Marine Macrophyte Wrack Inputs and Dissolved Nutrients in Beach Sands

• DOI: 10.1007/s12237-011-9375-9
• Publication Date: 2011-01-25T16:58:05Z
• Authors: Jenifer E. Dugan; David M. Hubbard; Henry M. Page; Joshua P. Schimel
• Keywords: Nutrient cycle; Primary producers; Macrocystis pyrifera

We investigated the role of sandy beaches in nearshore nutrient cycling by quantifying macrophyte wrack inputs and examining relationships between accumulation pore water nutrients during summer dry season. Macrophyte inputs, primarily giant kelp Macrocystis pyrifera, exceeded 2.3 kg m−1 day−1. Mean biomass varied 100-fold among (range = 0.41 to 46.43 m−1). concentrations dissolved inorganic nitrogen (DIN), NO x − -N, organic (DON) intertidal significantly (ranges 1 6,553 μM 7 2,006 μM, respectively). Intertidal DIN DON were correlated with biomass. Surf zone also strongly DIN, suggesting export from re-mineralized wrack. Our results suggest beach ecosystems can process re-mineralize substantial accumulate nutrients, which are subsequently available waters primary producers.