Bob,

You wondered about the fish, stacked several layers deep all along the
stretch of reeds parallel to Aurora Avenue, at Green Lake.

You put your finger right on it when you surmised they might be trying to
escape the (common) mergansers and (double-crested) cormorants out in the
lake. Add (great blue) herons (and some years green herons too) to that list
as well.

A few weeks ago, what looked like spawning activity was going on in this
area. Thousands of the fish (perch? carp? not sure) were in the shallows,
milling around. Underneath the willows, between the cattails. At that point
the water lilies had not died back yet and few mergansers were on the lake.
The Great Blue Herons were there and one adult (of two adults and a
juvenile) had staked out the area underneath the willows. As the lilies died
back and mergansers and cormorants were no longer impeded in their under
water pursuit of the fish, they showed up, these past two weeks. The fish no
longer look like they are there out of their free will.

This is a normal phenomenon. It happens regularly, not every year, but about
every other year. A few years ago the number of fish stuck in the reeds for
weeks on end, were noticed by lots of people who called the Parks Department
and Department of Ecology and complained about something or someone
poisoning the fish in Green Lake. Department of Fish and Wildlife fish
pathologist came and sampled the fish. He found lesions and abrasions on the
fish their outsides and hyperplasia in the gills. No sign of disease but
signs of rubbing against one another in shallow water, under stress, with
lack of oxygen. He concluded he wasn't sure what caused it, maybe it had
something to do with the fish-eating birds out in the lake. That year I had
watched the 150+ mergansers work cooperatively for more than three weeks,
driving the fish into the shallows.

One morning I was standing on shore at the Aqua Theater and 100+ Common
Mergansers came into view. They were literally porpoising, jumping out of
the water to breath and immediately shoot under water again. They were
apparently in full pursuit of a school of fish (dumb fish, think there's
safety in numbers...). A few days later when you walked on the wooden dock,
you could hear the fish below splattering around. That was before the lilies
had died back farther north. Once the lilies died back the concentration of
fish shifted to that area, again, presumably because the birds were no
longer hindered by lily stems.

As to why this particular area (NW corner) of the lake is better for
concentrating fish, I don't know. Perhaps the bottom gradually rises, so
fish don't realize they're going up a dead-end "road." Perhaps the fact that
this is a more quiet spot on the lake and the birds aren't as easily spooked
from their "work" makes this a better spot. Whatever the case, it's a great
spectacle and fun to watch. The fishy smell, I am perfectly willing to take
for granted.

We (Green Lake Park Alliance) would like to get interpretive signs up, that
explain this kind of stuff to people, so they won't go worrying about
poisons and calling "the authorities" who than spend tax dollars on
analyzing the non-problem (although that's better spent than some projects I
can think of...). But as you as a regular park user know, Bob, most signs
will eventually either be vandalized or end up in the lake. That's why we
organize naturalist programs. Hopefully the Parks Department will
acknowledge the need and start programs like those in Carkeek and Discovery
Park, with paid naturalist programs.

Best of holiday wishes to all,

Oh, and Tom, I think the majority of tweetsters got the joke, or there would
have been many more reactions...

I do so like jokes, I (we) need laughter.

Martin Muller, Seattle
MartinMuller at classic.msn.com