A number of studies have investigated the distribution of higher marine fungi in temperate estuarine systems. However, little is known of the distribution of higher marine fungi along tropical and subtropical estuarine salinity gradients and how the species composition may change seasonally. The purpose of this study was to examine the distribution and seasonal occurrence of higher marine fungi along a salinity gradient in a subtropical waterway, the New River estuarine system in southern Florida. In addition, a number of physical parameters such as water temperature, salinity, dissolved oxygen and pH were measured.
Five stations were established along the New River waterway. Mean salinity ranged from 2 ppt at the most freshwater station (station 1) to 32 ppt at the highest salinity station (station 5) . Physical parameters were measured every two weeks at each station. The substrates employed for fugal collection were wood panels of a hardwood, white oak (Quercus alba) and a softwood Douglas fir (Pseudotsugu menziessi). Four sets of panels were submerged at each station. One pair was removed every three months, at each station, for a period of one year.
Thirteen species of fungi were identified during the course of the study. The Ascomycotina were represented by four species and the Deutermycotina were represented by nine species.
Some fungal species displayed a physiological preference for higher saline waters. Trichocladium achrasporum was only isolated from station 5, with the highest salinity (32 ppt). Three known terrestrial species (Alternaria sp., Aspergillus sp. and Penicillium sp.) were isolated from the station that exhibited the lowest salinity, station 1 (2 ppt). These terrestrial species may be considered as contaminant species. Verruculina enalia, a known marine species (Kohlmeyer and Kohlmeyer 1979), was isolated from only the lower salinity regions and not the higher salinity sites. The distribution of fungal species did not appear to follow any seasonal pattern however patterns of succession were discernible. During the first period fungal diversity was at a maximum. Diversity gradually decreased with time consistent with previously observed successional patterns (Dix and Webster 1995).
Compared to temperate studies of marine fungal distribution (Kirk and Brandt 1980, Kirk and Schatz 1980, Shearer 1972) species diversity was relatively low. The main theme of this study was dominance. Halosphaeria quadricornuta and Verruculina enalia were the two dominant species. The ascocarp frequency of Halosphaeria quadricornuta was inversely proportional to Verruculina enalia. This abundance pattern may suggest interference behavior.
| Identifer | oai:union.ndltd.org:nova.edu/oai:nsuworks.nova.edu:occ_stuetd-1083 |
| Date | 01 January 2000 |
| Creators | Mickle, Fraser |
| Publisher | NSUWorks |
| Source Sets | Nova Southeastern University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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