Fungus Populations in Marine Waters and Coastal Sands of the Hawaiian, 
Line, and Phoenix Islands 1 
Carol Wright Steele 2 
ABSTRACT: Saprophytic and facultative parasitic fungi present in the coastal 
waters and adjacent pelagic areas of the Hawaiian Islands, and in coastal sands 
of the Hawaiian, Line, and Phoenix islands, were isolated by plating methods. 
Isolates from all areas sampled indicate that abundant and varied fungus popu- 
lations do exist in these environments. The number of fungi obtained from the 
inshore neritic zone was seven times that obtained from the oceanic zone. The 
fungus Aureobasidium pullulans (De Bary) Arnaud was isolated repeatedly from 
oceanic waters. A comparison is made between the genera and the average number 
of isolates per liter of water known from the Atlantic Ocean with those found in 
this study of the Pacific Ocean. The number of fungi isolated from sand samples 
of the different islands ranged from 2 to 1,600 per gram. Species diversity was 
evident throughout the samples. The leeward Hawaiian islands had a higher aver- 
age number of isolates per gram than any other island group. In conclusion the 
problems of defining a marine fungus are discussed. 
Oceanic areas in different parts of the world 
have been shown to be habitats for marine 
fungi (Johnson and Sparrow, 1961). Investi- 
gators, however, have usually concentrated on 
particular groups of fungi by use of selective 
isolation methods (Barghoorn and Linder, 
1944; Moore and Meyers, 1959; Jones, 1962). 
Only one extensive analysis of marine waters 
for a general fungus population is known, and 
it was made in the northwestern subtropical 
Atlantic Ocean (Roth et al., 1964). References 
to the occurrence of fungi in the Pacific Ocean 
are found (1) as incidental to studies of bac- 
teria in marine water (ZoBell, 1946); (2) in 
studies of specialized fungi such as lignicolous 
fungi (Cribb and Cribb, 1955, 1956, I960; 
Kohlmeyer, I960; Meyers and Reynolds, I960) 
and those on algae (Cribb and Cribb, 1955, 
1956, I960); and (3) in studies of particular 
kinds of fungi, e.g., Phy corny cetes in Japanese 
waters (Kobayashi, 1953) and pathogenic spe- 
cies (Van IJden and Castelo Branco, 1961). 
Reports of fungi from terrestrial environments 
of islands in the central and southern Pacific 
1 Prepared from a thesis submitted in partial ful- 
fillment of requirements for the Master of Science 
degree at the University of Hawaii. 
2 Department of Botany, San Diego State College, 
San Diego, California, 92115. Manuscript received 
June 20, 1966. 
also are very limited. These include a few rec- 
ords of higher fungi collected in the Marshall 
Islands (Rogers, 1947), the Society Islands 
(Olive, 1957, 1958), and Raroia in the Tua- 
motu Archipelago (Cooke, 1961); Phyco- 
mycetes recovered by plating soils of the atolls 
of Bikini, Eniwetok, Rongerik, and Ronggelap 
(Sparrow, 1948); and Ascomy cetes and Fungi 
Imperfecti from dung and soil samples col- 
lected by Olive in the Society Islands (Peter- 
sen, I960). Consequently, as Cooke points out, 
the geographic distribution of fungi occurring 
on the islands of the Pacific is poorly known. 
Although studies have been initiated on the 
soils of the Hawaiian Islands (Baker, 1964) 
and the phyllosphere (Marsh, 1965), no study 
has been made of fungi occurring in marine 
waters and intertidal environments of these 
islands or elsewhere in the central Pacific. This 
investigation was undertaken to determine the 
occurrence and distribution of the saprophytic 
and facultative parasitic fungi which constitute 
the fungal populations of these habitats. 
MATERIALS AND METHODS 
Collection 
Isolations for fungi were made from 59 
water samples and 50 sand samples collected 
317 
