September 15, 1977


            REPLY REQUESTED BY OCTOBER 3, 1977


Quality of Water Branch Technical Memorandum No. 77.12

Subject: PROGRAMS AND PLANS: Phytoplankton sampling for the 
         National Stream Quality Accounting Network (NASQAN)

Members of the Quality of Water Branch staff have reviewed many of 
the 1975 and 1976 taxonomic data on phytoplankton samples 
collected at NASQAN stations. The review covered data from 98 
stations in Alaska, Hawaii, Puerto Rico, Oregon, the Lower 
Colorado River basin, Florida and Georgia, Texas, the Ohio River 
basin, and New England. Emphasis was placed on finding the most 
efficient way to describe the phytoplankton community during the 
"growing" and "non-growing" seasons.

The studies showed that at most stations there is little variation 
in the composition of the phytoplankton community during the 8 
"non-growing" months of October through May. In general, except 
for Hawaii and Puerto Rico, the taxonomic makeup of the community 
during these 8 months can be represented adequately by 3 samples 
collected approximately in November, March, and May.

Data-collection plans for NASQAN have been revised to take 
advantage of the opportunity for increased efficiency of operation 
that is suggested by the results described above. One of the 
benefits of this increased efficiency will be a reduction of 
workload for the Biological Section of the Atlanta Central 
Laboratory. Revisions in the data collection program are as 
follows:

1. Except for stations in Puerto Rico and Hawaii, 7 phytoplankton 
samples are to be collected each year at each NASQAN station. The 
samples are to be collected approximately monthly during the 
"growing-season" months, June through September. During the 8 
months, October through May, only 3 samples are to be collected, 
preferably in the months of November, March, and May. Twelve 
samples per year, approximately monthly, are to be collected at 
stations in Hawaii and Puerto Rico as before. This change should 
be effected by field offices on October 1, 1977.

2. The Atlanta Laboratory has suspended analyses of samples 
collected during the "non-growing" months of the 1977 water year, 
except for the 3 months indicated above. In some cases, where the 
February sample was analyzed and the March sample was not, the 
March sample was deleted.

There may be a few instances where a district has a strong need or 
has made commitment for collection and analysis of monthly samples 
throughout the "non-growing" season of the 1977 water year. If 
there is such a need, it is possible for the samples to be 
analyzed at the district's expense. Requests for analysis of WY 
1977 samples that have been deleted from the NASQAN program should 
be sent together with full justification, to the Quality of Water 
Branch through the Regional Hydrologist. No requests can be 
considered that are received in Reston after October 3, 1977. 
Telephone requests should be followed up by a memo for 
documentation purposes.

Please call Phil Greeson, John Ficke, or John Briggs if you have 
any questions regarding this memorandum.



                             R. J. Pickering
                             Chief, Quality of Water Branch

WRD Distribution: A,B,S,FO,PO