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EN
Sixty morphospecies of Decapoda (Malacostraca: Crustacea) representing 34 families were recorded in the material collected in 2012 from 265 van Veen grab (0.1 m2) samples, from the nine transects distributed along the coast of Ghana in the 25–1000 m depth range. The examined material was dominated by the Diogenidae, Panopeidae, Leucosiidae, Pilumnidae and Xanthidae families. Species accumulation curves showed undersampling of the studied area and a large number of the morphospecies comprised singletons and doubletons. Panopeus africanus was the most frequent morphospecies in the analysed material (9.1% of all samples). We observed a substantial decrease of diversity (Shannon Index) and abundance along a depth gradient. Species richness also decreased with depth, starting from the highest number of morphospecies ‒ 38 at 25 m depth, then 33 at 50 m, 17 at 100 m, 11 at 250 m, 8 at 500 m and ending with 1 morphospecies at 1000 m bottom depth. Higher diversity was observed on the continental shelf (25–250 m – 57 morphospecies), while on the slope (500–1000 m) only eight morphospecies were recorded. Numerous factors of natural and anthropogenic origin may affect decapod communities on the coast of Ghana. Since our material was collected using a sampler collecting material at a very small scale, the observed patterns might be affected by the sampling method.
EN
The West African continental margin belongs to the least known areas in terms of the ecology of benthic ecosystems. At the same time, this region is influenced by various threats associated with human activities, including industrialisation and oil excavation. Here, we analyse the abundance and distribution patterns of macrozoobenthic communities along the coast of Ghana. The material was collected in 2012 on nine transects at depths ranging from 25 to 1000 m. Over 200 quantitative samples were collected using a 0.1-m2 van Veen grab. Generally, the mean density of macrozoobenthos decreased gradually from the shallow zone (25 m: 231.4 ± 262.2 ind./0.1 m2) down to bathyal depths (1000 m: 55.4 ± 51.4 ind./0.1 m2), but we observed intermediate scale variability in distribution patterns among the transects along the Ghanaian coast. Analysis of environmental factors showed no evidence of substantial pollution, although levels of hydrocarbons, barium and some other toxic metals show some local increases at particular stations, especially on the continental slope. Cluster analysis based on Bray-Curtis similarity and abundance of higher taxonomic groups of macrofauna yielded five groups of stations, while SIMPER analysis demonstrated that polychaetes and amphipods contributed most significantly to within-group similarity. Canonical Correspondence Analysis demonstrated that PAH, THC and toxic metal levels (Ba, Cd, Pb), as well as oxygen concentration, were the most important factors structuring benthic communities.
EN
This study investigates soil heavy metal contamination behind the green belts along National Highway 107 in China. Soil samples were collected from both sides of the highway to determine the concentrations of heavy metals such as copper, cadmium, chromium, lead, and zinc. The distribution patterns, ecological risks, and health hazards associated with these heavy metals were analysed. In order to provide more sample examples and data support for soil heavy metal pollution control. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was employed to detect the concentrations and speciation of these five heavy metals in the soil samples. The Geo-Accumulation Index method, the Nemerow pollution index method, and a health risk assessment model were used to evaluate the ecological and health risks of heavy metal pollution adjacent to the highway. Results indicated that: (1) The concentrations of Cu, Cd, Cr, Pb, and Zn in the soil decreased with the increasing number of protective forest layers, highlighting the significant role of protective belts in impeding the migration of heavy metals from the highway. (2) In terms of pollution assessment, the Geo-accumulation index method revealed prominent Cd contamination, the Geo-accumulation index of Cd peaked at 1.95 indicating a moderate to mild pollution level overall. Conversely, the Nemerow index method suggested a medium to extremely high risk of soil heavy metal Cd contamination. Specifically, the peak value of Cd single-factor pollution index in the study area reached 5.78, and the mean value of its Nemerow index (P) was 4.67. (3) In health risk assessment, it was found that children are more susceptible to heavy metal threats. The non-carcinogenic risk indices of all five heavy metals were less than 1, implying minimal risk. However, the total carcinogenic risk index for Cr ranged between 10–6 and 10–4, posing a certain level of carcinogenic risk to humans.
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