Náttúrufræðingurinn - 1984, Síða 69

Smáverulíf Skjálftavatna og þörunga-
gróður minnir nú þegar nokkuð á Vík-
ingavatn og Mývatn, t. d. hefur svif-
þörungurinn Paulschulzia pseudovol-
vox ekki fundist í öðrum vötnum hér á
landi, svo mér sé kunnugt.
ÞAKKIR
Sigurvin Elíassyni sóknarpresti á
Skinnastað og heimafólki í Framnesi,
Kelduhverfi, þakka ég fyrir ýmsar
upplýsingar varðandi fugl og fisk í
vötnunum.
HEIMILDIR
Árni Óla. 1941. Kelduhverfi og Tjörnes.
— Árb. Ferðafél. ísl. 1941.
Björn Guðmundsson. 1959. Kelduhverfi.
Lýsing Þingeyjarsýslu II. - Ritsafn
Þingeyinga II. Reykjavík.
Eysteinn Tryggvason. 1977. Landslags-
breytingar samfara jarðskjálftunum
1975—1976. — Náttúrufræðingurinn
46,3: 124-128.
Oddur Sigurðsson. 1976. Náttúruhamfarir
í Þingeyjarþingi veturinn 1975—1976.
- Týli 6,1: 3-20.
SUMMARY
Development of Life
in Skjálftavötn,
a New Lake in NE-Iceland
by
Helgi Hallgrímsson,
Museum of Natural History,
Akureyri,
Iceland
In the winter 1975 — 1976 a shallow lake,
about 4 km2, was formed by volcanic/
earthquake activity (subsidence) near
Keldunes in the parish Kelduhverfi,
NE-Iceland. The subsided area was a for-
mer bed of the glacial river Jökulsá á Fjöl-
lum, mainly sand and gravel with sparse
vegetation. In the following three sum-
mers (1976—1978) samples of plankton
were collected from the lake, and some
other observations made on the succession
of life in the water. Already in spring (30th
June) 1976 a rich and varied community
had developed in the lake, with masses of
filiform algae (Zygnema, Oedogonium),
rotatorians etc, and in the following sum-
mer some cladocerans and insect larvae
were found in quantity. In the summer
1978 both trout (Salmo trutta) and charr
(Salvelinus alpinus) were caught in the
lake, and a variety of water birds had
become established. In June 1976 about 30
species or groups were identified from the
samples, and in September 1978 about 45
species. Glacial water from the river has
on 2—3 occasions flowed into the lake in
late summer.
159