Stonewort checklist Baltic sea

c/o Klaprooslaan 67a, 9713 SK, Groningen; the Netherlands

Characeae are well developed green algae which are easily recognised. Often Characeae can be found in clear and oligo- or mesotrophic waters which contain Chara dominated plant communities or Potamotea-communities. Characeae communities are present all over the world and are sensitive for water pollution. So Characeae can be used for monitoring water quality. Stonewort are highly developed algae which are commonly known as indicators of clear and nutrient-poor water. Most species are pioneers and occur only in a specific stage of development from a newly formed vegetationless water until a well-balanced and stable ecosystem.

Chara species look like a Hippuris vulgaris, but where as Hippuris vulgaris is built with small cells that can hardly been seen by a loupe, the internodiums of Charas are just one large cell. These large cells are also the reason why Characea are sometimes preferred as a research object : The cells can easily be studied. Fourteen different Chara species -included are some variaties- were collected. Here are some short descriptions :

C. aculeolata limerich waters near european coast and in salt lakes

C. aculeolata var. pedunculata lime waters and more in brackish waters

C. aspera known from shallow waters with sandy soil, common in dune lakes

C. baltica used to be common in the East sea, clear brackish water

C. canescens rare, known from coasts from the East sea with Ruppia

C. contraria pioneer in coastal sandy dune lakes, if present than often abundant

C. globularis glob/barb/virgata saline poor waters, Estonia : fresh running waters

C. intermedia fresh brackis water with lots of lime in it (doubtful for Estonia)

C. major dune pools or lakes with calcerous rich water with sandy soil

C. tomentosa common in sourthern East sea and in lakes with very calcerous water

Nitella flexilis calcerous (running) poor water, seldom in lakes

Nitella species are more comparable with small leaved Potamogeton species. In the neighbourhood of Odalasi Alikad (Saarema) we found only one locality with Nitella, named Nitella flexilis. Is this lime rich regio special : N.flexilis is a acidlike species. This species was already known for Estonia.

Only three localiteit are not close to the coast and probably influenced by saline: Odalatsi Alikad (Saarema), the road Tallin-Tartu and the lake Vaaba Jarv near the camping site. On those last places C.globularis was present.

Some characea species were found in typical habitats.

Chara contraria was found in shallow temporary waters. This in comparisio with its pioneer habitat.

Chara aspera was always found in standing water near the sea (dune lake) or in a bay. In Holland this species often can be found in dune lakes. shallow with clear, alkalic waters with no phosphate on sandy soil. In Odalatsi a dominant vegetation of Chara major was present. This occurs on places with calcerous water. C.canescens and C.baltica were only found in the sea itself. It indicates shallow brackish waters with few organic components in saline waters. Saarema contained the most localities (46 localities, 14 species) followed by Virstu (10 localities, 4), Muhu (4 localities ,5 species).

The charophytes were classified to their milieu. In total 11 milieus were defined. As espected most localities were from dune lakes and from creeks. There was not much differences in species found between those habitats. Exceptthe sea : Typical sea species were present : C.baltica, C.tomentosa, C. canescens were only found in or near the sea. Nitella flexilis and C. globularis often in the interior in fresh water regions without influence from the sea. C.aspera seemed to be present in almost any dune lake while C. contraria preferred shallow temporary waters.

Table.. shows that Saarema contained the most different milieus. On this island in nearly every habitat characea were present. According to the literature C.globularis and N.flexilis are species with a large ecological amplitude. This table shows that C. aspera present was in most milieus. As table shows C.aspera, C.globularis and C. contraria were the charophytes which were found most.

In Odalatsi a dominant vegetation of Chara major (Charetum hispidae) was present. This occurs on places with calcerous water. C.canescens and C.baltica were only found in the sea itself. These species are known from the Charetum canescentis. It indicates shallow brackish waters with few organic components in saline waters.

The charophytes were often found in dune lakes (25%) or lakes (13%), brook (16%) or at the sea coast (25%). Most in standing waters only twomajor locations were running (Odalatsi and the creek at Pautsaare laht)

Nearly all samples were added to the collection of the Dutch National ‘Rijksherbarium’ in Leiden. Only the observations of David Templeman were not collected and checked.

1. A. Maemetz, 1965.

‘Angaben uber die Makroflora einiger kleiner Seen Sudost-Estland’

Loodusuurijave Seltsi Aastaraamat 57: 31-50. Estonian with German summary.

2. M. Pork, 1954.

‘Eesti NSV mandvetiktaimed (Charophyta)’, Abiks loodusevaatlejale 16. Tart

Eastern Saaremaa Vilsandi Rahvus park

On 13 july 1999 three groups of our camp went to north east Saaremaa. On the way to Laialepa laht we stopped at an island near the very shallow coast. This small island, hardly visible on this photo, but present a little to the left was called Tarja. This picture is made from the many, many watching towers build in the end seventies (the building years often were 1969 till 1977). Some were even to Estonian habits that dangerous that they removed the first 20 steps so it was not possible to climb the towers any more. Some of our group were dropped at Koruse (also the only place were we saw 'Wilde zwijnen') to watch the hot and dry alvar but most of them went to Kiipsaare nukk. This is a light house that is, just like the tower of Pisa, not stand straight up. In this sea charophytes were found.

In this photo album you can find pictures made during a Dutch summercamp of the senioren of the youth bond JNM and NJN (Jeugdbond voor Natuur en Milieu studie).

Characeae or Muskgrass

At Laialepa laht(Kiipsaare nukk) seven monsters were collected for determination in Holland. Only Chara aspera was present. This is species is also often found in dune waters in Holland. C. aspera is often known from shallow waters with sandy soil, common in dune lakes

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