INTRODUCED MARINE SPECIES IN PAGO ... - Bishop Museum

Skelton, P. A., Algae survey report
Results
A total of 313 specimens were analyzed comprising 139 taxa: 33 Chlorophyta, 9 Phaeophyta, 84
Rhodophyta and 13 Cyanophyta.
Station Location and Site Description
Stations 1 and 2: West and East Fagatele Bay (14 o 21.96'S, 170 o 45.85')
Stations 1 and 2 are located within the Fagatele Bay National Marine Sanctuary, which is a
moderately exposed bay with relatively steep cliffs and an undulating coastline. A few pockets of
flat intertidal areas exist joining the steep cliffs to a gradual sloping fringing reef. The two stations
are treated here as one algal ecological habitat due to the continuous fringing reef and their close
proximity to each other. The stations were dominated by articulate and non-articulate or crustose
coralline algae, as well as small turf algal communities. A buoy is located in the middle of the Bay,
and algae attached to it were collected. Algae were also collected from the intertidal area as well
as the splash zone. The two sites are not considered high risk sites to introduced species.
Station 3: Utulei Pago Pago Harbor (S14 o 17.04', W170 o 40.62')
The reef flat was surveyed from the shoreline toward the fringing reef crest. Subtidal sites were
surveyed by the team. The reef flat frequently has pockets of deeper (3-5 m depth) sandy pits,
which were barren at most parts or dominated by soft corals. Debris, rubbish and other structures
littered parts of the sandy pits. Digital photos were taken of the site as well as some specimens
collected. The current flow and the fact that the site is nearer to the harbor entrance may be a
reason why algal communities seem more abundant there. Small red algal turfs (Gelidiella
repens, Gelidium spp.) were common in crevices and on the undersides of limestone rocks and
volcanic rocks strewn throughout the site. A few green macro-algae were obvious (Valonia
fastigiata, Dictyosphaeria versluysii, Bryopsis pennata and Halimeda gracilis). Hypnea pannosa
was found abundant between coral colonies. Two main habitats were distinguished: (i) the
shallow reef flat and (ii) deeper sandy pits. Collections were also made from the sea-wall, which
consisted mainly of small algal fuzz. This site is considered a high risk to introduced species due
to its location.
Station 4 and 5: Main (14 o 16.59, 170 o 41.26') and Dry (14 o 16.32', 170 o 39.89') Docks, respectively
- Pago Pago Harbor
Stations 4 and 5 – algal samples were collected from hulls of vessels and pilings. Station 4 (Main
Dock) samples were scraped off the hull of an out-of-use landing craft ship with Oregon, USA
written on the side. At the water-line mark, little turf algae were collected. One of the
anchor/stabilizer ropes had a small clump of a black colored alga (Grateloupia filicina), mimicking
a feather-star. This was collected, with a few plants preserved in alcohol and the rest in formalin
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