Even us amphibious creatures could not catch a break from
the sweltering heat this summer as water temps soared and side-channels sizzled
dry under the unrelenting scorching skies.
As the waters recede the neighborhood can get a little crowded,
especially with all the new immigrants! From
the Mississippi to the Sugar River, we have seen unwanted guests flocking here like
snowbirds to Florida finding great pleasure in the heat.
In the Mississippi River near Alma, Wisconsin about 1,000 water hyacinth and water lettuce, two of the world’s worst invasive species that are
are not regulated here in Wisconsin due to their assumed intolerance of our winter, were
found last year. After a rapid response
to squelch this new invasion, WDNR and USFWS staff hoped that the literature
was right. However, low and behold this
summer the two plants (nearly 10,000 of them) reemerged from seed to be joined by yet another nasty
invader, parrot feather. For more on this infestation, http://www.fws.gov/midwest/News/release.cfm?rid=571
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| Water lettuce and water hyacinth in the Mississippi River (credit: Paul Skawinski) |
Zebra mussels are not new to the Wisconsin River. However, this year something monumental
happened; their populations exploded! In
a recent survey of a native mussel bed near Muscoda 90% of the native mussels
collected had juvenile zebra mussels attached to them. In total there were over 10,000 young zebra
mussels. That is 10,000 future heal
cutting shells to litter our sandbars. While they have been in the area since
2008, they have remained a mere minority until this year. Now at their current numbers they pose a
substantial threat to natives, recreational opportunities, and the bottom line
of river-based businesses.
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| Juvenile zebra mussels on from the Lower Wisconsin River |
A stone’s throw over the Military Ridge in the Sugar River
watershed the mosquitofish, an exotic species that was also thought to not like
our Wisconsin winters, is thriving much to the detriment of our native
blackstripe topminnow and state endangered starhead topminnow. This
year’s drought has decreased the back water slough habitat within the river where
these three species have competed for resources in years past. A survey last month discovered that there were now no topminnows and a plethora of mosquitofish in what was left of the
shallow sloughs.
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| Biologists walk through the site of a former slough |
One hot summer a trend does not make. Us river dwellers, like you, hope that this
season does indeed prove to be a fluke. In
the meanwhile, it’s time to get down to business to mitigate the damage that
has been done. Stay tuned for more
information on what the River Alliance and their partners are doing to keep
these invaders at bay. As for you,
please keep an eye out for the unusual while you visit your favorite
waters.
posted by the River Rat
