65 



3. 

 and motors and affect: navigation aids. The least understood but 

 potentially nost damaging inpact from zebra mussels is the shift of 

 energy within the trophic levels of the aquatic ecosystem, frop.. 

 pelagic or nidwater areas to the benthic or bottom environment, it- 

 is the midwater area vrtiere most of the oiirrently desirable species 

 of fish, such as salmon, trout, perch, bass, walleye, etc., make 

 their living. If the biological productivity of the aidwater area 

 is significantly reduced, these desirable fish species will also 

 decline. In 1991, freshwater anglers spent $15.1 billion (US Dept. 

 of Interior etal, 1993) nationwide. While I won't attempt to 

 predict the economic losses from displaced angling activity due to 

 the introduction of zebra mussels, it could reach several billion 

 dollars annually. ."-%v-.- 



Depending on whose estimate you use, over the next decade 

 costs to deal with just the physical and engineering problems 

 associated with zebra mussel colonization will approximate $4 to $8 

 billion (HcCommone, 1990) . It's important to emphasize these are 

 coete to adapt our culture's existing water usee to the presence of 

 this new organism. This is not a cost to ''control" the organism. 

 We are not controlling zebra mussels. At best we are slowing the 

 expansion of its range as we adapt to it. 



New York has a draft ■'Nonindigenous Aquatic Species Management 

 Plan" (Sinnott and Paul, 1993) . The four goals of the plan are 

 essentially to reduce the potential for new nonindigenous species 



