Potential establishment and ecological effects of bighead and silver carp in a productive embayment of the Laurentian Great Lakes

Lori N Ivan,Hongyan Zhang,Edward S Rutherford,Tim Hunter,Aaron T Adamack,Shaye Sable,Kenneth Rose,Doran M Mason

doi:10.1007/s10530-020-02263-z

Abstract

Bighead carp H. nobilis and silver carp Hypothalmichthys molitrix (collectively bigheaded carps, BHC) are invasive planktivorous fishes that threaten to enter the Laurentian Great Lakes and disrupt food webs. To assess the likelihood of BHC establishment and their likely effects on the food web of Saginaw Bay, Lake Huron, we developed a multi-species individual-based bioenergetics model that tracks individual bighead and silver carp, four key fish species, and seven prey biomass groups over 50 years. The model tracks the daily consumption, mortality and growth of all individuals and the biomass dynamics of interacting prey pools. We ran simulation scenarios to determine the likelihood of BHC establishment under initial introductions from 5 to 1 million yearling and older individuals, and assuming variable age-0 carp survival rates (high, intermediate, and low). We bounded the survival of age-0 BHC as recruitment continues to be one of the biggest unknowns. We also simulated the potential effects of an established population of 1 million bighead carp or silver carp assuming variation in age-0 survival. Results indicated that as few as 10 BHC could establish a population assuming high or intermediate age-0 survival, but at least 100,000 individuals were needed to establish a population assuming low age-0 survival. BHC had negative effects on plankton and planktivorous fish biomass, which increased with BHC density. However, piscivorous walleye Sander vitreus appeared to benefit from BHC establishment. The potential for BHC to establish and affect ecologically and economically important fish species in Saginaw Bay is a cause for concern.

Highlights

Over 180 non-indigenous aquatic species, including viruses, emergent and submergent plants, phytoplankton, zooplankton, benthic macroinvertebrates and fishes, have become established in the Laurentian Great Lakes (Pagnucco et al 2015; Ricciardi 2006; Sturtevant et al 2014)
Saginaw Bay is modeled as a single spatial unit, while its two tributaries are modeled two spatial units for spawning sites for fishes that spawn in rivers and Lake Huron is modeled as a single unit for holding migratory fishes that leave the bay (Fig. 1)
They found that the successful establishment of BHC was sensitive to survival rate, BM-bighead carp with intermediate age-0 annual survival rate, BL-bighead carp with low age-0 annual survival rate, SH-silver carp with high age-0 annual survival rate, SMsilver carp with intermediate age-0 annual survival rate, and SLsilver carp with low age-0 annual survival rate would find a river with suitable habitat for spawning

Summary

Introduction

Over 180 non-indigenous aquatic species, including viruses, emergent and submergent plants, phytoplankton, zooplankton, benthic macroinvertebrates and fishes, have become established in the Laurentian Great Lakes (Pagnucco et al 2015; Ricciardi 2006; Sturtevant et al 2014). The majority of these species have remained at very low abundance and/or had little or no detected effect on the ecology of the Great Lakes, a few species (e.g., sea lamprey Petromyzon marinus, alewife Alosa pseudoharengus, zebra mussel Dreissena polymorpha, quagga mussel D. bugensis, and spiny waterflea Bythotrephes longimanus have had substantial negative effects (Bunnell et al 2014; Vanderploeg et al 2002a; b). Still others, such as the white perch Morone americana, have increased to relatively high abundances but their net effects on resident species have been relatively uncertain (Pothoven and Hook 2015).

Methods

Results

Discussion

Conclusion