[acn-l] Barren's topminnow rescue mission!

Jay DeLong (thirdwind at att.net)
Thu, 04 Nov 1999 19:36:00 -0800

This was sent to me by J.R. Shute to share with the NANFA and ACN lists.
I'll pass future notes on as well. Chris Scharpf-- this should go into
American Currents!

Jay DeLong
Olympia, WA
------------------------------

A couple of weeks ago (on Oct 20th) CFI had to go on a
rescue mission to collect Barrens topminnows, Fundulus julisia. The Nature
Conservancy had a cooperative agreement with the landowner that has the Type
locality spring of the topminnow in his front yard. The spring is monitored
by the owner, the Nature Conservancy, TN Wildlife Res. Comm., Fish and
Wildlife Serv. and us. We got a call from the Conservancy that the spring
was
almost completely dry! They wanted us to come over right away, collect the
remaining topminnows and house them at our facility. We did this. We were
able to find just over 100 individuals. The spring was reduced to about 10
ft. across and two or three inches deep. There were numerous raccoon and
heron tracks around the edge!

The spring normally supports at least several hundred individuals. We had to
do a similar rescue last year, but the day after we collected the fish, the
rain came and refilled the spring. This year, there was no rain in sight and
indeed, the following week, the spring dried up. This is one of only two
known remaining sights where the topminnows are hanging on.

CFI has representitives of four populations in breeding colonies. Two of
these populations (I suppose you can say three right now!) no longer exist
in
the wild! In other words, they're down to one population! We are also
working
in cooperation with the Tennessee Aquarium who houses representatives of
several of these populations.

This year was a bad drought! No measurable rain since July in that area. But
we don't know if that's the whole problem. There's a huge nursery industry
in
the area. That puts a tremendous demand on the water table. We're concerned
that this might be a continuing problem. If all goes well, these fish will
be returned to their home in the spring. We were able to return all of the
individuals collected last year this past spring.

Also of interest, we have been removing Gambusia from the spring on an
annual
basis. They compete with the topminnows and we have seen many areas where
the
topminnows have been extirpated by Gambusia. Having the spring dry up might
help things (interestingly enough!). There's a spillway that would prevent
the Gambusia from re-entering the spring when it refills. We'll just have to
see what happens!

There's a cave where the spring originates. We have seen topminnows back in
the cave quite a ways in the past. This time, however, there was no water
flowing from the cave mouth. Again, we don't know.

I'll try to keep you posted on the plight of these really rare fish!

Take care!

J. R.

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