Ecological Monitoring of the Water Area of Port Vostochnyi (Wrangel Bay) in the Sea of Japan (1995–2002)

Benthic surveys carried out in 1989 (literature data), 1995, and 2001 (original data) revealed changes in the structure of soft bottom communities of Wrangel Bay (Peter the Great Bay, Sea of Japan), where a deep-water port of Vostochnyi is situated. The functioning of the port has caused no significant environmental pollution by heavy metals, hydrocarbons, and other pollutants. Bottom dredging and the siltation induced by it have drastically lowered the benthos biomass, changed benthic communities, and altered their trophic structure. Sestonophages have disappeared nearly altogether being replaced by detrivores. The ecological state of the benthos is characterized as unstable.     

Effect of the Razdol’naya River on structure of the free-living nematode community of the Amursky Bay,Sea of Japan

The effect of the Razdol’naya River on the littoral and sublittoral nematode community was studied in the innermost part of the Amursky Bay. Thanks to the seasonal abundance of juveniles of macrobenthic animals, pseudomacrobenthic species prevailed in the meiobenthos littoral community. Juvenile amphipods dominated (39.5%), the percentage of nematodes was 18.4% (45 species). The nematodes dominated in the meiobenthos community (65.7%, 71 species) at the sublittoral zone. The similarity of the species structure of littoral and sublittoral nematodes reached 36.5%. Low population density (2.6±1.7 thousand ind/m²) and poor species diversity of nematodes (7 species), the dominating form being Oncholaimium paraolium, were recorded at the littoral zone, which was subjected to direct riverine influence (1‰salinity). The correlation analysis revealed no relationship between salinity and population density of nematodes at the littoral zone. At the sublittoral zone (at stations of salinity less than 2.85‰) the parameters of population density (73.9±32.3 thousand ind/m²) and species diversity (12 species) of nematodes were the lowest, Parodontophora timmica dominated. A poor expressed dependence between the density of nematode populations and salinity was revealed. The correlation between the average size of ground particles and population density of nematodes was recorded. The greatest similarity of the species structure of littoral and sublittoral nematodes (26.67%) was recorded on gravel-sand bottoms.     

Nutrients and Primary Production in the Estuary of the Razdol’naya River (Amur Bay,Sea of Japan)

The behavior of the basic nutrients (NO₃, PO₄, SiO₂) was studied in the estuary of the Razdolnaya River in low and high water, the flow was 4.3 × 10⁶ m³/day and 10.8 × 10⁶ m³/day, respectively. It was shown that within the limits of the euphotic zone the nutrients were characterized by a pronounced nonconservative behavior caused by their removal by phytoplankton in primary production. It was determined that phytoplankton removal of nutrients occurred with ratios C : NO₃ : P : Si = 105 : 18 : 1 : 37 and C : NO₃ : P : Si = 93 : 11 : 1 : 29 at a respective ratio P : NO₃ : Si = 1 : 22 : 140 in low water and P : NO₃ : Si = 1 : 17 : 120 in high water. It was also determined that the maximum rate of nutrient removal was 4 times higher in the high water than in the low water. The maximum value of primary production of phytoplankton was 2.5–4.0 gC/m² day. The estuary area of the Razdolnaya River was specified by rather high production. Such a rate of estuarine primary production, caused by nutrients carried out by the river, being no less than 250 t of dry weight of phytoplankton a day, can provide daily production up to 800 t of biomass in the secondary chain of the ecosystem.Original Russian Text Copyright © 2005 by Biologiya Morya, Zvalinsky, Nedashkovsky, Sagalayev, Tishchenko, Shvetsova.     

Distribution and seasonal changes in fish abundance in the estuary of the Razdol’naya River (Peter the Great Bay), Sea of Japan

The distribution and seasonal dynamics of fish abundance in the estuary of the Razdol’naya River (Peter the Great Bay) depending on several abiotic factors are considered. It is established that fish biomass increases with an increase in salinity and decrease in water temperature (both in space and time). Freshwater stenohaline species dominate in the upper part of the estuary, semianadromous and freshwater euryhaline species dominate in the middle part, and semianadromous and marine species dominate in the lower part. The seasonal succession of ichthyocenosis includes two periods: warm (May–October) and cold (November–April). The warm period is characterized by a low biomass (4–10 g/m²) and maximum species richness (22–29 species) against the background of a decrease of the penetration into the estuary of high-saline waters and an increase in the water discharge, turbidity, and temperature. Freshwater species dominate in catches, and subtropical migrants appear. In the cold period, species richness is minimal (2–12 species), and biomass is, on the contrary, very high (on average, 71–374 g/m²); water temperature and discharge are minimal. In catches, the proportion of semianadromous and marine species is maximum.     

Bloom forming Alexandrium ostenfeldii (Dinophyceae) in shallow waters of the Åland Archipelago,Northern Baltic Sea

In the past years, late summer blooms of the bioluminescent dinoflagellate Alexandrium ostenfeldii have become a recurrent phenomenon in coastal waters of the central and Northern Baltic Sea. This paper reports exceptionally high cell concentrations (10⁵ to 10⁶ cells L^?1) of the species found during bioluminescent blooms in 2003 and 2004 in a shallow embayment of the Åland archipelago at the SW coast of Finland. Clonal cultures were established for morphological, molecular, toxicological and ecophysiological investigations to characterize the Finnish populations and compare them to other global A. ostenfeldii isolates. The Finnish isolates exhibited typical morphological features of A. ostenfeldii such as large size, a prominent ventral pore and an orthogonally bent first apical plate. However, unambiguous differentiation from closely related Alexandrium peruvianum was difficult due to considerable variation of sulcal anterior plate shapes. The Finnish strains were genetically distinct from other isolates of the species, but phylogenetic analyses revealed a close relationship to isolates from southern England and an A. peruvianum morphotype from the Spanish Mediterranean. Together these isolates formed a distinct clade which was separated from a clade containing other Northern European, North American and New Zealand populations. Toxin analyses confirmed the presence of the PSP toxins GTX2, GTX3 and STX in both Finnish isolates with GTX3 being the dominant toxin. Total relative PSP toxin contents were moderate, ranging from approximately 6 to 15 fmol cell^?1 at local salinities of 5 and 10 psu, respectively. Spirolides were not detected. Salinity tolerance experiments showed that the Finnish isolates were well adapted to grow at the low salinities of the Baltic Sea. With a salinity range of approximately 6 to 20–25 psu, Baltic populations are physiologically distinct from their marine relatives. Vigorous production of different cyst types in the cultures suggest that cysts may play a crucial role in the survival and retainment of A. ostenfeldii populations in the Baltic Sea.     

Conjugation in the spirotrich ciliate Halteria grandinella (Müller, 1773) Dujardin, 1841 (Protozoa, Ciliophora) and its phylogenetic implications

The conjugation of Halteria grandinella was studied in protargol preparations. The isogamontic conjugants fuse partially with their ventral sides to a homopolar pair. The first maturation division generates dramatic transformations: (i) the partners obtain an interlocking arrangement; (ii) the number of bristle kineties decreases from seven to four in each partner; and (iii) the right conjugant loses its buccal membranelles, the left the whole adoral zone. The remaining collar membranelles arrange around the pair's anterior end and are shared by both partners; finally, the couple resembles a vegetative specimen in size and outline. The vegetative macronucleus fragments before pycnosis. The micronucleus performs three maturation divisions, but only one derivative each performs the second and third division. The synkaryon divides twice, producing a micronucleus, a macronucleus anlage, and two disintegrating derivatives. Scattered somatic kinetids occur during conjugation, but disappear without reorganization. An incomplete oral primordium originates in both partners. The conjugation of Halteria grandinella resembles in several respects that of hypotrich spirotrichs; however, the majority of morphological, ontogenetical, and ultrastructural features still indicates an affiliation with the oligotrich and choreotrich spirotrichs. Accordingly, the cladistic analysis still contradicts the genealogy based on the sequences of the small subunit rRNA gene.     

Environmental DNA as a ‘Snapshot’ of Fish Distribution: A Case Study of Japanese Jack Mackerel in Maizuru Bay,Sea of Japan

Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R² value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10–150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a ‘snapshot’ of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.     

Soil and Rhizosphere Associated Fungi in Gray Mangroves(Avicennia marina) from the Red Sea—A Metagenomic Approach

Covering a quarter of the world's tropical coastlines and being one of the most threatened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea gray mangroves(Avicennia marina) remain poorly characterized, and understanding of their fungal communities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from gray mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum(76%–85%), while Basidiomycota was less abundant(14%–24%), yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the gray mangroves of the Red Sea, and show that they are significantly richer than previously reported.     

Vertical distribution and abundance of gymnamoebae (Rhizopoda) in bottom sediments of the brackish water Nivå Bay (Baltic Sea,The Sound)

The sandy sediments of Niv? Bay (Baltic Sea, The Sound, Denmark) are often covered with the mats of sulphur bacteria and are temporarily anoxic. The vertical distribution and abundance of naked amoebae species in three sediment cores from this bay were studied. Amoebae were most abundant and diverse in the upper 1 cm of sediment, and their number and diversity decreased with increasing depth into the sediment. Amoebae were recovered from both upper oxygenated and deep anoxic layers of sediments. The species composition and abundance of amoebae was very heterogeneous, even at spatial scales of several centimeters, suggesting the existence of microhabitats selectively occupied by particular species. All species found were recorded from aerobic cultures and some of these amoebae occur in both the aerobic and anaerobic layers of the sediment. Minimal possible number of amoebae in the sediments, estimated for the first time as areal abundance integrated for depth was: core 1 -597 cm(-2); core 2 -1,110 cm(-2); core 3 -1,430 cm(-2). These abundances are probably best regarded as "potential" abundances of amoebae hidden in the sediments, as the question of the ratio between active and resting amoebae remains open.     

Cryptic freshwater amoeba species in the bottom sediments of Nivå Bay (Øresund, Baltic Sea)

An aquarium containing a portion of freshly collected brackish-water sediment from Nivå Bay (Øresund, Baltic Sea) was sampled to determine the species of amoebae present and refilled with inorganic salt medium to achieve freshwater salinity. After 2 months incubation, the diversity of amoebae was again studied, and the salinity was restored to the original level. The aquarium was incubated for a further 2 months and the amoeba fauna was studied for the last time. A number of freshwater species appeared in the sample after the first salinity shift, while some marine species disappeared. Most marine species did not re-appear after the salinity in the aquarium was restored, but one marine species not noted previously was recorded. The experiment illustrates the presence of ‘cryptic diversity’ of amoebae in natural habitats and demonstrates that laboratory manipulation of the salinity of a sample prior to inoculation may achieve an increased recovery of species from a brackish-water habitat.     

Polychaeta “Sedentaria” of Terra Nova Bay (Ross Sea,Antarctica): Capitellidae to Serpulidae

Capitellidae, Maldanidae, Trichobranchidae, Terebllidae, Sabellidae, Serpulidae and Spirorbidae found in Terra Nova Bay (Ross Sea, Antarctica) have been studied. Thirty-one species have been identified, one of which, Praxillella praetermissa antantica is a new subspecies. About 75% of the species are endemic to Antarctica or sub-Antarctica. The geographic distribution of some species has been extended.     

Studies from the “UWL Helgoland” on the macrobenthic fauna of rocks and boulders in Lübeck Bay (western Baltic Sea)

During a fortnight's saturation mission with the Underwater Laboratory (UWL) Helgoland in May and June 1975, samples of the macrobenthic fauna of rocks and boulders at 15 m depth in the Lübeck Bay were collected from the same area as in October 1974, using a diver-operated suction sampler. Salinity varied from 11.1 to 15.0 S and water temperature from 7.5° C to 11.5° C. Visibility was usually about 3 to 4 m. On average, 10.449 individuals/m² were recorded in 1975 compared to 30.474 individuals/m² in 1974. Two species, the ascidianDendrodoa grossularia and the polychaetePolydora ciliata account for 90.8% of the total number of individuals sampled. Five species (Dendrodoa grossularia, Nereimyra punctata, Neoamphitrite figulus, Asterias rubens, Facelina drummondi) were significantly less abundant than in 1974, while two species and one group of species (Anaitides maculata, Corophium bonelli, Nemertini indet.) were more abundant in 1975. As in 1974, the angle of inclination of the substrate showed no relationship with species composition. In 1974, four motile benthic invertebrates,Nereimyra punctata, Idothea baltica, Diastylis rathkei, andFacelina drummondi were observed swarming. In 1975, onlyI. baltica was observed swarming and the individuals seemed to be less active than in 1974, perhaps related to the lower water temperatures recorded in May and June 1975 compared to those in October 1974.     

Bacterioplankton of the Kola Bay, Barents Sea, (micro-and nanoforms) based on 2002–2003 monitoring data

Hydrochemical and microbiological investigation in the Kola Bay in 2002–2003 demonstrated that the distribution of bacteria is notably influenced by biogeochemical barriers formed by mixing fresh and sea water. Seasonal changes in the appearance of filterable bacteria, considerable quantities of gram-positive bacteria with thick cell walls, dwarf bacteria, spheroplasts, elementary bodies, and cells with abnormal cell walls during the polar night have been revealed. Cultured bacterial colonies were represented by polymorphic cells. The data obtained refine our knowledge about organotrophic activity of bacterioplankton during the polar night.     

A Decade Later,How Much of Rwanda's Musculoskeletal Impairment Is Caused by the War in 1994 and by Related Violence?

Background

In 1994 there was a horrific genocide in Rwanda following years of tension, resulting in the murder of at least 800,000 people. Although many people were injured in addition to those killed, no attempt has been made to assess the lasting burden of physical injuries related to these events. The aim of this study was to estimate the current burden of musculoskeletal impairment (MSI) attributable to the 1994 war and related violence.

Methodology/Principal Findings

A national cross-sectional survey of MSI was conducted in Rwanda. 105 clusters of 80 people were selected through probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Enumerated people answered a seven-question screening test to assess whether they might have an MSI. Those who were classed as potential cases in the screening test were examined and interviewed by a physiotherapist, using a standard protocol that recorded the site, nature, cause, and severity of the MSI. People with MSI due to trauma were asked whether this trauma occurred during the 1990–1994 war or during the episodes that preceded or followed this war. Out of 8,368 people enumerated, 6,757 were available for screening and examination (80.8%). 352 people were diagnosed with an MSI (prevalence = 5.2%, 95% CI = 4.5–5.9%). 106 cases of MSI (30.6%) were classified as resulting from trauma, based on self-report and the physiotherapist''s assessment. Of these, 14 people (13.2%) reported that their trauma-related MSI occurred during the 1990–1994 war, and a further 7 (6.6%) that their trauma-related MSI occurred during the violent episodes that preceded and followed the war, giving an overall prevalence of trauma-related MSI related to the 1990–1994 war of 0.3% (95% CI = 0.2–0.4%).

Conclusions/Significance

A decade on, the overall prevalence of MSI was relatively high in Rwanda but few cases appeared to be the result of the 1994 war or related violence.     

Temporal variability in abundance and biomass of ciliates and copepods in the eutrophicated part of Kaštela Bay (Middle Adriatic Sea)

Seasonal variations in abundance and carbon biomass of ciliated protozoa and micrometazoa were studied from May 1998 to November 1999 in the eutrophicated area of Katela Bay (Middle Adriatic Sea). Ciliates showed peaks in spring and autumn, primarily due to changes in the abundance and biomass of tintinnines, which participated in total ciliate abundance and biomass with 40.48 and 60.02%, respectively. The highest tintinnine density was 4,278 ind. l^–1, while their average biomass varied from 0.611 to 26.557 gC l^–1 . Maximal average density and biomass of non-loricates were 1,430 ind. l^–1 and 3.925 gC l^–1, respectively. The micrometazoa community was dominated by copepod nauplii, especially during the summer and autumn. The copepod biomass ranged between 3.47 and 26.75 gC l^–1 . High abundance and biomass values of the investigated zooplankton groups point to an important role of these organisms in the secondary production in the Bay, indicating that they may be (1) a crucial factor in controlling the populations of nano-/pico-phytoplankton and heterotrophic nanoflagellates, and (2) a significant prey for larger micrometazoans.     

Potential distribution of Tridentiger barbatus (Günther 1861) and Tridentiger nudicervicus (Tomiyama 1934) in the Seto Inland Sea,western Japan

We developed distribution models for two near-threatened gobiid fishes, Tridentiger barbatus and Tridentiger nudicervicus, based on distribution data and geographic variables in the Ariake Sea, the Yatsushiro Sea, and Suonada Bay. Subsequently, we estimated the potential distribution of both species across all areas of the Seto Inland Sea based on the model predictions. The models indicated high accuracy and demonstrated that both species inhabit shoal and relatively enclosed waters. Predicted potential distribution areas of the two species included all sites with previous records and a few new sites without existing records.     

Trawl fishery resources in the “southern waters” of Japan

Settlement-stage larvae of the coral reef fishes Ostorhinchus doederleini (Apogonidae) and Pomacentrus coelestis (Pomacentridae) prefer the odor of their settlement reef to that of other nearby reefs. It was unknown whether these olfactory preferences are temporally stable or the result of recent olfactory experience. Ostorhinchus doederleini and P. coelestis larvae were held in aquaria and exposed to water from either their settlement reef or a neighboring reef for 5–9 days and their olfactory preference was tested. We show that exposure to water from another reef did not influence olfactory preference. Ostorhinchus doederleini olfactory preference declined slightly over time whereas P. coelestis preference was gradually lost after 2–3 days in captivity. Neither species switched their preference to the new reef odor. While we cannot determine conclusively the time window of odor learning, imprinting at or shortly after birth is logical and has been demonstrated in other fish species.