INTRODUCED MARINE SPECIES IN PAGO ... - Bishop Museum

Skelton, P. A., Algae survey report
Station 10 (Fagasa)
Forty-two taxa were recorded comprising of 4 Cyanophyta, 6 Chlorophyta, 4 Phaeophyta, and 28
Rhodophyta. One new addition to the Samoan flora is Chrysymenia kaernbachii a species with its
type locality from Papua New Guinea and which has recently been found in Fiji and neighboring
Western Samoa.
Comparison with Previous Surveys
Of the 318 algae recorded for the Samoa Archipelago, 262 are now known for American Samoa.
Our surveys found 65 new records for American Samoa (of which approximately 10 are new
records for the Archipelago’s flora).
Setchell (1924) in his treatment of algae from American Samoa compiled 100 species consisting
of 13 Cyanophyta, 47 Rhodophyta, 11 Phaeophyta, and 29 Chlorophyta. Setchell, with assistance
from three able collectors (Alfred G. Mayor, A. L. Treadwell, and F.A. Potts), collected from 15
different sites within the island of Tutuila plus nearby islets (Aunu’u and Goat). One of the sites
that received much attention during Setchell’s surveys was Aua Reef including Breaker Point.
From this site alone, he compiled 51 species of which four he described as new to science. Our
surveys yielded 34 taxa from the Aua Reef site, of which eight were found to be new additions to
Setchell’s 1924 list. The eight new additions have a pan-tropical distribution and most have been
recorded from Western Samoa and as far east as French Polynesia.
Setchell made a few collections from Fagasa (9 species) and Utulei (4 species – as Utelei), but
no collections were made from Vatia, Onesosopo, Leloaloa and Fagatele. Approximately 12 algal
taxa were collected by Richard Buggeln and Roy Tsuda from Vatia Bay and Fagasa Bay in 1964
(these are housed at Bishop Museum). Their collections need to be examined, although their
tentative identifications include species with a pan-tropical to subtropical distribution.
The Fagatele National Marine Sanctuary has been studied over the last fifteen years (Birkeland et
al., 1987, 1995) and is considered one of the best monitored marine ecosystems in the
Archipelago. In the surveys of Birkeland et al. (ibid) they found a very high algal cover (> 75%),
comparable to the estimation made during our surveys. The number of algal species reported
during their ecological surveys was 39 species in 1987 and 26 in the 1995 survey. This compared
to 47 species found during our surveys. This slight increase in species number is attributed
primarily on the different habitats that were sampled during our surveys, which include the upper
intertidal and the spray-zone, habitats not sampled by Birkeland and team.
Nonindigenous and Cryptogenic Species
As previously stated all of the identified species from our surveys have distributions that are either
pan-tropical or limited to the Indo-Pacific region. It is important to note that some marine plant
species have spread to as far as American Samoa and no further. For example American Samoa
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