Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund) and warmer Atlantic water (Kongsfjorden). Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical) of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m-2 y-1 in Kongsfjorden to 216 g C m-2 y-1 in Hornsund, with a dominant component of microplankton (90%) followed by macrophytes and microphytobenthos.

Silicon, an important clement for diatoms, is often beyond the main object of freshwater researches. In the last decade, many detergents containing silicon compounds have been released by municipal sewage to surface water ecosystems. In this paper, an influence of silicates and washing agents which contain silicates on algal primary production and biomass growth has been shown. The experimental analysis revealed that detergents with the silicate addition increased the rate of the biomass growth and had a direct impact on algal primary production.

The aboveground net primary productivity ( ANPP) of bofedales is one of the most important indicators for the provision of ecosystem services in the high Andean areas. In the case of bofedales, the evaluation of the ANPP supply capacity as a service on a spatial and temporal scale through remote sensing has been little addressed. The capacity, intra and interannual, to provide the ANPP of the high Andean wetlands was quantified at a spatial and temporal level through remote sensing. The normalized difference vegetation index ( NDVI) of the MODIS sensor was used according to the Monteith model (1972), product of the incident photosynthetically active radiation, fraction of the absorbed radiation, and the efficiency of using the radiation of the calibrated vegetation with dry matter sampling in the field. Results show an ANPP prediction R ² of 0.52 (p < 0.05), with no significant spatial difference between field samples. When applying the model, the intra-annual temporary ANPP supply capacity presents a maximum average of 160.54 kg DM·ha ^–1·month ^–1 in the rainy season (December–May) and a maximum average of 81.17 kg DM·ha ^–1·month ^–1 in the dry season (June–October). In 2003–2020, the interannual temporary capacity presented values of 1100–1700 kg DM·ha ^–1·year ^–1. This makes it possible not to affect the sustainability of the wetlands and prevent their depletion and degradation. Understanding the ANPP supply capacity of bofedales can favour the efficient use of the resource and indirectly benefit its conservation.