Volume 45 (2016): Issue 1 (March 2016)

The study presents changes in the total development time of Copepoda species, i.e. Pseudocalanus sp., Temora longicornis and Acartia spp. occurring in large numbers in the Southern Baltic Sea. The following factors were taken into account: temperature, salinity and concentration of food. The presented research involved simulations with greenhouse gas emissions scenarios A1B and B1. The analysis was performed for naupliar and copepodid stages combined together, and the results present the total development time of organisms from the naupliar stage to the adult form. The calculations were carried out using numerical methods based on the experimental data available in the literature.

The extracellular polymeric substances (EPS) produced by the bacteria associated with the gastropod Turbo sp. were isolated and screened for antibacterial activity against biofilm-forming bacteria. EPS of five out of 13 strains showed inhibitory activities in the antibacterial assay. Furthermore, the antibiofilm and antifouling activity of the most active EPS isolated from the strain KT1 was studied using various in vitro and in vivo bioassays. Results revealed that EPS significantly inhibited the growth and biofilm formation of bacteria. Furthermore, the antifouling coating developed with bacterial EPS considerably reduced the recruitment of fouling organisms on coated surfaces submerged in the seawater. The functional groups present in EPS, characterized by strong activity, were analyzed using FT-IR and the spectrum showed the presence of alcohol, amines, carboxylic acid and esters. The bacterium responsible for the production of bioactive EPS was identified as Pseudomonas aeruginosa, using the 16S rRNA gene. Since the findings of this study revealed the antibiofilm and antifouling activities of EPS, further long term field tests and characterization of the bioactive compound of the EPS could lead to the development of eco-friendly antifouling coating.

The relationship between the effectiveness of groins and their technical condition was studied. The supporting role of groins in artificial shore nourishment was tested using the theoretical modeling of hydrodynamic and morphodynamic processes in the nearshore zone. This modeling scheme was developed as to represent the actual coastal situation occurring on the shores of the Hel Peninsula (the Gulf of Gdańsk, the southern Baltic Sea). Based on the results of computations and the results of field observations, recommendations were prepared on the design and maintenance of groins. The second part of the paper is devoted to submerged breakwaters. The theoretical modeling of wave-current fields near the segmented submerged breakwaters led to the determination of coefficients of wave transmission and rip current velocities, which finally yielded a piece of design advice. In all numerical simulations, the Delft3D software was used.

Measurements relating to a yellow deposit covering large areas of the Baltic Sea in spring are reported. Analysis of water samples showed it to be of terrestrial origin and to consist mainly of pine pollen grains. The equivalent spherical diameter (ESD) of these grains ranged from 29.1 to 78.4 μm, with a maximum between 47.7 and 56.3 μm. Surface water concentrations of pollen in the coastal zone near Ustka showed that its proportion in the total suspended particulate matter (SPM) might be as high as 30-40%. Such high surface water concentrations of hitherto neglected substances critical to water color formation can give rise to serious errors in remote measurements of water composition and properties.

In the north-eastern part of Poland, the underground gas stores are being constructed by diluting salt deposits. Brine, a by-product of the technology applied, is discharged into the coastal waters of the south Baltic Sea by a system of diffusers. To assess the intensity of brine mixing in the near-field of the discharge installation, a monitoring program was carried out. The results demonstrated that under the mildly dynamic conditions of Puck Bay, the discharge of brine (saturation 250 kg m^-3, discharge 300 m³ h^-1) leads to salinity excess below 0.5 PSU. For parameters of a real brine discharge, the dilution coefficient estimated by formulas derived from analytical solutions, predictive models and laboratory experiments for stagnant water conditions, varied in the range of 123÷360. The dilution coefficient value estimated on the basis of measurements was 1.27÷3.72 times higher than its value obtained by the use of predictive models, while estimated by formulas obtained from laboratory experiments was in the range of 1.41÷2.26 of the dilution coefficient based on measurements.

The first comprehensive meiobenthos study was carried out in Turkey, the Southern Black Sea (Sinop) from August 2009 to July 2010.Sediment samples were collected monthly at eight stations at 3 m and 10 m water depths located on four transects. A metal push core sampler (surface area 12.56 cm² and length 10 cm was used to obtain the material. Meiofaunal abundance and composition were examined. The results revealed that the meiofaunal community consists of twenty five higher taxonomic groups. Four groups dominated the community; Nematoda, Harpacticoida, Foraminifera and Polyuchaeta. Spatial and temporal meiofaunal abundance fluctuated among stations and over time.

There are 150 meteorite craters worldwide, however, their aggregations are rarely noted. The nature reserve ‘Meteoryt Morasko’ in Poland with fishless meteorite ponds was analyzed as a unique ecosystem for biological analysis of invertebrate interactions. The aim of the study was to recognize the main environmental drivers of cladoceran and copepod community structure from among biotic (competitors and predators) and abiotic factors (i.e. oxygen and pH level) in the spring season.

The abundance of small cladocerans (Alonella excisa and Chydorus sphaericus) was the highest at the end of the spring season, i.e. in June, while large species (Daphnia pulex and Simocephalus exspinosus) were most abundant in May. Both size groups of Cladocera were negatively affected by invertebrate predators (Chaoborus crystallinus and carnivorous copepods), which are known to play an important role in structuring cladoceran communities due to the fishless character of the studied ponds. No negative effect of those predators was found for Copepoda, however, nauplii density was reduced by competitors (Aedes communis larvae and ostracods).

The temporary character of the examined ponds, oxygen depletion and low pH of water in the shallowest pond resulted in the abundant occurrence of cladoceran males, whose high densities are usually observed in autumn.

A comparative study was carried out on the growth characteristics of 33 strains of 12 species belonging to genera Acutodesmus (7), Botryococcus (1), Chlorella (5), Chloroidium (2), Desmodesmus (8), Euglena (2), Monoraphidium (2), and Parachlorella (6) from the Microalgae Culture Collection of the Institute of Botany, NAS of Ukraine (IBASU-A). All high biomass-producing strains considered as promising candidates for biofuel production demonstrated active growth (high maximum cell concentration, specific growth rate and productivity). The most promising strains included Acutodesmus dimorphus IBASU-A 251, 252, Desmodesmus magnus IBASU-A 401, D. multivariabilis var. turskensis IBASU-A 398, Chlorella vulgaris IBASU-A 189, 192, and Parachlorella kessleri IBASU-A 444. Their productivity varied from 0.58 g d.w. l^-1 to 1.6 g d.w. l^-1 per day. In general, the cultivation of these strains is considered both as a potential bioresource of feedstock for biodiesel production and other industrial demands.

In this paper, the genesis of carbonates in a shallow, polymictic and eutrophic coastal lake (Lake Sarbsko, Poland) is deciphered. Emphasis is placed upon the relationship between carbonate sedimentation and microbial degradation of organic matter, as well as on vertical mixing of sediments. The cycling of carbonates in the lake was investigated through the analysis of lake water chemistry (pH, Ca²⁺, Mg²⁺, alkalinity, SI_calc) and the stable carbon isotope composition of dissolved inorganic carbon and sedimentary calcite. It is shown that the calcite is precipitated within a relatively short time owing to the coincidence between the activity of photosynthesizing phytoplankton, the microbial decomposition of organic matter, and the physical mixing of lake deposits. In turn, the precipitated calcite is prone to dissolution within the sediments. The data presented in this paper can be applied to explain the processes affecting the carbonate saturation in freshwater systems and to interpret δ¹³C signatures in the sediments of shallow lakes.

Research on the diversity of thalli and mats built by freshwater Ulva flexuosa, as well as the impact of abiotic factors on the development and distribution of Ulva mats, was conducted from May to August 2013. The study describes the dynamics of “green tides” formation by U. flexuosa. The study assessed abiotic factors that may influence the colonization and the growth of Ulva populations in freshwater systems. The results are of major importance to the trade and industry sectors. In total, eleven environmental parameters were included in the analysis. The most important environmental parameters characterizing the Ulva sites are sodium chloride levels and conductivity. High values of pH inhibited the development of Ulva, leading to a lower percentage of mature thalli in the mats. The water depth was positively correlated with an increase in the density of thalli in the mats and the average thallus length. Significant differences were identified between the concentrations of nitrates under and outside the Ulva mats. Concentrations of nitrate under the Ulva thalli were always lower.

The hydrological characteristics and the rate of organic matter supply from coastal lagoons help to understand their responses to nutrient input by anthropogenic and natural sources. The aim of this study was to determine the hydrologic and trophic status of the El Rancho-Empalme lagoon system in a semiarid region in the Gulf of California, Mexico. This lagoon system consists of two geomorphological subsystems which are affected by nutrient inputs from shrimp farm effluents and coastal upwelling. Sampling was conducted over the course of one year and included measurements of temperature, salinity, and dissolved oxygen, surface water grab samples to analyze nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The trophic status was assessed using the TRophic IndeX (TRIX). The subsystems El Rancho and Empalme had a similar hydrological behavior throughout the year, reflecting a good exchange of water, materials and energy. The TRIX index showed oligotrophic state during spring, summer and autumn, and a mesotrophic state in winter. Nutrient inputs from shrimp farm effluents were not responsible for trophic status increases, however, coastal upwelling in the region plays an important role in the growing rate of seasonal supply of organic matter to these coastal lagoons.

Benthic species associated with hard substrate are known to form communities characterized by high abundance and biomass. Although the bottom of the Southern Baltic Sea is dominated by soft sediments, such communities find favorable conditions to thrive on artificial substrates of offshore constructions. The aim of this research was to characterize both short-term and long-term benthic communities associated with artificial hard bottom provided by man-made structures in the Southern Baltic Sea. Species composition as well as the abundance and biomass were examined at various sites. An inactive World War II torpedo testing facility in the Gulf of Gdansk served as a site for sampling long-term communities while short-term communities were sampled using settlement panels and PVC cylinders. Panels were deployed at the torpedo testing facility for 127 days. PVC cylinders were deployed for 141-190 days in the Polish Exclusive Economic Zone. Twenty six macrofaunal taxa, including 12 crustaceans, were identified during the research. Mytilus edulis and Amphibalanus improvisus were the most abundant invertebrates at sampled surfaces. Six non-indigenous species were found. For the first time adult individuals of Mytilopsis leucophaeata were found in the Polish Marine Areas indicating that it is possible for this non-indigenous species to reproduce in this region.

Secondary metabolites produced by plants, algae, bacteria and fungi may affect the growth and development of biological systems. This is a natural process which occurs worldwide and is known as allelopathy. A relatively small number of these allelopathic compounds has been identified. The majority of studies describe the inhibitory effect of investigated compounds, extracts, cell-free filtrates and living cells on other organisms, although stimulatory interactions have also been noticed. Allelopathic interactions in aquatic environments could provide a competitive advantage to some species over other primary producers. Furthermore, allelopathy occurs in all aquatic habitats and all groups of autotrophs are capable of producing and releasing allelopathically active compounds. Moreover, secondary metabolites obtained from phytoplankton could demonstrate other useful bioactive properties. This review is intended to summarize the current knowledge of allelopathic interactions between microalgae and cyanobacteria in aquatic environments, as well as to provide a brief overview of the ecological importance of these interactions and their potential practical application in different branches of industry.