Temperature stratification and photosynthetically active radiation distribution in the Zostera noltii Hornemann canopy under shallow water conditions at different solar elevation angles (the Black sea)

Морские травы экологически важны, но чрезвычайно уязвимы перед антропогенными изменениями в прибрежных зонах, которые влияют на доступность света в этих экосистемах. При разной высоте Солнца над горизонтом в зондирующем режиме проводилось одновременное измерение значений температуры воды и интенсивности фотосинтетически активной радиации (IPAR) по профилю полога Zostera noltii Hornemann (высота полога 32 см.) в мелководной части Казачьей бухты (г. Севастополь, Черное море, 44°57′26″ с.ш., 33°40′33″ в.д.). Для полога Z. noltii характерен одномодальный тип вертикального распределения биомассы с максимумом (65,7 г (сухой массы) / м2) в его нижней части. Рассматривается изменение температурной стратификации и распределения IPAR по профилю растительного полога Z. noltii в течение светового дня. Seagrass is environmentally significant but extremely vulnerable in coastal areas to anthropogenic changes, which affect light availability. Simultaneous measurements of water temperature and photosynthetically active radiation (PAR) intensity in the sounding mode were taken at different solar elevation angles for the Zostera noltii Hornemann canopy (canopy height 32 cm) in shallow waters of the Cossack Bay (Sevastopol, the Black Sea, 44°57′26″ с.ш., 33°40′33″ в.д.). Z. noltii canopy is characterized by a unimodal type of biomass vertical distribution with its maximum (65,7 g (dry matter)/m2) in the lower part. Temperature stratification and IPAR distribution changes within the Z. noltii vegetation canopy profile during daylight hours are considered.

Seagrass, bioindicator, light, water quality, Zostera marina, Zostera noltii, Halodule wrightii, monitoring, Chlorophyll fluorescence, stable isotope, nutrients.

This thesis aims to investigate the effect of environmental drivers on seagrasses by studying shoot-scale and meadow-scale responses, focussing on Zostera marina, Zostera noltii and Halodule wrightii. Seagrasses are plants that have evolved from being terrestrial to living in an entirely marine environment which means they have become highly adapted. The conditions that effect seagrass growth can also be described as drivers as they have the ability to modify seagrass meadows in a variety of ways. These drivers can either be natural environmental factors or anthropogenic processes directly or indirectly affecting the marine environment in which seagrasses are found. These responses environmental conditions allow seagrasses to be used as indicators of the health of our coastal waters with poor water quality causing substantial impacts on seagrasses. Better knowledge of seagrass responses to local environmental conditions will help the identification of stressors which can then be managed. It will also help to comprehend the degree of risk to be expected from the threat of climate change including increased storm events, rises in sea level and sea temperature, and ocean acidification. Mitigating existing or potential impacts that lead to a reduction in water quality will improve the overall health and resilience of the seagrass to future threats from climate change.

Towards new marine-coastal Natura 2000 sites in the central Adriatic Sea.

LIFE17 NAT/IT/000565 CALLIOPE aims to improve the coast-sea regional natural connectivity by improving the Natura 2000 Network. The main objectives are: improving the biodiversity knowledge of marine environments, testing integrated management strategies to increase the conservation of coastal-marine biodiversity and supporting the preparation of a Coastal Action Plan for the Abruzzo Region. We identified and mapped the HD-1110 here dominated by Cymodocea nodosa, the HD-1160 with the presence Zostera noltii and in correspondence of rocky environments the HD-1170.

Macrophytobenthos of Kazach’ya Bay (Black Sea) in autumn 2017

Over the last two decades Kazach’ya Bay area has been subjected to intensive coastal development resulted in deterioration of the environment quality. Considering the fact that the anthropogenic impact has already led to degradation of the key macrophythobenthos communities at many sites of Sevastopol coast, the assessment of the current state of the bottom phytocoenoses in Kazach’ya Bay is of great importance. The aim of the study was to investigate the species composition and quantitative parameters of the macrophytobenthos in Kazach’ya Bay and to analyze long-term changes in its bottom vegetation. Investigation was carried out in the western branch of the bay in September 2017 at depth of 3, 5, 6, 8 and 17 m; 41 macrophyte species were identified: 13 – Chlorophyta, 1 – Charophyta, 10 – Phaeophyceae, 13 – Rhodophyta, and 4 – Angiospermae. Such species as Chaetomorpha gracilis, Cladophora vagabunda, Lamprothamnium papulosum, Myrionema strangulans were recorded for the first time. Zostera noltii + Stuckenia pectinata phytocoenosis with biomass 905 g·m-2 was found at 3 m depth on the soft bottom, at 6 and 8 m it was replaced by monodominant Zostera noltii communities with biomass 691 and 390 g·m-2 respectively. At 5 m depth where alongside with soft sediments hard substrata occur, mosaic of patches dominated by Zostera noltii and Cystoseira crinita with mean biomass 1017 g·m-2 was found. Phyllophora crispa phytocoenosis with the biomass 290 g·m-2 was registered near the mouth of the bay at the depth of 17 m. Between 1999 and 2017 biomass of the seagrass communities decreased 2–3 times, moreover, Zostera marina phytocoenoses were replaced by the Zostera noltii dominated communities. Biomass of the Phyllophora community almost doubled over the same period.