Phytoplankton responses to marine climate change – an introduction

Phytoplankton are one of the key players in the ocean and contribute approximately 50% to global primary production. They serve as the basis for marine food webs, drive chemical composition of the global atmosphere and thereby climate. Seasonal environmental changes and nutrient availability naturally influence phytoplankton species composition. Since the industrial era, anthropogenic climatic influences have increased noticeably – also within the ocean. Our changing climate, however, affects the composition of phytoplankton species composition on a long-term basis and requires the organisms to adapt to this changing environment, influencing micronutrient bioavailability and other biogeochemical parameters. At the same time, phytoplankton themselves can influence the climate with their responses to environmental changes. Due to its key role, phytoplankton has been of interest in marine sciences for quite some time and there are several methodical approaches implemented in oceanographic sciences. There are ongoing attempts to improve predictions and to close gaps in the understanding of this sensitive ecological system and its responses

Physical Processes Influencing the Sedimentation and Lateral Transport of MOSSFA in the NE Gulf of Mexico

Accurate predictions of the transport and fate of oil spilled in the marine environment are essential for response and mitigation efforts. The sedimentation of oil-associated marine snow (MOS) has been shown to be an important pathway by which Deepwater Horizon (DWH) oil was removed from the water column; thus, information is needed on the vertical and lateral dispersion of MOS. Here, we simulated the physical environment in the NE Gulf of Mexico using the Connectivity Modeling System (Paris et al., Environ Model Softw 42:47–54, 2013). Field measurements of marine snow provided initial conditions for the simulations. High Mississippi River (MR) discharge during 2010 and 2013 resulted in strong eastward flowing fronts along the shelf break to the east of the MR, and an anticyclonic eddy at the shelf break retained and aggregated particles, which acted to enhance MOS sedimentation. Forward simulations suggested that particles with high sinking rates (200 m d−1) reached the seafloor withi