Page 8 - Round Goby Flipbook

What are the potential ecological Questions? Comments?
impacts of round gobies on the Contact: Chris Acy,
Winnebago system?
AIS Coordinator for the Winnebago Waterways
Predicting impacts of aquatic invasive species is chris@fwwa.org
difficult as every waterbody is unique and there are (920) 460-3674
numerous variables that can influence the level of impact
a particular invasive species will have on a specific Revised: January 2018
waterbody. Introduced species will have some sort of an
impact on the ecosystem, but the magnitude and direction
of impact is hard to predict. The impact will almost never
be all positive or all negative; the risk is in not knowing
exactly how bad (or good) that impact will be until the
ecosystem has already undergone change.

Another difficulty is that the impact may not be
immediately dramatic or even visible. Subtle changes
caused by the introduction of a new invasive species can
take a long time to display dramatic changes in the
system. The ecosystem may reach a tipping point where
those small changes add up to large ecosystem impacts
over time.

Larger fish have been known to eat gobies and
this invasive species can become another potential source
of food for game fish. The addition of round gobies into
the food web may be beneficial to certain species, while
detrimental to others. Each species has a niche, or “way
of life” which is defined by the environmental conditions,
resources, and interactions it needs to survive at various
stages of its life. The goby, like most other invasive
species, is very efficient at displacing native species
from their respective niches. As a result, the lakes
experience simpler food webs with fewer animal/plant
species. With fewer species, the system is more vulnerable
to collapsing if something happens to part of the food
web. Everything is interconnected like a spider web; if
one strand of the web is cut, the entire web is affected.

The Winnebago ecosystem is unique, and while it is
true that it contains many of the same fish species that are
present in other waters with established gobies, it doesn’t
mean that the ecosystem will experience the same results
as other established goby waters if the round goby gets
into Lake Winnebago. With the round goby situation in
the Winnebago system, we can say one thing with
absolute certainty; if we can prevent their introduction to
begin with, we will not need to take on the risk of the
potential negative effects on the ecosystem if they do
become established.