The Meroplankton of Amurskii Bay (Peter the Great Bay,Sea of Japan)

Russian Journal of Marine Biology - The composition and seasonal dynamics of meroplankton in Amurskii Bay (Sea of Japan) were studied for the first time. The total survey period exceeded two years....     

Centric diatom algae of volcanic Verkhneavachinsk lakes (Kamchatka)

Eleven representatives of diatom algae of the class Centrophyceae from the genera Aulacoseira (1), Conticribra (1), Cyclotella (5), Discostella (1), Stephanodiscus (2), and Thallasiosira (1) have been found in the phytoplankton of 5 volcanic lakes (Bakening volcano, Kamchatka). Stephanodiscus popovskayae, a species new for science, has been discovered in all the lakes, and a species new for the flora of Russia, Cyclotella gordonensis, has been found only in three lakes. The closest similarity in the composition of centric diatoms has been revealed between the lakes of a single water system: Lake Medvezh’e and Lake Verkhneavachinskoe.     

Meroplankton dynamics in a saline,turbulent, turbid shallow lake (Neusiedlersee,Austria and Hungary)

Phytoplankton species composition, horizontal distribution, seasonal- and long-term dynamics are investigated in relation to some environmental factors, based on about 700 samples taken between 1968 and 1992 in the shallow, turbid, turbulent, saline Neusiedlersee (Austria/Hungary). We deduced:

1. The phytoplankton is relatively poor in species which is attributable to high salinity and turbidity. Blue-green algae of picoalgal size, meroplanktonic diatoms, green algae either with gelée or elongated form are the most important groups in the plankton;
2. No consequent horizontal differences in the distribution of phytoplankton biomass were found; the high contribution of diatoms (69%) and green algae (22%) is characteristic;
3. Despite the low percentage contribution (0.54%) of phytoplankton dry weight in total seston, the two variables correlate closely because of simultaneous resuspension after wind actions. The prevalence of both low phytoplankton/seston ratio and significant correlation between these two variables is indicative to the presence of a meroplankton;
4. Phytoplankton biomass, especially that of diatoms, varies within wide limits in the short term as a combined effect of growth/loss, transport by horizontal water currents and periodic resuspension from the sediment surface. Diatoms like Fragilaria, Surirella and Campylodiscus are involved especially. Parameters of population dynamics (growth rate, annual cycles, length of stationary phases, standing crop) were estimated based on moving averages. Growth rates were smaller than those of ‘normal’ planktonic species; however, the similarities of seasonal pattern suggest that the carrying capacity of the lake is very constant;
5. Picoalgal biomass is very high in the lake; its contribution to total biomass can exceed 75%, especially in spring. The large cellular chlorophyll a content of Neusiedlersee's phytoplankton can most probably be explained by this high picoalgal standing crop, which is not included in the routine biomass estimations;
6. Concerning long-term changes of phytoplankton, periodic appearances and disappearances are very characteristic. Annual average biomass of most species is growing for several (3–5) years, then declining with a similar rate and these periods are recurrent. Climatic drying-out periods, during which water level lowers, conductivity increases, nutrients and their ratios change following trend-like periodicities, and they are supposed to be responsible for the observed longterm periodicity of dominant species. An increased nutrient load in the seventies was superimposed on this cyclicity;
7. Most of the species can be found in smaller or larger amounts in the littoral microhabitats (canals, inner ponds) of the lake in periods when they are absent or very rare in the open water. Thus, these littoral microhabitats play a very important role in the survival and recruitment of planktonic populations to the open water.

     

Peculiarities of Stone Cockscomb Alectrias alectrolophus (Stichaeidae) Diet in Avacha Bay (Eastern Kamchatka)

Journal of Ichthyology - Information on stone cockscomb Alectrias alectrolophus diet in Avacha Bay (eastern Kamchatka) are presented, and seasonal, local, age, and interannual changes in the...     

Bottom Communities of Semyachik Lagoon (Kronotskii Biosphere Reserve, Eastern Kamchatka)

Bottom communities of Potamogeton filiformis,Zostera marina+ Z. japonica+ Macoma balthica, Enteromorpha prolifera, and a stony block–boulder intertidal community were distinguished in Semyachik Lagoon. The macrobenthos associated with these communities is described. Generally, the biomass and occurrence frequency indices of the macrozoobenthic communities of the lagoon are an order of magnitude lower than those of macrophytobenthic communities (Kafanov, Plekhov, 1998); therefore, they do not play a significant role in bottom community structure. With the exception of the stony block–boulder intertidal community, their spatial distribution is entirely determined by the distribution of underwater vegetation, which is completely controlled by the geomorphological and hydrological features of the lagoon.     

Analysis of microsatellite variation in the rainbow trout (Parasalmo (Oncorhynchus) mykiss) from Kamchatka

Genetic variation of Kamchatka rainbow trout Parasalmo (O.) mykiss was examined using 10 microsatellite DNA loci, and phylogeographic comparison with other representatives of the species across the distribution range was performed. It was demonstrated that Kamchatka populations differed from other geographic groups of rainbow trout in a number of microsatellite loci. These populations also displayed distinct clustering and were characterized by lower genetic diversity. Analysis of a set of 26 different microsatellite loci (personal and literature data) demonstrated that most of the populations within the Kamchatka region were separated from one another, characterized by marked geographic differentiation, and affiliation to certain river basins. In Kamchatka rainbow trout, with high degree of probability, three geographic clusters (northwestern, southwestern, and eastern) were identified. In general, analysis of microsatellite DNA supported the data on low genetic diversity of the Kamchatka group Parasalmo (O.) mykiss, based on the variation estimates for a number of genes of nuclear and mitochondrial DNA, and allozyme loci.     

Succession following the catastrophic eruption of Ksudach volcano (Kamchatka, 1907)

Ksudach Volcano, southern Kamchatka Peninsula, erupted in 1907 and impacted over 2000 km² of forests with air-fall pumice deposits. We identified three impact zones. In Zone I, deposits deeper than 100 cm destroyed all vegetation. Two early successional stages occur, a lichen-dominated desert and isolated patches of a pioneer herb stage. Zone II is defined by pumice deposits 30 to 100 cm deep. Deposits of 70 to 100 cm destroyed all vegetation, but left scattered snags. Here primary succession dominates recovery, but its rate varies. Isolated trees survived in deposits of 30 to 70 cm and primary and secondary successional stages form a complex mosaic termed an intermediate succession. In Zone II, the primary stages found in Zone I are joined by a dwarf shrub-herb stage and a secondary birch forest stage. Zone III occurs where thinner deposits permitted some vegetation to survive in all locations. Secondary succession dominates in deposits of 10 to 30 cm. Trees suffered damage, but survived deposits of 20 to 30 cm, while other vegetation layers were eliminated. Deposits of 10 to 20 cm eliminated mosses and lichens and but only reduced the number of dwarf shrubs and herbs. Deposits of less than 10 cm damaged herb, moss and lichen layers but did not eliminate any species. All sampled vegetation remains in a pre-climax state, having yet to recover fully from earlier eruptions. Reconstructed vegetation maps for before 1907 and for ca. 1925 are compared to the map of vegetation in 1994. Based on degree of soil formation, vegetation recovery and colonization rates at different pumice depths, and the current vegetation, we estimate that full recovery of the soil-vegetation system will take more than 2000 years.     

PseudocalanusSpecies (Copepoda: Calanoida) in Avachinskaya Bay,Southeastern Kamchatka

The species composition of copepods of the genus Pseudocalanusthat dominate the zooplankton in Avachinskaya Bay was studied from samples collected in 1988. Three species were identified: P. minutus(Kröyer), P. newmani(Frost), and P. acuspes(Giesbrecht). The latter species is the first record for the fauna of the northwestern Pacific Ocean. Synonymy and original figures are given; the seasonal variations in the morphometric features and characteristics of Pseudocalanusare discussed.     

Detection of nitroxyl (HNO) by membrane inlet mass spectrometry

Membrane inlet (or introduction) mass spectrometry (MIMS) was used to detect nitroxyl (HNO) in aqueous solution for the first time. The common HNO donors Angeli's salt (AS) and Piloty's acid (PA), along with a newly developed donor, 2-bromo-N-hydroxybenzenesulfonamide (2-bromo-Piloty's acid, 2BrPA), were examined by this technique. MIMS experiments revealed that under physiological conditions 2BrPA is an essentially pure HNO donor, but AS produces a small amount of nitric oxide (NO). In addition, MIMS experiments also confirmed that PA is susceptible to oxidation and NO production, but that 2BrPA is not as prone to oxidation.     

On the quantitative characteristics of the pelagic ecosystem of Dalnee lake (Kamchatka)

The parameters of biomass and productivity of the main components of the pelagic ecosystem have been estimated in lake Dalnee (Kamchatka) during the first phase of the period of vegetation in July 1969. The water column in the lake during this period was stratified. The layer-character of vertical distribution of bacteria, phytoplankton, protozoa, rotifers and young stages of crustaceans was elucidated. The adult copepods migrate during the day. The nutrition of the mass species of zooplankton was studied using the C¹⁴-method. The data on the spectrum of feeding, on rations and on optimal food concentrations were ascertained. All these data, together with the observations in the lake, were used for the construction of a scheme of energy flow. The scheme shows that the ecosystem of the lake receives the third part of its energy from the land as allochtonous organic matter via microbial biosynthesis. The main part of energy accessible to the animals of the second trophical level is used by protozoa, and of a third part by the predatory rotiferAsplanchna.     

Investigation of Whalebone from the Miocene Kovran Locality (Kamchatka Krai,Russia)

New information on the microstructures, general morphology, and features of preservation of plates of a whalebone from the Miocene Kovran locality in the Kamchatka Peninsula are provided. The plates have a chevron-like bend which is absent in extant Balaenopteridae, Balaenidae, and Eschrichtiidae. This shape is possibly related to the filtration mechanism characteristic of these whales.     

Seasonal species composition and distribution of barnacle larvae in Avacha Inlet (Kamchatka)

The annual dynamics of the numbers and distribution of barnaclelarvae in Avacha Inlet were studied. Planktonic cirripede larvaewere found in the area studied from late March at a temperatureof –1–0°C until October. The highest densityof 18 000 m^–3 was observed in mid-April. Balanus crenatusand Semibalanus cariosus were the dominant species, Chthamalusdalli and Balanus balanus larvae being less abundant. Naupliardensity was maximal at 0–5 m and decreased with depth.Maximum densities of B.crenatus larvae were observed in RakovayaBay, where there are many ships and a seawater-cooled powerstation. Most nauplii of the intertidal barnacle S.cariosus,which prefers wave-exposed open coast, were taken in the AvachaInlet narrows Settling on artificial substrata was most intensivefrom late May to early June     

Genetic divergence of sympatric charrs of the genus Salvelinus from Nachikinskoe Lake (Kamchatka)

We studied genetic differentiation of two charr species, Dolly Varden Salvelinus malma malma Walbaum and resident lacustrine charr Salvelinus sp., which sympatrically inhabit Nachikinskoe Lake (the Bol'shaya River basin) in southwestern Kamchatka Peninsula. Using restriction analysis (RFLP), three mitochondrial DNA fragments (ND1/ND2, ND5/ND6, and Cytb/D loop) amplified in polymerase chain reaction (PCR) were compared. The divergence of the mtDNA sequences between Salvelinus sp. and S. malma malma was 2.8%; Salvelinus sp. and S. taranetzi, 0.36%; Salvelinus sp. and S. krogiusae, 0.21%; Salvelinus sp. and S. alpinus, 3.0%. These results point to reproductive isolation of charrs in Nachikinskoe Lake and support the earlier suggestion on a close relationship between Salvelinus sp., S. taranetzi, and S. krogiusae.     

Genetic divergence of chars of the genus Salvelinus from Kronotsky Lake (Kamchatka Peninsula)

Chars from the genus Salvelinus, inhabiting lakes and lake-river systems, belong to morphologically and ecologically different forms whose taxonomic status is under dispute. In the present work, we have examined genetic variation and divergence in various chars from the Kronotsky lake basin: the lacustrine chars (white, nose, and long-head) and Dolly Varden char Salvelinus malma. The study was conducted using analysis of allozyme and microsatellite loci, myogens, RAPD, and restriction analysis of two mtDNA segments. The estimates of heterozygoisty at allozyme and microsatellite loci were similar to the corresponding parameters in populations of northern Dolly Varden and Arctic char. Heterozygote deficit was recorded in both samples of individual forms, and in the combined sample of all chars from Kronotsky Lake. For both markers, appreciable genetic differentiation among the samples of different char forms was found, which was comparable to that among the spatially isolated populations of northern Dolly Varden. This result indicates reproductive isolation among the char forms examined. However, this isolation is not complete, because no fixed differences between the forms by any of the genetic systems analyzed was found. The genetic differentiation among different forms of lacustrine chars, which corresponds to the interpopulation rather than interspecies level, is thought to be explained by their comparatively recent divergence.     

Comparison of different methods of census of juvenile salmonids (Salmonidae) in the small river Mikocheva (Western Kamchatka)

Seinings of the lowland bed of a typical small river of Western Kamchatka demonstrated that of several methods for the census of juveniles of salmonids (Salmonidae) the most accurate result in comparison with complete removal is obtained by three-fold seining with calculation of abundance by the Zippin method. In comparison with a seine, a drive-in trap and electrofishing possess a lower average catching efficiency and a higher selectivity. The average density of fish estimated by the results of seining at the investigated stretch was 0.55–0.57 specimens/m².     

Variation of cytochrome b gene in sympatric chars from kronotsky lake (Kamchatka Peninsula)

In previously identified sympatric char forms (species) from Kronotsky Lake (Kamchatka Peninsula) and a number of other chars from the genus Salvelinus, nucleotide sequences of the mtDNA cytochrome b gene were determined and phylogenetic analysis of these chars was performed. The divergence estimate of the cytochrome b gene in the Kronotsky char group (0.48%) coincided with the interpopulation difference estimates in northern Dolly Varden, which indicates a relatively recent divergence of the chars from Kronotsky Lake. Haplotypes of each form of the Kronotsky Lake chars are divided into two groups, which belonged to two different phylogenetic mtDNA lineages of northern Dolly Varden from Chukotka and Kamchatka. The formation of the Kronotsky char forms proved to be unrelated to the observed variability of the mtDNA cytochrome b gene.