Portal de Periódicos da CAPES

Response of the Diatom Flora of the Hel Peninsula Vicinity, Puck Bay, Baltic Sea, to Anthropopressure

2019; IOP Publishing; Volume: 362; Issue: 1 Linguagem: Inglês

10.1088/1755-1315/362/1/012050

1755-1307

Dominika Hetko, Jarosław Pędziński, Małgorzata Witak,

Marine Biology and Ecology Research

Abstract The subject of this study was the diatom taphocoenoses preserved in the surface sediments of the northern part of Puck Bay, southern Baltic Sea. Three subbotom sedimentary cores ZP1/0518, ZP2/0518 and ZP3/0414 collected in the vicinity of the Hel Peninsula from a water depth of 65 m, 47 m and 50.2 m, respectively were analyzed with respect to diatom flora. Over 500 valves of diatoms were counted in each sample in order to estimate the percentage abundance of particular taxa. Habitat, salinity, trophy and saproby requirements of all identified species were established according to literature. The percentage content of distinguished ecological groups was counted in each core. Diatomological analysis indicates that the diatom flora observed in muddy and silty sediments of the study area was generally abundant, taxonomically diverse and well preserved. However, some valves were mechanically broken or/and chemically destroyed. In all cores anthropogenic assemblage with small sized planktic diatoms tolerating higher nutrient and pollution concentration as well as lower transparency of water column predominated. The most important components were euhalobous species Thalassiosira levanderi and mesohalobous one Cyclotella choctawhatcheeana. Both species achieved the highest frequency (up to ca. 80% and 38%, respectively) in core ZP1/0518. Other eutraphentic, α/β mesosaprobous taxa belonged to oligohalobous halophilous (Actinocyclus normanii f. subsalsa, Cyclotella atomus, C. meneghiniana ) and oligohalobous indifferent ( A. normanii f. normanii, Cyclostephanos dubius, Aulacoseira spp.) were observed rarely. Benthos was also dominated by diatoms preferring the high content of nutrients and organic matter. This group was represented by marine/brackish-water taxa (i.e. Catenula adhaerens, Cocconeis hauniensis, C. scutellum, Diploneis didyma, D. smithii, D. stroemii, Opephora krumbeinii ) and freshwater ones (i.e. Amphora copulata, A. pediculus, Cocconeis neodiminuta, C. neothumensis ). Our results clearly indicate the apparent human impact on the structure of the diatom flora in the northern part of the Puck Bay. At least two sources of anthropopressure can be determined in the vicinity of Hel Peninsula i.e. (1) at a local scale harbor in Hel city and municipal sewage linked to development of tourism, and (2) at a regional scale the Vistula River waters, which is the major source of pollution in the Gulf of Gdańsk.