Surtsey - The Volcano Island, Iceland.- Sealife

Our Beautiful World

The volcano Island Surtsey, Iceland :

SEALIFE

The first seals to visit Surtsey came frequently soon after its formation. Not many reports
exists from the first few years, but when divers began studying the sub-zone around Surtsey,
they also could now observe them underwater. So in late summer 1972, while diving to collect subtidal algae etc, a common seal, phoca vitulina L, was observed.

Common Seal, phoca vitulina (not from Surtsey)
Courtesy of: www.wildlife.shetland.co.uk/marine/seals.html

During the period 1980-1980 several seals where counted from aircraft.
1980 on August 11th a number of 20 common seals phoca vitulina, were observed,
and again in 1986 about 30 adults were registered.

Grey seal, here with a puppy.(not from Surtsey)
Recognition: Grey and brown fur, sometimes with pattern of blotches;
no ears visible; long muzzle; nostrils parallel.
Head/body length: average for males 207cm; for females 180cm; flippers about 25cm.
Weight: males 233kg; females 155kg.
© Photo: Gill Sinclair, The Mammal Society (not valid as per Sept. 2010)

Grey seals, halichoreus grypus, were observed breeding in 1982, and in 1986
as many as 34 puppies were seen on land as 16 adults in the sea during one overflight.
Over the years the number has increase, and in an observation on November 21st,
1989 35 pups where basking on land, but not all totally white. 3 weeks later,
on December 13th, 3 white pups and about 70 grown ups were basking on land.

So both common seals and grey seals have already several years ago started breeding
on Surtsey, as well as using it as a basking site. They have probably used the sandy
northernspit, as a basking site much earlier than they started to breed on it. Fishermen
from the isles of Vestmannaeyjar, have noticed seals there regularly, often in great
numbers, during the winter-time for many years.(1989)

Grey seal pups on the northern sandy spit of the island of Surtsay.
The picture is taken by Erlingur Hauksson from an aircraft on October 19th 1986.

Surtsey is in many respecs a good breeding place for seals. The animals there are hardly
ever disturbed. Visitors to the island are very few and come to the island mostly in the summertime. The sandy norther spti is low and beaching is easy for the animals, even in
windy weather.

Close to the island are good fishing grounds for seals. In the summer there is an
abundance of saithe, cod and herring just off the cliffs. All year around flatfishes and sea
scorpions can be found there to eat.

If the seals in Surtsey continue to get the same protection in years to come, as they have
had to daye (and the sea does not wipe away all of the northern tip), then a strong
breeding stock of grey seals will probably evolve as well as also a sizable herd of
common seals.

(This information on the seals on Surtsey are Based upon a report by Erlingur Hauksson,
Iceland Fisheries Laboratories, Reykjavik, in Surtsey Research Progress Report X, 1992.)

Around the Westman Islands, Killer Whales are often seen near Surtsey.
Photo: © Blair P. Mott
Photo courtesy of Ocean Futures Society

In the year 1964, a year after the eruption started, only bacteria and diatoms were detected
on the littoral rocks. The number of species increased rapidly until about 1970, and then
levelled off and has increased slowly since with the number of species fluctuating around
40 to 50 species recorded on each sampling occasion the last ten years. Alltogether up
to the year 1997 the number of different species totalled 76.

laminaria digitata
Photo by © Hans Christian Andersen
www.havbiologi.dk

Most of the species that have been recorded on Surtsey are not permanent residents of
the island, but are opportunists that have been found sporadically over the years.
Some of these species have only been found once after their discovery like e.g.
laminaria digitata an extremely common species in the other islands of the
Vestmannaeyjar archipelago.

One of the species, hincksia recurvata, has not been found elsewhere in Iceland.
(And I haven't found it anywhere on the web either)
Some faithful colonisers that were first found shortly after the eruption have been recorded
on every occasion since, such as .e.g. alaria esculenta that has been common in the sublittoral
zone ever since it was first found in 1966.

Among the faithful colonisers are both annual species that possibly invade the island
every year from a nearby stand, as propbably most of the littoral species do,
or survive through the winter in a recuced form. Other colonisers are perennial such
as laminaria hyperborea that has been found on every occasion since 1968
and plants of up to 9 years have been collected on Surtsey.

Laminaria hyperborea, a typical view of a Laminaria-stand on top of a boulder at the depth of 10 m
at the east coast of Surtsey, in July 1997. The highest plants measure about 1.5 m in stipe length.
© Karl Gunnarsson, courtesy of The Surtsey Research Society

Laminaria hyperboerea had its highest cover at 10 and 20 m where it formed dense stands
on the top of the highest stones, as shown on the picture above. Brown filaments that
consisted of a mixture of filamentous diatoms, hincksia spp. and/or ectocarpus spp. were
found at all depths in all years and generally had high cover.

In the sublittoral zone the most conspicuous herbivores observed were echinus esculentus, strongylocentrodus droebachiensis, lacuna vincta and padina pellucida.
Elsewhere along the basaltic cliffs the algal growth, although less abundant, represents
similar main features as on the east coast. See the picture below:

An underwater photograph showing an area of 60 x 40 cm of the bottom at 15 m at the west coast
of Surtsey in July 1997. Species appearing in the photo are the seaweed species delesseria sanguinea, phycodrys rubens, lomentaria orcadensis and juvenile alaria esculenta. Prominent animal species are sea star, asterias rubens, sponge, grantia compressa, mussel, mytilus edulis and hydroid, tubularia larynx.
© Photo Karl Gunnarsson, courtesy of The Surtsey Research Society

In the year 1997 or just before, another new record, not expected in Surtsey, was omphalophyllum ulvaceum. It was found in the sublittoral zone at the depth of 10m.
This species has not been recorded in sourthern Iceland before but its a common species
in northern Iceland. It has also been found in Greenland and elsewhere in the Arctic.
This species was recently also found on the French side of the English Channel.

The faunal assemblage of alcyonium digitatum at a depth of 30 meters off the island
Hæna. (not Surtsey) A deep water community situated between 20 and 30 m depth off Surtsey
is dominated by faunal assemblage of filter feeders, where the soft coral alcyonium digitatum
and hydroids are dominant.
©courtesy of The Surtsey Research Society

The highest cover of sublittoral species was in the depth interval from 5 to 15 m after
which the cover decreases rapidly with depth and is down to 1.6% at 30 m.
The main factor influencing the depth distribution of the algae is most likely light, which
is very reduced at 30 m depth. Increasing cover of animals coincides with the decrease
in algal cover. Below 25 m the algae have almost disapperaed and the animals
are predominating.

alcyonium digitatum at Surtsey in 1974
© Photo: Halldòr Dagsson. Courtesy of The Surtsey Research Society

Mermaid purses from Surtsey covered with seed.

Seeds came to Surtsey in many ways. Some by the birds, and some as passengers
on the mermaid purses, eggs of the skate-fish, (raja batis). These eggs are found
inside small packets that are drifting around in the sea. During the month of May 1969
several of those capsulated eggs drifted ashore on Surtsey.

Carex, from the Latin, "sedge, reed grass, rush"
lasiocarpa, from the Greek, lasios (lasios), "shaggy, woolly, hairy", and karpos (karpos), "fruit"; hence, "woolly fruited"
Common Name, from the distinctive seedhead, the "woolly fruit"
Other common names include: Woollyfruit Sedge, Slender Sedge, Trådstorr (Nor), Trådstarr (Swe), Tråd-Star (Dan), Jouhisara (Fin), Faden-Segge (Ger), Seisg Choilleanta (Gaelic), Ostrica Plstnatoplodá (Slovak)

The chitinous material of the purses was somewhat shedded into thin bristles which the seeds stuck to. Some of the seed were hairy which even increased the adhesion effect.
Except for one infertile fruit of carex (see yellow frame above), the seed found attached to the mermaid purses were all of grass species, which are common in Iceland.

A total of 131 seeds belonging to about 10 different species were collected.

Skate.
Photographer unknown.