CEYLON J.SCI.(BIO.SCI.) VOL.17&18,1984-85 
SOME ECOLOGICAL ASPECTS OF THE MANGROVES 
ON THE WEST COAST OF SRI LANKA 
* ** 
K.H.G.M. De Silva and S, Balasubramaniam 
?Department of Zoology, University of Peradeniya, Sri Lanka. 
"Department of Botany, University of Peradeniya, Sri Lanka. 
ABSTRACT 
Mangrove formations (mangals) on the west coast are 
not extensive and, in most places, are limited to narrow 
strips bordering river mouths and estuaries. A clear 
ecological zonation is difficult to discern, except for a 
Rhizophora-Bruquiera zone at the edge of the water followed 
by a zone containing the other core species. The low level 
of tidal amplitude as well as persistent and long-term human 
interference are major factors that led to the limitation 
of mangroves to narrow strips and to the disappearance or 
non-establishment of proper ecological zonation. Floristic 
composition of wet zone mangroves is somewhat different from 
that of dry zone mangroves. This difference appears to be 
due to prevailing salinity differences, wet zone mangroves 
experiencing lower salinity conditions and dry zone mangroves 
experiencing higher salinity conditions. In each zone, there 
are riverine and estuarine mangroves. Four types of high 
salinity (dry zone) estuarine mangroves, viz. fringing, scrub, 
overwash, and basin, could be. distinguished depending on the 
geomorphic and flooding characteristics. Basin mangroves 
are not found on the west coast. 
Mangroves in Sri Lanka have been subjected to man's 
' detrimental interference to a greater or lesser degree for 
a long time. In the north-east, mangroves have received 
23 
K.H.G.M. DE SILVA AND S. BALASUBRAMANIAM 
relatively less interference, but, those on the west and south?
 west coasts have been highly interfered with, and in some 
cases, mangroves have virtually disappeared. Urgent 
conservation measures are required to save Sri Lankan 
mangroves. 
INTRODUCTION 
Mangrove formations (or mangals, as some authors prefer 
to call these communities, reserving the term mangrove to 
individual plant species (Macnae, 1968)), are a prominent 
feature of the tropical coastal ecosystems and they develop in 
sheltered shores of lagoons and estuaries. They contain a 
characteristic assemblage of salt-tolerant trees and provide 
habitats for a variety of fauna and nursery grounds for 
juvenile finfish and shellfish. They produce large amounts 
of organic matter, which are used in food webs of lagoons and 
estuaries. They also help in the prevention of shore erosion. 
As Tansley & Fritsh (1905) pointed out at the beginning 
of the century, mangroves in Sri Lanka are confined to the 
muddy shores of the estuaries and are not found at all on the 
actual sea shores (which are sandy) in contrast to the 
extensive mangroves found in the shores of the Straits of 
Malacca? on the west coast of the Malay peninsula. 
Mangroves are perhaps the most misused coastal 
ecosystem in Sri Lanka, and through ignorance, people have 
destroyed most of this valuable natural resource. Even at 
present, for most of the general public, mangroves are an evil-
 smelling wasteland infested with mosquitoes and since they 
have only a very low "real-estate" value they should be 
reclaimed if possible and put to "better" use such as for 
growing crops and establishing human settlements. 
Mangroves in Sri Lanka received little attention even 
from ecologists until the last two decades. The present extent 
of mangroves in Sri Lanka has variously been estimated at over 
4,000 ha (Arulchelvam, 1968) to over 6,000 ha (Jayawardene, 
1985). Recently preliminary studies of mangrove flora in the 
Puttalam-Kalpitiya region (Amarasinghe & Perera, 1984), 
Vadamarachchi estuary in the north (Balasubramaniam, Rasiah 
& Ratnapala, 1970) and some of the islands in the mouth of 
Negombo estuary (Pinto, 1982) have been reported. 
Although virtually all macrophytes and most of the 
macrofauna of the Sri Lankan mangroves are known from various 
works, mainly of a taxonomic nature, little is known of the 
MANGROVES OF SRI LANKA 
l i f e cyc le s of most of the s p e c i e s . Studies on ecology, 
zonation and d i s t r ibut ion of mangrove spec ies in Sri Lanka 
are lacking except for those that are mentioned e a r l i e r . 
The present study deals mainly with the types of mangroves 
on the west coast of Sri Lanka, the i r eco log i ca l zonation 
and the e f f e c t of man's interference on them. 
MATERIALS AMD METHODS 
Mangroves in the r iver mouths of Gin Ganga, Kala Oya 
and Pomparippu Aru, and those on the shores of larger i s lands 
in Kalpi t iya , Negombo and Balapit iya e s tuar i e s as wel l as 
those on the mainland bordering these e s tuar i e s and Hikka-
 duwa estuary (F igs . 1, 2 and 3) were studied during 1985/86. 
Herbaceous and woody mangrove macrophytes in each mangrove 
were i d e n t i f i e d and t h e i r r e l a t i v e abundance est imated. 
Macrophytes in several transects in each mangrove were 
studied and t h e i r zonation noted. Samples of macrofauna 
such as crabs, gastropods, b iva lve s , hermit crabs, shrimps 
and prawns and f i sh were c o l l e c t e d from the mangroves as 
wel l as from the adjacent e s tuar ie s and r iver mouths, and 
were taken t o the laboratories of the University of 
Peradeniya for further s t u d i e s . Zooplankton were c o l l e c t e d 
from Kalpi t iya , Negombo, Balapit iya and Hikkaduwa e s tuar i e s 
by drawing a zooplankton net (mesh s i z e 335^um) through water 
from a slow running boat . In addi t ion , other mangroves on 
the west coast (Fig . 1) were a l s o examined and the 
macrophytes present in them were noted. 
RESULTS 
Mangroves on the west coast are not extens ive and 
are often l imited to narrow s t r i p s . The larges t mangrove 
area was seen in the Kala Oya-Pomparippu Aru e s tuar i e s in 
the north-west (Fig . 2 ) . I t s extent has been estimated as 
about 1,800 ha (Kanakaratne, Perera & Fernando, 1984) . On 
the other hand, the extent of the mangrove in Balapit iya 
estuary (Fig . 3) in the south west i s l e s s than 100 ha and 
that in the estuary of the Gin Ganga (Fig. 1) in the south 
i s even l e s s . The t a l l e s t t r ee s are seen in the Kala Oya 
mangrove with Rhizophora spp . , Bruguiera s:pp. and Avicennia 
spp. growing to 10-15 m. In a l l other mangroves, t r e e s 
growing over 10 m are except ional . 
K.H.G.M. DE SILVA AND S. BALASUBRAMANIAM 25 
Although many tree species were commonly found in 
all mangroves examined, the floristic composition in the 
dry zone mangroves (e.g. those in Kalpitiya area) is somewhat 
different from that of the wet zone mangroves (e.g. those 
in Balapitiya area) (Table 1 ) . Nypa fruiticans is found 
only in the wet zone mangroves. Sonneratia caseolaris, which 
is found in the wet zone, is replaced by S_j_ alba in the dry 
zone. Rhizophora apiculata and Bruguiera sexanqula are 
common in the wet zone whereas R^ mucronata and B. 
gymnorhiza are common in' the dry zone. Dry zone mangroves 
often have saltmarsh plants such as Salicornia brachiata 
and Sueda spp. in the back mangrove whereas wet zone 
mangroves have mangrove associates such as Polichandrone 
spathacea and Annona glabra. Well developed beds of sea 
grasses such as Enhalus acoroides, Halophila ovalis, and 
Thalassia hemprichii are usually found in the fore mangroves 
in the dry zone. Mangroves in the Negombo estuary- are 
intermediate in character between the wet and dry zone 
types as expected since the Negombo lagoon lies in the border 
region between the two zones. In both zones, mangroves along 
the banks of river mouths were more luxuriant than those 
found in the other estuaries as the amounts of sediment 
deposited in the river estuaries are richer in nutrients 
than those deposited on the shores of the other estuaries. 
In order to distinguish between the two types, the mangroves 
on the river banks (or river estuaries) will be referred 
to as riverine mangroves and those on the shores of the other 
estuaries (including those on the shores of the islands in 
these estuaries) will be referred to as estuarine mangroves 
in this study (see also Discussion). The low tidal amplitude 
and the slow rise and fall of tides could not flush riverine 
and estuarine mangroves to any significant extent. However, 
during rains, riverine mangroves are flooded and flushed 
to a great extent with freshwater, followed by the deposition 
of silt and other materials brought by the rivers. 
Degraded scrub mangroves are occasionally seen in 
the dry zone (e.g. on shores of Mundel estuary) (Fig. 1 ) . 
Rhizophora" spp., Bruguiera spp. and Sonneratia spp., which 
are prominent in other mangroves, were absent in the scrub 
mangrove. Even dominant species such as Avicennia marina 
is often found to be stunted. These areas show poor drainage 
and get water-logged when they are occasionally covered by 
extreme high tides and during rains. Thus, the salinity 
of the soil varies considerably, and hypersaline conditions 
develop with evaporation. Overwash mangroves, which are 
flushed at each tide, were observed on small islands and 
small, low-lying finger-like processes of mainland projecting 
into the lagoon, usually perpendicular to the tidal flow. 
The floristic composition of the overwash mangrove is 
similar to that of the marginal zone of estuarine mangrove, 
but when the area of the overwash mangrove is very small, 
usually only R^ mucronata grew on it. Such overwash 
26 
MANGROVES OF SRI LANKA 
mangroves were seen at Keerimundel and Kovilkudah along the 
Kalpitiya estuary (Fig. 2 ) . 
A clear ecological zonation of different tree species 
was not observed except for a zone of Rhizophora spp. ( 
Bruquiera spp. and sometimes Sonneratia spp., at the edge 
of the water followed by a mixed zone containing other core 
species such as Avicennia marina, Aeqiceras corniculatum, 
Ceriops tagal, Excoecaria aqallocha and Lumnitzera racemosa. 
Bruguiera spp., are usually found behind Rhizophora spp-. 
Avicennia marina is sometimes found towards the upper edge 
of the mixed zone, and sometimes extending right onto the 
water's edge. Occasionally, small areas free of trees but 
covered with breathing roots of A^ marina were seen in t h e 
mixed zone. Lqmn.itzera 1 ittorea was recorded only from onfe 
locality in one of the small islands in the Balapitiya; 
estuary at the edge of the water. 
A list bf mangrove core species as well as associates 
of Sri Lanka is given in Table 2 . 
On the whole, there was a paucity of mangrove fauna, 
both in numbers and in diversity. The commonest were 
cerifhidean gastropods and grapsid crabs. Portunid crab, 
Scylla serrata was found in all estuaries examined. Other 
decapods included the ocypodid crabs Uca lactea and 
Macrophthalmus depressus, the anomurans Eupagurus sp., 
Pagurus sp. and Thalassina anomala, and several species of 
Penaeus and Metapenaeus. The bivalves Anadara spp., Geloina 
spp.., Gaf f rarium tumidum, Perna spp.. Pinna bicolor, and 
the gastropod Pleuroploca trapezium were found in the mud 
and in the beds of sea grasses. The oyster Crassostrea 
cucullata was seen attached to the roots and stems of; 
Rhizophora spp., as well as in mud. 
The common fish species in the estuaries included 
mugilids, cichlids, ambassids, latids and siganids. 
Periophthalmus koelreuteri was seen in the mudflats and 
on the prop roots of Rhizophora spp. Fish fry and 
fingerlings and juvenile prawns were often seen within 
mangroves in small, more or less permanent, water holes 
and small channels. Larvae of prawns and crabs, copepods 
and their nauplii were common in the zooplankton of all 
estuaries. However, some differences in the zooplankton 
composition of the wet zone estuaries and dry zone estuaries 
were observed, with freshwater species occurring in the 
estuarxes? in the wet zone and marine species occurring 
in those of the dry zone. 
K.H.G.M. OE SILVA AND S . BALASUBRAHANIAM 27 
All mangroves were subjected to degradation by man 
to a greater or lesser degree. Very little mangrove was 
left in some of the estuaries such as at Hikkaduwa. In such 
areas, human settlements or crop plantations such as coconut, 
cinnamon and rubber extended almost to the edge of the water. 
Mangroves in many areas have been cleared for crop 
plantations from the early days of European rule of the 
coastal areas. For instance, cinnamon plantations were 
started after the Portugese landed in Sri Lanka in 1505. 
Such plantations could be seen in the areas of Balapitiya 
and Hikkaduwa estuaries (Fig. 3 ) . Even within the last 20 
years, the mangrove cover of Negombo estuary (Fig. 2) 
dwindled very much (by more than 10% according to some 
estimates). Nypa fruticans which flourished in Hikkaduwa 
estuary about 50 years back (according to some eye witnesses) 
has now completely disappeared from there. Even during the 
period of the present study in 1985/86 some of the mudflats 
were prepared for cinnamon plantations. 
Among the many uses of mangrove trees in Sri Lanka, 
such as for firewood, timber, tanning purposes, fodder, use 
of branches of trees such as Rhizophora spp., Bruguiera spp. 
and Avicennia spp. for brushpile fishing in the Negombo 
estuary merits special mention. As branches are required 
every two or three weeks to make new piles, mangrove trees 
are regularly cropped for this purpose. However, this 
necessity has encouraged some people to replant, degraded 
areas with mangrove trees, although to a very limited extent. 
DISCUSSION 
Development of mangroves depends on the interplay 
of many factors, the most important of which are climate, 
geomorphology of the shore area, tidal amplitude, salinity 
and sedimentation characteristics. Mangroves develop in 
intertidal mudflats or humid sands in places where the 
substratum is not much disturbed by wave action 
(Abeywickrama, 1964). Geomorphology and tidal amplitude 
are of major importance in determining the extent and width 
of the mangrove, while the floristic composition of the 
mangrove in a particular area will depend, among other 
factors on the salinity prevailing in the region. 
In Sri Lanka, most of the coastal brackishwater bodies 
are called lagoons. However, according to the generaly 
accepted definition of Pritchard (1967) an estuary "is a 
28 
MANGROVES OF SRI LANKA 
semi-enclosed coastal body of water, which has a free 
connection with the open sea, and within which sea water is 
measurably diluted with freshwater derived from land drainage". 
Thus, an estuary is subjected to the influence of regular 
tidal fluctuations. On the other hand, a lagoon does not 
normally have a free connection with the open sea and may 
be inundated with sea water at irregular intervals only. 
Furthermore, a lagoon receives freshwater mainly- from direct 
rainfall rather than from land drainage (e.g. lagoon within 
an atoll). River mouths, coastal bays, tidal marshes, and 
bodies of water behind barrier beaches are cited by-Odum (1971) 
as examples of estuaries. .Thus, the majority, if not all, 
of coastal brackishwater bodies in Sri Lanka including the 
so-called lagoons (e.g. Jaffna lagoon, Kalpitiya lagoon, 
Negombo lagoon) would come under the category of estuaries 
according to Pritchard's definition, and in the present study 
they are considered as such. 
The tidal amplitude in Sri Lanka is small and rarely 
exceeds 1.0 m. This may have played a major role in 
restricting mangroves to narrow strips. However, Tennent 
(1859), more than a century ago, noted dense growth of mangroves 
on the shores of estuaries. This, by no means, is true today. 
The possibility of mangroves spreading to areas which are 
covered by tides very occasionally or not at all is evidenced 
by the luxuriant growth of some trees of Bruquiera qymnorhiza 
growing to about 10 m and Ceriops taqal growing to about 7 
m, about 100 m away and about 2 m higher than the high water 
mark of the Negombo estuary. These trees were planted by man. 
It is also known that most mangrove species can be grown in 
freshwater (Mepham & Mepham, 1985). Thus, other factors would 
also have contributed significantly to restricting the 
mangroves in the west coast to narrow strips. Among these 
factors, human interference appears to be the most important 
which also would have caused the disappearance of the mangroves 
in some localities and the reduction of the extent of mangroves 
in the other localities to the present very low level. The 
relatively less interference seen in the Kala Oya mangrove 
can be attributed to the fact that it forms the south-west 
boundary of the Wilpattu National Park and is therefore 
strictly p r o t e c t e d . 
Five kinds of mangroves, namely, riverine, fringing, 
scrub, overwash and basin, are described in Sri Lanka depending 
on the topography, flooding characteristics and floristic 
composition. Balasubramaniam (1985) describes Nypa fruticans, 
Sonneratia caseolaris, Bruguiera sexanqula, Rhizophora 
apiculata and Dolichandrone spathacea communities as 
K.H.G.M. DE SZLVA AND S. BALASUBRAMANIAM 
29 
characteristic of the riverine type, and R.mucronata, B. 
qvmnorhiza, Avicennia officinalis, Aeqiceras corniculatum, 
Lmnitzera racemosa and E?coecaria agallocha communities as 
characteristic of the fringing type, and shows that riverine 
mangroves are present in river estuaries along the south and 
south west coasts, and fringing mangroves in Batticaloa, Rekawa 
and along other shallow estuaries. He also describes the 
floristic composition of the other types. Amarasinghe ? 
Perera (1984) recognize four types of mangroves, namely, 
riverine, fringing, scrub and overwash, in the Puttalam-
 Kalpitiya region (dry zone) on the topography and flooding 
characteristics. They consider the mangroves along the shore 
line of the mainland and of larger islands in the region as 
the fringing type, and those on the estuaries of KalaOya and 
Mi Oya as the riverine type. In the present study, no clear 
cut difference was observed in the floristic composition of 
the mangroves at river mouths and those bordering the other 
estuaries either in the dry zone or in the wet zone (Table 
1 ) . However, the trees in the mangroves in the river mouths 
showed more luxuriant growth than those in the mangroves of 
other estuaries, as has been noted by others in other countries 
as well. It appears that the communities cited as 
characteristic of the riverine type by Balasubramaniam (1985) 
are characteristic of . the wet zone mangroves, and those cited 
as characteristic of the fringing type are characteristic of 
the dry zone mangroves. The floristic compositions of the 
two types appear to depend on the salinity prevailing in the 
estuaries. For instance, Nypa fruiticans, found in the wet 
zone, has a low salinity tolerance whereas Avicennia marina, 
found predominantly in the dry zone, has a high salinity 
tolerance. Moreover, the presence of the freshwater atyid 
shrimps (Caridina spp.) as well as the freshwater zooplankton 
species in the wet zone estuaries indicate the low salinity 
conditions prevailing in them. The presence of marine 
zooplankton species such as Caprella sp. in Kalpitiya estuary 
indicates the high salinity conditions prevailing there. High 
rainfall and high and fairly evenly distributed drainage from 
the surrounding land as well as from the rivers throughout 
the year make the wet zone estuaries less saline. The wet 
zone receives rains throughout the year but specially during 
the periods April-May and October-December, and the annual 
rainfall in the coastal wet zone ranges from 1,900 to 2,500 
mm. The dry zone, on the other hand, receives rains mainly 
during the period October-December, and the annual rainfall 
in the coastal area ranges from 900 to 1,800 mm. The rains 
in the dry zone are very seasonal, whereas those in the wet 
zone are more evenly distributed. For each km 2 of catchment 
area the annual discharge ft.om rivers in the wet zone ranges 
from 4.8 x 10 to 2.4 x 10 m 3, whereas that from rivers in the 
30 
MANGROVES OF SRI LANKA 
dry zone ranges from 6.0 x 10 to 4 .8 x 10 m3 (Abeywickrama, 
1964). Thus the mean discharge of the r iver Kalu in the wet 
zone would be 125 cumecs whereas that of Kala Oya in the dry 
zone (which has a catchement area s imilar in extent t o that 
of r iver Kalu) would be only 26 cumecs. 
I t i s perhaps bet ter to d i s t ingu i sh between low-
 s a l i n i t y (wet zone) and high s a l i n i t y (dry zone) mangroves 
on the f l o r i s t i c d i f ferences (as discussed e a r l i e r ) . Each 
of these types could be further divided into r iver ine and 
estuarine types depending on whether they border r iver mouths 
or other e s t u a r i e s . Four types of high s a l i n i t y - e s t u a r i n e 
mangroves could then be dist inguished depending on the 
geomorphic and flooding c h a r a c t e r i s t i c s . These are ( i ) the 
fr inging mangrove, which i s commonly found on the shores of 
the mainland bordering the e s tuar ie s and on. the shores of the 
i s lands in the e s tuar i e s ; ( i i ) the scrub mangrove, which 
appears t o develop under hypersaline condi t ions; ( i i i ) the 
overwash mangrove, which are flushed at each t i d e ; and ( iv ) 
the basin mangrove (which i s not present in the wet zone) which 
develops in low-lying b a s i n - l i k e e s tuar ie s ( e . g . Vadamarachchi 
estuary in the north (Fig . 1) in which sediment from land 
drainage i s reta ined. 
Almost a l l mangroves on the west coast are disturbed 
by man to a greater or l e s s e r degree, and therefore , well 
marked eco log ica l zonation i s often not seen. According t o 
Watson's (1928) innundation -c lasses described for Malaysian 
mangroves (Fig . 4 ) , the following eco log ica l zonation could 
be expected: Avicennia marina/ Sonneratia .alba/ Rhizophora 
spp. at the lower edge followed by Aegiceras corniculatum/ 
Avicennia off ic inal is /Bruguieta- spp./Ceriops tagal/Xylocarpus 
granatum followed by Acanthus i l i c i f o l i u s / Excoecaria 
agallocha/Lumnitzera racemosa/Sonneratia caseo lar i s followed 
by the mangrove a s soc ia t e s in the back mangrove. Lack of c l ear 
eco log ica l zonation in the mangroves of Sri Lanka may be part ly 
due to the small t i d a l amplitude experienced. However, 
whatever eco log ica l zonation that ex i s ted has great ly been 
disturbed by man. I t i s well known that once the w e l l -
 es tabl i shed eco log ica l balance i s disturbed, i t takes a long 
time for the proper zonation t o r e - e s t a b l i s h . If the 
disturbance per s i s t ed , then the proper zonation w i l l not r e ?
 e s tab l i sh at a l l . Development of many back mangrove spec ies 
such as Acrostichum aureum among the cere species even in the lower border 
of the mangrove, and the absence of tall trees indicate that the dominant trees 
had been removed. Tansley & Fritsch (1905) even at the beginning of 
t h i s century noted the e f f e c t of human interference on the 
Sri Lankan mangroves. 
K.H.G.M. OE SILVA AND S. BALASUBRAMANIAM 
31 
The wide distribution of Acanthus ilicifolius in the 
islands of the Negombo estuary (Fig. 2) seems to have led 
Abeywickrama (1964) to postulate that the earliest 
phanerogamic colonizer in mudflats is A.ilicifolius. According 
to him, this will first cover the entire surface of the small 
islands, and species such as Bruguiera spp. and Aegiceras 
corniculatum will invade later and form a mixed mangrove. 
Pinto (1982) also supports this hypothesis and suggests that 
the succession of plants in the islands of Negombo estuary 
took place with A^ ilicifolius pioneering followed by 
Rhizophora spp./B. gymnorhiza mixed vegetation and finally 
by Rhizophora spp./Avicennia marina vegetation. According 
to this view, at least one island, which is at present almost 
covered with A? ilicifolius, is still at the first stage of 
succession. However, this is unlikely as the islands are not 
of recent origin and since there is also no evidence that the 
islands had been totally denuded of all vegetation recently. 
It is more likely that A.ilicifolius has become the dominant 
plant as a result of selective destruction of other mangrove 
species by man allowing A^ ilicifolius to spread. In the 
mudflats exposed even today by the denudation of the 
vegetation, seedling establishment of Rhizophora spp. and 
Avicennia marina could be-observed, in this connection, it 
is noteworthy that Macintosh (1982) in his study of Malayan 
mangroves showed that in the Indo-Pacific region the 
pioneering mangrove species in coastal deposition shores are 
Avicennia spp. and Sonneratia spp. and those in more estuarine 
localities are Rhizophora spp. 
In the south, west and east coasts considerable tracts 
of mangroves have recently been cleared for construction of 
hotels and provision of recreation facilities to tourists. 
The diversion of the Mahaweli Ganga, the largest river in 
the country, for irrigation purposes may affect the mangroves 
in Trincomalee area (Fig. 1) by reducing the amount of 
nutrients carried to the estuary and also by carrying and 
discharging agricultural pesticides and residues. This scheme 
may also affect the mangroves in Kala Oya (west coast) and 
Maduru Oya (east coast) estuaries as water from the Mahaweli 
is diverted into these two rivers as well. 
The clearing of mangroves and the reclamation of 
mangrove land for various purposes go on, and no serious 
attempt has still been made to educate the local people about 
the value of the mangrove ecosystem. Without such education, 
legislation against the destruction of the mangroves will be 
of little use. Unless serious steps are taken urgently to 
conserve at least what is left, Sri Lankan mangroves are doomed. 
32 
MANGROVES OF SRI LANKA 
ACKNOWLEDGEMENTS 
We wish to thank Professor M.D. Dassanayake of 
Department of Botany and Dr.(Mrs.)P. Kumari de Silva of 
Department of Zoology, University of Peradeniya for their 
help and advice during this study. We are also grateful to 
Mr. N.M. Moiyadeen, O.I.C., NARA Regional Research Station, 
Kalpitiya for the help and facilities provided during the 
study, - and to Dr. J.M.R.S. Bandara, Head, Department of 
Agricultural Biology, and Professor K. Jayasena, Head, 
Department of Pharraocology, University of Peradeniya for 
providing vehicles to visit various sites. Thanxs are also 
due to Mr. T.S.B. Alagoda for drawing the figures. This work 
was supported by the research grant RGB/Gen/50 of the Natural 
Resources, Energy and Science Authority of Sri Lanka and we 
wish to record our appreciation to Dr. R.P. Jayawardene, 
Director General, and Dr. S. Liyanage, Assistant Director, 
for provision of funds. 
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survey of peripheral vegetation communities of 
Puttalam lagoon and Dutch bay. Proceedings of the 
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1984 (Abstract). 
Arulchelvam, K. (1968). Mangroves. Ceylon Forester, VIII 
(3 ? 4 ) : 1-34. 
Balasubramaniam, S. (1985). Tree flora in Sri Lanka. In: 
Proceedings of the International Conference on Timber 
Technology, . 24-26 October, 1984. Jayatilleke, A. 
(ed.) Univ. of Moratuwa, Sri Lanka. 58-67. 
Balasubramaniam, S., Rasiah:, P. and Ratnapala,M.L. (1970). 
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1: 15-20. 
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Jayawardene, R.P. (1985). The mangroves of Sri Lanka. 
Bakawan, IV (1): 8-10. 
Kanakaratne, M.D., Perera, W.R.T. and Fernando, B.U.S. 
(1984). An attempt at determining the mangrove 
coverage around Puttalam lagoon in Sri Lanka through 
remote sensing techniques. Proceedings of the 4th 
Asian Conference on Remote Sensing, Colombo. 1983. 
9 PP. 
Macintosh, D.J. (1982). Fisheries and aquaculture 
significance of mangrove swamps, with special 
reference to Indo-West Pacific region. In: Recent 
Advances in Aquaculture. Muir, J.F. and Roberts, 
R.J. (eds.), Croom Helm, London. 3-85. 
Macnae, W (1968). A general account of the fauna and flora 
of mangrove swamps and forests in the Indo-West 
Pacific region. Adv. mar. Biol., 6: 73-270. 
Mepham, R.H. and Mepham, J.S. (1985). The flora of tidal 
forests - a rationalization of the use of the term 
'mangrove'. S. Afr. J. Bot. 51 (2): 77-99. 
Odum, E.P. (1971). Fundamentals of ecology. W.B. Saunders 
Co., London. 352 p. 
Pinto, M.L. (1982). Distribution and zonation of mangroves 
in the northern part of the Negombo lagoon 
(Sri Lanka). J. natn. Sci. Coun. Sri Lanka, 10 (2): 
245-255. 
Pritchard, D.W. (1967). what is an estuary: physical 
viewpoint. In: Estuaries, (Lauff, G.H. (ed.). Amer. 
Assoc. Adv. Sci. Publ. No. 83, Washington, D.C. 3-
 5 PP. 
Tansley, A.G. and Fritsch, F.E. (1905). Sketches of 
vegetation at home and abroad. I. - The Flora of 
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1-45. 
Tennent, E. (1859). Ceylon, an account of the island. Vol. 
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Watson, J.G. (1928). Mangrove forests of the Malay 
peninsula. Malay For. Rec. 6: 1-275. 
TABLE 1 
DISTRIBUTION OF MAJOR CORE SPECIES IN SOME OF THE MANGROVES IN WEST COAST OF SRI LANKA 
ABUNDANCE OF EACH SPECIES IS INDICATED IN AN ARBITRARY SCALE OF 1-5. 
(1 very common; 
W E T 
RIVERINE 
Gin Ganga 
Acanthus ilicifolius 
Aegiceiras corniculatum 
Avicennia marina 
Bruguiera cylindrica 
5 i gyronorhiaa 
sexangula 
Ceriops tagal 
Excoecaria i agallocha 
Lumnitzera racemosa 
N^ga fruticana 
Rhizophora apiculata 
R. mucronata 
Sonneratia alba 
4 
2 
4 
4 
4 
3 
common; frequent; 
Z O N E 
ESTUARINE 
Hikkaduwa 
estuary/ 
islets in 
Balapitiya 
estuary 
2 
3 
4 
3 
4 
3 
Islets in 
Negombo 
estuary 
rare; 5 - very rare) 
D R Y Z O N E 
RIVERINE 
Kala Oya 
Pomparippu 
Aru 
S. caseolaris 
1 
4 3 
1 2 
4 5 
2 3 
5 
3 2 
3 2 
3 3 
5 (Maha Oya 
river estuary) 
3 3 
1 1 
4 4 
ESTUARINE 
Islets and 
mainland in 
Kalpitiya 
area 
5 
3 
1 
Mainland in 
Mundel 
estuary 
2 
2 
3 
4 
1 
3 
5 
K.H.G.M. DE SILVA ANO S. BALASUBRAMANIAM 35 
TABLE 2 
SPECIES OF MANGROVE PLANTS, MANGROVE ASSOCIATES, ANO 
SEA6RASSES OF SRI LANKA 
Core species of mangroves 
Acanthaceae 
Acanthus i l ic i fol ius L. Katu Ikiri (S) Kadalmulll (T) 
Avicenniaceae 
Avicennia marina (Forsk.) Vierh Manda (S) 
A. officinalis L. 
Combretaceae 
LumAitzera littorea 
(Jack; J.O. Volgt 
L^ racemosa Willd. 
Meliaceae 
Xylocarpus granatum Koenig 
X. moluccensis (Lamx)M. Roem 
Myrsinaceae 
!
 icera 
lanco 
Aegi s corniculatum (L.) 
Rath beriya (S) 
Beriya (S) 
Mutti kadol (S) 
Mudu-delun (S) 
Avari kadol (S) 
Gin-pol (S) 
Mai kadol (S) 
Rath kadol (S) 
Ela kadol (S) 
Kanna (T) 
Venkandal (T) 
Kanna (T) 
Upu attha (T) 
Thlpparethai (T) 
Kontalai (T) 
Vettilaikanna (T) 
Narikandal (T) 
Palmae 
Nypa fruticans Wurmb. 
Rhizophoraceae 
Bruguiera cylindrica (L.) Blume 
B. gymnorrhiza (L.) Willd. 
B. sexangula (Lour.) Poir. 
Ceriops decandra (Griff.) Ding Hou Heen kadol (S) 
C tagal (Perr.) C.B. Rob. Heen kadol (S) 
Rhizophora apiculata Bl. Rana kadol (S) 
Rj. mucronata Lam. Murunga kadol (S) 
Rubiaceae 
Scyphiphora hydrophyllacea 
Gaertn.f. 
Sirukandal (T) 
Chlrukandal (T) 
Kandal (T) 
Kandal (T) 
36 [A] K.H.G.M. OE SILVA AND S. BALASUBRAMANIAM 
Dalbergia candenatensis 
(Dennst.) Prain 
Derris heptaphy)la (L.)Merr. 
D. heterophylla (Willd.) Back 
(=0.ul1q1nosa) 
Ponqaroia pinnata (L.) Pierre 
Gramineae (Poaceae) 
Cyperus rotundus L. 
Zoysia matrella (L.) Merr. 
Guttiferae (Clusiaceae) 
Calophyllum inophyllum L. 
Lythraceae 
Pemphis acidula J.R. & G. Forst 
Malvaceae 
Hibiscus tiliaceus L. 
Thespesia populnea (L.) 
Solander ex Correa 
T. populneoides (Roxb.) 
Kosteletsky 
Hernandiaceae 
Hernandia oviqera L. 
Lecythidaceae 
Barrinqtonia asiatica (L.)Kurz 
B. racemosa (L.) Bl . 
Pandanaceae 
Pandanus odoratissimus L.F. 
Stercullaceae 
Heritiera littoralis Dryand 
Tamaricaceae 
Tamarix qallica L. 
Verbenaceae 
Clerodendron inerme (L.) Gaertn 
Premna inteqrifolia Lam 
(=P. foetida Reinw.) 
Kala-wel (S) 
Kalanduru (S) 
Domba (S) 
Belipatta (S) 
Gan suriya (S) 
Suriya (S) 
Diyamidella (S) 
Dlyamldella (S) 
Wetakeyya (S) 
Athuna (S) 
Wal-gurenda (S) 
Wal midi (S) 
Pungal (T) 
Korai (T) 
Punnal (T) 
Vellai (T) 
Poovarusu (T) 
Samuthram (T) 
Thall (T) 
Chomunthiri (T) 
Pichuvilathi (T) 
Erumai-mullai (T) 
36[B] MANGROVES OF SRI LANKA 
Sonneratiaceae 
Sonneratla alba J. Sm. 
S. apetala Buch-Ham. 
S. caseolaris (L.) Engler 
Mangrove associates 
Annonaceae 
Annona glabra L. 
Apocynaceae 
Cerbera odollam Gaertn. 
Qchrosia oppositifolia 
(Lam) Scnum 
Ai zoaceae 
Sesuvlum portulacastrum (L.) L. 
Bignoniaceae 
Oolichandrone spathacea 
(L.f . ) K. Sehum. 
Chenopodi aceae 
Arthrocnemum Indicum (Willd.)Moq. 
Salicornia brachiata Roxb. 
Suaeda maritima (L.) Dumort 
Sj. monoica Forsk. ex J.F.Gmel 
S. nudiflora (Willd)Moq. 
Compositae (Asteraceae) 
Sphaeranthus amaranthoides Burmf. 
S^ africanus L. 
Cyperaceae 
? Fimbristylis ferruginea (L.) Vahl 
Schoenoplectus Uttoralis 
(Schrad)Palla. 
Euphorbiaceae 
Excoecarla agallocha L. 
Fabaceae (Leguminosae) 
Cynometra 1ripa Kostel 
C. bijuga var. mimosoides Merr. 
Sudu mal klrala (S) Vellal-kinnai (T) 
Rath mal klrala (S) Klnnal (T) 
Wal anoda (S) Kadal-attha (T) 
Gon-kaduru (S) Nachchukal (T) 
D1ya-Danga (S) V1lpath1r1 (T) 
Mankulanchl (T) 
Kotanal (T) 
Um1r1 (T) 
Um1r1 (T) 
Um1r1 (T) 
Thelakeerlya (S) Th1lla1 (T) 
Kadupull (S) 
MANGROVES OF SRI LANKA 3 7 
Healparasites on mangroves & mangrove associates 
Loranthaceae 
Dendrophthoe falcata (L.f .) Danser PI111a (S) Kuruvlchal (T) 
Aeglceras corniculatum 
Viscaceae 
Vlscum orlentale Willd. 
on 
Excoecaria agallocha 
and 
Tehspesla populnea 
Mangrove fern 
Adlantaceae 
Acrostichum aureum L. Karenkoku (S) M1nn1 (T) 
Sea grasses 
Hydrocharitaceae 
Enhalus acoroldes (L.f.) Royle 
Halophila deciplens Ostenf. 
H. oval1s (R.Br.) Hook f. 
Thalassia hemprichii (Ehrenb.) Aeschers 
Najadaceae 
Najas graminea Del. 
marina L. 
Potamogetonaceae 
Cymodocea serrulata (R. Br.) Aeschers & Magnus 
Halodule uninervis (Forsk.) Aeschers 
(aD1pianthera uninervis) (Forsk) Aeschers) 
Potamogeton pectinatus L. 
Ruppia maritlma L. 
Syrinqodium Isoetifolium (Aeschers) Dandy 
38 
K.H.G.M. DE SILVA AND S. BALASUBRAMANIAM 
LEGENDS TO FIGURES 
FIGURE 1: Inland water resources of Sri Lanka. Estuaries 
studied are] indicated by arrows. Dry zone and wet 
zone are also indicated. 
FIGURE 2. (a) upper part of Kalpitiya estuary and 
(b) upper part of Negombo estuary. Dotted 
are magroves. 
areas 
FIGURE 3: (a) Balapitiya estuary and 
(b) Hikkaduwa estuary and surrounding 
plantations. Dotted areas are mangroves. 
C- coconut; N-cinnamon; R-rubber; M-marsh. 
crop 
FIGURE 4: Ecological distribution of major mangrove core 
species according to Watson's (1928) innundation 
classes. Classes 1,2,3,4, and 5 indicate areas 
inundated by all high tides, medium high tides, 
normal high tides, spring tides and equinoctial tides 
respectively. 

INDIAN 
OCEAN E S T U A R Y 
PERIYA 
, A R C H C H A L 
K I R I M U N D E L 
S I N N A 
O O O A K A R E N T I V U ^ A R C H C H A L 
K O V J L K U D A H ^ K ^ N E R U M A T V U 
^ff " " M A T T U T I V U 
^ A M B A N T A T I V U 
PULLUPIDDI 
? ESTUARY 
Q 
K A N O A K U D A H 

Inundation Classes 
Acanthus ilicifolius 
Aegiceras corniculatum 
Avicennia marina 
A. officinalis 
Bruguiera cylindrica 
B. gymnorhiza 
8 . sexangula 
Ceriops tag a I 
Excoecaria agallocha 
Lumnitzera racemosa 
Nypa fruticans 
Rhizophora apiculata 
ft. mucronata 
Sonneratia alba 
S . caseolaris