via benthic recruitment, but our results show that stream resistance can be high even where drift is low, i.e., in the outflowing stream.

Effects of introduced fish on macroinvertebrate communities in historically fishless headwater and kettle lakes

2009 ◽  
Vol 142 (12) ◽  
pp. 3030-3038 ◽  
Author(s):  
Emily Gaenzle Schilling ◽  
Cynthia S. Loftin ◽  
Alexander D. Huryn
Keyword(s):  
Macroinvertebrate Communities ◽  
Introduced Fish

scholarly journals Using forensic geochemistry via fish otoliths to investigate an illegal fish introduction

2018 ◽  
Vol 75 (11) ◽  
pp. 1778-1783 ◽  
Author(s):  
Samuel L. Bourret ◽  
Niall G. Clancy
Keyword(s):  
Cutthroat Trout ◽  
Bull Trout ◽  
Introduced Fish ◽  
Fish Introduction ◽  
Oncorhynchus Clarkii ◽  
Ecosystem Impacts ◽  
Swan Lake ◽  
Resource Managers ◽  
Species Of Conservation Concern ◽  
Fish Otoliths

Illegal fish introductions create some of the most challenging problems for resource managers because of their potential to harm existing recreational fisheries and their impact on species of conservation concern. Determining the origin of a suspected illegal fish introduction can aid managers in preventing the colonization and subsequent ecosystem impacts of introduced species. In this study, we used forensic geochemistry via fish otoliths to investigate an illegal walleye (Sander vitreus) introduction in Swan Lake, Montana, which provides critical habitat for threatened bull trout (Salvelinus confluentus) and native westslope cutthroat trout (Oncorhynchus clarkii). Core to edge geochemical profiles of 87Sr/86Sr and Sr/Ca ratios in the walleye otoliths revealed that these fish had been introduced to Swan Lake within the past growing season, and their geochemical signature matched that of walleye sampled from Lake Helena, Montana, located 309 road kilometres away. This research highlights application of a tool fisheries managers can use to identify the natal waterbody source of illegally introduced fish.

Food Web Theory and Stability

Ecology ◽  
1988 ◽  
Vol 69 (6) ◽  
pp. 1665-1668 ◽  
Author(s):  
Alan Hastings
Keyword(s):  
Food Web ◽  
Food Web Theory
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