Foraminiferal zonation of Great Sippewissett salt marsh (Falmouth, Massachusetts)

1990 ◽  
Vol 20 (3) ◽  
pp. 248-266 ◽  
Author(s):  
D. K. Scott ◽  
R. M. Leckie
Keyword(s):  
Salt Marsh ◽  
Great Sippewissett Salt Marsh

scholarly journals Characterization, Seasonal Occurrence, and Diel Fluctuation of Poly(hydroxyalkanoate) in Photosynthetic Microbial Mats

2000 ◽  
Vol 66 (10) ◽  
pp. 4279-4291 ◽  
Author(s):  
Mary M. Rothermich ◽  
Ricardo Guerrero ◽  
Robert W. Lenz ◽  
Steve Goodwin
Keyword(s):  
Salt Marsh ◽  
Organic Carbon ◽  
Microbial Mats ◽  
Ebro Delta ◽  
Purple Sulfur Bacteria ◽  
Mole Percent ◽  
Pure Cultures ◽  
Great Sippewissett Salt Marsh ◽  
Artificial Shading

ABSTRACT In situ poly(hydroxyalkanoate) (PHA) levels and repeating-unit compositions were examined in stratified photosynthetic microbial mats from Great Sippewissett Salt Marsh, Mass., and Ebro Delta, Spain. Unlike what has been observed in pure cultures of phototrophic bacteria, the prevalence of hydroxyvalerate (HV) repeating units relative to hydroxybutyrate (HB) repeating units was striking. In the cyanobacteria-dominated green material of Sippewissett mats, the mole percent ratio of repeating units was generally 1HB:1HV. In the purple sulfur bacteria-dominated pink material the relationship was typically 1HB:2HV. In Sippewissett mats, PHA contributed about 0.5 to 1% of the organic carbon in the green layer and up to 6% in the pink layer. In Ebro Delta mats, PHA of approximately 1HB:2HV-repeating-unit distribution contributed about 2% of the organic carbon of the composite photosynthetic layers (the green and pink layers were not separated). Great Sippewissett Salt Marsh mats were utilized for more extensive investigation of seasonal, diel, and exogenous carbon effects. When the total PHA content was normalized to organic carbon, there was little seasonal variation in PHA levels. However, routine daily variation was evident at all sites and seasons. In every case, PHA levels increased during the night and decreased during the day. This phenomenon was conspicuous in the pink layer, where PHA levels doubled overnight. The daytime declines could be inhibited by artificial shading. Addition of exogenous acetate, lactate, and propionate induced two- to fivefold increases in the total PHA levels when applied in the daylight but had no effect when applied at night. The distinct diel pattern of in situ PHA accumulation at night appears to be related, in some phototrophs, to routine dark energy metabolism and is not influenced by the availability of organic nutrients.

Life cycle, demography, and production of Marenzelleria viridis in a salt marsh of southern New England

1995 ◽  
Vol 75 (3) ◽  
pp. 725-738 ◽  
Author(s):  
Rafael Sarda ◽  
Ivan Valiela ◽  
Ken Foreman
Keyword(s):  
Salt Marsh ◽  
New England ◽  
Dry Weight ◽  
First Year ◽  
Southern New England ◽  
Organic Sediments ◽  
Second Year ◽  
Marenzelleria Viridis ◽  
Great Sippewissett Salt Marsh ◽  
Competition For Resources

Population dynamics and production of the spionid polychaete Marenzelleria viridis were studied at Great Sippewissett salt marsh (Massachusetts, USA) for two years. Marenzelleria viridis was the main contributor in biomass and production to the macroinfaunal assemblages of the sandy organic sediments of the marsh. Marenzelleria viridis spawned during the cold part of the year and the appearance of settled larvae on sediments was observed from January to May. The density of M. viridis rose sharply from winter to late spring followed by a striking drop through summer. The estimated mean annual production of M. viridis was 60.0 g dry weight m2 during the first year and 26.3 g dry weight m2 during the second year. The population of M. viridis is affected by different processes during the year. The number of initial recruits seems to be largely governed by meteorological conditions. The numbers of recruits are then affected by competition for resources, and later, as predators become active, predation pressure determines the abundance of the population of M. viridis.

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