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Evaluating the negative effect of benthic egg predators on bloater recruitment in northern Lake Michigan

As the only extant deepwater cisco in Lake Michigan, bloater is at a   very low level of abundance but has historically undergone dramatic   oscillations in recruitment. In previous research, Bunnell et al.   (2  6) found strong bloater recruitment to correlate with balanced   sex ratios. Subsequent unpublished work reveals that the negative   effect of female predominance and other potential factors are not   sufficient to explain recent poor recruitment in Lake Michigan.   However, we found a strong inverse relationship between slimy   sculpin biomass and bloater recruitment: recruitment declines non-  linearly with increasing slimy sculpin biomass. We hypothesize that   slimy sculpins consume bloater eggs during the period of bloater egg   deposition and incubation (January ? April) because previous   laboratory and field studies have found slimy sculpin to be highly   effective egg predators.  If our hypothesis is correct, then the   recent record-high densities of slimy sculpin may be limiting   bloater recruitment and a potential bloater recovery.  In addition,   we will investigate the role of other benthic egg predators (i.e.,   deepwater sculpins, round gobies) on bloater recruitment success.    Our work has three objectives: 1) Estimate consumption rates of   bloater eggs by benthic egg predators during January to April 2  9   and 2 1  based on field and laboratory data. 2) Determine whether   benthic predator biomass densities and egg consumption rates are   sufficiently large to limit production of age-  bloaters in 2  9 and   2 1 . 3) Determine whether incorporation of consumption by benthic   predators on bloater population egg production significantly   improves the fit of the Lake Michigan bloater stock/recruit model   (using years 1962 to 2 1 ). 

In progress
Start Date
End Date
David BunnellPrincipal Investigator
Associated with 2 projects
Great Lakes Fishery Commission $ 89,013.00USDEstimates

Funding 54 projects for a total of $5,089,137.00
Scope of Study
Field Investigation
Laboratory Investigation
Scale of Phenomena
Impact of Pollutants
Exotic Species
Resource Management
Lake Basin Connecting Channels
Lake Michigan
State Province
Biology And Life History
Life History
Ecosystem Effects
Predator / Prey Interactions
Annex Numbers
Research & Development
Annex 17
Impact of water quality and AIS on fish and wildlife populations and habitats
  • Annex Numbers
    Annex Numbers
    Research & Development
  • Annex 17
    Annex 17
    Impact of water quality and AIS on fish and wildlife populations and habitats

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