Dynamics of mussel and mytilaster settlements on the hydraulic structures of recreational waters
In the coastal waters, hydraulic structures form additional areas for the development of the fouling community. In recent years, Mytilidae fouling of the solid substrates in the Crimean coastal waters undergoes a transformation. These phenomena cause a change in the natural biofilters aggregated on the surface of hydraulic structures and, as a result, a change in the self-cleaning capacity of the water areas. This work is aimed at the assessment of the inter-annual dynamics of the settlements of Mytilus galloprovincialis Lam. and Mytilaster lineatus Gmel. and the assessment of the capacity of the biofilter formed by Mytilidae molluscs on hydraulic structures in recreational waters during the beach season. On average, for the period from 2015 to 2018, the mussel abundance at the investigated structures decreased from 1,125±523 to 462±221 ind./m2. The biomass of this species decreased from 893±397 to 462± 221 g/m2. The length frequency in the mussel settlements has not changed. For certain areas, the characteristics of the length composition identified earlier have been preserved. A significant decrease in the abundance and biomass of mytilasters was recorded for 2015–2018. The abundance of these molluscs decreased from 33,443±11,084 to 1,094±228 ind./m2. The biomass of the investigated species decreased from 2,492±1,165 to 1,099±332 g/m2. The length composition of the mytilaster for the period of this investigation remained relatively unchanged. As a result of the decline in the settlement density and biomass of Mytilidae molluscs, the volumes of the water filtered by the molluscs were significantly lower in 2018 than in 2015. For mussels, the average value was 4,640±4,123 L/day·m2 in 2018, which is almost 4 times lower than the said value in 2015. In 2018, this value for mytilaters was, on average, 10,256±3,875 L/day·m2. Thus, the decrease in the total performance of the natural biofilter on the hydraulic structures in the recreational waters of Sevastopol and, as a result, the reduction in the self-cleaning capacity of these waters have been recorded.
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| Format: | Journal Contribution biblioteca |
| Language: | Russian |
| Published: |
2021
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| Subjects: | Mytilus galloprovincialis, Mytilaster lineatus, Biomass, Population density, Hydrotechnical constructions, Biofilters, Recreational areas, Биомасса, Плотность популяции, Гидротехнические сооружения, Биофильтры, Рекреационные зоны, Самоочищение, ASFA_2015::M::Marine molluscs, ASFA_2015::F::Fouling organisms, |
| Online Access: | http://hdl.handle.net/1834/41736 |
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