Southeast Island Observations

	Last updated
	August 10, 2003

Anchialine pond at Southeast Island, Pearl and Hermes Atoll

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Pearl and Hermes Water Chemistry

Water temperature and salinity in the Southeast Island pond were 24.6°C and 26.9 ppt, respectively. Chl a measured 0.4 mg/L. The H₂S concentration was 0.6 mM and total N and DON were 164.0 and 111.1 mM, respectively. The NO₃^- concentration (48.0 mM) exceeded by almost an order of magnitude that of NH₄⁺ (4.9 mM). Over 99% of the total phosphorus (41.30 mM) comprised SRP; SNP was less than 1% of TP. The SRSi concentration was 14.05 mM.

Pearl and Hermes Cultures

Twenty-nine pure cultures of bacteria from Southeast Island (designated PH) affiliated with 18 taxonomically distinct strains from 10 families within the a- and g-Proteobacteria, the Firmicutes and Cyanobacteria (Table1).

Three cultures from Southeast Island shared <97% 16S rRNA identities with cultivated strains in the literature (Table). PH27A is a highly motile, Gram negative rod that forms a distinct lineage within the Halomonadaceae; PH35 is similarly removed (91.58% 16S rRNA identity) from Serratia proteomaculans, its nearest described neighbor. One of three a-Proteobacteria from Pearl and Hermes (PH30) will be described as a new member of the genus Thalassospira (Rhodospirillaceae).

Pearl and Hermes Clones Table

Taxon	OTU	Representative clone	NT	Closest relative	Homology (%)	Family/Group	Accession #
a-Proteobacteria	1	PH-B13	1426	a-Proteobacterium AJ133762	1361/1413 (96.32)	Rhodobacteraceae	AF513936
g-Proteobacteria	2	PH-B39N	1497	Aeromonas bestiarum X60406	1491/1497 (99.60)	Aeromonadaceae	AF513938
Firmicutes	3	PH-B53N	1514	Bacillus sp. AB066347	1500/1506 (99.60)	Bacillaceae	AF513963

Pearl and Hermes Cultures Table

Taxon	Culture	NT	Closest relative	Homology (%)	Family/Group	Accession #
a-Proteobacteria	PH30	1396	a-Proteobacterium AB024595	1332/1361 (97.87)	Rhodospirillaceae	AF513476
	PH33	1363	Rhodovulum sulfidophilum D16422	1347/1348 (99.93)	Rhodobacteraceae	AF513477
	PH34B, PH34P	1364	Rhodobium marinum D30791	1354/1355 (99.93)	Rhizobiaceae	AF513478
g-Proteobacteria	PH1	1447	Vibrio orientalis X74719	1395/1428 (97.69)	Vibrionaceae	AF513461
	PH5	1431	Alteromonas alvinellae AF288360	1416/1422 (99.58)	Alteromonadaceae	AF513462
	PH8, PH2, PH6, PH7, PH9, PH22,PH24, PH26	1464	Vibrio proteolyticus X74723	1421/1432 (99.23)	Vibrionaceae	AF513463
	PH17, PH15	1442	Halomonas marisflavi AF251143	1421/1437 (98.89)	Halomonadaceae	AF513464
	PH19	1433	Vibrio furnissii X76336	1337/1368 (97.73)	Vibrionaceae	AF513465
	PH25, PH3	1448	Salinivibrio vallismortis AF057016	1428/1439 (99.24)	Vibrionaceae	AF513466
	PH27A	1436	Oceanospirillum maris AB006763	1151/1252 (91.93)	Halomonadaceae	AF513467
	PH29	1415	Uncultured soil bacterium AF423262	1406/1416 (99.29)	Enterobacteriaceae	AF513468
	PH31, PH34W	1435	Serratia marcesens AF124038	1408/1413 (99.65)	Enterobacteriaceae	AF513469
	PH35	1457	Uncultured Proteobacterium AJ310680	1339/1461 (91.65)	Aeromonadaceae	AF513470
	PH39	1440	Shewanella sp. AJ319767	1425/1429 (99.72)	Alteromonadaceae	AF513471
Firmicutes	PH28	1383	Halobacillus trueperi AJ310149	1366/1377 (99.20)	Bacillaceae	AF513472
	PH27B	1443	Bacillus cereus AF290548	1424/1426 (99.86)	Bacillaceae	AF513473
	PH32	1349	Bacillus sp. AB017591	1332/1342 (99.25)	Bacillaceae	AF513474
Cyanobacteria	PH40	1480	Synechococcus sp. AJ000716	1427/1434 (99.51)	Chroococcales	AF513475