Microbial biomass and productivity in seagrass beds

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Geomicrobiol. J.; (United States)

DOI:https://doi.org/10.1080/01490458509385919· OSTI ID:5127400

Moriarty, P J.W.; Boon, P I; Hansen, J A; Hunt, W G; Poiner, I R; Pollard, P C; Skyring, G W; White, D C

Different methods for measuring the rates of processes mediated by bacteria in sediments and the rates of bacterial cell production have been compared. In addition, net production of the seagrass Zostera capricorni and bacterial production have been compared and some interrelationships with the nitrogen cycle discussed. Seagrass productivity was estimated by measuring the plastochrone interval using a leaf stapling technique. The average productivity over four seasons was 1.28 +- 0.28 g C/m/sup 2/ day (meand +- standard deviation, n = 4). Bacterial productivity was measured five times throughout a year using the rate of tritiated thymidine incorporated into DNA. Average values were 33 +- 12 mg C/m/sup 2/ day for sediment and 23 +- 4 for water column (n = 5). Spatial variability between samples was greater than seasonal variation for both seagrass productivity and bacterial productivity. On one occasion, bacterial productivity was measured using the rate of /sup 32/P incorporated into phospholipid. The values were comparable to those obtained with tritiated thymidine. The rate of sulfate reduction was 10 mmol SO/sub 4//m/sup 2/ day. The rate of methanogenesis was low, being 5.6 mg CH/sub 4/ produced/m/sup 2/ day. A comparison of C flux measured using rates of sulfate reduction and DNA synthesis indicated that anaerobic processes were predominant in these sediments. An analysis of microbial biomass and community structure, using techniques of phospholipid analysis, showed that bacteria were predominant members of the microbial biomass and that of these strictly anaerobic bacteria were the main components. Ammonia concentration in interstitial water varied from 23 to 71 ..mu..M. Estimates of the amount of ammonia required by seagrass showed that the ammonia would turn over about once per day. Rapid recycling of nitrogen by bacteria and bacterial grazers is probably important.

• Research Organization: CSIRO, Queensland, Australia
• OSTI ID: 5127400
• Journal Information: Geomicrobiol. J.; (United States), Journal Name: Geomicrobiol. J.; (United States) Vol. 4:1; ISSN GEJOD
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
140504* -- Solar Energy Conversion-- Biomass Production & Conversion-- (-1989)
AMMONIA
AQUATIC ORGANISMS
BACTERIA
BIOCHEMICAL REACTION KINETICS
BIOMASS
COMPARATIVE EVALUATIONS
ENERGY SOURCES
GRASS
HYDRIDES
HYDROGEN COMPOUNDS
KINETICS
MEASURING METHODS
MICROORGANISMS
NITROGEN COMPOUNDS
NITROGEN CYCLE
NITROGEN HYDRIDES
PLANTS
PRODUCTIVITY
REACTION KINETICS
RECYCLING
RENEWABLE ENERGY SOURCES
SEDIMENTS