Náttúrufræðingurinn - 1958, Blaðsíða 43

ÐÝRASVIFIÐ í SJÓNUM
185
SUMMARY
Zonplankton in Icelandic Waters
by I/igvar Hallgrimsson.
University Research Institute, Department of Fisheries, Reykjavik.
This article gives a rough outline of the main features of the zooplankton
in Icelandic waters. The drift of the zooplankton from Icelandic waters west-
wards to Greenland is discussed, ancl Ranish investigations on the drift of
the cod larvae from Icelandic waters are mentioned. A short account on the
lifc history of Calanus finmarchicus is given and it is pointed out that thcre
exists at least two or even three generations of Cal. finmarchicus per year in
Icelandic waters, the life cycle of each generation lasting about two mounths.
It is emphasized that Icelandic investigations have clearly shown that spaw-
ning of Cal. finmarchicus takes place both in coastal and oceanic waters off
the south, west and north coasts. Besides the increase of the stock because of
spawning, great quantities of oceanic zooplankton — Calanus and other species
— are brought into Icelandic waters frorn tlie Irminger Sea.
This has often been observed and is clearly shown on Fig. 4. It is not yet
known how much this inflow of zooplankton from the Irminger Sea affects
the stock of the zooplankton off the nortli coast of Iceland in sumrner. But
judging from hydrographical data one can presume, that only a part of this
Irminger Sea plankton does reach the north coast, thc other part being
brought west towards Greenland.
For the purpose of clarifying this problem, a continuous plankton recording
program was started in February this year. A Continuous Plankton Recorder
is towed by an Icelandic cargo liner from Reykjanes through the Irminger
Sea. This program would not have been realized except for the kind cooper-
ation of the Oceanographic Laboratory in Edinburgh where the material
collected is worked up.
Ingimar Óskarsson:
Dúdúfuglinn
í Indlandshafi, um 20 gráður sunnan við miðbaug og 800 km
austan Madagaskar, liggur lítill og sérkennilegur eyjaklasi, hinar
svonefndu Maskarenhas-eyjar. Voru þær heitnar í höfuðið á manni
þeim, er fann þær fyrst, en það var Portúgalinn Maskarenhas.
Þetta gerðist í byrjun 16. aldar. Portúgalar námu þó ekki land á