Nutrient accumulation and nutrient retention in coastal waters – 30 years investigation in the Darss‐Zingst Bodden chain

Abstract

Coastal waters are transitional zones between limnic waters and marine systems. The anthropogenic impact on these water bodies is high and a rapid change of trophic level was observed within the last 50 years. In the Darss-Zingst Bodden chain (southern Baltic Sea -MecklenburgWest Pomerania, Germany), the change in trophic state during the last thirty years can be reconstructed by long-term monitoring of chemical, hydrographical and biological parameters with an up to daily resolution. Until the 1980s, increased input of the anthropogenic nutrient load from the catchment area has been documented. However, with the implementation of the HELCOM recommendations the input of phosphorus and nitrogen was reduced in the 1990s. In contrast to the reduction of nutrient inputs, a decrease in nutrient concentrations and primary production could not be observed. The reasons are a high internal nutrient load and the release of nutrients out of the sediments. Numerous research projects allowed the description and quantification of these processes. Today, the internal phosphorus pool exceeds the external phosphorus load several fold. These results are the scientific basis for the development of restoration strategies of coastal waters. The development of suitable management plans is necessary for the implementation of the EU Water Framework Directive to guarantee a good ecological state by 2015. The long time acquisition of monitoring data and voluminous complementary specific research projects was enabled by the local field research conditions of the Biological Station of the University of Rostock in Zingst.

Phytoplankton diversity and photosynthetic acclimation along a longitudinal transect through a shallow estuary in summer

“…Hydrographical and hydrological conditions (Table 1) determine a high productivity level. Besides the typical estuarine salinity gradient, riverine nutrient input leads to gradients of nutrients along the estuary, which include high concentrations of dissolved nutrients, especially in winter and spring (Selig et al 2006). Massive storage of phosphorus and nitrogen is linked to organically rich sediments (Schlungbaum & Nausch 1988).…”

Laboratory studies on the coprecipitation of phosphate with calcium carbonate in the Salton Sea, California

“…These concentrations are only one-quarter of those found in the pore water of other lakes in southern California (Oza, 2003) and one-tenth reported for Mediterranean lagoon sediments (Souchu et al, 1998). The P fluxes from the sediments of the Salton Sea are one-quarter of that reported for nutrient-rich coastal sediments (Selig et al, 2006;Swan et al, 2007). Recent measurements of the P budget for the Sea suggest that 15-20% of the total annual external P inputs are being sequestered or permanently buried within the Sea (unpublished data of the authors).…”

Long-term stability of the seasonal succession of different zooplankton species in a brackish water lagoon (southern Baltic Sea)

“…The larvae of M. neglecta were also associated with higher concentrations of oxygen, lower water temperatures and additionally lower pH-values. But they were not closely associated with very high concentrations of nitrate and nitrite, which were typically observed from January until March in the DZL (Selig et al, 2006). The copepods A. tonsa and E. affinis exhibited slight associations to the abiotic factors.…”