Modeling potential impacts of three benthic invasive species on the Lake Erie food web

Hongyan Zhang,Timothy B Johnson,Marion E Wittmann,David M Lodge,Xinhua Zhu,Andrew Tucker,Edward S Rutherford,Doran M Mason

doi:10.1007/s10530-019-01929-7

Abstract

Assessing the potential for aquatic invasive species (AIS) to impact ecosystem function and services is an important component of ecological risk assessment. This study focuses on quantifying changes in biomass of food web groups in response to changes in AIS biomass as a function of variable AIS prey vulnerabilities (i.e. food availability) and AIS vulnerabilities to predators (i.e. predation pressure). We modified an existing Lake Erie food web model to assess the potential food web impacts of three benthic AIS (Eurasian ruffe Gymnocephalus cernua, killer shrimp Dikerogammarus villosus, and golden mussel Limnoperna fortunei) that may invade Lake Erie in the near future. Simulated biomass of golden mussels was most affected by bottom-up control, while killer shrimp and ruffe were affected by both top-down and bottom-up controls. AIS food web impacts showed both monotonic and non-monotonic responses to AIS biomass. Impacts from ruffe were highest when their biomass was high, while killer shrimp and golden mussels had maximal impacts at intermediate biomass levels on some food web groups. Our results suggest that golden mussels, which can feed at a lower trophic level and have fewer predators than ruffe or killer shrimp, may reach much higher equilibrium biomass under some scenarios and affect a broader range of food web groups. While all three species may induce negative effects if introduced to Lake Erie, golden mussels may pose the highest risk of impact for Lake Erie’s food web.

Highlights

Biological invasions, especially unintentional introductions, have increased in recent decades in spatial scale, frequency and number of species involved as a consequence of the expansion of worldwide commerce, fluvial transport of goods, and range expansion (Darrigran and Damborenea 2011; Drake and Lodge 2004; Levine and D’Antonio 2003; Seebens et al 2013), which may be further enhanced by climate and land use changes (Mandrak 1989; Vilaand Pujadas 2001)
Our results suggest that golden mussels, which can feed at a lower trophic level and have fewer predators than ruffe or killer shrimp, may reach much higher equilibrium biomass under some scenarios and affect a broader range of food web groups
The treatment (AISV1Prey40), which had the lowest vulnerability to predation and highest prey vulnerability, resulted in the highest equilibrium biomass of invasive species, while the treatment (AISV2Prey2), which had the lowest prey vulnerability, resulted in the lowest equilibrium biomass

Summary

Introduction

Biological invasions, especially unintentional introductions, have increased in recent decades in spatial scale, frequency and number of species involved as a consequence of the expansion of worldwide commerce, fluvial transport of goods, and range expansion (Darrigran and Damborenea 2011; Drake and Lodge 2004; Levine and D’Antonio 2003; Seebens et al 2013), which may be further enhanced by climate and land use changes (Mandrak 1989; Vilaand Pujadas 2001) These invasive species are often tolerant of a wide range of environmental conditions, have rapid growth rates and high reproductive rates, and low vulnerability to natural predators (Boltovskoy et al 2006a; Ogle 1998; Simberloff 2013), which allows them to rapidly exploit food and habitat resources, out compete native species, or modify habitat. Food web models can simulate the population changes of the invasive species within the receiving environment, and capture the direct and indirect trophic effects of invasive species on the whole food web (BlukaczRichards and Koops 2012; Kao et al 2014; Kitchell et al 2000), providing a comprehensive prediction of invasive species establishment and impacts (David et al 2017)

Methods

Results

Discussion

Conclusion