Major declines in NE Atlantic plankton contrast with more stable populations in the rapidly warming North Sea.

Plankton form the base of marine food webs, making them important indicators of ecosystem status. Changes in the abundance of plankton functional groups, or lifeforms, can affect higher trophic levels and can indicate important shifts in ecosystem functioning. Here, we extend this knowledge by combining data from Continuous Plankton Recorder and fixed-point stations to provide the most comprehensive analysis of plankton time-series for the North-East Atlantic and North-West European shelf to date.

Methodology for defining homogeneous water bodies for management purposes.

European legislation requires monitoring of toxic algae in marine areas where shellfish are harvested for consumption. Monitoring assumes the existence of homogeneous water bodies, the definition of which have important implications for stakeholders and consumers. Yet, the definition of homogeneous water bodies remains unclear.

Metabolomics-derived marker metabolites to characterize Phaeocystis pouchetii physiology in natural plankton communities.

Phaeocystis pouchetii (Hariot) Lagerheim, 1893 regularly dominates phytoplankton blooms in higher latitudes spanning from the English Channel to the Arctic. Through zooplankton grazing and microbial activity, it is considered to be a key resource for the entire marine food web, but the actual relevance of biomass transfer to higher trophic levels is still under discussion. Cell physiology and algal nutritional state are suggested to be major factors controlling the observed variability in zooplankton grazing.

Non-indigenous species refined national baseline inventories: A synthesis in the context of the European Union's Marine Strategy Framework Directive.

Refined baseline inventories of non-indigenous species (NIS) are set per European Union Member State (MS), in the context of the Marine Strategy Framework Directive (MSFD). The inventories are based on the initial assessment of the MSFD (2012) and the updated data of the European Alien Species Information Network, in collaboration with NIS experts appointed by the MSs. The analysis revealed that a large number of NIS was not reported from the initial assessments.

Distributions of three Alexandrium species and their toxins across a salinity gradient suggest an increasing impact of GDA producing A. pseudogonyaulax in shallow brackish waters of Northern Europe.

Blooms of Alexandrium spp. are a well-known phenomenon in Northern European waters. While A.

Application of Cytosense flow cytometer for the analysis of airborne bacteria collected by a high volume impingement sampler.

Characterization of airborne bacterial cells requires efficient collection, concentration, and analysis techniques, particularly to overcome the challenge of their dilute nature in outdoor environments. This study aims to establish a rapid and reliable approach for quantification of bacteria in air samples. To do this, a high volume impingement sampler was applied to collect airborne bacteria from a wastewater treatment plant (WWTP).

Effects of Bacillus cereus Endospores on Free-Living Protist Growth.

We studied the predator-prey interactions between heterotrophic protists and endospores of Bacillus cereus group bacteria, in order to gain insight on survival and dispersal of B. cereus endospores in the environment. It has been hypothesised that the spore stage protects against digestion by predating protists.

Future climate scenarios for a coastal productive planktonic food web resulting in microplankton phenology changes and decreased trophic transfer efficiency.

We studied the effects of future climate change scenarios on plankton communities of a Norwegian fjord using a mesocosm approach. After the spring bloom, natural plankton were enclosed and treated in duplicates with inorganic nutrients elevated to pre-bloom conditions (N, P, Si; eutrophication), lowering of 0.4 pH units (acidification), and rising 3°C temperature (warming).

Co-transport of polycyclic aromatic hydrocarbons by motile microorganisms leads to enhanced mass transfer under diffusive conditions.

The environmental chemodynamics of hydrophobic organic chemicals (HOCs) are often rate-limited by diffusion in stagnant boundary layers. This study investigated whether motile microorganisms can act as microbial carriers that enhance mass transfer of HOCs through diffusive boundary layers. A new experimental system was developed that allows (1) generation of concentration gradients of HOCs under the microscope, (2) exposure and direct observation of microorganisms in such gradients, and (3) quantification of HOC mass transfer.

Dynamics of dissolved and particulate polyunsaturated aldehydes in mesocosms inoculated with different densities of the diatom Skeletonema marinoi.

A survey of the production of polyunsaturated aldehydes (PUA) of manipulated plankton communities is presented here. PUA are phytoplankton-derived metabolites that are proposed to play an important role in chemically mediated plankton interactions. Blooms of different intensities of the diatom Skeletonema marinoi were generated in eight mesocosms filled with water from the surrounding fjord by adding different amounts of a starting culture and nutrients.

Grazer cues induce stealth behavior in marine dinoflagellates.

Chain formation is common among phytoplankton organisms but the underlying reasons and consequences are poorly understood. Here we show that chain formation is strongly impaired by waterborne cues from copepod grazers in the dinoflagellate Alexandrium tamarense. Chains of Alexandrium cells exposed to copepod cues responded by splitting into single cells or shorter chains.

Unsteady motion: escape jumps in planktonic copepods, their kinematics and energetics.

We describe the kinematics of escape jumps in three species of 0.3-3.0 mm-sized planktonic copepods.

LOW THERMAL LIMIT OF GROWTH RATE OF SYMBIODINIUM CALIFORNIUM (DINOPHYTA) IN CULTURE MAY RESTRICT THE SYMBIONT TO SOUTHERN POPULATIONS OF ITS HOST ANEMONES (ANTHOPLEURA SPP.; ANTHOZOA, CNIDARIA)(1).

Symbiodinium californium (#383, Banaszak et al. 1993) is one of two known dinoflagellate symbionts of the intertidal sea anemones Anthopleura elegantissima, A. xanthogrammica, and A.

Mechanisms and feasibility of prey capture in ambush-feeding zooplankton.

Many marine zooplankters, particularly among copepods, are "ambush feeders" that passively wait for their prey and capture them by fast surprise attacks. This strategy must be very demanding in terms of muscle power and sensing capabilities, but the detailed mechanisms of the attacks are unknown. Using high-speed video we describe how copepods perform spectacular attacks by precision maneuvering during a rapid jump.