crop; however, an alternate method is suggested which measures pro- 

 duction as a dynamic process and accounts for certain inherent dis- 

 crepancies which occur in the initial method. The alternate method, 

 which is termed "true net production," was found nearly to 

 double the production calculated by summation of the monthly change in 

 standing crop. The two methods are compared and discussed. 



The rates of decomposition and loss of dead standing Spartina from 

 the marsh were examined by utilizing nylon mesh litterbags. The 

 streamside marsh, inland marsh, and tidal channel were considered in 

 the measurement of loss rates. Dead material was found to decompose 

 most rapidly in the tidal channel. 



The decomposition rates of four particle-size fractions of dead 

 Spartina , considered small enough to have been easily washed off the 

 marsh surface, were studied under laboratory conditions. At a con- 

 stant temperature of 30°C, particles of 111 microns or less were com- 

 pletely decomposed in 30 days, whereas those larger than 111 microns 

 were more slowly affected. (A. A.) 



Keywords: primary productivity, Spartina alterni flora , estuary, 

 Louisiana, Barataria Bay 



II-B-6 



Stowe, W.C, C. Kirby, S. Brkich, and J.G. Gosselink. 1971. Primary 



production in a small saline lake in Barataria Bay, Louisiana. Louisiana 

 State University Coastal Studies Bulletin No. 6, pp. 27-37. 



Production rates of three groups of primary producers (marsh grass, 

 epiphytic algae attached to the marsh grass, and phytoplankton) were 

 studied in a small saline lake. The biggest gap in the information 

 is acknowledged to be examination of benthic and mudflat production. 

 The paper identifies the contribution of each producing group 

 to the total primary production of the lake. 



Net production of the marsh grass Spartina alterni flora was estimated 

 by monthly clipping of the aboveground plants with allowances for loss 

 in dead standing crop. Annual production estimates from these samples 

 were found to be 13 percent higher than those reported for the Georgia 

 marsh and 200 percent higher for the inland and 180 percent for the 

 streamside than those reported in a New York salt marsh. 



Epiphytes were collected by gathering samples of stems at the water 

 edge and also 5 to 7 feet inland. Summer production was determined by 

 the light-dark bottle method. The figures derived are low compared 

 to those found in California and Florida. Measurements had not yet 

 been taken in winter, but are expected to be higher than summer. 



36 



