标题：A comparison of summer nutrient data obtained in Königshafen Bay (North Sea, German Bight) during two investigation periods: 1979–1983 and 1990–1992
摘要：A comparison of summer nutrients obtained during the investigation periods 1979–1983 and 1990–1992 was made, to elucidate whether or not changes have occurred in Königshafen Bay during the last decade. In both the flood current as well as in the ebb current, concentrations of silicate, phosphate, nitrite and nitrate have decreased. Ammonia, however, has increased by a factor of two in the flood current waters, but was similar in both investigation periods in the ebb current waters. In addition, a significant increase of salinity has been observed. The differences between flood and ebb current median nutrient concentrations suggest that the bay was a source of nutrients during the 1979–1983 period, exporting large amounts of silicate, nitrite and ammonia with the ebb current. Today, the bay appears to be more a sink than a source of nutrients. Export rates of silicate and nitrite are greatly reduced and phosphate and ammonia are imported nowadays. Nitrate fluxes were in balance during both periods. Reasons for the observed changes are discussed.
