Fish Virus

"Tim Lysyk" wrote in message
news:te91i.7991$g63.2980@edtnps82...
Wolfgang wrote:

The encouraging news is [insert encouraging news
here......someone.....anyone].

Wolfgang

The encouraging news is that epidemics (epizootics in this case) are
usually self limiting, the media tends to greatly over-exagerate the
effects of such outbreaks, etc.

You're right, one tends to become numb and different, but how many
disasters have been said to be about to befall us, and nothing really,
come of them?

True enough, bad news sells and that's reason enough to amplify. And, yes,
many epizootics have established themselves in all corners of the world to
such an extent that most residents don't know that they aren't natives (but
then, they don't know whether or not the natives are natives, either), and
without causing economic or environmental upheavals.....that most people
noticed. But this is by no means always the case.

Precisely what the cost has been (and continues to be) is difficult to
determine in large part because the value of what is lost is not universally
(or even widely) agreed upon even when a figure can be put to it, and
because the changes generally take long enough that most people, who aren't
paying attention anyway, scarcely notice. The current concerns about a
possible collapse of the Great Lakes ecosystem due to the introduction of
VHS is a good example of how these things work, I think. Odds are that it
won't kill every fish in the lakes. Many.....perhaps the vast
majority.....will probably survive. On the other hand, this COULD be the
exception to the rule. There are only so many empty chamber in the gun.
Meanwhile, most people, even including those who cry doom at each new
invasion, are blithely unaware that the Great Lakes ecosystem already HAS
collapsed.

I grew up, and have spent most of my life, within a few miles of Lake
Michigan. The changes that have occurred within the last half century are
staggering. Today, there is just a pitiful remnant of a once thriving
commercial fishery. As a boy, I participated in an annual summer-long
slaughter of yellow perch from the lighthouse jetty in the Kenosha harbor
that would have made the proud authors of three hundred dead fish per day
adventures in the trout streams of old New England blanch. In those days,
you could, if you were enterprising and had the rare luxury of a large
freezer, feed a family for the year on the catch in the yearly spring run of
smelt, itself an introduced species. If you could afford a nickel for a
beer you could gorge yourself on free fried fish in any of a hundred local
taverns. Lake trout, perch, whitefish and chubs were sneered at by anyone
with a decent income because they were so cheap that they couldn't possibly
be any good. Granted, the demise of this seemingly inexhaustible larder was
not due entirely to the introduction of exotics. In fact, the smelt alone
is a strong argument to the contrary. Pollution and over-harvesting also
played an obvious and major part. But there is no denying that the sea
lamprey did incalculable damage to the large predatory fishes by the time it
peaked in the 50s and the alewife population exploded as a result. Anyone
who spent time on (or within a mile of) a Lake Michigan beach on a hot
summer day in the 60s should have a keen appreciation the possible
consequences of epizootic invasions.

In the last decade or so, the effects of the zebra mussel have come....or at
least started to come....to fruition. Despite encrusting every solid
surface, including, importantly, such things as water intakes (thereby
reducing their effective diameter....which can be a serious problem in
applications like cooling a power plant) and changing the composition of
beaches and lake bottom, and changing the chemical composition of the water
through uptake of carbonate ions....despite all this, it looked for a while
(at least to the casual observer) like they might actually prove to be
somewhat beneficial in that they were highly efficient at filtering the
water and thereby improving its clarity vastly. Well, that's the trouble
with the casual observer. They increased water clarity by filtering out
(among other things) much of the food that forms the base of the Lake's food
chain. This is a bad thing....very bad. To make matters worse, the
increased light penetration has also triggered algal blooms that currently
leave the beaches piled high with a reeking mass of rotting vegetation that
must strike a nostalgic chord in the heart of anyone who remembers millions
of tons of putrescent alewives and stupendous hordes of flies and maggots
fondly.

There's more......LOTS more.....but, you get the picture.

Just this parting thought, though. All of this would have been a lot easier
to deal with if it had just happened a bit sooner. In the 50s, the beach
was a wonderful place to go and play in the water (despite the
crowds.....which no longer exist there), but it wasn't necessary to go there
to beat the summer heat. One could have sat in the cool shade on the front
porch along any of thousands of elm roofed tunnels that used to be the urban
streets in this part of the world and been philosophical about all of it.
Anyone who has seen those streets then and now has a visceral understanding
of what the word "hideous" means.

Wolfgang