Primary production rates calculated by different concepts - an opportunity to study the complex production system in the Baltic Proper
Wasmund, N.; Nausch, G.; Schneider, B. (2005). Primary production rates calculated by different concepts - an opportunity to study the complex production system in the Baltic Proper. J. Sea Res. 54(4): 244-255. https://dx.doi.org/10.1016/j.seares.2005.07.004
In: Journal of Sea Research. Elsevier/Netherlands Institute for Sea Research: Amsterdam; Den Burg. ISSN 1385-1101; e-ISSN 1873-1414, more
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| Keywords |
Biological production > Primary production
Cycles > Chemical cycles > Geochemical cycle > Biogeochemical cycle > Nutrient cycles > Carbon cycle
Methodology
Nutrients (mineral)
Population characteristics > Biomass
ANE, Baltic, Gotland Deep [Marine Regions]
Marine/Coastal |
| Author keywords |
new production; net community production; nutrient; Redfield ratio;f-ratio Baltic Sea |
| Authors | | Top |
- Wasmund, N., more
- Nausch, G., more
- Schneider, B.
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| Abstract |
Primary production in the eastern Gotland Sea was calculated by three different approaches: (1) the nutrient concept based on the consumption of inorganic nutrients, (2) the biomass concept based on the increase of POC + DOC, and (3) the CO2 concept based on the consumption of total CO2 in the water. The comparison of these three integrating methods concentrated on a 108-d period of new production (28 March-13 July 2001), when all concepts were applicable. New production on the basis of winter nitrogen was approximately 1352 mmol C m-2 (108 d)-1. The excess PO4, still available after the spring bloom, allowed an additional new production of 1245 mmol C m-2 (108 d)-1 if additional nitrogen was supplied, e.g. by nitrogen fixation. The sum of 2597 mmol C m-2 (108 d)-1, based on the Redfield ratio, increased to 3098 mmol C m-2 (108 d)-1 if the measured POC/PON ratios were applied. The net community production, derived from the biomass concept, was 3294 mmol C m-2 (108 d)-1. Literature data from the CO2 concept were extrapolated to the euphotic zone, resulting in a net community production of 3327 mmol C m-2 (108 d)-1. In the period considered, new production and net community production were close to each other. The three concepts agree well and reveal a close range of 3098-3327 mmol C m-2 (108 d)-1 of net community production in the eastern Gotland Sea. The difference between net primary production rates and net community production is attributed to the respiration by the heterotrophs within the euphotic zone (3144 mmol C m-2 (108 d)-1). The share of new production in net primary production (f-ratio) was 48%. Differences of the CO2 concept and the biomass concept in the upper mixed layer owing to sedimentation across the thermocline were estimated at 1717 mmol C m-2 (108 d)-1. If calculated from the nutrient concept, nitrogen fixation accounts for 19-23% of net primary production. |
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