m
range. The system was tested during two cruises of r/v `Oceania´ in the
southern Baltic in May and September 1997. The first experimental results are
presented and the system's possibilities and limitations are discussed.
Jacek Piskozub, Violetta Drozdowska, Miroslaw Irczuk
Institute
of Oceanology, Polish Academy of Sciences, Sopot
Keywords: Lidar, Remote sensing, Oil spills Manuscript received January 23, 1998, in final form February 26, 1998.
A new FLS–UV lidar system using the extinction of the laser-induced water
Raman signal for detecting thin oil slicks on the sea surface was employed.
The system uses a solid state laser with frequency multiplication and an array
of photomultipliers to measure oil film thicknesses in the 0.5–10 m
range. The system was tested during two cruises of r/v `Oceania´ in the
southern Baltic in May and September 1997. The first experimental results are
presented and the system's possibilities and limitations are discussed.
Selected physical properties of Baltic crude oil
Oceanologia 1998, no. 40 (1), pp. 11–25
Adam Stelmaszewski
Physics Department, Maritime Academy, Gdynia
Keywords: Baltic Sea, Crude oil, Mass decrease, Density, Viscosity Manuscript received January 12, 1998, in final form February 17, 1998.
Selected physical properties of Baltic crude oil describing its behaviour during spills on water surfaces have been investigated. The temperature relationships of the density and dynamic viscosity coefficient of fresh crude oil in the 0–35 oC range are presented. The linear decrease in crude oil density and exponential decrease in its dynamic viscosity coefficient with increasing temperature were confirmed. Using these data, the mean activation energy of crude oil particles was determined (0.27 eV). The results of investigations into mass and viscosity variations during crude oil evaporation are given. The variations in mass, density and dynamic viscosity coefficient are described using power functions. The dependence of crude oil layer thickness on the rate of oil evaporation was examined: the results indicate that the greatest changes occur during the first 20 hrs of evaporation.
Maria Lotocka
Institute of Oceanology, Polish Academy of Sciences, Sopot
Keywords: Carotenoids, Pigment biomarkers, Sediment, Baltic Sea Manuscript received March 16, 1998, in final form March 31, 1998.
Carotenoid pigments were examined in vertical profiles of Baltic sediments in early summer (June 1994). High-performance liquid chromatograms (HPLC) displayed high concentrations of carotenoids in an anoxic environment in cores from the Gotland Basin, Bornholm Deep and Gdansk Deep. Cyanobacterial pigments were found to be present in the surface sediments of the Gdansk and Bornholm Deeps. Dinoflagellate and diatom carotenoids were the major contributors of pigments in the Gotland Basin. Carotenoids were used as biogenic indicators of the diagenesis of organic matter and the condition of Baltic Sea sediments.
Joanna Kozuch, Janusz Pempkowiak
Institute of Oceanology, Polish Academy of Sciences, Sopot
Egil Gjessing
Adger College, Kristiansand, Norway
Keywords: Mytilus trossulus, Cadmium, Accumulation, Marine humic substances, Lacustrine humic substances Manuscript received February 4, 1998, in final form March 4, 1998.
The accumulation of cadmium by the Baltic mussel Mytilus trossulus
in the presence of marine and lacustrine humic substances (HS) was
investigated under laboratory conditions. The tested organisms were exposed
to Baltic Sea water (salinity 7.0 PSU, pH 7.85) spiked with cadmium
(50 g Cd l -1) and humic substances (6.0 mgHS l -1),
isolated from either marine (6 sampling sites) or lacustrine (8 sampling sites)
environments. Experiments were carried out at a constant seawater temperature
of (10oC
1oC). The exposure time was 21 days.
On average, the humic substances, a fraction of naturally occurring organic matter, were found to stimulate cadmium accumulation in the mussels. Lacustrine humic substances stimulated cadmium uptake to a lesser extent than the marine ones. Cadmium was accumulated preferentially in the hepatopancreas, and to a smaller extent in the gills and muscles, regardless of the presence, properties and origin of the humic substances. However, the effect was modified by the dissimilar physical and chemical properties of the substances, which were related to their place of origin.
Daniel Markowski
Department of Oceanography, Sea Fisheries Institute, Gdynia
Jozef Wiktor
Institute of Oceanology, Polish Academy of Sciences, Sopot
Keywords: Phytoplankton, Arctic, Water masses, Polar front Manuscript received January 26, 1998, in final form March 9, 1998.
Phytoplankton and hydrological data were collected during the Greenland Sea Project between 74o and 76oN, 13o and 20oE, in July 1988 and 1991. The water masses were very different with regard to their hydrology in the two years, especially with regard to the displacement of the frontal zone. The phytoplankton community was similar in both years, however. Multivariate analyses have not shown any significant relationship between phytoplankton abundance, salinity, nutrients and temperature. It was assumed that the water mass as a single, comprehensive system influences phytoplankton occurrence, and its origin determines the phytoplankton recorded in the frontal zone.
Grazyna Kowalewska
Institute of Oceanology, Polish Academy of Sciences, Sopot
Boris Winterhalter
Department of Surficial Geology, Geological Survey of Finland,
Espoo, Finland
Joanna Konat
Institute of Oceanology, Polish Academy of Sciences, Sopot
Keywords: Chlorophyll a, Chlorins, Deep sediments, Baltic Sea Manuscript received January 13, 1997, in final form January 23, 1997.
Deep sediments (to 660 cm) from the Baltic Sea, collected in 1996–1997, were analysed for content of chlorophyll a and its immediate derivatives (chlorins: phaeophytin, pyrophaeophytin, phaeophorbides and steryl chlorin esters) using the diode-array HPLC method. These compounds were generally well preserved. The concentrations of both particular and total chlorins varied greatly depending on the sediment layer and were surprisingly high in some cases, comparable to concentrations in contemporary Baltic sediments (0–1 cm layer).