If the bad guys were bigger…

A poster in my doctor’s office showed a boy looking down at his hands, which were infested with all sorts of big, ugly, wormlike green, purple and pink creatures. And the poster says, If germs were bigger, would you wash your hands more? It’s useful to think of this when we consider cleaning the boats we move from one lake to another for fishing and other recreation. We all (I should hope) regularly remove weeds from our boat and trailer, and before launching at another lake we check for and remove any hitch-hikers that might be clinging.

But some of the invasive species are not much more visible to the naked eye than the germs we wash off our hands. Two obvious examples are the spiny water flea and the larvae (veligers) of zebra and quagga mussels – insidious pests that infest a growing number of lakes. These species are native to Europe and Asia and got into the Great Lakes by way of ballast water discharges from ocean-going ships. Spiny water fleas are a variety of small animals (zooplankton) that float in the water and provide food for growing fishes. The spiny fellows eat native water fleas called Daphnia on which native fish depend. They have spread across the Great Lakes and have prospered in some inland lakes. They can travel to new lakes by clinging to fish line, anchor ropes and landing nets. Female spiny water fleas dry out and die once out of the water, but they produce eggs that can survive the drying process. Live specimens can travel in bait pails or boat livewells.

Zebra and quagga mussels essentially dominate Lake Michigan, filtering out the algae and zooplankton that form the base of the food chain. Adult mussels are big enough to spot clinging to boat or trailer. The greater danger is their veligers, which can travel in water left in boats and containers. For these reasons, it’s essential to drain our boat livewell, bilge and motor before leaving a landing and to avoid transporting any water from one lake to another. It’s also advisable to let boats and equipment dry for about five days before going to another lake.  Maybe we would take more precautions against these invaders of we could easily see them. Regardless, we all need to practice good boat hygiene. If we don’t, we forfeit the right to criticize others who may pollute our lakes and streams.