Volume 39 (2010): Issue 1 (March 2010)

To evaluate the potential to control red tides using the mass-cultured heterotrophic grazer, rotifer Brachionus plicatilis, the effects of environmental factors (water temperature and salinity) on physical activities (filtration and oxygen consumption rate) of B. plicatilis were estimated. Experiments were conducted at different water temperatures (15, 20, 25, 30 and 35°C) and salinities (20, 25, 30, 35 and 40 PSU), in 25 different combinations (5 temperatures × 5 salinities). Results showed that water temperature and salinity had significant effects on the filtration rate of B. plicatilis (F=41.66, P<0.05). The results of multiple regression analysis yielded the following functional dependence of filtration rate (F) on water temperature (T) and salinity (S): F=-1.658+0.917 T+0.63S (R²=0.769, P<0.001). The highest filtration rate (4.23 ±0.74 μl rot^-1 h^-1) was obtained at 30°C and salinity 35 PSU, and the lowest one (0.869 ±0.13 μl rot^-1 h^-1) was observed at 15°C and salinity 20 PSU. Both water temperature and salinity had significant effects on the oxygen consumption rate of B. plicatilis (F=34.08, P<0.05). The results of multiple regression analysis yielded the following functional dependence of oxygen consumption rate (O) on water temperature (T) and salinity (S): O=-3.133+0.165T+0.81S (R²=0.938, P<0.001). The highest oxygen consumption rate (5.38 ±0.66 ng rot^-1 h^-1) was observed at 35°C and salinity 40 PSU, and the lowest one (1.01 ±0.15 ng rot^-1 h^-1) was observed at 15°C and salinity 20 PSU. Results from this present study indicated that the filtration and oxygen consumption rate of the rotifer were significantly influenced by the water temperature and salinity. The utilization of rotifer for red tide control has to consider the influence of environmental factors.

In this study, the effect of multiple heavy metal stress on ascorbate (AsA), glutathione (GSH) and related enzymes was investigated in the leaves, stems and roots of Kandelia candel and Bruguiera gymnorrhiza. Mangrove seedlings were treated with five different concentrations of a heavy metal mixture (Cd²⁺, Pb²⁺ and Hg²⁺). Antioxidants in both the species were analyzed after one month. AsA, GSH, ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) exhibited a similar trend with initial increase and subsequent decrease in response to heavy metal stress. At the highest metal concentration, a significant decrease of AsA and GR was observed in K. candel and B. gymnorrhiza. Glutathione peroxidase (GPX, EC 1.11.1.9) in the leaves, stems and roots of K. candel reached their respective maximal values at the highest metal concentration, whereas GPX activity in roots and stems of B. gymnorrhiza was similar to the controls at higher metal concentrations. Our results demonstrate that AsA, GSH, APX, GR and GPX in K. candel may play more important roles in defending against reactive oxygen species (ROS) than those in B. gymnorrhiza.

The sequence of biofilm formation on a hard surface during the first 24 hours in a coastal environment was studied by suspending acrylic coupons. Adsorption of carbohydrates, proteins, calcium, magnesium, nitrite, nitrate and phosphate were monitored along with microbes. The results showed that carbohydrate, protein, nitrite and nitrate were adsorbed on the coupons within an hour of exposure. Carbohydrates showed a maximum value of 0.28 mg cm^-2 after 24 hours and protein concentration reached up to a maximum of 0.41 mg cm^-2. Adsorption of calcium and magnesium was observed after three hours. Settlement of bacteria was also observed on coupons within an hour and diatoms were observed after 15 hours. Diatoms such as Navicula and Nitzschia were the dominant colonizers during the early stages of biofilm development.

The offshore macrozoobenthos and selected environmental parameters were studied in a small artificial reservoir, created through sand and gravel extraction. The results are rather surprising. Despite the shallow depth and good wind exposure of the reservoir, a thermal and oxygen stratification developed in the summer, causing hypoxic conditions near the bottom, even though the organic matter content in the sediments was <5%. Furthermore, despite the high fish abundance, chaoborids prevailed in zoobenthos, while Tanytarsus sp. and Chironomus sp. co-dominated among chironomids. This study attempts to explain the observed phenomena, though the presented hypotheses still need further confirmation.

The aim of this work is to detect how 3,5-diacetamido-2,4,6-triiodosodium benzoate (sodium amidotrizoate), a synthetic derivative of the anti-auxin triiodonezoic acid (TIBA), influences the growth and content of primary metabolites in the green alga Chlorella vulgaris Beijerinck. It strongly suppressed cell number by 6-20%, chlorophyll a by 6-14%, chlorophyll b by 20-24%, total carotenoids by 7-13% and monosaccharides by 7-8% at the concentration of 10^-4 M, in comparison to the control. On the other hand, sodium amidotrizoate applied at lower concentrations (10^-7 - 10^-6 M) acted as a weak stimulator of analyzed biochemical compounds in algal cells. No statistically significant effect was detected with the application of sodium amidotrizoate at a concentration of 10^-8 M. It seems that sodium amidotrizoate plays an important role in algal growth and development and probably possesses anti-auxin activity, like TIBA.

The investigations were conducted in northeastern Poland near Lidzbark Warmiński (54° 08" N, 20° 36" E). Five mid-field ponds situated on grasslands were chosen: four of them were dredged and deepened, and one of them remained as a natural reservoir. The aim of this paper was to assess the influence of weather conditions on the quantity and quality of water in mid-field ponds situated in agricultural areas. It was found that the quantity of water in mid-field ponds was related much more to the air temperature, which was responsible for either water evaporation or snow melting, rather than to the amount of precipitation. The reduction in the volume of water stored in the ponds during very dry years had a negative influence on its quality. During the observation period, the dredged ponds were characterized by permanent water tables, whereas the natural reservoir dried out in very dry years. Atmospheric conditions influenced the concentrations of ammonium nitrogen and calcium and chlorine ions in the studied water bodies. The volume of water retained in mid-field ponds influenced the concentrations of phosphorus and sulphates. Increased precipitation sums caused lower water pH; however in warmer periods, at increased pH and COD_Cr, a decrease in dissolved oxygen was noted. It was revealed that increases in precipitation sums during the year caused increases in the load of mineral nitrogen and calcium and magnesium ions in pond water.

The floristic composition, abundance, and biomass of phytoplankton in the Cybina River and the Maltański Reservoir were examined from April to October 2005. The analysis of the phytoplankton in the samples revealed statistically significant differences in both composition and abundance. The maximum abundance (39.2 × 10³ ind. cm^-3) and biomass (56.8 μg cm^-3) of phytoplankton was noted in July 2005 at the outlet from the Maltański Reservoir. The lowest phytoplankton density was most often noted at the site located at the inlet of the Cybina River into the Maltański Reservoir. The quantitative and qualitative compositions of the phytoplankton varied at different sites. The highest taxonomical similarity was noted among the samples collected in the reservoir and at the outflow from it.

The aim of this work was to present a quantitative and qualitative analysis of a phytoplankton assemblage under the influence of Ceratophyllum demersum L. during a two-year field study. Literature data obtained under laboratory conditions indicate that C. demersum may cause a decrease in the blue-green algae biomass, which is considered to be evidence of the significance of allelopathy. The observations reported in the current paper indicated that there was no clear effect on cyanoprokaryota whereas decreases in the quantity of Cryptophyta, Dinophyta, Chlorophyta, and Chrysophyceae are noted.

The present study of factors which affect the load of water ecosystems with mineral nitrogen compounds (N-NH₄ and N-NO₃) was conducted in the Olsztyn Lake District and covered the time period from 1992 to 1999. Three capture basins were investigated: agricultural drained with a drain network, agricultural drained with a drainage ditch, and agricultural-forested drained with scattered drains and ditches. It was found that the concentration and load of mineral forms of nitrogen in waters running off from rural areas were closely dependent on meteorological conditions, the kind of artificial drainage system in use, and the type of land use in the catchment area. In waters carried away through the drainage systems, average annual concentrations of N-NH₄ ranged from 0.16 mg dm^-3 (the agricultural capture basin drained with ditches) to 1.09 mg dm^-3 (the agricultural catchment drained with a network of drains); the amounts of N-NO³ ranged from 0.29 mg dm^-3 (the agricultural-forested catchment) to 8.06 mg dm^-3 (the agricultural catchment drained with a network of drains). It was also observed that a larger share of arable lands in the land use structure in a given catchment caused an increase in the load of N-NO₃ determined in drained waters. In addition, it was confirmed that the amounts of mineral nitrogen carried away with drained waters annually varied from 12.78 kg N (6.7 kg N on average) per 1 ha of an agriculturally used catchment, of which N-NO₃ was a dominant form (12.23 kg).

In total 47 rotifer taxa were found in the psammon of Włocławek Reservoir; 36 at the site in Dobiegniewo and 38 at Dobrzyń. Five species were classified as psammobionts, 14 as psammophiles, and the remaining ones as psammoxens. Psammobionts and psammophiles were observed mostly in the psammon at Dobiegniewo.

The highest density of psammon rotifers was noted in the euarenal zone of the flooded part of the reservoir. However, the highest density in the area near the swift current was noted in the hygroarenal zone. While the flooded part of the reservoir had four dominant species of rotifer: Lecane closterocerca, L. scutata, Lepadella patella and Cephalodella catellina, the area near the swift current had only two: Cephalodella catellina and Brachionus quadridentatus.

The most favorable conditions for the development of psammon rotifers was in the flooded area of the reservoir. In comparison with other dam-reservoirs in Poland, the community of these rotifer types in the Włocławek Reservoir was characterized by considerable species richness.

The study was conducted on the upper reach of the Czarna Maleniecka River from Furmanów to the ford at Piekło. Nine sampling sites were selected along this 20-km section. Detailed studies of flora and the physicochemical water parameters were performed in the 2004-2006 period. Data on macrophytes were collected with the Mean Trophic Rank (MTR) method. The results of physicochemical measurements were analyzed in reference to the water quality classification of the Polish Ministry of the Environment. Based on the results of these studies, the authors recommend adding two species, Utricularia intermedia and Glyceria fluitans, to the list of bioindicators.

The results of investigations performed in Lake Wielkowiejskie showed the influence of macrophyte architecture, understood as plant density, on the structure of plankton communities as well as the habitat preferences of particular species in both seasonal and spatial aspects.

The structure of plankton in a lowland river was studied with a particular focus on autotrophic as well as heterotrophic picoplankton cells. Water samples were collected in the middle, meridional section of the Warta River in 2005. Heterotrophic picoplankton (HPP) were represented by bacteria varying in size and form, but mainly by cocci and rods. HPP abundance ranged from 3.5 × 10⁶ to 9.5 × 10⁶ cells ml^-1. Autotrophic picoplankton (APP) densities were considerably lower and ranged from 1.2 × 10³ to 92 × 10³ cells ml^-1. They were represented by prokaryotes (picocyanobacteria) and eukaryotes (small chlorophytes). Both components occurred together but eukaryotic APP usually prevailed in terms of biomass. In terms of biomass, APP seemed to play a minor role in this ecosystem in comparison with heterotrophic picoplankton.

The aim of this study was to show the influence of environmental conditions on the ionic composition of fish bones. The analysis concerned the ionic structural composition of the operculum in fish species with different abiotic habitat preferences. Three species of fish were examined: cod, Gadus morhua L., 1758; sea trout, Salmo trutta morpha trutta L., 1758 and perch, Perca fluviatilis L., 1758. Results from hydrochemical research on salinity in the Pomeranian Bay (Southern Baltic) were also utilized. Using the determined ratios (Ca:Mg, Na:Mg, Sr:Ca and Na:Ca in the operculum and Ca:Mg, Na:Mg and Na:Ca in the waters of the Pomeranian Bay), typical correlations were determined for the analyzed habitat.

Macrocation structure in the operculum bones for each species were found to be as follows:

- cod: Ca - 32.3%, Mg - 29.8%, Na - 1.4%, K - 0.8%, Sr - 2.1%;

- sea trout: Ca - 22.8%, Mg - 13.5%, Na - 0.8%, K - 0.2%, Sr - 1.7%;

- perch, Ca - 37.9%, Mg - 15.1%, Na - 2.4%, K - 0.7%, Sr - 1.6%.

Of the total number of freshwater red algae (ca. 180 taxa), one third are found in Europe (ca. 60 taxa). Over one third (24 taxa) of European taxa have been found at only one single location or at very few locations. The majority of taxa live in running waters, but some occur in lakes, on wet ground, in hot springs or in garden ponds. Diversity in the Nordic countries of Sweden and Finland seems to be somewhat higher (27 and 28 taxa, respectively) than in the central and southern parts of Europe (e.g. Austria 23, Belgium 22, Hungary 9, Poland 22, Slovakia 15, Switzerland 12 and Spain 20 taxa).