DEPARTMENT OF OCEAN DEVELOPMENTICMAM PROJECT DIRECTORATE, CHENNAI

GOVERNMENT OF INDIA

CRITICAL HABITAT INFORMATION SYSTEM FOR ISLANDS OFF KARWAR,

KARNATAKA, INDIA

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CONTENTS

Programme

CHIS for Karwar islands

Ecological Significance

Environmental Status

General Description

Geomorphology

Landuse/Landcover

Water Quality

Biodiversity

Socio-Economic Aspects

Suggestions

Conclusion

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Karwar Islands

The islands are located in mid west coast of India, between 14°45’ and 14°55’ N and between 74°03’ and 74°07’30” E.

All islands are within 1-3.6

nautical miles from the mainland.

Karkalgudda and Mandalgudda islands are located between 10 and 20 metres depth contour and the rest of the islands within 10 m depth.

Islands are rocky in nature with pocket beaches of boulders and sand.

The islands are categorised as Reserved and Minor forests.

Island (km2)Kangigudda island

1.9Kurmagadagudda island

5.3Shimisgudda island 1.8Karkalgudda island 1.8Mandalgudda island 1.2Mogeragudda island 1.8Anjadeep island

9.2

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Rocky islands off Karwar are 13 to 60 metres in elevation.

Islands are covered by semi ever-green forests and grass lands.

Karwar coastline is socio-economically significant and ecologically sensitive as majority of the coastal population is engaged in marine fishing.

Karwar group of islands are unique by the combination of rocky islands laden with silt rich substratum supporting benthic organisms of hard and soft substratum.

About Islands off Karwar

Kangigudda island AKurmagadagudda island BShimisgudda island CNearshore D,EKarkalgudda island FMandalgudda island GOffshore H,KAnjadeep island I,JMogeragudda island L

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Of the 7 islands off Karwar, 5 islands (except Anjadeep and Kangigudda islands) have been declared as Reserved Forests.

Ecological Significance

The sandy/rocky beaches, the tidal flats, etc, offer the most conducive niche for a variety of interstitial and sedentary organisms.

Some of the endangered species, such as, Olive Ridley turtle, Lepidochelys olivacea and Bottle-nosed dolphin, Tursiops truncatus, were also observed in these island groups.

On the mainland Karwar, one Wildlife Sanctuary (at Dandeli) and one National Park (at Anashi) are located.

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Islands of Karwar are influenced by discharge of Kali river and tidal rhythms.

Nearshore waters are subjected to upwelling during monsoon.

Maximum salinity observed was 36.6 PSU at around 40 m depth.

Average annual rainfall is about 3400 mm.

Human activities include fishing in coastal waters, agriculture, industries, etc.

Environmental Status

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Karwar islands are tropical with rocky cliffs covered with dense forests and a few sandy pocket-beaches.

In the Karwar mainland, the coastal landforms include sandy to rocky beaches, estuary, tidal flats and rocky promontories.

Coastal Morphology

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Forests 55427 sq.kmAgriculture 9800 sq.kmBarren land 8411 sq.kmGrass land 115 sq.kmBeach sand 5.87 sq.km

Island vegetation 66 ha

The islands are covered with evergreen forests.

Landuse/Landcover

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MethodologyGIS based information system was developed

using remote sensing data, SOI toposheets and data collected through field surveys.

Primary data on various physico-chemical and biological parameters were collected in the selected sampling points during 1998-99.

Data were collected during pre-monsoon (May’98), post-monsoon (Dec’98) and summer (Apr’99) seasons.

Secondary data on fishery resources and socio-economic aspects were also collected.

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Water Quality

Physico-chemical parameters studied include light extinction co-efficient, turbidity, temperature, pH, salinity, dissolved oxygen, nutrients, etc.

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Dissolved oxygen (mg/l)

May ’98 Dec ’98 Apr ’99

Spatial distribution of water quality parameters could be visualised in GIS using the 3D spatial analysis facility. Data on other parameters could also be overlaid to analyse the relationship among the parameters.

Dissolved oxygen was in normal levels and was more during Dec’98 due to influence of Kali river discharge.

5.60 - 5.865.86 - 6.136.13 - 6.406.40 - 6.666.66 - 6.93

6.93 - 7.207.20 - 7.467.46 - 7.737.73 - 8.00

5.91 - 6.55 6.55 - 7.19 7.19 - 7.84 7.84 - 8.48 8.48 - 9.12

9.12 - 9.779.77 - 10.4110.41 - 11.0511.05 - 11.70

6.40 - 6.836.83 - 7.277.27 - 7.707.70 - 8.138.13 - 8.57

8.57 - 9.009.00 - 9.439.43 - 9.879.87 - 10.30

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Turbidity (NTU)

0.70 - 1.071.07 - 1.431.43 - 1.801.80 - 2.172.17 - 2.532.53 - 2.902.90 - 3.273.27 - 3.633.63 - 4.00

1.00 - 2.672.67 - 4.344.34 - 6.006.00 - 7.677.67 - 9.339.33 - 11.00

11.00 - 12.6712.67 - 14.3314.33 - 16.00

3.71 - 3.973.97 - 4.224.22 - 4.474.47 - 4.734.73 - 4.984.98 - 5.245.24 - 5.495.49 - 5.755.75 - 6.00

May ’98 Dec ’98 Apr ’99

Turbidity range was low during premonsoon (May’98) and summer (Apr’99) than in postmonsoon (Dec’98). High turbidity in Dec’98 may be due to land runoff.

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Phosphate (µmol/l)

0.76 - 0.960.96 - 1.161.16 - 1.361.36 - 1.561.56 - 1.751.75 - 1.951.95 - 2.152.15 - 2.352.35 - 2.55

0.85 - 1.171.17 - 1.481.48 - 1.801.80 - 2.122.12 - 2.432.43 - 2.752.75 - 3.073.07 - 3.383.38 - 3.70

0.8 - 1.01.0 - 1.21.2 - 1.41.4 - 1.61.6 - 1.81.8 - 2.02.0 - 2.22.2 - 2.42.4 - 2.6

Apr ’99May ’98 Dec ’98

Phosphate level was high in postmonsoon (Dec’98) than other seasons. Runoff from agricultural fields and upwelling may be the factors for high phosphate levels.

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Biological Parameters

Biological parameters studied include primary productivity, qualitative and quantitative aspects on phytoplankton, zooplankton, intertidal and eulittoral benthos, macrophytes, etc.

Biodiversity indices were also calculated for different groups of organisms, based on the data collected.

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Primary Productivity

Net Maximum Productivity Net Minimum Productivity

The net maximum and minimum primary productivity during different seasons are given below.

mgC/l/hrSeasons Maximum Stn. Minimum Stn.

May’98 0.1393 B 0.0472 IDec’98 0.3323 L 0.1179 CApr’99 0.2251 E 0.0322 F

B: Kurmagadagudda IslandI : Anjadeep IslandL: Mogeragudda IslandC: Shimisgudda IslandE: Binaga CoastalF: Karkalgudda Island

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58 species of phytoplankton and 40 species of zooplankton constituted the planktonic forms.

10 species of macrophytes (seaweeds) and 1 mangrove species were recorded.

A total of 60 species comprising gastropods, bivalves, echinoderms, crustaceans and others formed the inter-tidal faunal composition.

Biodiversity

During the study period (1998-99), flora and fauna of neritic and benthic (intertidal, eulittoral) environments of Karwar islands and adjoining waters were studied.

34 species of macrobenthos comprising polychaetes (16), gastropods (17), echinoderm (1), and 64 species of meiobenthos comprising foraminifers (38), ostracods (12), polychaetes (6), etc, were recorded.

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Phytoplankton58 species of phytoplankton were observed during 1998-99, comprising Bacillariophyceae (38 species), Dinophyceae (17) and others (3).

Number of species observed was 46 in May’98, 38 in Dec’98 and 28 in Apr’99.

Numerical abundance ranged from 5 lakh to 13 lakh cells/m3 in May’98, from 354 lakh to 1286 lakh cells/m3 in Dec’98 and from 519 lakh to 1250 lakh cells/m3 in Apr’99.

Important species were of the genera, Coscinodiscus, Ceratium, Fragilaria, Trichodesmium, Protoperidinium, Planktoniella etc.

Diversity index ranged from 0.125 in Dec’98 to 1.198 in May’98.

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10 species of macrophytes were recorded. They are Enteromorpha sp, Ulva sp, Caulerpa racemosa, Hypnea sp, Sargassum sp, Padina gymnosphora, P. tetrastomatica, Gracilaria sp, Porphyra vietnamensis and Bangia fucopurpurea. Sargassum dominated all the species in terms of biomass (wet weight) in all the islands during Dec’98 and Apr’99.

Macrophytes

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Zooplankton

40 species comprising Arthropoda (30 species), Chaetognatha (2) and other taxa (8) were recorded. The number of species observed was 28 in May’98 and Dec’98 and 36 in Apr’99.

Copepods dominated the zooplankton composition in May’98 and Apr’99. In Dec’98, copepods and siphonophores were the dominant constituents.

Dominant species were of the genera Acartia, Paracalanus, Acrocalanus, Temora, Oithona, Lucifer (crustaceans), Tintinnopsis, Favella (protozoans), Diphysis, Vogtia (coelenterates), Sagitta (chaetognaths) and Oikopleura (appendicularians).

Diversity index ranged from 0.854 to 2.552. In general, diversity was high during May’98 than other seasons.

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A total of 60 species was found distributed in all the islands comprising 32 species of gastropods, 10 species of bivalves, 8 species of crustaceans and 10 species of other taxa. No significant seasonal variation was observed.

Number of species was more in Anjadeep island and less in Mogeragudda island throughout the study period.

Intertidal Fauna

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Polychaetes, gastropods and bivalves dominated the composition.

Diversity index was more in Anjadeep island throughout the study period, while it was less in Mogeragudda island.

Intertidal Macrobenthos

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30 species comprising polychaetes, gastropods, bivalves and other taxa were observed. Polychaetes and gastropods dominated the composition.

Number of species and abundance was more in May’98 and Apr’99 and less in Dec’98.

Diversity index ranged from 0.44 to 1.33 in May’98, 0.24 to 0.74 in Dec’98 and 0.42 to 1.12 in Apr’99.

Eulittoral Macrobenthos

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10 species of ostracods (crustaceans) and 17 species of foraminifers (protozoans) dominated the composition. Other taxa observed were polychaetes, nematodes, etc.

Diversity index was more in Anjadeep island throughout the study period. Less diversity was observed in Shimisgudda island and Mogeragudda island.

Diversity index ranged from 4.6 to 5.9 in May’98, 3.4 to 5.6 in Dec’98 and 4.6 to 6.2 in Apr’99.

Intertidal Meiobenthos

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Nematodes and protozoans dominated the composition. Other taxa observed were Arthropods, Polychaetes, Coelenterates, Lamellibranchs, etc.Number of species and abundance was more in May’98 and Apr’99 and low in Dec’98.Diversity index ranged from 6.71 to 8.48 in May’98, 4.9 to 7.78 in Dec’98 and 6.39 to 8.65 in Apr’99.

Eulittoral Meiobenthos

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Socio-economic AspectsPopulation : 1,40,282

Male : 71,674 Female : 68,608Literacy Male: 85%, Female: 67 %Employed : 46,672Livestock : 1,02,191

MajaliKarwarBinagaArgaChendiaKodar

2340 3100 312 242 610 690

Active fishermen population (1998-99)

Revenue of 6 major sectors

Uttar Kannada Dist

36%

7%

6%20%

12%

19%

Agriculture & Animal Husbandry

Forestry

Fisheries

Industries

Construction

Trade and hotels

Aquaculture is gaining momentum with about 20 units with an area of 113 ha and prawn hatchery area of 1100 m2.

A chemical industry is located at Binaga and a cement industry at Majali.

Large number of small scale industries on textile, leather, rubber, glass, ceramics, engineering, etc, provide employment to large number of people.

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Fishery Aspects

Average fish catch in tonnes 1994-95 8818

1995.96 14156 1996-97 22056

1997-98 13504

1998-99 12025

No of Crafts / gears during 1998 -99

Purse seiners TrawlGill NettersLong linersOthers

28183230 10 10

Landing Station Men Women ChildrenMajali 2278 2559 1913Karwar 3681 3481 2526Binaga 281 218 512Arga 240 141 480 Chendia 360 380 962Kodar 363 361 846

Drag netsGill NetsTrawl netsCast netsShore seinesPurse seinesOthers

212379365

105011547

1617

Fishermen Population during 1998-99

Source : KFDC Booklet

Majali

Karwar

BinagaArga

Chendia

Kedar

ARABIAN SEA

Major fish landing centres

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Studies on Karwar environment such as water quality, hydrography, plankton, fishery resources, etc., reveal that the aquatic environment of Karwar is highly productive. Upwelling is one of the important factors for high productivity. Oil sardine and mackerel form the major fisheries. Largest sized mackerel in India has been recorded from Karwar waters.

Declining trend in fisheries from 1996-97 to 1998-99 may be due to unsustainable fishery practices.

Importance of Karwar Environment

Fish catch

05000

10000150002000025000

94-95 95-96 96-97 97-98 98-99Year

(in

tonn

es)

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Data on the physico-chemical parameters of water, sediment and biological diversity do not indicate any adverse environmental conditions. However, considering the ecological significance of this ecosystem, efforts need to be taken for conservation, management and development of these areas.

Suggestions

Impacts of the project on environmental quality and biodiversity need to be studied.

“Sea-Bird” Naval Project is coming up in the vicinity of Mogeragudda and Anjadeep islands. Currently, 180m north breakwater from Binaga Bay to Anjadeep island and the south breakwater from Round island to Arga have been constructed.

Development of GIS based Information System for Karwar islands and their surrounding environment, has enabled understanding the present status of water quality, occurrence of endangered organisms and biodiversity of these ecologically sensitive habitats. Protection and conservation of the biodiversity of these coastal areas and introduction of appropriate strategy for rational and sustainable utilisation of their resources, are called for.

Conclusion

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