MACROPHYTES OF WETLANDS OF GOA
THESIS SUBMITTED TO THE GOA UNIVERSITY FOR THE AWARD OF DEGREE OF
DOCTOR OF PHILOSOPHY IN
BOTANY
BY
SIMA V. KAMAT, m.sc.
Guide Dr. R. V. Gaonkar
Reader, Department of Botany,
S. P. Chowgule Cultural Foundation's College of Arts & Science Margao - Goa.
r, p Co-guide
/11 /," Dr. D. J. Bhat
/ Professor & Head, Department of Botany Goa University.
6- 8 0
Margao - Goa
7-- 9
Smt. Parvatibai Chowgule Cultural Foundation's College of Arts and Science
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Countersigned by
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(Si amat)
I
DECLARATION
I hereby declare that the Ph.D. thesis entitled " STUDIES ON DISTRIBUTION, ECOLOGY AND TAXONOMY OF MICROPHYTES AND MACROPHYTES OF WETLANDS OF GOA " submitted to Goa University, forms an independent work carried out by me in the Department of Botany, Smt. Parvatibai Chowgule Cultural Foundation's College of Arts and Science, Margao-Goa, under the supervision of Dr. R.V.Gaonkar, Reader, Department of Botany, S.P.Chowgule Cultural Foundation's College of Arts and Science and Dr. D.J.Bhat, Professor and Head, Department of Botany, Goa University and the thesis has not formed previously the basis for the award of any degree, diploma, associateship or other similar titles.
CERTIFICATE
We certify that the thesis entitled 'STUDIES ON DISTRIBUTION , ECOLOGY AND TAXONOMY OF MICROPHYTES AND MACROPHYTES OF WETLANDS OF GOA' SUBMITTED BY Ms. Sima V. Kamat , is a record of research work done by her during the period from 2000 - 2003 when she worked under our supervision . The thesis has not formed the basis for the award of any degree , diploma or any associateship to Ms. Sima V.
Kamat .
We affirm that the thesis submitted by Ms. Sima V. Kamat incorporates the independent research work carried out by her under our supervision.
III
CONTENTS
PAGE NO.
INTRODUCTION 1 -22
REVIEW OF LITERATURE 23-33
CHAPTER I DISTRIBUTION OF 34-46
FRESHWATER WETLANDS IN THE STATE OF GOA.
CHAPTER II DESCRIPTION OF 47-92
FRESH WATER WETLANDS OF GOA.
CHAPTER III MICROPHYTES OF 93-127
FRESHWATER WETLANDS OF GOA.
CHAPTER IV MACROPHYTES OF 128-175
FRESHWATER WETLANDS OF GOA.
CHAPTER V A CASE STUDY OF TWO 176-205 FRESHWATER WETLANDS.
CHAPTER VI POSSIBLE THREATS REALIZED 206-215 AND NEEDFUL CONSERVATION
MEASURES RECOMMENDED.
RFERENCES 216-230
APPENDIX
ACKNOWLEDGEMENT
I am highly indebted to Dr. R.V. Gaonkar, Reader, Department of Botany, Smt. Parvatibai Chowgule Cultural Foundation's College of Arts & Science and Prof. D.J. Bhat, Head, Department of Botany, Goa University, for their valuable guidance, help and constant encouragement throughout the period of this research.
I am grateful to Dr. S. Raghukumar, Scientist, National Instiute of Oceanography for his valuable suggestions, help and constant encouragement throughout the period of this research.
I sincerely acknowledge the following for various help extended to me during the course of my Ph.D. work: Dr. H.B. Menon, Reader, Department of Marine Science, Goa University, for extending material and information on remote sensing; Dr. M.K. Janardhanam, Reader, Department of Botany, Goa University, for helping with plant identifications; Shri Ashok Kumar, ICAR, Old Goa for lending statistical packages; Shri Anant Patil, Department of Computer Science, Smt. S. P. Chowgule College of Arts & Science, Margao for digital photography and formats of Tables.
I am very much thankful to Dr. A.G. Untawale, former Deputy Director, National Institute of Oceanography, Goa, Prof. S.R. Yadav, Department of Botany, University of Delhi, and Dr. P. Bhattacharya, my colleague in the Department, for useful suggestions, encouragement and help.
I am grateful and indebted to Dr. A.K. Heblekar, ex- Principal and Dr. A.S.
Dinge, Principal, of P. E. S. College for persuading, encouraging and providing me all facilities to conduct research in the College.
I am indebted to the staff members of Soil Testing Laboratory, Ella Farm, Meteorology Department, Goa, and my own teaching and non-teaching staff in the Department for their assistance during this work.
I wouldn't have accomplished everything in my thesis without the support of my family members whose persuasion, encouragement and help were simply enormous.
Sima V. Kamat
INTRODUCTION
Water being an important component of life forms, its abundance on planet earth has given this planet a unique status of being the only body known to date supporting millions of life forms varying in size and complexity. Even though life forms on earth have adopted to a variety of geo-climatic conditions, it has been found that biodiversity and population density of all life forms is several times more in places where there is abundance of water than the drier ones. As per the estimates made by Scientists, the five Oceans covering about 70% of earth's surface (60% of northern hemisphere and 80% of southern hemisphere) together hold about 97% of earth's total water. The water held by five oceans has varying degree of salinity. The remaining 3% of earth's total water is freshwater.
Major portion, i.e. 70% of earth's freshwater, is again trapped in Antarctica's ice cap (on an average 2.2 km thick spread over 14,000,000 km2). The remaining 30% of earth's freshwater is found in the glaciers of other continents. Statistically very small amount of earth's freshwater is found as ground water, or in springs, streams, rivers, ponds, lakes and various other freshwater wetlands. The longest river in the world is said to be Nile with a course length of 6,671 km, followed by river Amazon with a course length of 6,437 km. In terms of water flux river Amazon ranks
2
first with its water content exceeding that of next three rivers put together, including river Nile and river Yangatse. (World Book, Millennium 2000) .
India receives a total precipitation of about 4,000 b m 3 as rainfall and snowfall annually. Out of these 1,869 b m 3 is accessible. Out of the accessible water, 690 b m3 are used and 1,179 b m 3 drain back into the sea as unused (India Today, Jan 20, 2003).
Freshwater environment has been part of human evolution and revolution since time immemorial which is evident from the historical fact that all the ancient civilisations were on the banks of perennial rivers or at least in places where freshwater was easily available. Wetlands in addition to providing mankind with it's basic requirement of water for direct consumption and irrigation also provide food, fodder, fiber, etc. on account of their high productivity and rich plant resources. With ever increasing population and its ever increasing demands exerting strain on earth's limited resources it became pertinent to study the functioning of one of the earths richest and renewable resources. No wonder that wetlands attracted the attention of a number of researchers all round the globe.
Wetlands are widespread in large areas of the world especially in the humid tropics on one hand and the arctic zone on the other. Wetlands support spectacular concentration of wetland-dependent wildlife, such as the more than 2 million shorebirds visiting both the Banc d'Arguin National Park in Mauritania and the Wadden Sea in northern Europe, or the 30,000
black lechwe antelope that inhabit the Bengweulu Basin in Zambia. They also support charismatic species such as the hippopotamus, shoebill stork, and jaguar. Wetlands may be individually recognized for their endemic species such as Lake Tanganyika, with 1,470 animal species, 632 of which are found in that lake only, and the Amazon river which boasts 1,800 species of endemic fish.
Spectacular statistics aside, wetlands in general are home to a great diversity of species. Although freshwater ecosystems cover only 1 % of the earth's surface, they hold more than 40 % of the world's species and 12 % of all animal species. On the marine front, coral reefs are among the most biologically diverse ecosystems on the planet, rivaling tropical rainforests, the most diverse of the land ecosystems. Although they cover only 0.2% of the ocean floor, coral reefs may contain 25% of all marine species. The Great Barrier Reef in Australia alone is home to 1,500 species of fish and 4,000 types of molluscs. Four thousand species of fish and 800 species of reef- building corals have already been described for reefs, but the total number of species associated with reefs is quite likely to be more than a million.
India by its unique geographical position (8 ° 4' to 37° 6'N latitude and 68° 7' to 97° 25'E longitude) and a coastline of over 7,516 km, with its major river systems and some of world's highest mountains has a wealth of wetlands. India has three major river systems in the north, the Indus, the Ganga and the Brahmaputra. The largest wetland of India is the
Indo-Gangetic flood plains. In the south we have three major river systems, the Krishna, Godavari and Cauveri. They are rain-fed and non-perennial. In central India we have the Narmada and Tapti. Most of the natural wetlands of India are connected with the river systems of north and south. There are also various man made and natural wetlands like Harika Barrage, Bhakra Nangal Dam, Kabar lake, Chilka lake, the Picchola complex and Sukhana lake. In all, India has about 4.1 million hectares of wetlands of which 1.5 millions are natural and 2.6 millions are man made (Chatrath,
1992). The total area of wetlands (excluding rivers) in India is 58,286,000 ha. or 18.4 % of the country, 70 % of which comprises areas under paddy cultivation. A total of 1,193 wetlands covering an area of about 3,904,543 ha. were recorded of which 572 were natural (DST 1989).
Definition
Wetlands have been defined as swamps and other damp areas of land but in common parlance the word is used interchangeably with "lakes", which denotes a large body of water surrounded by land (Chatrath, 1992). The internationally accepted definition of wetlands given at Ramsar Convention, 1971 describes them as "areas of marsh fen, peat-land or water, whether natural or man made permanent or temporary with water that is static or flowing fresh brackish including areas of marine water the depth of which does not exceed six metres.
Wetland ecosystem is characterised by poor drainage and the consequent presence of sluggishly moving or standing water saturating the soil either all or most of the time. Wetlands are transitional systems between purely terrestrial and aquatic ones, where water table is usually either at or near the ground level or up to six metres above it.
In general wetlands are lands where saturation with water is dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface. The water creates severe physiological problems for all plants and animals except those that are adapted for life in water or in saturated soils. In its broader sense, all rivers, lakes, ponds, paddy fields and periodically flooded lands can be called wetlands.
As per the U.S. Department of International Fresh and Wildlife Services, wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface of the land is covered by shallow water. Any land to be called as wetland should have following attributes:-
1) At least periodically the land supports predominantly Hydrophytes.
2) The substrate is predominantly un-drained hydric soil.
3) The substrate is non-soil and saturated with water or covered by shallow water at some times during the growing season of each year.
By which ever criteria we define wetlands one fact is indisputable - these are crucial to our well being.
Freshwater wetlands associated with both lentic and lotic water bodies are widely distributed throughout the sub-continent from sea level to Himalayan ranges. The diversity of wetlands is enhanced by the large and seasonal variability in the rainfall. There are more man-made wetlands than natural wetlands. The man-made wetlands are used for agriculture, aquaculture and water storage for human settlements and/or industries. The natural wetlands range from temporary ponds and seasonal flood plains to permanent freshwater marshes. Wetlands perform useful functions in the maintenance of overall balance of nature. Man-made wetlands include shallow ponds small reservoirs and numerous village tanks.
Classification of Wetlands
In earlier works (Cowardin et al.,1979 ) as quoted by (Abbasi, 1997) the wetlands have been classified as follows
Natural Wetlands Saltwater wetlands
Marine a) Subtidal example Coral Reef and
Esturine a) Subtidal e.g. Esturian Waters b) Intertidal e.g. Swamp Forest
c) Lagoonal e.g. Saline or Brackish Lagoons.
d) Salt lake e.g. Alkaline Lakes.
Freshwater wetlands
Riverine a) Perennial e.g. Rivers and Streams b) Temporary e.g. Riverine Flood plains Lacustrine a) Permanent, e.g. Lakes and Ponds
b) Seasonal e.g. Lakes and Ponds
Palustrine a) Emergent e.g. Marshes, swamps, fens, pitlands b) Forested e,g. Swamp Forest.
Artificial (Man-made) Wetlands Aquaculture e.g. Fish Pond
Agriculture e.g. Rice fields, Canals and Farm Ponds Salt Exploitation e.g. Salt pans.
Urban/Industrial e.g. Sewage Farms Water storage e.g reservoirs
Commonly recognized major categories are bogs, fens, marshes, swamps and flood plains. Bogs are characterized by acidic peat. Fens have less acidic or somewhat alkaline or partly decomposed peat layers. Marshes are characterized by mineral soils with little or no peat accumulation. They
are associated with standing or running waters, both temporary and permanent. Swamps are with or without peat deposits. Both marshes and swamps occur along sea coast and in esturian delta region. Flood plains also called as bottom land are areas lateral to rivers and streams, whose overflow results in periodic flooding. Flood plains represent a complex of diverse habitats including marshes, swamps and shallow lakes.
In 1973, an aquatic weed survey was conducted by Department of Science and Technology, New Delhi, and estimates of wetland area were made. A wetland survey was attempted in 1984 by the Department of Environment, Government of India. The Ministry of Environment and forest, Government of India published another list of wetland which comprises mostly the temple tanks and multipurpose reservoirs. Recently, the WWF- India has revised and updated the Indian section of the Asian wetland directory with information on 77 wetlands.
Nutrient status of the wetland
The important physico-chemical and biological processes which occur in a wetland include sedimentation, storage, ion-exchange, nutrient uptake, absorption, adsorption, bacterial and fungal dissimilation, nitrification and de-nitrification. Rain fed peats are the most mineral deficient biotopes while ground water fens and swamps receive continuously mineral supply and also maintain conditions favourable for Nitrogen fixation. The
requirement for macronutrients and conservational mechanisms such as evergreen leaves which limit loss of nutrients. Some eutrophic wetland species particularly those of swamps and shallow water are capable of enormous growth rates and in favourable climates they are amongst the most biologically productive eco-systems.
In general, wetland plants exhibit high growth rates during flooding and also have a high turn over in photosynthetic organs (Gopal, 1992).
Alternate flooding and drying have stimulant effect on growth. The large proportion of the nutrients absorbed during growth is translocated to below ground storage organs during senescence. These nutrients are then transported to young shoots for use in the next growing period.
Nitrogen fixation and de-nitrification processes occur in most of the tropical wetlands. The nitrogen balance of rain-fed wetlands is dominated by contributions from blue-green algal functions. Blue-green algal nitrogen fixation is also found in the rice fields. The high temperature and flooded soil encourage both free living algal species and the symbiosis of Anabena with Azolla.
Functions and significance of wetlands
Wetlands are more productive than adjacent eco-system in a region.
The wetland vegetation is an important source of human food, fodder and fuel (Gopa1,1992). They also serve as gene pools act as regulators of
nutrients and sediment transport to the water systems. They regulate the water flow, trap silt, process nutrients and regulate the supply of detritus to open water systems. The plants growing in these wetlands act as traps for suspended soil particles in the water and also dissolved nutrients. The macrophytes and lower plants like algae act as prime producers. The macrophytes provide habitats and food for insects and spawning ground for fishes of various types. Aquatic fungi and bacteria help in recycling of dead organic matter. Wetlands not only trap sediments and prevent siltation, they also control erosion by binding sediments to their root systems. They also act as sponges and can absorb enormous amounts of water passing through them, thus preventing floods downstream. Wetlands have a very high biodiversity. Besides the important functions stated above protection of floral and faunal habitats, and gene pool, utility as recreational grounds, providing outputs of commercial value and economic sustenance for the people are some of the major benefits of wetlands. The classic case of biodiversity in wetlands turning out to be a valuable reservoir of genes is that of rice. Rice is a common wetland plant and the staple diet for over half the world's population. Wild rice continues to be an invaluable source of new genetic material for developing disease resistance, yet many different varieties of rice have disappeared in recent years leaving us dependent on a shrinking genetic base. A typical lifespan of a commercially-bred crop variety has been estimated at 5-10 years before
new genetic material is required to combat pest and disease problems. The value of such traits on a global scale is counted in billions of dollars.
Benefits of wetlands
1. Benefits directly cognizable in monitory terms such as agriculture, fishing, water supply and power generation.
2. Indirect benefit not encashable such as flood control, food chain support and biodiversity.
3. Asthetic benefit such as providing sites, creative stimulus and mental relaxation.
Previous Work
Although many wetlands were studied for their vegetation, water quality, systematic survey and their distribution, the area covered and general characteristics had not been made long before. In 1973, aquatic weed survey conducted by the DST, New Delhi, it was reported existence of 1193 wetlands covering an area of 39,045 km 2 from 274 districts out of a total 385 in the country. The Ministry of Environment and Forests, Government of India, has published another list of wetlands which comprises mostly of temple tanks, fishery reservoirs and some multipurpose reservoirs (Annonymous, 1990). Recently the WWF- India has revised and updated the Indian section of the Asian Wetlands Directory with information on 77 additional wetlands (WWF- India, 1993).
As far as India is concerned a detailed study of wetlands of Kolleru, Picchola, Kashmir, Bihar, Kerala, etc. has been conducted and information of these wetlands is available. However, information on freshwater wetlands of the State of Goa is scanty; presence of only four out of numerous such wetlands existing in the state has been recorded. An effort has been made by Inamdar et. al. (1998) to prepare an atlas of all wetlands of the state using remote sensing technology (satellite imagery). To a major extent, barring the limitations of the technology, the work has been successful and has served as a guide in locating major freshwater wetlands for the
present study. As noted by the said authors, most of wetlands smaller than 2.25 ha. in area have been merely located in the atlas on account of limitations of the technology. Still some smaller wetlands were not shown in the map, e.g. Mopa, Torsem, Sirsai, etc. In all, the wetlands of Goa, whose atlas was prepared by Inamdar et.al . (1998) numbered 44 bigger wetlands (area more than 2.25 ha.), occupying between 10683 to 10881 ha. of land surface. These bigger wetlands included marine, esturine and freshwater and both natural and man-made wetlands, as well as coastal and inland wetlands. Among the smaller ones (area less than 2.25 ha.) 68 wetlands covering all types were located on these maps. As observed by Inamdar et.al . (1998), 18 number of inland wetlands occupied 2,145 ha of land, tidal flat/mud flat category occupied 6,579 ha., reservoirs occupied 978 ha. and Chorao Bird Sanctuary occupied approximately 240 ha. The wetlands put to regular agricultural use have not been included.
14
The State of Goa Geographical location
The state of Goa is a small, coastal enclosure in peninsular (southern half) India. It is located almost halfway mark of the western coast, with the states of Maharastra and further up Gujarat on its north and states of Karnataka and further down Kerala to its south. The geographical position is between 14° 53' 54" to 15 ° 48' 00"N latitude and 73° 40' 33" to 74° 20' 13"E longitude (Gazetteer Part I, 1979) ( Fig. 1) .
Geo-morphology and Geology
Substantial part of Goa belongs to basaltic outflows of deccan lavas with typical land forms of flat-topped summit levels with terraced flanks, wide opening valley courses with sides rising more as a succession of steps than as smooth slopes (Fig.2). The sahyadrian scarp steep and in many places bold, has been regarded as due to major faulting which created the western flank of the sahyadris as a whole. The topography of the basalts is due to weathering and water erosion on an intense, though highly seasonal scale.
Extensive laterisation is attributed to the tropical moist climate. There are limited outcrops of Granite rocks, metamorphic schists and shales belonging to Dharwarian series. More important are the recent alluvia spread along the river courses and coastal plains. These and the coastal sandy deposits along the coast are the most recent formations.
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The coastal plains sparingly interrupted by plateaus forming headlands:
The coastline of the State consists of long stretches of sandy plains interrupted at some points by low, flat plateaus forming headlands. Out of the seven coastal tehsils of Pernem, Bardez, Tiswadi, Mormugao, Salcette, Quepem and Canacona, the longest stretch of uninterrupted plains with no coastal plateaus, is found in Salcette tehsil, followed by Bardez. The other tehsils have small pockets of plain land interrupted by coastal plateaus forming headlands in some places except Quepem. Quepem tehsil has a coastline formed entirely by a single coastal plateau forming a prominent headland at Cabo-De-Rama.
The Central Region (between the coast on the west and the sahyadris on the east):
This region is mainly hilly. Flat-topped, broad plateaus with deep notched out gullies are common in this region as one proceeds from coast towards the interior of the State. These plateaus with an elevation of between 30-
100 m above MSL have sharp rims or edges and the scarp slope is steep and transition to lower coastal plains is abrupt. As one proceeds further east towards the Sahyadris the plateaus appear to be replaced by series of hills, higher in elevation and with rounded tops and numerous deep valleys between them.
16
The Sahyadris of Goa or the Western Ghats of India:
This range, with an average elevation of 800 m above MSL, on the eastern flank of the state occupies approximately 600 km 2 . Its crest-line extends almost like an arc of 125 km. The segments of this range are divided into three segments viz. Morlegad-Vagueri Complex, scarp of the eastern Goa border and the southern complex of extensions between Goa and Dharwar-Karwar (Uttar Kannada district). The prominent peaks are Sonsagar or Sosogad at 1300 m MSL, Catlanchimauli at 1200 m MSL, Vagueri at 1150m MSL and Morlegad 1050 m MSL, all of which are situated in Sattari tehsil.
Major portion of the State of Goa at the ground level, except for the coastal plains and riverine alluvia is covered by compact, hard, laterite crust or laterite soil. This laterite which is geologically very recent is hydrologically very important. Its thickness varies from 5 to 50 m. Also it is encountered from ground level on hills and plateau tops to as low as 75 m below ground level in coastal plains. This laterite cover is the main aquifer within boundaries of Goa. The laterite cover is in three forms, viz.
The hard, magenta-coloured crust usually found on the plateau tops, the gravelly laterite usually found below the hard laterite and clayey lithomarge. The base rocks whose top portion has undergone metamorphosis to form the laterites are both pre-Cambrian and Metavolcanic.
Rock type
Goa is almost entirely covered by rocks of the Goa group belonging to the Dharwar super-group of the Archaean /Proterozoic age, except for a narrow strip at the north — eastern corner occupied by deccan trap of the Upper Cretaceous/Lower Eocene age (Fig.3). The Goa group consisting of green schist species of metamorphic rock is divided into Barcem Formation, Sanvordem Formation, Bicholim Formation and Vageri Formation in the ascending order of superposition. The narrow strip of deccan trap has some sporadic cover of laterite.
Soil types
The difference between the mean annual summer temperature and mean annual winter temperature is 4 ° Celcius. Hence the soil temperature regime is Isohyperthermic. The soil moisture regime is Ustic, except in the Central region where the soil moisture regime is assumed to be Udic ( Goa-Soil Series, 2002). The soil map of Goa state is annexed hereto (Fig. 4).
Hydrology
The precipitation received by the state of Goa is under the influence of south-west monsoons which lasts for a maximum period of five to five and a half months (Table 1). After the monsoons the water supply to the various water bodies is supported by innumerable springs which are found
Table 1 showing rainfall record of the weather out-posts of Goa during the period 1993 - 2003
Outpost Canacona Mapusa Margao Mormugao Pemem Ponda Quepem
Tehsil Canacona Bardez Salcette Marmagoa Pemem Ponda Quepem
Year in mm. in mm. in mm. in mm. in mm. in mm. in mm.
1993 2925.5 2414.7 2544.2 2450 2874 3404.9 3297.4 1994 3484.1 3118.5 3028 2803.1 2878.1 3521.7 3477.1 1995 3267.8 3631.2 3658.6 3383 3395.6 3489.1 3878 - 1996 3592.4 3379.8 2886.4 2709 2917.4 3098.9 3181.8 1997 3805.1 3635.2 3214.1 3134:6 3392.6 3687.7 3777.2 1998 *2247.4 3162.1 3406.1 2864.6 2872.8 3281.9 3325.4 1999 2879 *3816.6 3533.8 *3438 *3568.6 *3819.4 4027.1 2000 *4337.8 3563 *3753.2 3390.8 3382.8 3533.3 *4207.3 2001 2794 *2241.5 *2201.7 *1989.3 2575.9 2763 3112.3 2002 2531.7 2284.9 2231.6 2070.6 *2402.2 *2640.8 *2882.6
5 6 7 10 8 4 2
Mean rainfall 3186.5 3124.7 3045.7 2823.3 3026 3324 3516.6 Deviation for 2000 1151.3 438.3 707.5 567.5 356.8 209.3 690.7 36.10% 14% 23.20% 20.10% 11.70% 6.29% 19.60%
Deviation for 2001 -498.6 -883.2 -844 -838 -450.1 -561 -404.3 -15.60% -28.20% 27.70% -29.60% -14.80% -16.87% -11.89%
Deviation for 2002 -654.8 -839.8 -814.1 -752.7 -623.8 -683.2 -634 -20.50% -26.80% -26.70% -26.66% -20.60% -20.55% -18.02%
Table 1 cont.
Outpost Sanguem Valpoy Panaji
Tehsil Sanguem Sattari Tiswadi Year in mm. in mm. in mm.
1993 *1963 not aval.
1994 3666.8 not aval.
1995 3317.3 not aval.
1996 3183.9 3782 1997 3904.9 *5001.4 1998 3708.9 3956.4 1999 4460.6 4734.2 2000 *4661.4 4282.8
2001 3159.8 *3207.3 2128.1 2002 2695 3434.7 2270.4
3 1 9
Mean rainfall 3432.1 4057 Nrm.3000 Deviation for 2000 1229.3 225.8
35.81% 5.56%
Deviation for 2001 -272.3 -849.7 -871.9 -7.90% -20.94% -29.06%
Deviation for 2002 -737.1 -622.3 -729.6 -21.47% -15.22% -24.32%
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Fig. 3 Map of Goa showing it's geology.
either at the base of the hills or plateaus or half way down their slopes.
The laterite layer which is porous and permeable soaks the rain water during the rainy season and releases it slowly much like a huge hard sponge during the drier months. It is the laterite layer which forms the aquifers of the state. The lower base rocks are impermeable in nature and prevent the rain water from sipping deeper into the ground. Laterite layer sustains the supply of water to rivers and wetlands for a long time after the monsoon season in major parts of the state, except to the South-East of Sanvordem where it is done by Quartz-chlorite-schists or Granite-gneiss.
In the north-west part of the state some schistose rocks have been found to be acting as aquifers.
Climate
The climate is tropical, warm and humid and the state receives major part of it's precipitation under the influence - of south-west monsoon. The 11--.
details of temperature, relative humidity, rainfall, sunshine hours, wind speed etc. are given in Tables 2 and 3. Thirty six % of the rainfall comes in the month of July if distribution is normal. On 70-100 days in a year, the daily rainfall exceeds 1 cm near the coast. Number of such days in ghats is more.
Diurnal temperature range is 4-6° Celsius during monsoons and pre- monsoons, whereas it is 10-12° Celcius during December to February.
Warmest month is May with mean daily temperature of 30 ° Celcius and
Wr Odl fr •11,1
SANDY COASTAL SOILS SALINE SOILS MARSHY SOILS
Fig. 4 Map of Goa state showing soil types.
Table 2 showing weather report from June 2000 to September 2003 Panaji station
Year,Month Max.Temp Min.Tenq Mean Max Mean Min Rainfall Wind Relative Relative Sunshine in Deg. Ce Deg. Cel. Deg. Cel. Deg. Cel. in mm. speed Hemidit3Humidity hrs.
Km.sihr. 8.30 hrs. 17.30 hrs.
June, 2000. 31.9 21.9 29.5 25.1 1176.2 12 88% 81% n.r.
July, 2000. 30.2 22.1 28.3 23.9 *1361.7 12 90% 89% 119.7 August, 2000 31.5 21.8 28.5 24.1 496.6 10 90% 87% 124.4
Sept,2000 31.8 23.2 30.1 24.4 119.5 8 87% 83% 184.2
Oct,2000 33.1 23.2 31.5 24.6 61.6 7 87% 78% 213.5
Nov,2000 *35.8 20.6 *33.6 22.7 4.5 7 78% 66% 246.6
Dec,2000 34.5 *17 32.8 *19.8 0.5 7 69% 58% 277.3
Jan,2001 35 18.8 32.3 *20.7 8.4 7 83% 59% 263.9
Feb,2001 *374 19.2 31.5 *20.7 0 8 87% 62% 267.3
March,2001 34.2 19.5 31.4 22.3 0 9 83% 64% 285.8
Apri1,2001 34.4 21.5 32.9 25.9 6.3 8 79% 69% 271.1
May,2001 34.8 23.2 33.2 26 167.6 11 80% 72% 262.2
June,2001 32.7 23 30.5 25.5 527 14 87% 81% 142.8
July,2001 30.1 22.8 28.8 24.3 *832.4 13 98% 93% 87.3
August,2001 30.7 22.6 28.9 24.3 414.4 11 94% 88% 131.9
Sept,2001 33.2 22.8 30.8 24.3 96.3 7 92% 81% 188.3
Oct,2001 35.3 21.6 31.4 24 70.1 7 91% 79% 199.4
Nov,2001 35.5 21.1 *34 23.1 5.6 6 81% 65% 271.4
Dec,2001 34.2 *18.4 33.3 21.3 0 7 72% 58% 267.6
Jan,2003 34.2 *17.5 31.3 *20.1 0 8 78% 57% 289
Feb,2003 35.1 20 32.8 22.2 0 8 80% 63% 256.1
March,2002 35.5 21.8 32.7 24.2 0 8 85% 69% 278.8
Apri1,2002 34.8 23.8 33.5 26.3 0.1 8 80% 68% 268.8
May,2002 35 24.2 *34 27.6 63.3 10 79% 70% 273.7
June,2002. 34.4 22.7 30.2 25.3 *1136.9 11 91% 83% 106.3
July,2002. 31.9 23.3 30.5 25.4 303.5 12 85% 81% 149.4
August,2002. 30.8 23 28.8 24.3 547.5 12 95% 87% 95.2
Sept,2001 32.5 23.3 30.1 24.2 121.6 7 91% 79% 215.1
Oct,2001 34.7 23.2 31.9 24.7 97.5 7 90% 79% 186.2
Nov,2001 *36 20.8 33.8 22.9 0 6 80% 65% 266.6
Dec,2001 35.8 19 33.1 20.6 0 7 79% 58% 274.6
Jan,2003 34.8 *18.4 32.4 *21.4 0.5 7 83% 60% 262.7
Feb,2003 *35.2 19 32.2 21.7 0 7 88% 66% 265.1
March,2003. 34.6 20.7 32.8 23.8 0 8 85% 64% 257.9
Apri1,2003. 35.1 23.5 33.7 25.4 0 8 75% 67% 258.4
May,2003. 35 24.8 *342 26.5 0 11 73% 68% 275.2
June,2003. 34.2 22.4 31.4 25.2 907.4 11 89% 84% 101.4
July,2003. 31.1 23.3 29.4 24.3 *1115.7 11 93% 89% 51
August,2003. 31.6 23.3 30.3 24.6 410.4 9 91% 84% 125.6
Highest temperature recorded during the study period 37.4deg.cel.(Feb,2001) Highest Mean temp. recorded during the study period 34.2deg.cel.(May,2003) Lowest temperature recorded during the study period 17.0deg.cel.(Dec,2000) Lowest Mean temp. recorded during the study period 19.8deg.cel.(Dec,2000) Highest Mean wind speed recorded during the period 14 kms./hr.(June,2001) Maximum sunshine hours/month recorded 285.8 hrs.(March,2001) Maximum rainfall /month recorded during the period 1361.7mm.(July,2000)
19
coolest is January with MDT of 25 ° Celcius. The lowest temperature recorded in the coastal area is 12.2 ° Celcius at Marmagoa on November 18, 1948. Humidity ranges from a low of 43% in December to a high of 100% in July (Tables 2 & 3 ).
Cloudiness of the skies is light from November to March which gradually increases up to the onset of monsoons in June. The skies are totally cloudy during the monsoons, if the same is normal and the cloudiness falls sharply in the post-monsoon season mostly by the end of October or first half of November.
Wind is fairly strong during the monsoons otherwise moderate.
Nature of the study sites
The study sites are wetlands which include paddy fields converted for water storage, uncultivated water logged areas under freshwater, spring beds, temple tanks, and lakes formed by bunds and dams. The freshwater wetlands of Goa, as they exist today, are all man-made or at least modified by men in the past as per their requirements. Their requirements were chiefly that of agrarian society of the past which functioned in the absence of any technology or mechanization. From available geological data on soil types, it is evident that the marshy soils in the State are found only in coastal tehsils of Bardez, Salcette, Quepem and Canacona. As far as expanse of these marshy soils is concerned the maximum area covered by the soils is in Salcette tehsil, followed by Bardez and Quepem.
Canacona tehsil has very little area covered by these soils. This coupled with the geomorphology of the State is a clear evidence, that the natural marshes as they existed before any major interference by humans, existed in the coastal tehsils of Bardez, Salcette, Quepem and Canacona. In the interior of the state the land being hilly, with valleys and deep gullies opening out and descending into some rivulet or stream bed (water occupies the lowest part) the possibility of marshes and/or swamps is ruled out. So the narrow beds of the rivulets, streams, etc. must have been the only natural freshwater wetlands in the interior parts of the State. Now the areas where the marshy soils are found are used for paddy cultivation with coconut groves on bunds but in many areas along the roads apartment buildings are being constructed by land filling (dumping rocky reject into marshy places, compacting by rolling and raising the ground level on which a building is constructed).
History of the wetlands
The majority of the wetlands in the State as said, are either man-made or modified by man for potable water (e.g. small spring beds carved out of laterite crust), water storage for irrigation of areca plantations and paddy fields (e.g. small and large tanks) and water supply (dams constructed by Public Works Department and Irrigation Department). The dams are very recent but the spring beds and tanks have their roots in history. The capital of Goa during ancient times under various rulers was Chandrapur
(present village of Chandor) and during medieval times it was Gopakpattan (present old Goa), both situated on rivers Zuari and Mandovi respectively.
The earliest archeological evidence (Naveparv) recorded about farmland of
`Khajan' (paddy field separated from brackish estuary by single narrow bund, and which gets inundated by brackish water in summer due to either breaching of the bund or simply by diffusion of water through the bund during high tide) category donated by a ruler of "Bhoj" dynasty dates back to 5 th century A.D. (The Gazetteer Part I,-Goa, 1979), indicating that paddy cultivation in Goa may have started approximately 2,000 years back.
`Khajan' cannot be cultivated without erection of a proper bund and for any grain other than paddy. Incidentally the same technique with some modification is required for traditional type of water storage tanks for paddy irrigation. Previous evidence is of hunters' dwellings and some of neolithic man, who possessed polished pottery, tools and probably also produced food but lived in cave dwellings dating back to 2,000 B.C.(4,000 years back). It is highly unlikely that a cave dweller would cultivate paddy, which requires sophisticated techniques. More over, cave dwellers lived in smaller groups and it is highly unlikely that they had any political or revenue system in force, which most of the paddy cultivating cultures generally possess. So, it may not be inaccurate to conclude that paddy cultivation in Goa and simultaneous development of freshwater wetlands might have begun prior to `Satvahana' or `Bhoj' rulers.
Objectives of the study
1. Identification of wetlands of Goa.
2. Identification of microflora and macroflora of these wetlands.
3. Chemical analysis of soil, water and dominant macroflora of two representative wetlands one each on the banks of two major rivers.
4. Economic importance of macrophytes of the wetlands.
5. Threats and conservation measures recommended.
Present Work
In absence of any detailed investigations on the distribution, ecology, taxonomy of microphytes and macrophytes of wetlands of Goa, an effort has been made to study the same. Investigation was carried out for a period of three years, from July, 2000 to June, 2003 (both months included.) The observations made have been compiled in the form of thesis.
REVIEW OF LITERATURE
Review of literature
The Ramsar convention (world's oldest environmental convention, named after the town of Ramsar in Iran where it was launched in 1971) defines wetlands as submerged water saturated lands, natural and artificial, permanent or temporary with water that is static or flowing, fresh or saltish including areas of marine water, the depth of which does not exceed six meters for major part of the year.
In order to prepare status of wetlands in United States, the U.S. department of interior fish and wildlife services followed the definition of Cowardin et , al. 1979.
Cowardin (1979) gives the classification of wetlands. Chatrath (1992) in his book wetlands of India mentions the definition, methods for conservation of
important wetlands of India.
Salodia (1996) describes the ecology of the freshwater, water bodies and other aspects dealing with it.
W.W.F. India 1993 mentions about the distribution of the lentic and lotic freshwater wetlands through out India. Updated systematic survey of the distribution of wetlands of India is available in the Asian wetland directory (W.W.F India
1993).
24
Wetland management is associated to several goals and most wetlands serve multiple uses. Management of wetlands requires scientific understanding, co — ordination and co-operation from laymen, Planners, administrators and managers.
This is well described by Kulkarni etp al ( 2002) in the book titled "Threats and Ecology of wetlands of India".
Abbasi 1997 also makes contribution towards the various threats faced by the wetlands.
Water is one of the primary factors which *structures plant communities within wetland ecosytems. Hydrological factors which influence the development and productivity of aquatic plant communities include water depth, nutrient availability, flow rates and soil and sediment characteristics. (Fennessy, _ - -ienrs`,-;t2(1994).
Successional processes may also be effected by the movement of water into and out of a wetland. In a study of 12 restored wetland areas, Brodowicz (1991) found the greatest plant diversity in flow through wetlands and found that low species diversity was co-related with heavy sediment loads on inflowing water.
Water depth is one often invoked as one of the key factors influencing successional processes in wetland (Van der Valk, 1987).
The rates and patterns of water inflow to a wetland ecosystem represent a nutrient and energy subsidy which is an important factor in determining the productivity of that system Fennessy, _ _ '1994).
Literature is available also on the definition of the macrophytes. The term macrophytes is defined as plants regardless of their organization and taxonomic status that are observable with the naked eye. Any macroscopic vegetation is considered to be macrophytes.
Aquatic plants are an important source of easily available organic material to drive the aquatic system. Their wholesole removal from the water during normal management depletes the system of valuable aquatic plant material. (Dawson 1980), (Dawson and Hallows 1983) derived aquatic light weight gas permeable opaque material for the control of rooted macrophytes in flowing waters. Submerged macrophytes were more rapidly controlled than emergent ones, primarily because the build up of detritus in submerged material reduced the light penetration.
Numerous investigations conducted during recent years in a broad variety of aquatic systems have demonstrated that sediment composition plays a major role in effecting the growth of distribution of submerged aquatic macrophytes. Schiemer and Prosser (1976 ).
GO
Macrophytes like Trapa jeponica have been studied by Kunni (1988) for its seasonal growth and Biomass in Ojega-ike Pond Japan. Similarly sediment interactions with submerged macrophyte growth and community dynamics have been reported by Barko, Gunnison, Stephen, Carpenter (1991). Nutrient interactions between both organic and inorganic exist between the submerged macrophytes and epiphytic algal and bacterial population (Wetzel and Hough 1973).
Rooted aquatic macrophytes rely primarily on sediment as a source of nitrogen (N) and Phosphorus (P); Nicholas and Kenny (1976); Barko and Smart 1980.
Availability of these and other sediment nutrients to submerged macrophytes depends on physical and chemical characteristics of the sediment and microbial activity in the rhizosphere. Barko and Smart (1986); Barko et, al. (1988). These factors in turn are affected by the development of macrophyte roots in sediment profile.
Literature dealing with the ecology of Indian wetland were limited to qualitative sampling of aquatic vegetation by (Biswas and Calder 1936). Quantitative studies on dry matter productivity in wetlands have been carried by (Kaul 1978) (Gopal 1973) .
Productivity and role of aquatic macrophytes are links an assessment (Wetzel 1973). Ponds besides being a store house of water could also be a good
source for biomass and harvesting nutrients (Gopal and Chamanlal 1991) record their observations that emergent macrophytes and most of the free floating plants grow over a wide range of habitat conditions and therefore, their growth alone has apparently little value as indicators of pollution.
Majid Khatun (1992) carried out the series of experiments on aquatic weeds of Bangladesh wherein protein content of the ten commonly available aquatic weeds like Azolla, Eicchornia, Lemna etc. were determined and these were found to be suitable for satisfying at least to some extent, the existing acute demand for proteins. Several aquatic weeds were found to be superior to many conventional sources when yield of protein was considered. Barko and Smart (1978) studied the growth and biomass distribution of two emergent freshwater plants Cyperus esculentus and Scirpus validus on different sediments . A series of research articles are available like photorespiration and productivity in submersed aquatic macrophytes Hough, (1974), photosynthetic pathways of some aquatic plants Hough, Wetzel (1977), nutrient removal potentials of various aquatic plants.
In India, the systematic and ecological study of the hydrophytes as a group has not received adequate attention although such a study has always yielded very useful data on the ecology, floristic composition and various other aspects of these interesting plants. Mention must be made of a few notable contributions such as Biswas and Calder (1937) book on the marsh and aquatic plants of India. .Jha (1965) reports a detailed study on hydrophytes of Ranchi.
28
Similarly Mirashi (1954) has carried out studies in the hydrophytes of Nagpur.
Fassette (2000) in his manual of aquatic plants gives the identification of aquatic plants.
Information regarding aquatic plants, identification, collection and other issues pertaining to wetlands has been given by the newsletter Aquaphyte, University of Florida.
There has been dramatic increase in the recognition of the importance of wetland ecosystems over the past two decades. This has resulted not only in efforts for their preservation, but also the creation and restoration of destroyed and degraded areas in order to increase both the quantity and quality of protected lands. Jha and Meena Kumar (1978) reported species of Utricularia found growing in nitrogen deficient soils and low nitrogen containing waters. This compels them to adopt to a carnivorous habitat which may effect fish production adversely. The chemical characters of the habitats indicate that an acidic medium is essential for their proper growth. Ca, Mn, Zn and Mo are not essential for the growth of this species.
Kant (1975) reports that aquatic macrophytes play quite a significant role in the productivity of inland water bodies of J and K. Apart from being a good source of food and manure, they have a nuisance value also causing a great hindrance in the local irrigation and transport.
The mobilization of sediment phosphorus by submerged freshwater macrophytes species was investigated on five different sediments. ( Barko, Smart
1980). The species investigated were Hydrilla verticilleta, Myriophyllum spicatum, This mobilization represents an important aspects of the Phosphorus cycle and may effect the overall metabolism of lacustrine system.
Yakushin (1987) reported that oxidation of dissolved organic matter is intensified and its adverse effect on microbiological and hydrochemical indices of water quality is decreased by the presence of aquatic macrophytes.
Research has shown that many wetlands are formed in places where water seeps out of the ground, research also indicates that evatranspirational losses from open water can either be increased or decreased by the presence of aquatic plants.
In general submerged aquatics give a far greater manganese concentration than those plants with aerial leaves. Further it is also reported that wide variations of Mn and Ca content occurred within different aquatic plants of the same species from the same habitat . (Brodowicz 1991) .
Kunni (1982) again reports about the life cycle and growth of Petamogeton crispus L. in a shallow pond Ojoga-ike. Brewer and Smith (1995) reports in American Journal of Botany about the leaf surface wetness and gas exchange in the pond lily Nuphar polysepalum,
30
Smaller water bodies such as tanks and ponds have attracted greater attention because of their easy accessibility. Contributions are available on tanks and ponds of North India. Sreenivasan (1965), Michael (1969).
Hydrological studies in hilly areas have also been made in the recent years such as those of Das (1982) on the ecology of Dal lake. Trivedy and Goel (1987) made a useful contribution by bringing together information on methodology based on work in India.
Periphytes are the most important primary producers in shallow water bodies.
They play an important role as a food for such fauna inhabiting the littoral zone of lakes and rivers. (Wetzel and Hough 1973) are of the opinion that in less fertile sites the periphyton constitute the dominant part of the microphytic productivity.
Ecological studies carried out in Karnataka for the last decade include physical and chemical measurements and phytoplankton estimation of freshwater habitats. Hosmani and Bharati (1980). Certain algal blooms are given by, Somashekhar and Ramswami (1982). Nutritional requirements of green algae are essentially similar to that of phanerograms growth and morphology of algae are influenced by nutritional conditions. Diatoms are said to grow well in unpolluted water, Seenaya (1972). Nutrient induced regulation of reproduction in algae has been reported by Agarwal (1998). Factors like Ca nitrate favour the growth of
Chlorococcales Hegde (1988 and 1989). Quick succession of algae is another unique features of temple tanks reports Hegde (1985).
Liminological and taxanomic studies on some alga of Karnataka is given by Bharati and Hosmani (1976), Hegde (1982, 1985, 1986, 1988, 1989); Hegde and Bharati (1984, 1985, 1986) report about comparative phytoplankton ecology of freshwater ponds and lakes of Dharwad Karnataka state. A report on zygospores of some species of Desmids is available by Hegde (1984).
Blue green algae from various parts of India have been studied by numerous workers. Andra Pradesh have attracted the attention of number of workers viz. Jana and Sarkar (1971), Munawar (1970), Seenaya (1972),
Subrahmanyan (1973), Venkateswarlu (1976) and Zafar (1964) who have studied species of blue green algae to assist the physiochemical conditions of inland .c waters. Noteworthy work on cyanophyceae of Assam are those by Biswas (1934).
Comprehensive accounts of cyanophyceae of Jammu and Kashmir were given by Anand (1976, 1979). The cyanophyceae of Karnataka state has been extensively worked out by Bharati (1965), Bharati and Bongale (1975), Bharati and Magadi (1978), Bongale and Bharati (1980). Goyal (1982), Saxena ,et al ., (1973), studied the algal flora of Kerala state including blue green algae. Papers by Bendre and Agarkar (1965), Desikacharry and Mall (1955), Dikshit and Agarkar (1974) provided information regarding blue green algae of Madhya Pradesh.
.JZ
Biswas (1930, 1934), Bharadwaja (1933) were the contributions from Manipur.
Prasad (1977) gave an account of members of cyanophyceae from North India. While dealing with the algal floristics of India, many workers viz. Biswas (1923), Biswas and Caldar (1936), Biswas (1949), have given a good account of the distributional pattern of various freshwater chlorophyceae. Randhawa (1936a) has described many taxa of chlorophyceae from North India
The diatoms of Tamil Nadu have been studied very extensively by Desikachary (1959, 1962). Distribution of Desmids have been dealt at length by Ramnathan (1962). Algal flora of Andaman and Nicobar Islands volume I and II Prasad and Misra (1992) is a book which deals in detail about cyanophyceae and chlorophyceae.
Srinivasan (1965) gave about the state of Orrisa. Presence of blue green algae from Punjab have been reported by Chandhyok (1966). Trivedy (1982), Venkataraman and Neelkantan (1968) had given information about Rajasthan.
The Volvocales forms from different parts of India were recorded by.
Iyengar and Desikachary (1981) and from Gujarat by Patel (1974). Philipose (1967) in his monograph on the order Chlorococcales has mentioned the occurrence of these algae in different regions of our country.
