marine indicator species of reefs: iii. calcareous reefs … · baldock, r. n. (2015). marine...
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Baldock, R. N. (2015). Marine indicator species of reefs: III. Calcareous reefs of dune rock (aeolianite) in rough, cold-temperate waters. Algae Revealed. 4pp.
Adelaide: State Herbarium of South Australia. flora.sa.gov.au/algae_revealed
MARINE INDICATOR SPECIES OF REEFS:
III. CALCAREOUS REEFS OF DUNE-ROCK (AEOLIANITE) IN ROUGH,
COLD-TEMPERATE WATERS Examples: Cape Dombey, Robe and Beachport South Australia
Steep cliffs, pot-holed, flat rock platforms, isolated sea-stacks and arches at Cape Dombey
vertical cliff-face grazed bare by
molluscs and dense algal mats
exposed at low tide
pot-holed reef shelf wave-pounded reef edge with
Bull Kelp
fronds of Giant Kelp floating at
the surface from attachments deep below and distant rock arches
eroded
cliffs
mar
ine
lich
ens
litt
ori
nid
sn
ail
bar
nac
les
lim
pet
s
Nep
tun
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fing
ers
blu
e-g
reen
alg
ae
lav
er
wh
ite
wo
rm t
ub
es
sea
lett
uce
rock
-po
ol
alg
ae
alg
al m
at
Nep
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eck
lace
cun
jevo
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larg
e ch
ito
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bull
kel
p
cray
wee
d
gia
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kel
p
2 3a-c. 65
3a-c
5
7 6
.
78 9 10 11 12 13 151a-b. 4a-b. 14
8
9
10 11 12 13
14
15
16
4a-c
1
2
10
15
11
17
low tide
high tide
high tide
low tide
sea stacks and bridges
17
strong wave action
16
Baldock, R. N. (2015). Marine indicator species of reefs: III. Calcareous reefs of dune rock (aeolianite) in rough, cold-temperate waters. Algae Revealed. 4pp.
Adelaide: State Herbarium of South Australia. flora.sa.gov.au/algae_revealed
THUMBNAIL SKETCHES OF INDICATOR ORGANISMS ― DISTRIBUTED ON THE REEF ACCORDING
TO TIDE LEVELS
1a. the marine lichen, Caloplaca, in the “splash” zone above high tide dries and becomes bright
orange during summer. Tiny blue snails create a
distinct browse-line lower in the splash zone
1b, 2. blue snails, Austrolittorina, to 16 mm tall,
grazing black marine lichen, Lichina, in the
region above high tide, kept moist by occasional wave splash
3a.
3a. six-plated barnacle, Chthamalus antennatus,
about 12mm across may grow high up in the
intertidal region
3b. honeycomb barnacles, Chamaesipho tasmanica, about 6 mm across, seen here with a few blue
snails, squash together in groups in the upper
intertidal, and can be difficult to see against the eroded background rocks.
3c. surf barnacle Catomerus polymerus, 30 mm
across, seen here with a few black mussels.
grows in the mid-intertidal on rough coasts
4a-b. a variety of molluscs graze the mid-intertidal
clean of algae. Because they do not venture down
into the lower intertidal due to predation, sea-lettuce and other algae can grow there prolifically
4a. pied limpet, Patelloida latistrigata to 25 mm
wide is often common but unnoticed, It occupies
small rock depressions. The top of the shell is
usually heavily eroded
4b. the orange-edged limpet, Cellana solida, found
on rough coasts, may be 60 mm across
5, 6. brown, wrinkled Neptune’s fingers, Splachnidium, amongst lozenges of blue-green
algae Calothrix australis (formerly C. firma)
7. the red alga laver, Porphyra, may grow in the
mid-intertidal during winter
8. white worm tubes, Galeolaria caespitosa, may
form a prominent band on more vertical rocks in
the mid-intertidal
9. sea lettuce, Ulva, seen here with stunted Hormosira surrounding a rock pool in the lower
intertidal can be prolific in spring
Baldock, R. N. (2015). Marine indicator species of reefs: III. Dune rock (aeolianite) reefs in rough cold-temperate waters. Algae Revealed.4pp. Adelaide: State
Herbarium of South Australia. flora.sa.gov.au/algae_revealed
10. rock pools, full of a mix of flat or tufted brown algae and red algae
11. the algal mats in the lower intertidal can be dense
and species rich. Shown above: the red alga
Griffithsia teges with yellow tips to filaments, and three species of the green alga Caulerpa
12. Neptune’s necklace, Hormosira banksii, about 300 mm tall, in the lower intertidal, forms chains
of brown beads
13. cunjevoi, Pyura stolonifera, is a seasquirt
attached to rocks in the lower intertidal, often with a fuzzy coating of red algae
14. the large chiton, Plaxiphora albida, previously Poneroplax, to 100 mm long, with broad girdle
coated with a fuzz of algae, grazes the lower
intertidal
15. in the region of wave surge at the reef edge, bull kelp, Durvillea, stands on a trunk-like stalk to
400 mm tall, its large, broad rubbery blade
shredded at the edges into belt-like strands
16. algal mats extend under the reef edge.
They contain many red species, but the largest
algae are brown, such as crayweed, Phyllospora, shown above
16. beds of bright green Caulerpa contrast with the dominant brown algae of shallow waters
17. giant kelp, Macrocystis, from shallow water to
20 m deep, attaches to rocks with a branching,
root-like holdfast giving rise to elastic strands ending in wrinkled, narrow blades held at the
water surface by gas bladders
17. detail of Macrocystis blades and gas bladders
17. leafy fronds of Macrocystis may rise from 20m
deep
Baldock, R. N. (2015). Marine indicator species of reefs: III. Dune rock (aeolianite) reefs in rough cold-temperate waters. Algae Revealed.4pp. Adelaide: State
Herbarium of South Australia. flora.sa.gov.au/algae_revealed