Surveys of the benthic infauna of the Crouch Estuary (UK) in relation to TBT contamination

Author(s):  
R. Waldock ◽  
H.L. Rees ◽  
P. Matthiessen ◽  
M.A. Pendle

Fieldwork on the estuary of the River Crouch in Essex between 1987 (when the use of TBT antifouling on boats less than 25 m in length was banned) and 1992 revealed marked increases in the species diversity of sublittoral benthic communities in the areas which had originally been most contaminated with TBT. These increases were mirrored by a decrease in the TBT contamination of the sediments. The bivalve molluscs and amphipod crustaceans showed the most marked increases in abundance and diversity.

Author(s):  
Aybek Sarmanov ◽  
Nurlan Khabibullovich Sergaliev ◽  
Kazhmurat Maksutovich Akhmedenov ◽  
Erzhan Sakhypzhanovich Sultanov ◽  
Gleb Sergeevich Kashevarov ◽  
...  

The article presents the results of the study of macrozoobenthos communities of six lakes in the West Kazakhstan region in the summer-autumn period: Shalkar, Balykty Sarkyl, Edilsor, Glubinnoye, Prorva and Sulukol. Lakes Prorva and Sulukol are located within the steppe, the lakes Shalkar, Balykty Sarkyl, Glubinnoye - in the semi-desert, Lake Edilsor - in the desert zone. In total, 197 samples of zoobenthos were taken according to generally accepted hydrobiological methods. There are analized the indices of the number and biomass of aquatic organisms in the studied reservoirs. According to the results of the studies carried out, the organisms of 66 taxa from the groups Oligochaeta, Hirudinea, Bivalvia, Gastropoda, Crustacea, and Insecta were found in benthic samples. Of thesethere were found oligochaetes - 2 species, leeches - 1 species, bivalves and gastropods - 3 species each, crustaceans - 4 species and insects - 53 taxa. Among insects, dip-terans (23 taxa, of which chironomids - 18), mayflies, caddis flies, dragonflies, bugs and beetles were distinguished by the greatest species diversity. It was noted that in the composition of benthic communities, diptera larvae dominated in abundance, the main contribution to the biomass was made by bivalve molluscs. Calculations of the Shannon – Weaver index demonstrate a low species diversity of communities for all water bodies. The highest indices of species diversity were noted in Lake Edilsor - 1.64 bit / specimen, the lowest - in lakes Sulukol and Shalkar - 0.6 bit / specimen. and 0.7 bit / copy. respectively. According to the calculations of the saprobity index, lakes Glubinnoye, Prorva and Balykty Sarkyl belong to the ß-mesosaprobic zone, Lake Edilsor (S = 2.72) to the ɑ-mesosaprobic zone, and the indicators of Lake Sulukol (S = 3.8) correspond to the polysaprobic zone. The values of the saprobity indices of the studied lakes lie within the beta-mesosaprobic – polysaprobic zones. By water quality the studied lakes are assessed as moderately polluted and polluted. According to the classification of S.P. Kitaev (2007) the investigated water bodies are assessed as water bodies of medium feeding. The conducted studies have significantly expanded the taxonomic lists of benthic organisms in this region


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
ZAHLUL IKHSAN ◽  
HIDRAYANI ◽  
YAHERWANDI ◽  
HASMIANDY HAMID

Abstract. Ikhsan Z, Hidrayani, Yaherwandi, Hamid H. 2020. The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia. Biodiversitas 21: 1020-1026. Hymenoptera is one of the four largest insect orders and it plays a vital role in human life as pollinators, parasitoids, and predators. Hymenoptera parasitoids are particularly important as agents of biological control of pest. The objective of this research was to study the diversity and abundance of Hymenoptera on tidal swamp rice field in Indragiri Hilir District, Riau Province, Indonesia. Samplings were conducted in 3 sub-districts of rice production centers, namely Batang Tuaka, Keritang and Reteh, using four trapping techniques (i.e. insect net, malaise trap, pitfall trap, and yellow pan trap). Shannon diversity index (H '), Krebs evenness index (E), and Jaccard similarity index (Is) were calculated. We found 4,701 individuals consisting of 39 families and 319 species of Hymenoptera at the three studied areas. Tidal swamp rice in Indragiri Hilir District had a high species diversity of Hymenoptera parasitoids and Hymenoptera predators, but a moderate species diversity of Hymenoptera pollinators. Species diversity and evenness of Hymenoptera parasitoids and predators were higher in Keritang than in Batang Tuaka and Reteh. The families of Formicidae, Braconidae, Ichneumonidae, and Scelionidae had the highest number of species, while Formicidae, Scelionidae, Diapriidae, and Braconidae had the highest number of individuals. Based on these findings, the abundance and diversity of Hymenoptera insects in Indragiri Hilir District have the potentials to be developed as biological agents to control pests on tidal swamp rice in this area.


Paleobiology ◽  
1993 ◽  
Vol 19 (3) ◽  
pp. 322-334 ◽  
Author(s):  
Melissa Clark Rhodes ◽  
R. J. Thompson

This paper presents scaling equations relating suspension-feeding rates to body size for articulate brachiopods and bivalve molluscs, two classes which represent a significant component of the fossil record of marine benthic communities. Clearance (feeding) rates of five species of living articulate brachiopods and three species of epifaunal suspension-feeding bivalve molluscs collected from mid-latitude fjords of Newfoundland and New Zealand were measured in similar experimental conditions. In comparisons within and between the two classes, we found that both plectolophous and spirolophous brachiopods had significantly lower feeding rates than mytilids, which are filibranchs, but that a sympatric primitive eulamellibranch veneroid bivalve had rates comparable to the brachiopods. Articulate brachiopods do not appear to feed effectively at the high algal concentrations which bivalves can exploit. The data on comparative suspension-feeding rates support the hypothesis that past changes in diversity and distribution of bivalves and brachiopods may be related to an overall increase in energy flux and escalation of metabolic rates during the Phanerozoic.


Author(s):  
M. Rajkumar ◽  
Jun Sun ◽  
I. R. Jenkinson ◽  
M.M. Rahman

A twelve-month investigation was undertaken on how copepod community structure varied in relation to environmental factors in the Coleroon estuary, south-east India. Sampling was monthly, from Station 1 in the sea to Station 4 in the Vettar backwaters. Canonical correspondence analysis (CCA) was applied to elucidate the environmental factors affecting the copepod community. A total of 104 copepod species in 38 genera and 26 families were recorded, with the Calanoids, Acartia erythraea and Oithona brevicornis being the most dominant. At all four stations, both these species loaded near the intercept of CCA axes 1 and 2, perhaps reflecting that they were autochthonous. Most species occurred in distinct seasonal patterns. Abundances ranged from 13 × 103 to 215 × 103 (ind. m−3). Coleroon waters showed high diversity (bits/ind.), from 5.29 at Station 3 to 4.97 at Station 4. Abundance correlated positively with temperature and salinity and negatively with rainfall, dissolved oxygen concentration (DO) and pH. Species diversity correlated strongly with abundance (P < 0.01). Abundance and diversity were highest during the summer, and both correlated positively with salinity. Temperatures (air and water), salinity, pH and DO varied in the ranges 26–36°C, 25–34.2°C, 9–38, 7.0–8.7 and 3.0–6.8 ml l-1, respectively. Nitrate, nitrite, phosphate and silicate (µM) varied in the ranges: 4.7–64.5, 0.4–14.1, 0.2–12.9 and 9.3–148, respectively.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yeneayehu Fenetahun ◽  
You Yuan ◽  
Xu Xinwen ◽  
Wang Yongdong

A grazing enclosure (GE) is one of the most effective techniques for restoring degraded rangelands by modifying the composition, abundance, and diversity of species. However, the effect of GEs on different grazing intensities and durations compared to open-grazing (OG) rangelands is not well known. We aimed to assess the effect of GE on the characteristics of plant species. We established five plots in a short-term enclosure, a long-term enclosure, and an OG treatment to examine the effect of GE on vegetation species’ height, abundance, diversity, phenology, biomass, heterogeneity, and the carrying capacity (CC) of rangeland under grazed and enclosed conditions. We found that GE significantly (P &lt; 0.05) increased vegetation height, abundance, biomass, CC, phenological period, and species diversity. However, the increase in height, diversity, and phenological periods were not consistent with enclosure duration, and higher increments were recorded at the short-term enclosure site. The highest Shannon index value recorded at StGE (2.45) was 28.6 and 12.2% greater than the LtGE (1.75) and OG (2.15) sites, respectively. The advanced phenological periods were higher at the StGE site and showed 22.6 and 60.3% higher values than the LtGE and OG sites, respectively. The highest carrying capacities of 23.4 and 114.3% for livestock were observed at the LtGE compared to the StGE and OG grazing sites. In addition, the heterogeneity of the plants’ community was significantly higher in the long-term GE, due to the decrease in species’ diversity. In conclusion, this paper further contributes to the development of the theoretical basis on the effects of GEs and recommends strategies like rotational grazing and reseeding to be used in tandem with a GE for sustainable management of rangelands.


2018 ◽  
Author(s):  
Luis Miguel Pardo ◽  
Ignacio Garrido ◽  
Paulina Bruning ◽  
Charlotte Carrier ◽  
Rossana Reveco ◽  
...  

Western Antarctic shows one of the fastest responses to climate change on Earth. Glacier meltdown and freshening are perhaps the most conspicuous evidence of anthropogenic impacts, that together with ice scouring can strongly modify benthic communities. The spatial extension of these impacts has been rarely explored in rocky subtidal environments. This study describes changes in benthic communities across glacier and bathymetric gradient in Fildes Bay, Antarctica. Suction samples were taken from four sites at increasing distance from the Collin glacier (0 - 2.5 – 5 - 7 km) and three depths (5 – 10 - 15 m). Macrofaunal diversity increased with depth across all distances from the glacier; these changes were associated with the increase in diversity of amphipods and echinoderms. The lowest and highest species diversity occurred at zero and two km from the glacier, indicating a strong, but localized, glacier effect. Variation in salinity tolerance and the abundance of key habitat forming algae could explain the spatial variation in these communities. This result remarks the importance of facilitation as a structuring force in Antarctic benthic communities. We suggest that the fate of communities in future climate-change scenarios will depend on how habitat-forming species respond to these environmental changes.


2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Mohammad Belal Hossain ◽  
MD. ABU NOMAN ◽  
JAHANARA AKHTER LIPI ◽  
ABU HENA MUSTAFA KAMAL ◽  
MOHD HANAFI IDRIS

Abstract. Lipi JA, Noman MDA, Hossain MB, Abu Hena MK, Idris MH. 2020. Effects of ship-breaking activities on the abundance and diversity of macrobenthos in Sitakundu Coast, Bangladesh. Biodiversitas 21: 5085-5093. To articulate the ecological processes or anthropogenic impacts, it is necessary to explore various distributional patterns of benthic communities. The study was conducted to investigate the variability of macrobenthos between a ship braking and non-ship-breaking area along the Sitakunda coast, Chittagong, Bangladesh. This is the first comprehensive study that addresses the effects of ship-breaking activities on the variability of benthic communities in the study area. Macrobenthos were sampled from two different regions namely Bhatiary (ship-breaking area) and Banshbaria (non-ship-breaking area/reference area) in two different time periods (April and July) for comparative analyses. During the study period, Polychaeta was the most dominant group comprising 60% of the total macrobenthos all over the study area. Macrobenthos abundance and diversity demonstrated strong spatial variability. The mean abundance varied from 3799.75±3452.28 ind./m2 to 4107.25±2743.6 ind./m2 from the ship-breaking to non-ship-breaking area. Similar to macrobenthos abundance, the diversity index (H′) (varied between 2.45 and 1.85), species richness (D) (varied between 1.99 and 1.04), and the number of taxa (varied between 17.25 and 9.25) were higher in the non-ship-breaking area compared to the ship-breaking area. Multivariate analyses, nMDS, and CCA plot showed a distinct grouping for different location. Besides, the diversity indices of the Polychaeta community, and the presence or absence of several pollution indicator taxa revealed that Bhatiary (the ship-breaking area) was confronting deleterious effects of ship-breaking activities.


2011 ◽  
Vol 7 (2) ◽  
pp. 60 ◽  
Author(s):  
Unstain NWJ Rembet ◽  
Mennofatria Boer ◽  
Dietriech G Bengen ◽  
Achmad Fahrudin

ABSTRACTCommunity structure of target fishes was analyzed to understand their response to different conditions of coral reefs in several places of Hugow and Putus-Putus islands. This study focused on species abundance and diversity including Shannon-Wiener’s species diversity (H’), species richness (SR), species evenness (J’) and dominance (d) indices, respectively. A multivariate analysis was used for the classification or correspondence factorial analyses. The result recorded 4,501 individuals belonging to 52 species of target fishes. Both cluster and correspondence analyses clearly recognized 3 groups of target fish with 2 major controlling factors for the development of these 3 ecological groups, i.e. coral reef conditions and geographic position to the hydrodynamic condition.ABSTRAKStruktur komunitas ikan target dianalisis untuk melihat respon ikan target terhadap perbedaan kondisi terumbu karang di beberapa lokasi Pulau Hogow dan Putus-Putus. Penelitian ini dilakukan pada bulan Oktober 2010 dengan pengambilan data di 6 stasiun. Dalam penelitian ini telah dikaji variabel komunitas seperti kelimpahan dan keanekaragaman spesies termasuk indeks keanekaragaman spesies Shannon-Wiener (H’), indeks kekayaan spesies (SR), indeks kemerataan spesies (J’) dan indeks dominasi (d). Untuk melihat assemblage ikan target dilakukan analisis multivariat baik analisis klasifikasi maupun analisis faktorial koresponden. Dalam penelitian ini diperoleh 4501 indidu yang termasuk dalam 52 spesies ikan target. Analisis multivariat baik analisis cluster maupun analisis koresponden telah memisahkan dengan jelas 3 grup ikan target, dimana terdapat dua faktor utama pengendali pembentukan 3 grup ekologis ini yakni faktor kondisi terumbu karang dan faktor posisi lokasi terhadap kondisi hidrodinamika perairan.


2013 ◽  
Vol 14 (3) ◽  
pp. 64 ◽  
Author(s):  
A. SANTELLI ◽  
E. PUNZO ◽  
G. SCARCELLA ◽  
P. STRAFELLA ◽  
A. SPAGNOLO ◽  
...  

The aim of this study is to increase the knowledge on the distribution of decapod crustaceans associated with an artificial reef positioned on sandy-mud bottoms in the central Adriatic Sea. The reef is constituted of concrete modules assembled in pyramids and concrete poles. Hard and soft bottom samples were collected from 2001, just after reef construction, to 2005 (4 surveys per year). Regarding the soft seabed, three sites close to a pyramid, three inside the reef area at a distance of 10-15 m from the structures, and three 200 m outside the reef (control sites) were randomly sampled during each survey. At the same time, three pyramids (vertical and horizontal walls) and three poles were also investigated. After taxonomical analysis, decapod crustaceans were analysed using abundance and species richness. Sites and years were compared using a balanced, fixed effect, 2-way ANOVA and PERMANOVA. In addition, SIMPER analysis was performed to identify those species typifying each community inhabiting both the soft bottom and the artificial substrates. The results showed that the artificial reef induced an increase in both abundance and diversity of the decapods of the natural habitat. In fact, man-made substrates may offer new available space for biological colonization and allow the settlement of new species usually living on hard bottoms, thus increasing the complexity of the original benthic communities.


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