Observations of Ebria tripartita (Schumann) Lemmermann in Baltic sediments
Tóm tắt
Sediment finds of Ebria tripartita (Schumann) Lemmermann in the Baltic Sea are reported and light and electron micrographs of the remains of the taxon are presented. Stratigraphic ebriid analysis performed on two sediment cores (one from the deep Gotland Basin and the other from the shallow Töölö bay, central Helsinki) provided clear indications of frequency changes of E. tripartita. These changes are apparently related to the variations in trophic status and salinity, yet competition and degree of preservation may also have contributed to the distributions. Due to identification problems, the species may actually be more common in the sediment material of the Baltic Sea than has hitherto been recognized. E. tripartita may have a significant potential as an indicator species in paleolimnological research as more information is gathered about its present-day ecological requirements.
Tài liệu tham khảo
Andr´en, E., 1995. Recording environmental changes in the Southern Baltic Sea-current results from a diatom study within Project ODER. In D. Marino & M. Montesor (eds), Proceedings of the 13th International Diatom Symposium, Maratea, Italy, 1st7th September 1994: 43–455.
Baltic Marine Environment Protection Commission, Helsinki Commission, 1990. Second Periodic Assessment of the State of the Marine Environment of the Baltic Sea, 1984–1988; Background Document. Baltic Sea Environment Proceedings 35 B: 432 pp.
Brander, G., 1937. Zur Deutung der intramor¨anen Tonablagerungen an der Mga, unweit von Leningrad. Bull. Comm. G´eol. Fin. 119: 93–113.
Edler, L., G. H¨allfors & f. Niemi, 1984. A preliminary checklist of the phytoplankton of the Baltic Sea. Acta Bot. Fenn. 128: 26 pp.
Elmgren, R., 1989. Man's impact on the ecosystem of the Baltic Sea: Energy flows today and at the turn of the century. Ambio 6: 326–332.
Eriksson, B., T. Gr¨onlund & R. Kujansuu, 1980. Interglasiaalikerrostuma Evij¨arvel¨a Pohjanmaalla (English summary: An interglacial deposit at Evij¨arvi in the Pohjanmaa region). Geologi 32: 65–71.
Flower, R., 1993. Diatom preservation: experiments and observations on dissolution and breakage in modern and fossil material. Hydrobiologia 269/270: 473–484.
Gr¨onlund, T., 1991. The diatom stratigraphy of the Eemian Baltic Sea on the basis of sediment discoveries in Ostrobothnia, Finland. Geol. Surv. Fin., Report 102: 26 pp.
Gr¨onlund, T., 1993. Diatoms in surface sediments of the Gotland Basin in the Baltic Sea. Hydrobiologia 269/270: 235–242.
Korhola, A. & T. Blom, 1996. Marked early 20th century pollution and the subsequent recovery of T¨o¨ol¨o Bay, cental Helsinki, as indicated by subfossil diatom assemblage changes. Hydrobiologia 341: 169–179.
Lewin, J., 1961. The dissolution of silica from diatom walls. Geochim. Cosmochim. Acta 21: 182–198.
Lipps, J., 1979. Ebridians. In R.W. Fairbridge & D. Jablonski (eds), Encyclopedia of earth sciences. Vol 7. Dowden, Hutchinson & Ross, Stroudsburg: 276.
Loeblich, A. R. III, 1982. Dinophyceae. In S. P. Parker (ed.), Synopsis and classification of living organisms, Vol 1. McGrawHill, New York: 101–115.
Meril¨ainen, J., 1973. The dissolution of diatom frustules and its palaeoecological interpretation. Rapport fr°andiatomeesymposium in Lund, Maj 1973. University of Lund, Department of Quaternary Geology. Report 3: 91–95.
Miller, U. & J. Risberg, 1990. Environmental changes, mainly eutrophication, as recorded by fossil siliceous microalgae in two cores from the uppermost sedimens of the northwestern Baltic. Nova Hedwigia 100: 237–352.
Niemel¨a, J. & R. Tynni, 1979. Interglacial and interstadial sediments in the Pohjanmaa region, Finland. Geol. Surv. Fin. Bull. 302: 48 pp.
Niemi,f., 1972. Observations on phytoplankton in eutrophied and noneutrophied archipelago waters of the southern coast of Finland. Mem. Soc. Fauna Flora. Fenn. 48: 63–74.
Preisig, H. R., 1994. Siliceous structures and silification if flagellated protists. Protoplasma 181: 29–42.
Rosenberg, R. (ed.), 1984. Eutrophication in marine waters surrounding Sweden, A review. Statens naturv°ardsverk, Solna. PM 1808: 140 pp.
Salonen, V.P., T. Gr¨onlund, M. Sturm & I. Vuorinen, 1992. Crustfreeze sampler cores from two Baltic stations. In W. Lemke, D. Lange & R. Endler (eds), Proceedings of the Second Marine Geological Conference-The Baltic held in Rostock fromOctober 21 to October 26, 1991. Meereswiss., Ber. 4: 129–131.
Saxon, M. & U.Miller, 1993. Diatom assemblages in superficial sediments from the Gulf of Riga, eastern Baltic Sea. Hydrobiologia 269/270: 243–249.
Tappan, H., 1980. The paleobiology of plant protists. Freeman, San Francisco.
Taylor, F. J. R., 1990. Ebridians. In L. Margulis, J. O. Corliss, M. Melkonian & D. J. Chapman (eds), Handbook of Protoctista. Jones and Bartlett, Boston: 720–721.
Tikkanen, M., A. Korhola, H. Sepp¨a & J. Virkanen, 1997. A longterm record of human impacts on an urban ecosystem in the sediment of T¨o¨ol¨onlahti Bay in Helsinki, Finland. Envir. Conservat. 24: 326–337.
Tikkanen, T., 1986. Kasviplanktonopas (Guide to Phytoplankton). Suomen Luonnonsuojelun Tuki Oy, Forssa.
Vuorela, I., T. Gr¨onlund & T. Lempi¨ainen, 1996. A reconstruction of the environment of Rettig in the city of Turku, Finland, on the basis of diatom, pollen, plant macrofossil and phytolith analyses. Bull. Geol. Soc. Fin. 68
Witkowski, A., 1994. Recent and fossil diatom flora of the Gulf of Gdansk, Southern Baltic Sea. Origin, composition and changes of diatom assemblages during the Holocene. Bibliotheca Diatomol. 28: 1–230.