Consultant's Report - Minnesota State Legislature

MINNESOTA DEPARTMENT OF NATURAL RESOURCES
Feasibility Study to Limit the Spread of Zebra Mussels from Ossawinnamakee Lake
zebra mussel production (Stewart and Haynes 1994). Within Lake Erie (Dermott et al. 1993)
and Lake St. Clair (Griffiths 1993), these populations of benthic invertebrates have increased
proportionately with zebra mussels.
Diving Waterfowl
Diving waterfowl have been known to prey on zebra mussels within North America. The
following species have been observed feeding extensively on zebra mussels in Ontario and
throughout the Lake Erie region: greater scaup, lesser scaup, common goldeneye, and the
bufflehead (Wormington and Leach 1992, Hamilton et al. 1994).
Aquatic Nuisance Species (ANS)
Nonindigenous species (NlS), also called exotic, alien or nonnative species, are generally
referred to as those plants and animals that are found beyond their natural geographical ranges
(US Congress, OTA 1993). It is estimated that as many as 50,000 nonindigenous species (plants,
animals, invertebrates, microbes, etc.) have been introduced into the United States (pimentel et
al. 2000). Not all nonindigenous species are harmful; some are beneficial including many food
crops (US Congress OTA 1993, Pimentel et al. 2000). In more specific terms, an invasive
species is one category ofnonindigenous species that is defined as 1) non-native (or alien) to the
ecosystem under consideration and 2) whose introduction causes or is likely to cause economic
or environmental harm or harm to human health (Executive Order 13112 1999). Invasive
species can cause direct harm to species and habitat by directly competing for resources and
competitively interacting with native, indigenous species. Additionally, invasive species can
result in indirect impacts to species and the general ecology of a system such as the Upper
Mississippi River Basin (UMRB). In either case, the impacts are often irreversible and costly.
In a 1993 study produced by the United States Congress, Office of Technology Assessment, it
was estimated that 79 nonindigenous species had caused approximately $97 billion in damages
from a period of 1906 to 1991. However, more current estimates indicate that some
nonindigenous species in the United States may cause as much as $137 billion of damage per
year (Pimentel et al. 2000).
Most plant and vertebrate introductions were intentional, compared to invertebrate and microbe
introductions that are mainly unintentional (Pimentel et al. 2000). Although intentional, not all
introductions were malicious attempts to directly alter ecosystems but rather attempts to
biologically control or enhance environments. Despite the introduction intentions, some
nonindigenous species are spreading at alarming rates and threaten ecologically significant areas
such as the Upper Mississippi River Basin.
A sub-classification of invasive species are the Aquatic Nuisance Species (ANS) described as
nonindigenous species that threaten the diversity or abundance of native species; the ecological
stability of infested waters; or commercial, agricultural, aquacultural and recreational activities
dependent on waters (ANS 2000). The threat of ANS has prompted action at local, state and
federal levels. In 1990, The Nonindigenous Aquatic Nuisance Prevention and Control Act
IV-16 Review of Zebra Mussel (Dreissella polymorpha) Species