Production of pelagic Sargassum and a blue-green epiphyte in the western Sargasso Seal
North of 30”N Sargassum production averaged about twice that to the south, possibly re-lated to the degree of winter mixing. Production rates were relatively high in continental shelf areas or near land masses but showed no major seasonal variations nor was there an obvious relationship with concent...
| Main Authors: | , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.585.9747 http://www.aslo.org/lo/toc/vol_19/issue_3/0429.pdf |
| Summary: | North of 30”N Sargassum production averaged about twice that to the south, possibly re-lated to the degree of winter mixing. Production rates were relatively high in continental shelf areas or near land masses but showed no major seasonal variations nor was there an obvious relationship with concentrations of NO,, NOa, NH:,, and POA. Under normal day-light conditions in October Sargassum photosynthesizes at a maximum rate. Average car-bon turnover time is no more than 40 days and Sargassum and its epiphytes contribute no more than 0.5 % of the total primary production in the western Sargasso Sea. Carbon turnover rate of the epiphyte Dichothrix cxcceded that of its host Sargassum by an average of foul-fold. Dichothrix production on the shelf averaged as much as 15 % of the pelagic macroalgal production in October. Dichothrix is most abundant in the continental shelf waters and lowest in the Sargasso Sea; this distribution may be related to the avail-able iron in the seawater. Sargassum and its associated flora and fauna form a community that ranges over 7 x 10G km2 of the North Atlantic Ocean. It provides physical support for a diverse group of organisms and may represent an important source of energy for benthic communities of the deep sea ( Schoencr and Rowe 1970). The Sargassum standing crop has been estimated by Parr ( 1939) how-ever, production rates have been published only for Gulf Stream samples, taken in May near North Carolina (IIoward and Menzies 1969). We have made further measurc-ments of production rates of Sargassum and its principal epiphyte Dichothrix sp. in dif-ferent seasons and over a wide geographic range. We have also measured Dichothrix standing crop and pertinent production parameters of Sargassum as well. |
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