Rocky littoral macroorganisms that live between the high and low water marks were sampled in the summers of 1988 and 2007-2008 in Hornsund Fjord and along the adjacent Sorkappland coast (76-77°N). The same sampling stations and methodology were used to collect the samples. Over the last 20 years, the study area has been exposed to well-documented increases in air and sea temperature, increased windiness, and marked decreases in both the duration and extent of sea ice cover. The study revealed a twofold increase in the number of species found intertidally, a threefold increase in the biomass of macrophytes, and an upward shift in algae occurrence on the coast. Subarctic boreal species occupied new areas, while arctic species retreated. There were no species new to the area in 2007-2008, and all newcomers to the intertidal zone were noted in 1988 in the sublittoral zone. The relative stability of intertidal flora and fauna after 20 years is explained by the fact that the warm Atlantic waters (the main warming agent) are distant from the Sorkappland coast. Current observations show a marked change in the coastal belt biocenosis.

No abstract

No abstract

Horizontal and vertical distribution of meiofauna on sandy beaches of the North Sea (The Netherlands, Belgium, France) Abstract Sandy intertidal zones were analysed for the presence of meiofauna. The material was collected on six macro-tidal sandy beaches along the North Sea (The Netherlands, France, Belgium), in order to analyse the vertical and horizontal meiofaunal distribution patterns. Eleven higher meiofauna taxa (one represented by larval stage-Copepoda nauplii) were recorded. The maximum total meiofauna abundance was observed on the Dutch beach (4,295±911 ind. 10 cm À2 ) in the Westerschelde estuary, while the lowest values (361±128 ind. 10 cm À2 ) were recorded in France at the Audresselles beach. Meiofauna of the different localities consisted mainly of nematodes, harpacticoids and turbellarians. Nematodes numerically dominated all sampled stations, comprising more than 45% of the total meiofauna density. Meiofauna was mainly concentrated at the sand surface with about 70% present in the uppermost 5 cm. Meiofauna occurred across the entire intertidal zone. A clear zonation pattern in the distribution of meiofauna taxa across the beaches was observed. The present work suggests that designation of exposed sandy beaches as physically controlled (McLachlan 1988) does not explain their biological variability.

We present a multi-model ensemble study for the Baltic Sea, and investigate the combined impact of changing climate, external nutrient supply, and fisheries on the marine ecosystem. The applied regional climate system model contains state-of-the-art component models for the atmosphere, sea ice, ocean, land surface, terrestrial and marine biogeochemistry, and marine food-web. Time-dependent scenario simulations for the period 1960–2100 are performed and uncertainties of future projections are estimated. In addition, reconstructions since 1850 are carried out to evaluate the models sensitivity to external stressors on long time scales. Information from scenario simulations are used to support decision-makers and stakeholders and to raise awareness of climate change, environmental problems, and possible abatement strategies among the general public using geovisualization. It is concluded that the study results are relevant for the Baltic Sea Action Plan of the Helsinki Commission.

No abstract

No abstract

The discharge of groundwater into the sea affects surrounding environments by changing the salinity, temperature and nutrient regimes. This work reports the spatial effects of a submarine groundwater discharge (SGD) on the abundance and structure of the meiofaunal community in the shallow area of Puck Bay (Baltic Sea). Several field expeditions in the years 2009 and 2010 found that low-saline groundwater escapes into the bay from permeable, sandy, near-shore sediments. The SGD literature has grown rapidly during the current decade; however, the effects of this type of disturbance on the shallow sandy bottom fauna have thus far been little studied. We provide evidence that the discharge of groundwater has a clear effect on meiofaunal assemblages in the research area. This effect was reflected in a significant decline of certain meiofaunal taxa, mainly nematodes and harpacticoids, as well as in altered patterns of temporal distribution and small-scale (vertical) zonation of meiofaunal assemblages. Overlooking submarine groundwater discharge processes may lead to serious misinterpretations of ecological data. It is clear that groundwater discharge phenomena should be considered in future scientific studies.