Macrozoobenthos Samples Research Articles

Abundance of Macrozoobenthos in the Seagrass Field Ecosystem in Cemara Besar Island, Karimunjawa Islands

Seagrass has several important ecological functions which protected some species of invertebrates such as crustaceans, bivalves, gastropods, echinoderms, and other marine organism. Seagrass have ecological processes, where any interaction of several biotic and environment components. One of the biotic components associated with seagrass is macrozoobenthos. This study aims to determine the type and abundance of macrozoobenthos, the value of ecological index and covering percentage of seagrass at Cemara Besar Island, Karimunjawa. This study was conducted at Cemara Besar Island, Karimunjawa. The method used in this study was survey method with descriptive data analysis. Measurement of seagrass and macrozoobenthos using transect quadrant size of 1 x 1 meter. Macrozoobenthos living on the surface susbtrat (epifauna) was taken directly, while macrozoobenthos living within the substrate (infauna) using a corer was inserted into the substrate to a depth of 25cm. After conducting the samples were treated, the sediment sample sieved using benthos filter with a pore diameter of 1 mm and put macrozoobenthos into a sample bottle which has been given a 4% formalin solution and dye rose bengal, then identification of macrozoobenthos using a microscope and magnifying glass. Macrozoobenthos samples were analyzed using the calculation of abundance, the diversity index, the evenness index and the domination index. The result show that, in seagrass ecosystems in Cemara Besar Island Karimunjawa was found 4 classes macrozoobenthos consisting of Bivalve 3 species, Polychaeta 5 speseies, Echinoidea 4 species, and Gastropoda 25 species. The value of abundance in marine protection zone ranging from 6.32 to 8.42 ind/dm3 and the value of abundance in utilization zone marine ranging from 6.85 to 7.37 ind/dm3. The value of diversity index in the marine protection zone ranging from 1.42 to 2.57 are included in the category of low to moderate, while in the Marine Utility Zone ranging from 3.26 to 3.47 are included in the high category. The value of evenness index in the marine protection zone (E = 0.61 to 0.74) and utility zone (E = 0.77 to 0.82) were included in the high category (E > 0.6) in the second zone. The value of domination index in the marine protection zone (C = 0.20 - 0.48) and utility zone (C = 0.13 - 0.17) indicates that there are not macrozoobenthos species dominates. The Percentage cover of seagrass in marine protection zone from 68.75 to 76.04%, while the percentage cover of seagrass in utility zone ranging from 59.38 to 65.63%.

Impact of water salinity on long-term dynamics and spatial distribution of benthic invertebrates in the Small Aral Sea

Abstract In 1996–2008, macrozoobenthos of the Small Aral Sea was investigated. A total of 320 macrozoobenthos samples were collected. Statistical analysis and statistical mapping were performed using Statistica and Photoshop software. Ten taxa of macrozoobenthos were identified, with an average water salinity of the Small Aral Sea ranging from 6.3 to 19.0 PSU. Average annual community abundance reached 1962 specimens m−2, with biomass of 107.1 g m−2. Quantitative variables of macrozoobenthos decreased by an order of magnitude by the end of the analyzed period. The polychaete Hediste diversicolor and mollusks Abra ovata, Cerastoderma glaucum, Caspiohydrobia sp. were the dominant taxa. Statistical mapping and correlation analysis revealed that the high biomass of A. ovata and Caspiohydrobia sp. occur in areas with high water salinity. Aggregations of the mollusk C. glaucum were observed in various areas of the sea. The polychaete H. diversicolor preferred areas with relatively low salinity. Analysis of the results showed that the optimum salinity gradient with Aral salt composition was 17–27 PSU for A. ovata, Caspiohydrobia sp. and C. glaucum, while 1–27 PSU for H. diversicolor. Along with changes in water salinity, the currently growing pressure from freshwater fish is an additional factor affecting the structure of benthic communities in the Small Aral Sea.

KEANEKARAGAMAN LAMUN DAN MAKROZOOBENTOS SEBAGAI INDIKATOR KONDISI PERAIRAN PANTAI SINDHU, SANUR, BALI

Sindhu Beach is part of the Sanur beach area. Sanur area is one of 11 strategic national tourism areas in Bali. Beach tourism activities have the potential to cause degradation of coastal ecosystems. Ecosystem changes can be determined using bioindicators. This study aims to determine the condition of the Sindhu Coast waters ecosystem based on seagrass diversity and macrozoobenthos as indicators. This research was conducted in November 2019 at Sindhu Beach. Seagrass observations and macrozoobenthos sampling were carried out at four stations with three replications at each station. Data and samples were collected using the quadratic transect method. Eight species of seagrass were found in Sindhu Beach with a percentage of cover between 16.33% - 63.37% and density between 1572 ind / m2 - 3314.4 ind / m2. The average value of the seagrass diversity index was 1.24, the average uniformity index was 0.78, and the average dominance index was 0.32. Types of macrozoobenthos found were 23 species with abundances ranging from 2.33 ind / m2 - 28.33 ind / m2. The average value of macrozoobenthos uniformity index is 1.50, the average diversity index is 0.68 and the average dominance index is 0.36. Based on the index value shows that the waters of Sindhu Beach are in good condition or there is no ecologically significant pressure.

New data on the taxonomic composition of macroinvertebrates in marine habitats from the Livingston Island, Antarctica

Antarctic marine organisms are characterised by a significant level of endemism. This is due to geological, climatological and oceanographic reasons, such as the break-up of Antarctida from Gondwana during the Cretaceous; the formation of a circumpolar current; the extremely low water temperatures (close to freezing); the short summer seasons. The South Shetland Islands (West Antarctic Peninsula) are one of 29 known biogeographic areas in the Southern Hemisphere (Griffiths et al. 2009). King George Island is the largest island from the South Shetlands and eight countries have their polar bases there. Marine bottom macroinvertebrates from the surrounding seawaters are very well studied (Siciński et al. 2011). Less research was carried out in the region of the nearby Livingston Island. There are located two polar bases: "St. Kliment Ohridski" (Bulgaria) and "Juan Carlos I" (Spain). We can assume that in the seawaters of the South Bay we can also expect a rich bottom macroinvertebrate fauna because of the similar conditions and the close distance between the two islands. The aim of this study is to present the first Bulgarian results on the taxonomic composition of marine macroinvertebrates from the South Bay, Livingston Island. The samples were collected during the XXVIIth Bulgarian Antarctic Expedition (2018–2019 austral summer). Various sites in four areas were sampled: the coastal zone in front of the Bulgarian Polar Base (Costa Bulgara); a small bay south of Cape Hesperides (Reservnoto port); Johnsons Dock Bay near the Spanish research station and Walker Bay near Hannah Point. Samples were collected mainly through bottom trawling at depths of 2 to 20 meters on different types of bottom substrates using Zodiac boats. A total of 11 macrozoobenthos samples were collected. Our preliminary results show that the main macrozoobenthic species are well known in the seawaters of the South Shetlands and usually they have a circumpolar distribution. At the site with soft muddy bottoms (Johnsons Dock Bay), the corrugated ribbon worm Parborlasia corrugatus (McIntosh, 1876) (order Heteronemertea, class Pilidiophora, phylum Nemertea) as well as ascidians (order Phlebobranchia, class Ascidiacea, phylum Chordata) had the highest biomass. The most abundant in the Johnsons Dock Bay were the Antarctic bivalve Aequiyoldia eightsii (Jay, 1839) (order Nuculanida, class Bivalvia, phylum Mollusca); the scale worm Barrukia cristata (Willey, 1902) and the catworm Aglaophamus trissophyllus (Grube, 1877) (both of order Phyllodocida, class Polychaeta, phyllum Annelida). The seroid isopod Spinoserolis beddardi (Calman, 1920) (order Isopoda, class Malacostraca, phyllum Arthropoda) dominated in the muddy / sandy bottom of Hannah Point. The habitats of the rocky bottom (Costa Bulgara) were inhabited mainly by crustaceans (order Aphipoda, class Malacostraca, phyllum Arthropoda) and gastropods (phylum Mollusca). In the tidal zone of this habitat (0–2m), the predominant species was the Antarctic limplet Nacella concinna (Strebel, 1908) (order Patellogastropoda, class Gastropoda, phylum Mollusca).

Community Structure of Macrozoobenthos at Blanakan Fish Pond, Subang, West Java

Macrozoobenthos has an important role as detritivore in water ecosystem. Macrozoobenthos community also act as a biomonitoring instrument. The purpose of this study is to know the composition, density, diversity, evenness, and dominance of macrozoobenthos at Blanakan Fish Pond. This study was done from February to June 2018. Macrozoobenthos samples were collected from 3 stations and each station consist of 3 fish ponds. Sampling on each ponds was done by purposive random sampling on 3 sampling points with twice repetition on each point. Water abiotic factors sampling was done on each points. Macrozoobenthos samples were identified and analyzed using Shannon-Wiener diversity index, Pielou evenness index, Simpson’s dominance index, Sorensen similarity index, and t-test. The results showed that there are six species of macrozoobenthos from 3 classes found, which are Melanoides tuberculata, Brotia costula, Cerithidea cingulata, Nephtys inornata, Cossura sp., and Erpobdella sp. Highest species density at Blanakan Fish Ponds is Brotia costula, amounting to 10907 ind./m3. The diversity and evenness of macrozoobenthos at Blanakan Fish Ponds classified as low and there is a dominant species at Blanakan Fish Ponds. There is no difference between macrozoobenthos diversity on 3 stations.

Content of Fatty Acids in Forage Objects of Juveniles of Salmonids from Rivers of the Lake Onega Basin

The forage base of juveniles of salmonids (Atlantic salmon and brown trout) from six rivers of the Lake Onega basin has been analyzed: invertebrate organisms of 23 taxa have been identified. In the macrozoobenthos samples, the content and ratio of fatty acids (FAs) of total lipids are determined. Differences in the ratio of essential 18:3ω-3/18:2ω-6 FAs are found, and the ratio is higher in zoobenthos collected from “salmon” rivers than in those of “brown trout” rivers (within 1.68–2.83 and 0.44–1.08, respectively). The ratio of saturated FAs/polyunsaturated FAs (0.66–0.97 and 0.33–0.59, respectively) in the zoobenthos from salmon rivers is higher than in forage from the brown trout rivers. The content and ratio of physiologically important FAs in the feeding objects of young fish of salmonids have a significant effect on their growth and development.

Zmiinyi Island Coastal Zone Macrozoobenthos State in 2016-2017

Purpose. To study the state of macrozoobenthos in the Zmiinyi Island coastal zone in 2016-2017. Methods. Standard methods of macrozoobenthos sampling, determination, number and biomass estimation. Results. Results of analysis of biodiversity, structural characteristics and taxonomic composition of macrozoobenthos in the Zmiinyi Island coastal zone have been presented. Seasonal dynamics of its number and biomass has been studied. Assessment of marine environment quality has been performed based on the metrics of macrozoobenthos. Conclusions. Altogether, 132 taxa of benthic invertebrates belonging to 10 biggest taxonomic groups of macrozoobenthos have been identified in the Zmiinyi Island coastal zone in 2016-2017. Analysis of taxonomic composition identified 1 species of Porifera (0.8%), 7 taxa of Cnidaria (5.3%), 3 taxa of Platyhelminthes (2.3%), 1 taxon of Nemertea (0.8%), 3 taxa of Bryzoa (2.3%), 52 taxa of Annelida (39.4%), 25 taxa of Mollusca (18.9%), 35 taxa of Arthropoda (265%), 2 taxa of Echinodermata (1.4%) and 3 taxa of Chordata (2.3%). Out of 132 macrozoobenthos taxa 6 are enlisted in the Red Data Book of Ukraine and 8 – in the Black Sea Red Data Book. Macrozoobenthos number varied from 0.317х104 (27.11.2016) to 16.943х104 (19.08.2016) ind/m2 on soft substrate and from 2.683х104 (17.05.2016) to 30.725х104 (19.08.2016) ind/m2 on rocky substrate; biomass varied from 0.017 (17.05.2017) to 34.857 (19.08.2016) kg/m2 on soft substrate and from 1.531 (27.11.2016) to 46.147 (19.08.2016) kg/m2 on rocky substrate. Maximal development of benthos was registered in summer period. Quality of marine environment on the AMBI and M-AMBI indices was assessed as Good in 21 cases out of 23 and as Moderate in 2 cases 2 out of 23. Mean values of AMBI and M-AMBI indices for different seasons made respectively: May, 2016 – 2.56 and 0.59; August, 2016 – 1.86 and 0.69; November, 2016 – 1.70 and 0.71; June, 2017 – 1.87 and 0.75.

Macrozoobenthos State in Odessa Bay Coastal Waters in 2016-2017

Purpose. Study of macrozoobenthos contemporary state in Odessa Bay coastal waters in 2016-2017. Methods. Standard methods of macrozoobenthos sampling, determination, estimation of number and biomass Results. The results of macrozoobenthos biodiversity, structural characteristics and taxonomic composition in Odessa bay coastal waters have been presented. Seasonal dynamics of its number and biomass. has been studied. Assessment of marine environment quality has been performed on the metrics of macrozoobenthos. Conclusions. Altogether 121 taxa of benthic invertebrates were identified in Odessa Bay in 2016-2017. Taxonomic composition and quantitative indicators of macrozoobenthos had clear seasonal variation with maximal development of benthos in summer period. In spring of 2016, 75 taxa of macrozoobenthos were registered in samples, in summer – 82 taxa, in autumn – 60 taxa, in summer of 2017 – 62 taxa. The basis of macrozoobenthos community was formed be mollusks (Mollusca) with domination of species М. galloprovincialis, as well as representatives of Arthropoda and Annelida. Significant input into macrozoobenthos species composition was made by representatives of the following groups: Bryozoa, Nemertea and Platyhelminthes. Contribution of Porifera, Cnidaria and Ph%

Biodiversity of macrozoobenthos in the Bulaksetra and Batukaras mangrove area, Pangandaran, West Java

Nurfajrin AR, Rosada KK. 2018. Biodiversity of macrozoobenthos in the Bulaksetra and Batukaras mangrove area, Pangandaran, West Java. Pros Sem Nas Masy Biodiv Indon 4: 248-253. Mangrove forests are coastal areas with various advantages, one of which is natural resources that are not owned by other regions. Pangandaran has two mangrove forest areas, namely Bulaksetra and Batukaras Mangroves located in two different sub-districts. This study aims to determine the biodiversity of macrozoobenthos as one of the natural resources of mangrove areas in the Bulaksetra and Batukaras Mangrove Forests in Pangandaran. This research is an explorative research. The taking of macrozoobenthos samples at the bottom of the waters was carried out using Surber mesh while the macrozoobenthos samples from the roots and stems of mangrove plants were taken by hand picking method. The results showed that overall in the Pangandaran mangrove area there were nine types of macrozoobenthos which all included in the Gastropod class and three of them were found in both mangrove areas. Bulaksetra Mangrove area which is dominated by vegetation Rhizophora sp. found six types of macrozoobenthos dominated by Faunus ater while the Mangrove Forest Batukaras dominated by vegetation Avicennia albafound six types of macrozoobenthos with a low level of dominance. Based on the Shannon-Wiener Diversity Index, the diversity and evenness of the macrozoobenthos species in Mangrove Bulaksetra Forest are lower than that of Batukaras Mangrove Forest.

STUDI KOMUNITAS MAKROZOOBENTOS DI HUTAN MANGROVE KECAMATAN INSANA UTARA KABUPATEN TIMOR TENGAH UTARA

The development in Wini Beach coastal area will have an impact on the destruction of the mangrove ecosystem which is a habitat for the life of the macrozoobenthic fauna. This study aims to determine the community structure of macrozoobenthos including abundance, diversity, evenness and dominance of the type of macrozoobenthos in the mangrove area. The study was carried out in the District of North Insana which included the mangrove area of Temkuna Beach (station I) and the mangrove area of Tanjung Bastian Beach (station II). Taking macrozoobenthos samples was carried out at low tide using the line transect method which was made perpendicular to the land in the mangrove forest area. The results of the study found 13 types of macrozoobenthos fauna spread over 2 stations namely the 8-type gastropod class, bivalvia class 4 types and 1 type crustacean class. Medium category (H ') = 2.41 index, Uniformity Index (E) = 0.938 classified as stable community and Dominance index (D) = 0.10 low category. The Equity Index score is classified as a stable condition where no macrozoobenthos species dominate. Virtual sex chat with porn models on webcam. Moscow and the world! Hundreds of guys and girls online. Start chatting now! Come in live cam girl naked free-naked scared, pussy get pictures with the inscription, mom wants more porn. Watch porn video chat with naked girls you can without registration, enjoy free erotic sex show in real time.

Assessment of water quality in the upper parts of Wisłoka River (south Poland) by using macrozoobenthos

In October 2017, macrozoobenthos samples were collected on six positions in the upper parts of the Wisłoka River. Based on them, the quality of water purity was assessed and the purity classes were assigned to them using the BMWP-PL method and the Margalef index. The quality of waters in Wisłoka is unsatisfactory - the most common result of the quality assessment is the 3rd and 4th water purity class. This result is much worse than the assessment of the water quality of the upper parts of the Jasiołka River and the Ropa River using the same water quality method. These rivers are similar physiographically and situated near Wisłoka.

Макрозообентос Придунайского озера Кугурлуй (Одесская область, Украина)

<p><span lang="EN-US">The taxonomic composition and quantitative characteristics of macrozoobenthos of the Danube Lake Kugurlui have been studied. In 2006-2012 on the littoral and sublittoral of the lake, 278 macrozoobenthos samples were collected. There are 172 species of Spongia, Hydrozoa, Turbellaria, Annelida, Crustacea, Insecta, Acarina, Gastropoda, Bivalvia. All species are found on the littoral, in the sublittoral - 48 species. There are 36 species new to the lake. Ponto-Caspian faunal complex is represented by 19 species. The number of species on the littoral decreased from 129 in the upper reaches to 98 in the lower reaches, in the sublittoral was within 35-37 species. On the littoral, the abundance and biomass of macrozoobenthos increased on average throughout the lake from winter to summer, in the sublittoral biomass increased from winter to autumn, the maximum number was recorded in the spring. The number was dominated by oligochaetes and chironomids, and by mollusks by biomass.</span></p>

Komunitas Makrozoobentos di Sungai Gua Pintu Ngalau pada Kawasan Karst di Sumatera Barat

Pintu Ngalau cave is flowed by river from irrigated rice fields that flows into the cave. This cave has a source of organic matter derived from bats and swallow dirts, litter that falls on enterance of the cave and the organic material carried by the flow of the river. The study on the macrozoobenthos communities of river in Pintu Ngalau Cave has been conducted from October until November 2016. The study used survey method, where stratified random sampling was applied in three zones (light zone, dim zone and dark zone) at study site. Macrozoobenthos samples was collected by surber net. This study also measured the physic-chemical of water. The results showed the composition of macrozoobenthos in the Pintu Ngalau cave river consisted of 43 genera i.e Gastropods (2 genera), Hirudinea (2 genera), Insects (36 genera) and Oligochaetas (3 genera). Total density of macrozoobenthos in this site was 2100 ind/m2 and the highest density was found in dark zone. The highest total relative density (KR total=79,89%) on genus level at every zone was Hydropsyche. Diversity index of macrozoobenthos was classified as medium (H'=2.68) with evenness distribution was evenly (E=0.61) and no dominant genus (C=0.14). The existence of macrozoobenthos was not influenced by light intensity, but instead was more influence by the condition of the substrate and the flow of water in the cave.

Keterkaitan Komunitas Makrozoobentos dengan Kualitas Air dan Substrat di Ekosistem Mangrove Taman Hutan Raya Ngurah Rai Bali

Ngurah Rai forest park located in two districts of Badung and Denpasar city which is as the main centre of anthropogenic activities. There is an estuary in this area that used as run off of those activities. This area faces directly into the ocean. Wastes from anthropogenic activities indirectly affected biotic and abiotic components such as water quality, substrate, and macrozoobenthos. This research aims to discover the community of macrozoobenthos and its relation to the water quality and substrate in Ngurah Rai forest park. This research used purposive sampling metode to determine of stations. Sampling was conducted at four different stations covering macrozoobenthos samples, measuring water quality (salinity, pH, DO, temperature, turbidity) and substrate samples. A total of 19 types of macrozoobenthos was found out of 5 classes, i.e. Polychaeta, Oligochaeta, Bivalves, Gastropods, and Crustaceans. The diversity index was categorized as low to moderate. The uniformity index value of community was categorized as balanced. The dominant index on the fourth station states that the level of dominance was categorized as low. Water quality parameter measurement results were still within normal limits, but the turbidity value of the first station exceeds the normal limits due to high content of organic matter. The substrate type at first station to fourth station were sandy clay loam, sandy loam, clay loam, and sandy loam respectively. Temperature, salinity, turbidity were the parameters that greatly affected the abundance of macrozoobenthos, while substrates such as sand and clay have a major influence on the abundance of macrozoobenthos.

Macrozoobenthic community structure in a large shallow lake: Disentangling the effect of eutrophication and wind-wave disturbance

Biological communities in shallow lakes are often subject to the combined effects of eutrophication and wind-wave disturbance. However, their relative importance in regulating macrozoobenthic community assembly has not been well addressed. In the present study, a monthly sampling of macrozoobenthos and environmental parameters was conducted at ten sites from December 2012 to November 2013 in Lake Hongze, the fourth largest freshwater lake in China, which has undergone serious water quality deterioration over the past few decades. A total of 30 taxa were recorded during the 12 sampling occasions, including 6 chironomids, 6 bivalves, 4 gastropods, 4 oligochaetes, 4 polychaetes, 4 crustaceans and 2 other aquatic insects. The mean abundance and biomass of total macrozoobenthos varied greatly among the ten sites and presented distinctive taxonomic composition between the protected bays and the offshore zone. Three eutrophication parameters (including permanganate index (CODMn), chlorophyll a, and total phosphorus in surficial sediments) and three wind-wave variables (including Secchi depth, turbidity, and mean effective fetch) were highly related to spatial variation of macrozoobenthic assemblages. When eutrophication variables were controlled, there was a significant correlation between community similarity and wind-wave disturbance condition, and vice versa. Variation partitioning showed that wind wave disturbance explained 15.9% of the variation in benthic community composition, slightly lower than that explained by eutrophication (17.9%). These results indicate that wind-wave disturbance is as important as eutrophication in regulating benthic community structure in this large shallow lake. Wind-wave disturbance imposed opposite effects on benthic community relative to eutrophication, and were more prominent in the offshore zone weakening the role of eutrophication.

Agriotypus armatusCurtis, 1832, a parasitoid ofSilo pallipesFabricius, 1781: the first record for the Balkan Peninsula

Key-words: Agriotypus, parasitoid, Serbia, distribution, ecological parameters Among the diverse order of Hymenoptera, aquatic species are of special interest. During macrozoobenthos sampling in the rivers of Serbia in 2003 and during the period 2011−2012, pupae of Silo pallipes Fabricius, 1781 were recorded which were parasitized by an ichneumonid wasp Agriotypus armatus Curtis, 1832, this being the first record of it for the Balkan Peninsula. A total of 217 A. armatus specimens were collected at 29 localities situated along 16 watercourses of Serbia. All four parasitoid stages (egg, larva, pupa and resting adult) were recorded. The identity of the parasitoid was confirmed using standard molecular methods. This study also focuses on the ecology of the parasitoid and its host. The widespread distribution of A. armatus in Europe suggests the presence of this species in other Balkan countries, but this has not yet been confirmed due to a lack of surveys and/or the constantly increasing pollution of freshwaters.

Water Quality and Ecological State Assessment of the Blagoevgradska Bistritsa River (South-West Bulgaria) Based on Macrozoobenthos Collected by Two Sampling Standards

ABSTRACTComplex investigations of the Blagoevgradska Bistritsa River, left tributary of the trans-boundary Struma River, were carried out in the summer of 2008. Seven representative sites were sampled. Physico-chemical parameters such as water temperature, pH, oxygen concentration, oxygen saturation, conductivity, nitrates and phosphates were measured. The biological assessment was based on macroinvertebrate communities—one of the obligatory biological quality elements according to the Water Framework Directive requirements and the national legislation. Canonical Correlation Analysis (CCA) was used for the explanation of the site-physico-chemical factors relationship. Indices of species diversity (c, e, H), saprobiological index (SR), biotic index (BI) and trophic index (RETI/PETI) were used to determine the water quality and the ecological state of the water bodies.According to the values of the physico-chemical parameters, indices of species diversity and the saprobiological index, the water quality of the sites from the source to the city of Blagoevgrad was I—II category. The ecological state was assessed as high, according to BI and high and good, based on the trophic index RETI. The water quality at the Blagoevgradska Bistritsa mouth, influenced by the waste waters of the city of Blagoevgrad, was assessed as II—III category, and the ecological condition, as moderate and poor (BI) and bad (PETI). The distribution of the physico-chemical parameters at the ordination diagram divided the studied sites into two groups: upstream (clean, unaffected sites) and downstream (anthropogenically influenced sites) of the city of Blagoevgrad.Two periods of investigation (2002–2003 and 2008) and two standard methods for macrozoobenthos sampling (handnet sampling of aquatic benthic macroinvertebrates and quantitative samplers for benthic macroinvertebrates on stony substrata in shallow freshwater) were compared. The results showed that for a five-year period of time changes in the water quality and the ecological state of the studied sites had not been observed. The two sampling methods gave similar results as regards the values of the indices used.

Effects of Oxbow Reconnection Based on the Distribution and Structure of Benthic Macroinvertebrates

AbstractThis study focuses on the assessment of relationships between flow and macrozoobenthos structure that was performed in a reconnected oxbow lake located in the Słupia River floodplain (northern Poland). The lake was created during river straightening at the beginning of 20th century by cutting off the right‐bank meander. The oxbow restoration was performed to enhance the ecological viability of this water body and restore riverine wetland. In July 2000 the oxbow was connected with the river channel through PVC pipes which enabled free water movement. Macrozoobenthos sampling, as well as chemical analyses of water and hydrological measurements, took place both before and after the oxbow reconnection. Before the oxbow reconnection, the dominant species was Asellus aquaticus, whereas after the reconnection the structure of benthic species changed significantly. During the first year it was replaced by bivalves and Chironomidae larvae and then A. aquaticus. After the reconnection, macrozoobenthos mean density was 5‐fold higher and the mean wet biomass was 77‐fold higher than before the reconnection. The number of taxa increased from 4 before the oxbow reconnection to 17 during the first year after the performed works and 20 in the next year. We stated that the revitalization process of the reconnected oxbow lake has long‐term consequences for the benthic communities. The most significant feature of the oxbow reconnection is the qualitative and quantitative recolonization by riverine macrozoobenthos species. The performed restoration significantly improved ecological status of the oxbow lake by the increase in biodiversity and water quality.

About the Distribution of Hydromermis contorta Linstow, 1889 (Nematoda: Mermithidae) in Waterbodies of the Kaliningrad Eegion (Russia)

The purpose of the current study was to investigate the distribution of aquatic mermithid Hydromermis Contorta in the main waterbodies of the Kaliningrad region. Benthos samples were collected during the summer, autumn and winter of 2008 in the littoral zone (0.5–1.0 m depths) of the Neman, Deyma, Angrapa, Pissa, Sheshupe and Primorskaya Rivers as well as in the Pravdinsk Reservoir, Lake Vishtynetskoe, and in the Vistula and Curonian lagoons. H. contorta was recorded in eight water bodies. Parasitic juveniles were found in the hemocoel of Chironomus plumosus larvae in summer and winter. The highest infestation of chironomids was revealed in the Neman River. Postparasitic larvae and adult helminths were found in macrozoobenthos samples throughout the research period. The free-living juvenile stage of H. contorta reached the highest abundance and biomass in the Angrapa River, the lowest abundance and biomass being recorded in the Deyma and Primorskaya Rivers.

COROPHIIDS (AMPHIPODA, COROPHIOIDEA) OF THE RIVER DANUBE— THE RESULTS OF A LONGITUDINAL SURVEY

Three species of Corophiidae (Amphipoda) were identified in the macrozoobenthos samples of the “Joint Danube Survey 2” (organized by the ICPDR). Chelicorophium sowinskyi (Martynov, 1924) and Chelicorophium robustum (G. O. Sars, 1895) were found for the first time in the Upper Danube. It is likely that C. sowinskyi has been overlooked in this area for decades, while C. robustum is a recent invader probably spreading downstream in the river. Chelicorophium curvispinum (G. O. Sars, 1895) was present in the whole navigable course of the river, whilst the other two species showed a discontinuous distribution with a gap in the Middle Danube. In the case of C. sowinskyi this gap is likely to reflect that this area is not tolerable for it for some reason, while C. robustum has probably not reached this section yet.