Hendrarto, Ignatius Boedi (1992) Distribution and abundance of benthic diatoms in a tropical mangrove forest and effects of grazing on them by Telescopium telescopium (Linnaeus, 1758). PhD thesis, James Cook University of North Queensland.

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Abstract

[Extract] The term of mangrove is given to a group of angiosperm plants which grow on the sea shore between mean sea-level and the high water mark of the highest tide. These plants are widely distributed in tropical oceans and are common in areas sheltered from strong wave action. They often grow on coral reef lagoons that provide suitable habitats. They also penetrate deep into the estuaries of rivers. Their distribution is always related to the penetration of salt water. They can tolerate saline conditions but other tropical angiosperm plants species do not (De Haan, 1931; Richards, 1964; MacNae, 1968; Chapman, 1975).

Occupying as it does the region between land and sea, the ecosystem of mangroves may have sharp environmental gradients. The tidal factor causes high fluctuations in some environmental factors, such as temperature and salinity. Hence, only a few animals and plants have a sufficiently wide tolerance of these extreme conditions to survive and settle in mangrove areas. Because of this the heterogeneity of living organisms is restricted, but the population abundance may be high. The number of trees and shrubs constitutting in the mangrove forest is limited and conversely the mangrove plants are generally restricted to this habitat and are not found inland. It appears that each mangrove species has its own niche, in accordance with its own requirements as to habitat and life cycle (Steenis, 1958). Hence, mangrove forests differ in composition from place to place, and even contain a limited amount of zonation.

The existence of mangrove forests in an area provides a big contribution to marine life in the adjacent sea. Heald and Odum (1970) showed that leaf detritus from mangroves contributes a major energy input into coastal fisheries. The detritus is produced by the activity of fungi, bacteria and protozoa, which use the plant remains as an energy source which is decomposed and accumulates as organic detritus. Studies of these microorganisms associated with mangroves have been appearing in recent years. Kohlmeyer and Kohlmeyer (1979) for example published a summary of mangrove fungi whereas Hendrarto (1984), who carried out an intensive study of mycoflora living in mangrove sediment in Java, Indonesia, found that soil fungal assemblages within seaward and landward habitats were different.

Another group of microorganisms living in mangrove sediments is benthic diatoms. Compared to the other microorganisms, studies on benthic diatoms which live predominantly in and on mangrove sediments are few. The majority of recent ecological investigations on sediment-associated diatoms have been in non-mangrove, intertidal areas (Foged, 1975; John, 1983). Diatoms in soft-bottom and sublittoral habitats have been investigated extensively (Taasen & Hoiaseter, 1989). In tropical mangrove habitats, however, ecological studies on benthic diatoms are few (Cooksey, 1984). Studies on diatoms in natural mangrove areas have been limited to investigations of species composition of diatoms associated with mangrove roots that exist in sediments adjacent to mangrove areas (Foged, 1978; Navarro, 1982; Maples, 1983; Cooksey, 1984) and on various substrata (Foged, 1978; Wah and Wee, 1988). However these studies did not emphasise investigations of benthic diatoms living on mangrove sediments. Therefore studies of benthic diatoms living on mangrove sediments are needed.

Item ID:	33770
Item Type:	Thesis (PhD)
Keywords:	Chunda Bay; mangroves; benthic fauna; diatoms; telescopium; mangrove whelk; grazing; distribution; abundance; growth; community structure; seasonal variation; productivity
Additional Information:	No abstract in thesis.
Date Deposited:	21 Jul 2015 04:23
FoR Codes:	06 BIOLOGICAL SCIENCES > 0605 Microbiology > 060504 Microbial Ecology @ 80% 06 BIOLOGICAL SCIENCES > 0602 Ecology > 060207 Population Ecology @ 20%
SEO Codes:	97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 100%
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