The History of Eutrophication in the Sea Area of Helsinki in the 20<sup>th</sup>Century

Finni, Terttu; Laurila, Sari; Laakkonen, Simo

doi:10.1579/0044-7447-30.4.264

Cited by 22 publications

(2 citation statements)

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“…The eutrophication of the estuaries in the northern coast of the GOF started along the industrialization and intensification of agriculture in the late nineteenth century (Finni et al 2001; Laakkonen and Lehtonen 1999). The point source loads into the waterways and the coastal area have decreased considerably since the worst situation in the middle of the twentieth century thanks to effective water pollution control measures.…”

Section: Discussionmentioning

confidence: 99%

Interaction between the land and the sea: sources and patterns of nutrients in the scattered coastal zone of a eutrophied sea

Raateoja

Kauppila

2018

Environ Monit Assess

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A long-term trophic development of three geographical transects—including a river mouth, an estuary, and an archipelago—were studied in the southern Finnish coast in the Baltic Sea. Each transect was studied to clarify how far off the coast the land-based nutrient sources (catchment factor, CF) had a decisive role in shaping the wintertime regimes of dissolved inorganic nitrogen and dissolved inorganic phosphorus and where the marine processes (marine factor, MF) start to play a major role. Generally, CF controlled the nutrient regime from the coast to the outer brink of the inner coastal area, after which MF started to dominate. The estuaries exhibited steep vertical nutrient gradients, above which the riverine input dominated the nutrient regime. The extent of the area where CF dominated the nutrient regime was therefore decisively dependent on estuarine stratification, i.e., whether the conclusions were drawn based on the surface layer data, including the riverine impact, or on the data beneath that layer, including the marine impact. This result deviates from the current consensus that the trophic regime of the sea is most directly assessed by the surface layer nutrient content. The estuarine nutrient regime is unrepresentative to that of a typical coastal water body due to the strong land-based impact on the estuary. Therefore, any generalization of the trophic condition of an estuary to represent areas farther off the coast should be done cautiously. The estuaries should also be defined as belonging to transitional waters according to the typology related to European Marine Legislation.

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Section: Discussionmentioning

confidence: 99%

Interaction between the land and the sea: sources and patterns of nutrients in the scattered coastal zone of a eutrophied sea

Raateoja

Kauppila

2018

Environ Monit Assess

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“…Oscillatoriales showed also a significant positive correlation with temperature and a negative correlation with salinity indicating its freshwater origin and preference for warm water. Based on recent plankton data and considering the relationship between plankton and trophic level, Finni et al (2001b) attribute the dominance of oscillatorean cyanobacteria (Planktothrix agardhii, Pseudanabaena limnetica, Planktolyngbya) to considerably eutrophic or hypereutrophic conditions. On the other hand, Nixdorf et al (2003) also state that the dominance of Oscillatoriales in lakes is a result of the humaninduced eutrophication process, but analysing phytoplankton data from shallow hypertrophic lakes they concluded that turbid mixed layers with highly light deficient conditions seem to be the key factors favouring the dominance of some oscillatorean genera like Pseudanabaena.…”

Section: Discussionmentioning

confidence: 99%

Selecting potential summer phytoplankton eutrophication indicator species for the northern Baltic Sea

Toming

2007

Estonian Journal of Ecology

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The composition, abundance, and biomass of aquatic flora, including phytoplankton, belong to the key biological indicators according to the EU Water Framework Directive. The changes in physico-chemical conditions lead directly or indirectly to impacts on biological quality elements. In order to identify which phytoplankton taxa may be indicative of ambient nutrient concentrations, we analysed the seasonal biomass pattern of selected dominant species and simultaneously measured hydrographical and chemical parameters. High frequency data were collected on the transect of the central Gulf of Finland in summer periods (from June to August) of 1997-2004. The relationships between abiotic and biotic variables were studied by linear correlation, regression, and multivariate BIO-ENV analyses. Among 14 selected taxa we found only 3 species (the diatoms Skeletonema costatum, Cyclotella choctawhatcheeana, and Cylindrotheca closterium) that responded regularly to enhanced nutrient concentrations having higher biomasses in coastal areas and following a similar temporal pattern. We suggest that some species (e.g. Heterocapsa triquetra, Eutreptiella gymnastica) are opportunistic and short-term changes in their biomass are not related to eutrophication levels.

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Potential phytoplankton indicator species for monitoring Baltic coastal waters in the summer period

Jaanus¹,

Toming²,

Hällfors³

et al. 2009

Eutrophication in Coastal Ecosystems

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The History of Eutrophication in the Sea Area of Helsinki in the 20^thCentury

Cited by 22 publications

References 4 publications

Interaction between the land and the sea: sources and patterns of nutrients in the scattered coastal zone of a eutrophied sea

Interaction between the land and the sea: sources and patterns of nutrients in the scattered coastal zone of a eutrophied sea

Selecting potential summer phytoplankton eutrophication indicator species for the northern Baltic Sea

Potential phytoplankton indicator species for monitoring Baltic coastal waters in the summer period

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The History of Eutrophication in the Sea Area of Helsinki in the 20thCentury

Cited by 22 publications

References 4 publications

Interaction between the land and the sea: sources and patterns of nutrients in the scattered coastal zone of a eutrophied sea

Interaction between the land and the sea: sources and patterns of nutrients in the scattered coastal zone of a eutrophied sea

Selecting potential summer phytoplankton eutrophication indicator species for the northern Baltic Sea

Potential phytoplankton indicator species for monitoring Baltic coastal waters in the summer period

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The History of Eutrophication in the Sea Area of Helsinki in the 20^thCentury