Quantifying Background Nutrient Concentrations in Coastal Waters: A Case Study from an Urban Embayment of the Baltic Sea

Abstract

Successful management of damaged coastal ecosystems requires reliable scientific evidence of their past state. Here we demonstrate that the sediment record of biotic indicators can be used to quantitatively reconstruct nutrient concentrations preceding the short time span covered by monitoring records. We generated a diatom-based weighted-averaging partial least squares transfer function model for total dissolved nitrogen with a prediction accuracy of 0.09 microg L(-1) (log10 units). The model was applied to sediment core data from Laajalahti Bay, an urban embayment in Helsinki, Finland, where its performance was validated against a approximately 30 yr record of water-quality data and known land-use changes in the watershed. The model tracked well the trends in the nutrient record, although it underestimated very high nutrient concentrations in this highly impacted embayment. The generally good agreement between the actual and predicted values implies that the approach has considerable potential in assessing background nutrient concentrations in coastal waters.

A diatom dataset and diatom-salinity inference model for southeast Australian estuaries and coastal lakes

“…However, some inference models have been developed and applied (e.g. Juggins 1992;Gehrels et al 2006;Ryves et al 2004;Ellegaard et al 2006;Horton et al 2006;Weckström et al 2004;Hassan et al 2009). In Australia, diatom inference models for coastal lake and estuarine environments have so far been developed for relatively small geographic regions (e.g.…”

Diatoms as indicators of eutrophication in the SW part of the Gulf of Gdańsk, the Baltic Sea

“…Recorded commonly in sediments surrounding the Vistula River Mouth (Witkowski 1994, Witkowski & Pempkowiak 1995, Stachura & Witkowski 1997, Stachura-Suchoples 1999, this halophilous taxon proved to be an indicator of the influence by riverine waters (Leśniewska & Witak 2008). This diatom was also observed in samples from the Szczecin Lagoon (Andrén 1999, Bąk et al 2001, Bąk 2004, the Gulf of Finland (Weckström et al 2004, Clarke et al 2006 and the Roskilde Fjord (Clarke et al 2003(Clarke et al , 2006.…”

“…In the study area it was observed by Witkowski (1994), Witkowski & Pempkowiak (1995), Stachura & Witkowski (1997), Stachura (1999), Witak (2000), , Leśniewska & Witak (2008) and Witak (2010). This species was recorded also in the Gulf of Finland (Weckström et al 2004, Clarke et al 2006) and the Gulf of Riga (Olli et al 2008) and the Szczecin Lagoon (Bąk et al 2001). Another species representing the same genus is C. meneghiniana.…”

“…It was frequent in diatom assemblages preserved in the superficial sediments of the Gulf of Gdańsk (Witkowski 1994, Witkowski & Pempkowiak 1995, Stachura & Witkowski 1997, Stachura-Suchoples 1999, Witak 2000, Leśniewska & Witak 2008, Witak 2010. It was encountered also in sediment samples from the Gotland Basin (Andrén et al 2000a), the Bornholm Basin , the Arkona Basin, Oder Rinne and Greisswalder Bodden , the Szczecin Lagoon (Bąk et al 2001(Bąk et al , 2006, the Archipelago Sea (Tuovinen et al 2009), the Gulf of Finland (Weckström et al 2004, Olli et al 2008, the Gulf of Riga, the Kattegat (Olli et al 2008) and the Roskilde Fjord sediments in Denmark (Clarke et al 2003(Clarke et al , 2006. In the studied cores, C. atomus was quite abundant and its percentage content usually reached 3 -5%.…”

“…Its percentage content in the studied cores did not exceed 3%. It was observed in the Gulf of Gdańsk (Stachura-Suchoples 1999), the Gotland Basin (Grönlund 1993, Andrén et al 2000a, the Bornholm Basin (Andrén et al 2000b), the Gulf of Finland (Weckström et al 2004), the Gulf of Riga, the Bothnian Sea, (Olli et al 2008), Oder Rinne ) and the Szczecin Lagoon (Andren 1999, Bąk et al 2001, Bąk 2004). It was reported as an invasive species in the Great Lakes, USA (Edlund et al 1999).…”