Total Benthos Biomass Research Articles

Specific Features of the Macrozoobenthic Communities of Small Arctic Lakes in Eurasia

The taxonomic structure, typology, species richness, and total abundance of bentic and littoral macroinvertebrate communities from small lakes of the Arctic and Subarctic zones are considered on the basis of original data from three northern Palearctic regions (the foot of the Putorana Plateau, Kolguev Island, and Western Svalbard Island). A comparative analysis of the communities of these regions has been carried out. The features of High Arctic insular, Low Arctic, subarctic, and boreal lake communities are discussed using a large volume of literature data. The complex pattern of changes in the total benthos biomass of small lakes has been revealed: it decreases in the subarctic taiga, increases in the hypoarctic tundra, and decreases again in the High Arctic.

Seasonal dynamics and quantity distribution of zoobenthos in the north-west part of the South Caspian Sea

The article is devoted to the study of seasonal dynamics and quantity of the zoobenthos distribution in the north-west part of the South Caspian Sea. During the research covering the period from 2009 until 2010, 59 macrobenthos organisms belonging to the ten systemic groups were identified. Maximum quantity of species was identified in spring and summer (31 - 59 species), while minimum in autumn (24 - 42 species). Maximum development of organisms was identified in summer (146.27 g m-2), while minimum in autumn (77.12 g m-2). The key role in the benthos biomass formation belonged to shellfish, comprising 67.7 to 69.1% of total benthos biomass

ASSESSMENT OF THE BOTTOM FAUNA BIOMASS OF THE LOWER REACHES OF THE ANGARA RIVER IN THE AREA OF THE GOREVSKY ORE MINING AND PROCESSING INDUSTRIAL COMPLEX

In the article, the general biomass of zoobenthos is considered on the basis of the results of studies conducted during July-September 2016 in the river bed of the Angara River in the area of the water area planned for alienation. The total biomass of benthos is the main feature in the calculation of damage to aquatic biological resources. Studies were conducted in the left half of the Angara River at a distance of 40–43 km from the estuary. The results of the work were compared with the results of a comprehensive study of the Angara in its lower reaches, conducted in 1947–1948. In this work, the species composition of the zoobenthos is not considered. The aim of the work is to estimate the average total biomass for an accurate determination of the damage to aquatic biological resources. The greatest value of the total biomass of benthos was observed in September in the aquatic vegetation near the shore, represented by river mud with sand and plant remains at very low flow velocity. This value is 28.4 g/m2 , with an average value for the study period of 6.57 g/m2 . In the river bed, the greatest value of biomass (4.39 g/m2 ) was also noted in September on the shore, consisting of sand, pebbles, boulders at significant flow velocities. The average value in the river bed during the study period was 0.57 g/m2 . The average size of the total biomass of the zoobenthos in the alienation area is calculated by the ratio of the area of the coastal parts of the river bed and the river bottom, taking into account the average values of the biomass of benthos. This value is 3.86 g/m2 . The value obtained is comparable to the value determined in 1947–1948, which is 46.9 kg/ha. The previously calculated harm was 190.8 tons, with an average biomass of 68.2 kg/ha. The calculated damage is 105.5 tons.

Biodiversity and food web indicators of community recovery in intertidal shellfish reefs

In conservation strategies of marine ecosystems, priority is given to habitat-structuring foundation species (e.g. seagrasses, mangroves and reef-building corals, shellfish) with the implicit goal to protect or restore associated communities and their interactions. However, the number and accuracy of community level metrics to measure the success of these strategies are limited. Using intertidal shellfish reefs as a model, we tested to what extent foundation species alter community and food web structure, and explored whether basic metrics of food web structure are useful indicators of ecosystem complexity compared to other often-used indices. We found that shellfish reefs strongly modified community and food web structure by modifying habitat conditions (e.g. hydrodynamics, sediment grain size). Stable isotope-based food web reconstruction captured important differences between communities from bare mudflat and shellfish reefs that did not emerge from classic abundance or diversity measures. On shellfish reefs, link density and the number of top predators were consistently higher, while both connectance and the richness of intermediate species was lower. Species richness (+42%), species density (+79%) and total biomass of benthos, fish and birds (+41%) was also higher on shellfish reefs, but this did not affect the Shannon diversity or Evenness. Hence, our results showed that basic food web metrics such as link density and number of top consumers and intermediate species combined with traditional measures of species richness can provide a robust tool to measure conservation and restoration success. We therefore suggest that these metrics are included as Essential Biodiversity Variables (EBV), and implemented as ecosystem health indicators in legislative frameworks such as the Marine Strategy Framework Directive (MSFD).

Some features of the quantitative distribution of sipunculan worms (Sipuncula) in the central and southern Barents Sea

The article reports on the current state of the sipunculan fauna of the central and southern parts of the Barents Sea. The main quantitative parameters (biomass and abundance) of the sipunculan populations are obtained, and the contribution of sipunculids to the total benthos biomass is assessed. The major factors causing long-term variations in Sipunculidae distribution and abundance are evaluated for the area in question.The investigations show that the most commonly encountered sipunculan species are Nephasoma diaphanes diaphanes, N. abyssorum abyssorum and Phascolion strombus strombus. The main contribution to the total benthos biomass comes from the two species most typical of the Barents Sea benthic fauna: Golfingia margaritacea margaritacea and G. vulgaris vulgaris. It is possible that the reduction in Golfingia biomass between the 1970s and 1990s, described in the article, is due to changes in the sampling methodology.

Modern distribution of polychaetes along the Kola section (Barents Sea)

282 Among sea bottom invertebrates dwelling in the Barents Sea, polychaetes (Polychaeta) are the most widespread in terms of both biolodiversity and quantitative characteristics [1, 2]. They are present in all biocenoses, being the dominant or background species in many of them and accounting from 50 to 80% of the total benthos biomass. Previously, it was shown that the biodiversity and structure of polychaete settlements reflected the tendency in the development of bottom communities [3]. Therefore, the changes in the settlements of this taxonomic group may serve for assessment of the general state of benthos. The purpose of this study was investigation of changes in the species composition and quantitative characteristics of polychaetes in the latitudinal direction. As the model area, we used the standard sixth section referred to as the Kola meridian. The Kola section is situated in the central part of the Barents Sea at a longitude of 33°30 ′ E. It crosses the waters of the Murmansk Coastal Current ( 69°30 ′ – 70°30 ′ N, stations 1–3), Murmansk Current 70°30 ′ – 72°30 ′ N, stations 3–7), and the central branch of the North Cape Current ( 73°00 ′ –74°00 ′ N, stations 8–12) [4]. Standard stations have a depth of more than 200 m in the section, except stations 2 and 12, with depths of 140–150 m (Fig. 1). The study was based on the materials of zoobenthos quantitative collection obtained by the expedition of Murmansk Marine Biological Institute on the research ship Dal’nie Zelentsy in 2000. The samples were taken using a van Veen grab with a grab area of 0.1 m 2 . The bottom sediment samples were washed using a kapron sieve with a mesh diameter of 0.5 mm and postfixed with neutral 4% formalin. Invertebrates were then placed into 70 % ethanol. The cameral treatment and data analysis was performed using standard methods. E.A. Frolova assisted me in identifying Polychaetes. Subdivision of the studied area according to similarity of the polychaete species composition was perModern Distribution of Polychaetes along the Kola Section (Barents Sea)

Trophic structure of invertebrate communities in ecosystems of salmon rivers in the southern Far East

The formation of trophic structure has been studied in communities of amphibiotic insects (mayflies, stoneflies, caddis flies, and dipterans) and gammarids accounting for 90% of the total benthos biomass. The results show that the trophic groups prevailing by biomass in the metarithral subzone of small rivers are as follows: filtering collectors in rivers of the moderately cold-water type, collectors and scrapers in rivers of the cold-water type, and scraping predators and scrapers in rivers of the moderately warm-water type. Predators, scraping predators, and scrapers show seasonal changes in abundance and biomass. In the rithron of Far Eastern rivers, the abundance of predators regularly decreases in a south-north direction. The change of dominant groups along the longitudinal profile of the river is related to its zones and subzones. In the trophic structure of rivers exposed to anthropogenic impact, the number of trophic groups decreases and the remaining groups undergo changes in their qualitative composition and the ratio of their individual members.

Composition and quantitative distribution of macrozoobenthos in Amur Bay

The data on the species composition, trophic structure, and distribution of macrozoobenthos in Amur Bay obtained in 2001 are presented. Long-term changes in the benthos are analyzed. In 2001, the total benthos biomass significantly increased, although the parameters of the species richness declined as compared to 1986–1989. In 2001, as well as in the 1970s and 1980s, the benthos trophic structure was characterized by the prevalence of deposit feeders. The entire structure of the benthos is evaluated as an eutrophic one. Eutrophication of the bay is considered to be the most probable cause of the negative changes in the benthic communities of the bay in 2001, as well as 15 years ago.

Vertical distribution of benthic community responses to fish predators, and effects on algae and suspended material

The vertical positioning of benthic invertebrates should be a trade-off between the risky, but productive, sediment surface and the safer, but physiologically harsher, conditions deeper down in the sediment. This is because the foraging efficiency of benthic fish decreases with sediment depth, whereas the sediment surface is generally better oxygenated and has a higher resource quality than lower layers. We studied how two benthic fish predators, bream (Abramis brama) and ruffe (Gymnocephalus cernuus), affected the community composition and vertical distribution of benthos, and their indirect effects on algae and suspended material, in field enclosures. Whereas bream had significant effects on the density, composition and distribution of the benthos, ruffe had no such effects. The total benthos biomass in bream treatments was an-order of magnitude lower in the upper sediment layer (0–1 cm) and three times lower in the middle layer (1–3 cm) than in the controls, whereas there were no significant effects in the deepest layer (3–10 cm). Bivalves persisted in the deepest layer although their density was reduced in shallow sediment, whereas gastropods faced the risk of local extinction in the presence of bream. As indirect effects, small-bodied cladocerans, phytoplankton, periphyton and both organic and inorganic suspended material were higher in the bream treatments. We␣conclude that the impact of bream diminished substantially with increasing sediment depth, enabling invertebrates to survive in the sediment and to persist in the presence of bream. However, there were␣no␣indications of any group adjusting their vertical position behaviourally as a response to predation threat.

Long-term (30 years) dynamics of Chironomidae (Diptera) fauna in the Kuibyshev water reservoir associated with eutrophication processes

Benthos investigations were carried out in the channel and flood-plain of the Kuibyshev water reservoir during 1958–1985. Hydrobiological monitoring data obtained at 12–16 stations in all Deeps excluding littoral areas are discussed. In 1987–1900 benthofauna distribution was also studied at the Priplotinny Deep. An increase of the reservoir trophic state is reported. The observed trend was an increase of the total benthos biomass. Changes in both species and trophic structure of the chironomid community due to the eutrophication problem are discussed.