CONTENTS
Flora index
Fauna index
guide to the mangroves of singapore
The Ecosystem: Abiotic components
Peter K L Ng and N Sivasothi (editors)
 
Salinity

The salt content of water is given as parts per thousand (ppt), i.e. the amount of salt (g) dissolved in 1,000 g of water.

Common salt (sodium chloride) is the main dissolved solid in seawater, and the average salinity is 35 ppt.
Mangrove Ecosystem
Abiotic components
Soil
pH
Oxygen
Nutrients
Winds and currents
Light, temperature, humidity
Tides
Salinity

Biotic components
Vegetation
Zonation

The degree of salinity may be categorised into oligohaline waters of low salinity (0.5-5 ppt), mesohaline waters of intermediate salinity (5-18 ppt) and polyhaline waters of high salinity (18-30 ppt).

The term brackish water actually refers to oligohaline to weakly mesohaline waters. Specific readings of salinity within a mangrove may range from 0.5-35 ppt! One of the reasons for this variation is the tide—when the sea floods the mangrove, the salinity is that of polyhaline seawater.

Salinity also varies with estuarine depth, for salty seawater tends to sink, being heavier. When the sea recedes, tide pools can become hypersaline (>30 ppt) especially during the long exposure during lower low water springs. Inside the mangroves, however, the influence of freshwater runoff from the land becomes significant, particularly during monsoons. Small streams in the mangrove are oligohaline and further inland, some are even freshwater! In our narrow mangroves, the effect of freshwater inflow is considerable.

Conditions in the sea are more constant, but within the narrow Straits of Johor and Singapore waters, the pattern of salinity does exhibit two maximas (Mar/Apr and Oct/Nov) and two minimas (Jan and Jul/Aug), ranging between 28.5 and 32 ppt.
What is mangrove?
Introduction

The Ecosystem

Abiotic
Biotic

Value
Intro
Products
Indirect uses
Potential uses

About Mangroves
in Singapore

History
Mangroves to visit
Conservation
 
From "A Guide to Mangroves of Singapore", Peter K. L. Ng and N. Sivasothi (editors)
Volume 1: The Ecosystem and Plant Diversity and Volume 2: Animal Diversity
Authors: Kelvin K. P. Lim, Dennis H. Murphy, T. Morgany, N. Sivasothi, Peter K. L. Ng,
B. C. Soong, Hugh T. W. Tan, K. S. Tan & T. K. Tan
BP Guide to Nature Series published by the Singapore Science Centre, sponsored by British Petroleum
2001 Raffles Museum of Biodiversity Research, The National University of Singapore & The Singapore Science Centre