Nomination of

SURTSEY – NOMINATION FOR THE UNESCO WORLD HERITAGE LIST
Invertebrate diversity on Surtsey island
Average number of
specimens per day
> 300
200 < 300
451 100 < 200
50 < 75
25 < 50
10 < 25
Plots
The results of pitfall trapping within permanent plots show that the diversity of Surtseyan invertebrates is
considerably greater within the gull colony than in other parts of the island. Furthermore, the
abundance, or number of individuals, is also shown to be greater (Fig 2.15).
However, a few permanent plots, located in a shore community on the eastern part of the island
also appear to be relatively rich in invertebrates. One of these plots is located at the helicopter
platform, where gulls tend to rest and enrich the soil with nutrients. The high abundance recorded at
two other sites is caused by numerous individuals of a single species, the thrip Taeniothrips atratus,
which has sea sandwort as its host plant.
A total of 335 invertebrate species has been
found on Surtsey (Appendix 7; Table 2.6).
These include arthropods, molluscs, annelids,
nematodes and rotatorians, approximately
half of which have become permanently
established. Although flying insects are most
conspicuous, soil animals are most numerous.
There are as of yet no endemic invertebrates
on Surtsey. One species of special interest
is Ceutorrhyncus insularis, a very small
38
13
21
100
Total number of
species recorded
50
235
30
20
10
0
39
57
451
72
176
13
72
176
41
14
34
230
189
24
28
146
13
111
31
19
200 m
The tiny weevil Ceutorhynchus insularis, which is
abundant on scurvygrass on Surtsey, was first discovered
in 1968 on one of the Vestmannaeyjar
islands. It was originally believed to be a new
species to science and was described as such in
1971. Later on, similar specimens were discovered
in samples from the Hebrides Islands off Scotland.
The forb-rich grassland vegetation of the gull
colony supports a higher diversity and abundance
of invertebrates than do other parts of the island.
snout beetle that feeds on scurvy grass and is
extremely rare on a global scale.
The establishment of a gull colony clearly
boosted the insect fauna on Surtsey (Fig. 2.15).
A few species such as Atheta graminicola are
completely dependent on the gull colony, even
though others such as Amara quenseli prefer
the harsh tephra ground elsewhere (see box
on this page).