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Both of colonies types consisted of several species of diatoms and had an almost identical species
composition. Basis of macrocolonies was transparent polymer matrix filled with jelly dichotomously
branching strands of fresh-brackish Gomphonema olivaceum (Lyngb.) Kütz. In addition, the most
numerous G. olivaceum in the composition of the colonies included other пеннатные diatoms -
Surirella ovata Kütz., Cymbella affinis Kütz., Cymbella cf. lanceolata var. notata Wist. et Poretzky,
Fragilaria ulna (Nitzsch) Lange-Bertalot, Fragilaria cf. pinnata Ehr., Fragilaria spp., Diatoma tenuis
Ag., Achnanthes spp. The cells of the littoral centric diatom Melosira varians Ag. were also present in
the floating colonies. Most of these algae refers to fresh-brackish or indifferent species.
Diatom colonies provide specific biotope for a range of invertebrates and
protozoa: inside them were found oligochaetes, nematodes, rotifers, ciliates
(including sit-ins) and other protozoa, and ostracods (the latter were present
only in floating colonies).
Colony of diatoms - mucous formation olive color,
spherical or back-ovoid form, firmly attached to the
gravel by gradually tapering part – “leg”. Colony with
a diameter of 0,5-3,0 cm and a height of up to 3,0 cm
had a dense consistence, transparent slimy centre,
and a few more dark, transparent outer layer.
“Leg” of colony and sedentary ciliate
Nematodes in diatom colonies
Information about similar colonial diatom formations in the literature virtually none. Indicated the
formation of a mixed type macrocolonies diatoms ( the dominant species of the genus Fragilaria)
below the bottom surface of the ice in the Arctic waters [ Stunzhas Sapozhnikov , 2000].
Cells composition of poly-species colonies
Introduction
The diatom colonies densely cover the pebble of littoral
zone in average 3m wide and about 36km in length
This phenomenon was first discovered in
2011 by photographic materials shoreline
monitoring (provided by EE Esyukova, AB
IORAS ). From March 2012 to currently
under field and laboratory studies of this
phenomenon are perform.
Elena Ezhova, Evgeniia Lange, Mariia Smirnova
igelinez@gmail.com, evlange@gmail.com, smirnova-mm@mail.ru
Atlantic Branch of P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Kaliningrad, Russia
Baltic sea Vistula
Lagoon
In April, the first detected colonies
represented by single free-floating
formations with a diameter of 0,5-2,5
cm. They have a relatively dense
centre, loose rough edges and not
maintain a permanent form.
Single free-floating colony
Results
Diatom colonies appear in late March - early April, when the
water temperature is 6 ºС and exists about 1-1.5 months.
Maximum development is achieved when the water
temperature reach 16-17 ºС and lasts about 1 week, after
that the water temperature continues to rise, and the
colonies disappear.
Diatom species belonging to the macrocolonies, throughout
the growing period are present in the periphyton and are
found on the surface of algal fouling (Cladophora, Ulva), but
in single quantities. In the early spring period diatoms
acquire the last - year not dead Cladophora remains on the
pebbles, as well as any available objects (small floating
debris in the water: branches, thin roots, etc., leaf rank and
mussels). With a sharp jump in the development of diatoms,
they grow on the surface of Cladophora and mix with each
other.When the new Cladophora appear on the stones it’s
also acquires by diatoms, but to a lesser extent in
comparison with the old, in that some are similar to the bulb,
and somewhere there is a line of green with brown beads.
The Vistula Lagoon - brackish water (1 to 8 ‰) eutrophic shallow lagoon
(838 km2 area, the volume of 2.3 km3, the average depth of 3.1 m),
located in the South-Eastern Baltic. The hydrological regime of the bay is
defined by intense water exchange with the sea, shallow water, runoff,
wind currents and strong mixing. Features of the hydrological regime of the
Gulf associated, primarily, with the salinity regime, limiting the one hand the
development of sea, and on the other - freshwater forms are reflected in
the structure of its biota. The data on the development of diatoms
macrocolonies in periphyton of pebble- sand littoral of the desalinated
northeastern part of the Vistula Lagoon are presented.
MACROCOLONIES FORMED BY EPIBIOTIC DIATOMS IN LITTORAL
OF THE VISTULA LAGOON