Náttúrufræðingurinn - 2010, Side 27

27
Tímarit Hins íslenska náttúrufræðifélags
Þakkir
Jörundur Svavarsson prófessor las yfir handrit þessa pistils og færði margt
til betri vegar. Ég hef átt samstarf við mikinn fjölda kollega, aðstoðarmanna
og nemenda um marga þætti sem imprað er á í pistlinum. Of langt mál yrði
að telja þá alla upp, en ég vil þó sérstaklega geta Maríu Bjarkar Steinars-
dóttur, sem verið hefur aðstoðarmaður minn og ómissandi samstarfsmaður
í nær 15 ár.
Heim ild ir
Agnar Ingólfsson & Ingi Agnarsson 1999. 1. Anonyx sarsi: a major unrecog-
nized scavenger and predator in the intertidal zone. Journal of the
Marine Biological Association of the United Kingdom 79. 1127–1128.
Árni Waag Hjálmarsson 1982. Vaðfuglar. Rit Landverndar 8. 117–148.2.
Agnar Ingólfsson & Ingi Agnarsson 2003. Amphipods and isopods in the 3.
rocky intertidal: Dispersal and movements during high tide. Marine
Biology 143. 859–866.
Agnar Ingólfsson 1976. Smádýralíf og gróður á sjávarfitjum við Gálga-4.
hraun (Zonal distribution of plants and arthropods on a salt marsh in
SW Iceland). Náttúrufræðingurinn 46. 223–237.
Raffaelli, D. & Hawkins, S. 1996. Intertidal Ecology. Chapman and Hall, 5.
London. 356 bls.
María Björk Steinarsdóttir, Agnar Ingólfsson & Emil Ólafsson 2003. Sea-6.
sonality of harpacticoids in a tidal pool, south-western Iceland. Hydro-
biologia 503. 211–221.
Gómez, S. & María Björk Steinarsdóttir 2007. On three new species of 7.
Mesochra Boeck, 1865 (Harpacticoida: Canthocamptidae) from Iceland.
Journal of Natural History 41. 2247–2478.
Downes, J.A. 1988. The post-glacial colonization of the North Atlantic 8.
islands. Memoirs of the Entomological Society of Canada 144. 55–92.
Rundgren, M. & Ólafur Ingólfsson 1999. Plant survival in Iceland during 9.
periods of glaciation. Journal of Biogeography 26. 387–396.
Wares, J.P. 2001. Intraspecific variation and geographical isolation in 10.
Idotea balthica (Isopoda: Valvifera). Journal of Crustacean Biology 21.
1007–1013.
Wares, J.P. & Cunningham, C.E. 2001. Phylogeography and historical 11.
ecology of the North Atlantic intertidal. Evolution 55. 2455–2469.
Lokaorð
Ég tileinka þetta greinarkorn vini
mínum, hinum merka vísindamanni
og baráttumanni fyrir náttúruvernd,
Arnþóri Garðarssyni, sjötugum.
Kynni okkar Arnþórs hófust 1951,
er við settumst í Gagnfræðaskól-
ann við Hringbraut. Sameiginlegur
áhugi á fuglum leiddi okkur saman
og brátt hófum við reglulegar athug-
anir á fuglalífi Seltjarnarness undir
handleiðslu Finns Guðmundssonar,
og stóðu þær í nokkur ár.56,57 Veru-
leg samvinna milli okkar hefur svo
haldist allar götur síðan, í hálfa öld,
einkum á sviði þjónusturannsókna.
Fyrir þá samvinnu vil ég þakka af
alhug.
Summary
The conservation value of the
Icelandic intertidal, and major
concerns
Worldwide, the intertidal zone has been
the subject of intensive studies, due to
for example the steep environmental
gradient and ease of access to this part
of the marine realm. Studies of the inter-
tidal have contributed very significantly
to the science of ecology. The special
value of the intertidal zone in Iceland
hinges to a great extent on the fact that
Iceland is an island, far from the nearest
continents. Although most intertidal
species that live under similar condi-
tions as are to be found in Iceland, in
Europe and America, have managed to
colonize Iceland, possibly mainly by
drifting seaweed, some key species are
lacking. Therefore, Iceland can be com-
pared with an experimental setup on a
geographical scale, where these key spe-
cies have been removed. Some key spe-
cies, such as the seaweed Fucus serratus
and the shrimp Crangon crangon have
reached Iceland only recently or at least
have become abundant in some parts
only recently. This allows comparisons
of state of communities before and after
invasions (Crangon crangon) or compari-
sons of adjacent areas were a colonizer
is absent and were it is present (e.g.
Fucus serratus). In other instances key
invertebrate predators, such as the green
crab Carcinus maenas and the dogwelk
Nucella lapillus are more or less confined
to the warmer coasts in Iceland, while
their main prey, the blue mussel Mytilus
edulis and the acorn barnacle Semibalanus
balanoides appear to enjoy optimal phys-
ical conditions on all suitable (i.e. rocky)
coasts. This makes possible comarisons
of abundance of prey species in differ-
ent geographical areas which differ in
the abundance of predators, which can
then be judged against results of local
experiments were predators are re-
moved to varying extent. The presence
of hot springs in the intertidal of Iceland
provides unique opportunities for re-
search on physiology and ecology of
intertidal organisms. The people of
Iceland live mostly near the coasts,
where the majority of schools are locat-
ed. The value of the intertidal as a rec-
reational area or as a teaching area in
ecology and marine biology is undis-
puted. Many species on the Icelandic
shore are accessible and active through-
out the year, in contrast to what often
obtains in fresh waters and terrestrial
environments, enhancing its value, e.g.
for teaching. The Icelandic intertidal
plays a major role as a feeding area for
many birds and fishes. The traditional
exploitation of the intertidal by man
(e.g. for food, fertilizers) has decreased
in the last century.
Human activities have severely af-
fected the Icelandic intertidal. Building
roads across shallow fjords has in some
cases dramatically affected the biota,
both inside and outside the roads.
Closure of lagoons for aquacultural or
other purposes has also led to loss of
intertidal areas. Land fillings now cover
almost all of the shoreline around
Reykjavík. It is estimated that human
activities have resulted in the loss of
about 6.8%, by area, of sediment shores,
and about 2.5% of rocky shores.
Industrial harvesting of the seaweed
Ascophyllum nodosum in the Bay of
Breiðafjörður inevitably leads to the
death of huge numbers of invertebrates,
including species that are important
food for birds. This has not, however,
been investigated. The Icelandic shore-
line is littered with plastic objects, some
of which may carry new colonizers. The
risk of introducing new “unwanted”
species via ballast waters of ships, ap-
pears high. Some of these could radi-
cally alter intertidal communities.
Pollution on Icelandic shorelines (apart
from plastic objects) is mostly confined
to harbours and their neighbourhoods.
Plans to build a large oil refinery in the
northwest cause great concerns, as do
plans to harness tidal power.
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