Impact of Climate Changes on Marine Environments

Climate has a large influence on marine environments. Thus, any shifts in global or regional climate result in more or less significant changes in structure and functioning of the marine ecosystems. The recently observed high anthropogenic pressure causes that climate changes and thus also alterations in marine ecosystems are faster and more distinct than before.

In this paper we discuss local impact of breaking waves on production of sea salt aerosols and hence on the change of aerosol size distribution and particle optical properties. Our studies were made between 17 and 27 July 2012 at the Coastal Research Station (CRS) in Lubiatowo on the Polish Baltic coast. During the studies aerosol optical depth was measured using Microtops II sun photometers and AERONET and MODIS data were used to support the further analyses. We show that with the local wave breaking phenomenon the aerosol optical depth may increase by a magnitude of even one order and that the ensemble of aerosol particles may shift from the dominating fine mode to coarse mode (sea salt). Such shift may have a strong local impact on the radiative forcing and hence on a local climate.

In this work we present the annual changes of two major, climate related aerosol optical parameters measured at three Spitsbergen locations, Ny-Alesund, Longyearbyen and Hornsund over a period between 2000 and 2012. We discuss the changes of aerosol optical depth (AOD) at 500 nm and the Ångström exponent (AE) (440–870 nm) measured with use of different types of sun photometers. For the measurement data we adopted several data quality assurance techniques and the calibration of the instruments was taken into consideration. The results obtained show that marine source has been a dominating of aerosol sources over Spitsbergen. Some years (2005, 2006, 2008 and 2011) show very high values of AOD due to strong aerosol events such as the Arctic Haze. In general the mean AOD values increase over the period of 2000 and 2012 over Spitsbergen. This may indicate the presence of larger scale of atmospheric pollution in the region.

This chapter is dedicated to small particles (solid or liquid) generated from the sea surface, so called sea spray aerosol (SSA). Undeniable importance of SSA on climate determines oceanographers and atmospheric scientists to make lots of efforts in resolving all uncertainties connected with measurements, flux parameterizations or transformation processes in the marine boundary layer. A view of the seriousness of the problem gives a fact that the estimated SSA mass emission is still loaded with 80 % relative error. The goal of this text is to briefly introduce the reader to the issue of SSA emission from the sea surface, the main aspects of SSA flux measurements based on selected, most influential articles from recent years.

Concurrent acoustical and optical measurements have a great potential to describe zooplankton distribution over large temporal and spatial scales. It is difficult to collect complete information on zooplankton distribution with traditional methods (e.g. nets), that provide discrete and low resolution data on distribution of zooplankton biomass, abundance, as well as community structure of zooplankton. Acoustic sounding makes environmental studies fast, non-intrusive, and relatively cheap with high temporal and spatial resolution. LOPC delivers real-time information on zooplankton abundance and size spectra. In this review we present the results of study on zooplankton distribution in two fjords of Spitsbergen in the summer of 2013. Data for this study was collected during simultaneous profiling with high frequency (420 kHz) echosounder and LOPC along the main fjord axes. Zooplankton size spectra obtained by LOPC were used as input parameters in “high-pass” model of sound scattering on fluid-like particles. Model output values of acoustic backscattering strength were compared with values obtained by echosounding. In most cases there was a good agreement between measured and modeled values, except conditions of very low zooplankton abundance and events of fish presence. Zooplankton size structure is helpful in validating and refinement of “high-pass” acoustic model for specific set of scatterers. This gives a possibility to determine the theoretical backscattering strength of zooplankton. Implementing two complementary methods allows to obtain fast and more complete information on zooplankton distribution.

The climate change is an ongoing phenomenon causing numerous environmental problems, including modifications of the already seriously influenced by anthropogenic activity hydrological cycle. Estimating the climate change influence on groundwater is challenging because climate change can modify hydrological processes and groundwater resources directly and indirectly. Under the climate scenarios for the southern Baltic, precipitation is projected to increase in the entire Baltic Sea watershed in winter, while in summer increase of precipitation is mainly projected in the northern part of the basin. Thus, the precipitation will impact the groundwater discharge to the sea (SGD). Consequently, the already substantial SGD to the Bay of Puck, southern Baltic Sea can increase. Not only the additional amount of water will enter the marine environment by means of SGD but also significant load of chemical substances.

The Arctic is particularly vulnerable to environmental changes connected to climate change. Most of assessments of the climate change impact to the Arctic environment concentrate on direct effects to the marine and terrestrial ecosystems. There is little understanding of numerous indirect effects of global change and their impact on cycle of different compounds e.g. man-made substances. The global change effects will not always be predictable but may be abrupt. Environmental changes connected to climate change will influence contaminant transport and migration within the Arctic marine ecosystem. Main effects of global change will be visible through changes of large scale contaminant transport pathways e.g. air mass transport, ice transport, marine currents transport and the changes of in situ environmental conditions e.g. changes of pH, temperature, oxygen content. In this review article we describe major environmental factors that may influence global transport of contaminants and migration of contaminants within the arctic ecosystem elements. We also discuss possible further changes in contaminant sources and distribution within the Arctic related to global changes.

In marine environments Ostracoda and Foraminifera have been very successful invaders. During the Phanerozoic they colonised the majority of shallow, marginal to deep water, fully marine habitats. Both groups had developed physiological adaptations which pre-adapted them to the invasion of new marine habitats. They adopted a broad range of feeding strategies and reproduction modes. The production of resting stages and brood care may also have contributed to them being efficient invaders. They are also both highly tolerant to variations in salinity. The first invasions of non-marine habitats by ostracods appear to have taken place at the turn of the Devonian and Carboniferous. It is estimated that there had been between 9 and 12 independent invasions of fresh waters by the ostracods. In contrast Foraminifera are typically marine organisms, and only a few species of agglutinated and organic-walled Foraminifera are to be found in brackish and freshwater environments. Agglutinated species build their test using ambient components but are not commonly regarded as calcifying organisms. An impact of salinity on foraminiferal calcification has been observed in several studies. It seems that Foraminifera are incapable of constructing a fully calcified test in low salinity regimes; they use sea water not only as a source of ions to construct shell, but also as a biomineralisation solution. Thus, the success of ostracods in invading freshwater habitats can be attributed to their development of a more effective mechanism of calcification in low mineralisation waters. The core question of this study is to examine possible causes for the differences in success between the two taxa.

Two microbiological parameters: total bacterial number (TBN) and biomass (BBM) were studied in two Arctic fjords: Hornsund and Kongsfjorden. Samples were collected from three sampling points in each fjord, from various water depth layers: from the surface to 75 m depth. Total bacterial number and biomass were examined using the DAPI staining and direct count method. The greater amount of bacteria, as well as highest bacterial biomass were observed in the colder fjord Hornsund, located on the southern part of Spitsbergen. Local TBN maximum was found at a depth of 15 m at station KG2, which corresponds to the presence of pycnocline. Better adaptation of Arctic bacteria to the low water temperatures and availability of substrates coming from the bird colonies may explain the higher TBN and BBM in Hornsund. Moreover, greater phytoplankton abundance in Hornsund may have an impact on better feeding conditions. Detected increased amounts of particulate inorganic matter also provides favourable habitat for bacterial consortia.

In recent years, numerous new proxies have been developed for the reconstruction of past environmental conditions in the polar regions. In this review we focus on the selected methods that are used in the reconstruction of the Arctic marine paleoenvironments, i.e., organic (IP₂₅ and PIP₂₅ index, \({\text{U}}_{37}^{\text{K}}\) and \({\text{U}}_{37}^{\text{K'}}\) and GDGT palaeothermometry) and inorganic geochemical indices (Mg/Ca and fragmentation/dissolution analysis) as well as genetic (ancient DNA) and physical (XRF, magnetic susceptibility) proxies. A brief description of each of them is presented with example applications.