Subject: Filamentous Algae problem

From: [email-masked] (David Hughes)
Date: Sun, 23 Jun 1996 07:17:18 GMT

I have been recently appointed to serve on a lake committee for a small 
lake in North East Texas (175 acres with depth up to 25 feet)  For 
several years we have been pursuing an agressive fertilization program 
which most fish biologists recommend.  however, this has created a huge 
problem of filamentous algae.  We have used Cutrine, but because of the 
vast amound of this algae, this has not been successful, and I 
understand that to use the needed amount of Cutrine, we could damage 
the fish population.  We are now considering introducing Mozambique 
Tilapia.  I would be most interested in hearing from some that have had 
the same experience with algae and how you have controlled it.  Also 
would like to hear from anyone with knowledge about this tilapia.
David -- Tyler TX   [email-masked]

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From: [email-masked] (Chauncey W. Anderson)
Date: 25 Jun 1996 18:27:03 GMT

> David -- Tyler TX   [email-masked]

I would hate to see you introduce another species to take care of a
problem (filamentous algae ) that was created (aggressive
fertilization) to take care of another "problem" (not enough fish) to
satisfy the fish biologists. These measures just begin to snowball. I
hate to say it but it looks like fertilization was not a well thought
out action -- anyone can tell you that aggressively fertilizing a lake
will lead to algae problems. Fish biologists know this too (usually).

My suggestion would be to cut back (as much as possible) on the
fertilization program.  Hopefully your lake is such that the nutrients
will eventually be exported and the algae might go away.  Some further
investigations would be warranted, however.  

Chauncey Anderson, Hydrologist 	      e-mail:[email-masked]
USGS-WRD			      tel: (503) 251 - 3206
10615 SE Cherry Blossom Dr.           FAX: (503) 251 - 3470
Portland, OR  97216                   http://wwworegon.wr.usgs.gov/index.html

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From: [email-masked](brett rowley)
Date: 26 Jun 1996 12:53:44 GMT

In <[email-masked]> [email-masked] (Chauncey W.

>10615 SE Cherry Blossom Dr.           FAX: (503) 251 - 3470
David,

Have you called the Texas A&M Extension Service and asked them for help? 
They have an office near you in Overton.

Tilapia mossambique will not control filamentous algae.  They are a good
forage species for bass, and will enhance the growth and standing crop of
bass in your lake, but won't control algae.  Other tilapia species might
help with algea, but are not yet re-legalized in Texas.  The best for that
purpose would be T. zillii, also a great forage for bass.  The cutrine you
mentioned will work pretty well, but is pricey and lots of work to put
out.  Grass carp will also control algae, as long as there is not much
else for them to eat in the lake.  They are not a quick fix, and usually
take a year or more to become effective.  Fertilizing your lake is a good
idea, but a tricky proposition at best.  You must fertilize early in
the spring and stop as water temps go above 70 or so.  I assume you
have a threadfin shad stocking program along with your fertilization? 
Also, have you limed the lake in recent years?  

There are also several other herbicides you might want to investigate
for algae control.  The best one being diquat dibromide, it comes in
several trade names, including Diquat and Reward.  It is best to get a
licensed applicator to put this and cutrine or other chemical controls
out effectively.  I know a good biologist in your area and if you
e-mail to me, I'll send his name and number to you.  He deals with lots
of lakes in your area and might have a good answer.

Brett Rowley
Fisheries Biologist
Great Lakes Sportfishing Resort and Koi Breeding Farm
West Columbia, Texas

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