Foraminiferal response to environmental changes in Kiel Fjord, SW Baltic Sea

Abstract

Abstract. The living benthic foraminiferal assemblages in Kiel Fjord (SW Baltic Sea) were investigated in the years 2005 and 2006. The faunal studies were accomplished by geochemical analyses of surface sediments. In general, sediment pollution by copper, zinc, tin and lead is assessed as moderate in comparison with levels reported from other areas of the Baltic Sea. However, the inner Kiel Fjord is still exposed to a high load of metals and organic matter due to enhanced accumulation of fine-grained sediments in conjunction with potential pollution sources as shipyards, harbours and intensive traffic. The results of our survey show that the dominant environmental forcing of benthic foraminifera is nutrients availability coupled with human impact. A comparison with faunal data from the 1960s reveals apparent changes in species composition and population densities. The stress-tolerant species Ammonia beccarii invaded Kiel Fjord. Ammotium cassis had disappeared that reflects apparently the changes in salinity over the last 10 years. These changes in foraminiferal community and a significant increase of test abnormalities indicate an intensified environmental stress since the 1960s.

Calcifying invertebrates succeed in a naturally CO<sub>2</sub>-rich coastal habitat but are threatened by high levels of future acidification

“…Mytilus edulis was collected from a subtidal population in Kiel Fjord (54 • 19.8 N; 10 • 9.0 E, see Nikulina et al, 2008 for a detailed map of the study site). For extracellular acidbase status experiments (Exp.…”

Sub‐arctic Holocene climatic and oceanographic variability in Stjernsund, northern Norway: evidence from benthic foraminifera and stable isotopes

“…; Nikulina et al . ). The turnover in the benthic foraminiferal fauna is probably also influenced by eustatic uplift and a relative sea‐level fall of ∼10 m, which constricted the space over the sill for the inflowing NAC between 9.4 and 3.2 ka BP (López Correa et al .…”

“…) and in the Baltic Sea today, where E. excavatum clavatum prefers the deeper areas within and below the halocline (Lutze , ; Nikulina et al . ). Increased abundances of the Arctic‐Polar group in Stjernsund are interpreted to reflect colder conditions in the bottom water.…”

“…The species N. labradorica has a wide temperature range (Conradsen 1995), but its maximum abundance (>20%) is in colder waters where temperatures are lower than~2°C (Sejrup et al 2004). E. excavatum clavatum and I. norcrossi are characteristic of Arctic-Polar conditions and are abundant in glaciomarine fjords (Hald & Aspeli 1997;Korsun & Hald 1998;Sejrup et al 2004) and in the Baltic Sea today, where E. excavatum clavatum prefers the deeper areas within and below the halocline (Lutze 1965(Lutze , 1974Nikulina et al 2008). Increased abundances of the Arctic-Polar group in Stjernsund are interpreted to reflect colder conditions in the bottom water.…”

“…Species such as C. laevigata and E. albiumbilicatum still show high abundances (Fig. 5), which can be explained by their ability to successfully withstand changing conditions (Schmiedl 1995;Corner et al 1996;Nikulina et al 2008). The turnover in the benthic foraminiferal fauna is probably also influenced by eustatic uplift and a relative sea-level fall of~10 m, which constricted the space over the sill for the inflowing NAC between 9.4 and 3.2 ka BP (López Correa et al 2012).…”