ICMAM-PD. Contents Programme Development Team Introduction Gahirmatha Coast Marine Sanctuary Geomorphology Landuse/Land Cover Marine Turtle Seaturtle.

ICMAM-PD

ICMAM-PD

Contents

Programme

Development Team

Introduction

Gahirmatha Coast

Marine Sanctuary

Geomorphology

Landuse/Land Cover

Marine Turtle

Seaturtle Rookeries

Nesting Habit

Shifting of Nesting

Shoreline changes

Marine Organisms

Mangrove

Threats

Suggestions

Conclusion

Hydrological parameters

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Gahirmatha Coast - Orissa

Gahirmatha is a sandy coast, which extends approximately to a stretch of about 35-40 km from Maipura river mouth in the north to Hansua river mouth in the south. The beach is more or less flat with scattered sand dune of 2-3 m height. The beach spreads to about 80 m above the high tide line with a maximum spread up to 100 m. The vegetation is scanty and represented by Ipomea sp. and Spinifex sp. Wetland, backwater/brackishwater regions are also characteristic features of this coast.

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Gahirmatha Marine SanctuaryThe Gahirmatha Marine Sanctuary extending from 86o 45’ 57” to 87o 17’ 36” E long and 20o 17’ 32” to 20o 46’ 58” N lat covers an area of 1435 sq. km which includes 1408 sq. km. of water body and 27 sq. km. of land mass (Reserve Forest, Mangroves, Mud flats and Sand bar). The notification declaring the Marine Sanctuary was published in the Extraordinary Issue No.1268 dated 17th October 1997 of Orissa Gazette.

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Gahirmatha Marine Sanctuary

Core Zone

Area of turtle breeding ground of the sanctuary is 725 sq. km. This has an average width of 11 km offshore from Ekkulanasi in the North-East and an average length of 10 km from Barunei muhana to Mahanadi muhana.

Buffer Zone

Turtle nesting ground stretches over an average length of 10 km where fishing is restricted during the nesting season from November to May.

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GeomorphologyGeomorphologyThe coast of Gahirmatha is a low laying sandy area, drained by the river Baitarani, Brahmani, Dhamra, Maipura, Bansgarh and Ranhansua with commonly occurring tidal creeks and mudflats. A number of sandy islands are found along this coast. Presence of barrier ridge (Barrier island) is an important feature of this area, which protects the sandy islands from erosion.

Sandy Islands

Ocean

Sandy Beach

River

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The land use/land cover could be classified into mangroves (136 sq. km), sandy islands (12 sq. km), open shrub (17 sq. km) and settlements (10 sq. km). Dense mangrove vegetation is found in and around Gahirmatha coast. Cultivation is entirely rainfall dependent. A small part of the land is used for paddy cultivation.

Land use/ Land cover

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Marine turtles in Gahirmatha CoastMarine turtles in Gahirmatha Coast

Of the five species of sea turtles known to occur in the Indian coast, four species occur in the coastal waters of Orissa - Gahirmatha. In order of abundance these are Lepidochelys olivacea (olive ridley), Eretmochelys imbricata(hawksbill), Dermochelys coriacea (leather back) and Chelonia mydas (green turtle).

Lepidochelys olivacea

Click on species

Eretmochelys imbricata

Dermochelys coriacea

Chelonia mydas

Lepidochelys olivacea

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Marine turtles in Gahirmatha CoastMarine turtles in Gahirmatha Coast

Click on species

Eretmochelys imbricata

Eretmochelys imbricata

Dermochelys coriacea

Chelonia mydas

Lepidochelys olivacea

Of the five species of sea turtles known to occur in the Indian coast, four species occur in the coastal waters of Orissa - Gahirmatha. In order of abundance these are Lepidochelys olivacea (olive ridley), Eretmochelys imbricata(hawksbill), Dermochelys coriacea (leather back) and Chelonia mydas (green turtle).

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Marine turtles in Gahirmatha CoastMarine turtles in Gahirmatha Coast

Click on species

Dermochelys coriacea

Eretmochelys imbricates

Dermochelys coriacea

Chelonia mydas

Lepidochelys olivacea

Of the five species of sea turtles known to occur in the Indian coast, four species occur in the coastal waters of Orissa - Gahirmatha. In order of abundance these are Lepidochelys olivacea (olive ridley), Eretmochelys imbricata(hawksbill), Dermochelys coriacea (leather back) and Chelonia mydas (green turtle).

ICMAM-PD

Marine turtles in Gahirmatha CoastMarine turtles in Gahirmatha Coast

Click on species

Chelonia mydas

Eretmochelys imbricata

Dermochelys coriacea

Chelonia mydas

Lepidochelys olivacea

Of the five species of sea turtles known to occur in the Indian coast, four species occur in the coastal waters of Orissa - Gahirmatha. In order of abundance these are Lepidochelys olivacea (olive ridley), Eretmochelys imbricata(hawksbill), Dermochelys coriacea (leather back) and Chelonia mydas (green turtle).

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Sea turtle rookeries in Orissa CoastSea turtle rookeries in Orissa Coast

Olive ridley turtle (Lepidochelys olivacea) is the most common species of sea turtle occurring along the east coast of India. These turtles migrate every winter to nest en-mass at three major rookeries viz. Gahirmatha, Devi River, Rushikulya River in this area.

GahirmathaRGahirmathaRookeryookery

DeviDeviRookeryRookery

RushikulyaRushikulyaRookeryRookery

Click on individual rookery site.Click on individual rookery site.

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Gahirmatha Rookery

The Gahirmatha rookery The Gahirmatha rookery extending approximately extending approximately to 35-40 km long stretch of to 35-40 km long stretch of Orissa coastline, hosts the Orissa coastline, hosts the largest known nesting largest known nesting concentration of olive concentration of olive ridley turtles. About 0.2 to ridley turtles. About 0.2 to 0.7 million turtles are 0.7 million turtles are estimated to be visiting estimated to be visiting the beach every year for the beach every year for mass nesting.mass nesting.

Main

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Devi River Rookery

This rookery is located at the Devi river mouth (Jatadhar “Muhana” to Kadera river mouth) in Cuttack district, 100 km South of Gahirmatha. About 0.05 to 0.1 million turtles visit this region for mass nesting every year (December to April).

Main

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Rushikulya River RookeryThis rookery is located near Rushikulya river, 300 km South of the Gahirmatha mass nesting beach. It extends to a distance of 6 km from Paruna Bandha village (1 km north of the Rushikulya river mouth) to Kantiagada village. About 0.02 to 0.2 million turtles are estimated to be visiting this beach every year for mass nesting.

Main

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Nesting of Olive Ridley Turtle(Lepidochelys Olivacea)

Nesting of Olive Ridley Turtle(Lepidochelys Olivacea)

Nesting EnvironmentNesting Environment Nesting BehaviourNesting Behaviour

HatchlingsHatchlingsMass NestingMass NestingMass NestingMass Nesting

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Nesting EnvironmentNesting EnvironmentThe mass nesting occurred due to the availability of suitable nesting environment like sandy beach, more or less flat topography, presence of wetland, backwater, brackishwater and mangrove vegetation in Gahirmatha coast.

Nesting season is from December to the end of April with a peak in the middle of March. Olive ridley turtles appear to nest during night time.

MainMain

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Egg laying

After nesting

Nesting behaviour

Nesting BehaviourNesting Behaviour

Female turtles emerge at night to lay eggs. The turtles make a body pit for about 15-20 cm and an egg pit of 40 cm depth. The depth of egg pit is equal to the length of the rear flipper. The time taken to complete nesting and laying of olive ridley turtles is about 1½ - 2 hours. The average number of eggs per clutch was found to be 111 (range 60-186).

Female turtles emerge at night to lay eggs. The turtles make a body pit for about 15-20 cm and an egg pit of 40 cm depth. The depth of egg pit is equal to the length of the rear flipper. The time taken to complete nesting and laying of olive ridley turtles is about 1½ - 2 hours. The average number of eggs per clutch was found to be 111 (range 60-186).

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Egg laying

After nesting

Nesting behaviour

Nesting BehaviourNesting Behaviour

Female turtles emerge at night to lay eggs. The turtles make a body pit for about 15-20 cm and an egg pit of 40 cm depth. The depth of egg pit is equal to the length of the rear flipper. The time taken to complete nesting and laying of olive ridley turtles is about 1½ - 2 hours. The average number of eggs per clutch was found to be 111 (range 60-186).

Female turtles emerge at night to lay eggs. The turtles make a body pit for about 15-20 cm and an egg pit of 40 cm depth. The depth of egg pit is equal to the length of the rear flipper. The time taken to complete nesting and laying of olive ridley turtles is about 1½ - 2 hours. The average number of eggs per clutch was found to be 111 (range 60-186).

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MainMain

Egg laying

After nesting

Nesting behaviour

Nesting BehaviourNesting Behaviour

Female turtles emerge at night to lay eggs. The turtles make a body pit for about 15-20 cm and an egg pit of 40 cm depth. The depth of egg pit is equal to the length of the rear flipper. The time taken to complete nesting and laying of olive ridley turtles is about 1½ - 2 hours. The average number of eggs per clutch was found to be 111 (range 60-186).

Female turtles emerge at night to lay eggs. The turtles make a body pit for about 15-20 cm and an egg pit of 40 cm depth. The depth of egg pit is equal to the length of the rear flipper. The time taken to complete nesting and laying of olive ridley turtles is about 1½ - 2 hours. The average number of eggs per clutch was found to be 111 (range 60-186).

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Mass NestingMass Nesting

During 1988, 1997 and 1998, only a few thousand turtles visited the coast for nesting. However, a record number of 0.7 million turtles visited the Barrier Island presently called Ekakulanasi, during 2000.

During 1988, 1997 and 1998, only a few thousand turtles visited the coast for nesting. However, a record number of 0.7 million turtles visited the Barrier Island presently called Ekakulanasi, during 2000.

Table & Chart

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Year Nesting Population

(Nos.)

Source

1976 15000 Kar & Bhaskar 1982

1978 200000 Kar & Bhaskar 1982

1979 130000 Kar & Bhaskar 1982

1983 200000 Silas et. al. 1983

1984 500000 Silas et. al. 1985

1985 287000 Silas et. al. 1985

1986 80000 The Samaja (Orissa Newspaper)

1987 600000 The Samaja (Orissa Newspaper)

1988 50000 The Samaja (Orissa Newspaper)

1990 258000 The Samaja (Orissa Newspaper)

1995 339500 The Samaja (Orissa Newspaper)

1996 200000 The Samaja (Orissa Newspaper)

1997 50000 Forest Dept. & RRL Data

1998 50000 Forest Dept. & RRL Data

1999 253000 Forest Dept. & RRL Data

2000 700000 Forest Dept. & RRL Data

Nesting PopulationNesting Population

MainMain

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The emergence of hatchlings commences about 58 days The emergence of hatchlings commences about 58 days after egg laying. At the mass nesting site, it was observed after egg laying. At the mass nesting site, it was observed that about 6,000 hatchlings emerged from 53 nests in a 100 that about 6,000 hatchlings emerged from 53 nests in a 100 m stretch. The percentage of live hatchlings emerging from m stretch. The percentage of live hatchlings emerging from natural nests varied from 51.4 to 95.2 with an average of natural nests varied from 51.4 to 95.2 with an average of 74.5. The hatchlings entering the sea get washed ashore 74.5. The hatchlings entering the sea get washed ashore during high tide and they re-enter the sea with subsequent during high tide and they re-enter the sea with subsequent retreating waves.retreating waves.

Hatchlings

Hatchlings (Mass)

Hatch out

Entering the sea

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Hatchlings

Hatchlings (Mass)

Hatch out

Entering the sea

The emergence of hatchlings commences about 58 days The emergence of hatchlings commences about 58 days after egg laying. At the mass nesting site, it was observed after egg laying. At the mass nesting site, it was observed that about 6,000 hatchlings emerged from 53 nests in a 100 that about 6,000 hatchlings emerged from 53 nests in a 100 m stretch. The percentage of live hatchlings emerging from m stretch. The percentage of live hatchlings emerging from natural nests varied from 51.4 to 95.2 with an average of natural nests varied from 51.4 to 95.2 with an average of 74.5. The hatchlings entering the sea get washed ashore 74.5. The hatchlings entering the sea get washed ashore during high tide and they re-enter the sea with subsequent during high tide and they re-enter the sea with subsequent retreating waves.retreating waves.

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Hatchlings

MainMain

Hatchlings (Mass)

Hatch out

Entering the sea

The emergence of hatchlings commences about 58 days The emergence of hatchlings commences about 58 days after egg laying. At the mass nesting site, it was observed after egg laying. At the mass nesting site, it was observed that about 6,000 hatchlings emerged from 53 nests in a 100 that about 6,000 hatchlings emerged from 53 nests in a 100 m stretch. The percentage of live hatchlings emerging from m stretch. The percentage of live hatchlings emerging from natural nests varied from 51.4 to 95.2 with an average of natural nests varied from 51.4 to 95.2 with an average of 74.5. The hatchlings entering the sea get washed ashore 74.5. The hatchlings entering the sea get washed ashore during high tide and they re-enter the sea with subsequent during high tide and they re-enter the sea with subsequent retreating waves.retreating waves.

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During the last 20 years, there has been a shifting of mass nesting site towards the north Orissa Coast, owing to gradual change of beach profiles in the Gahirmatha Coast. The newly formed Island is called the “Nasi Island” where mass nesting continued from 1990 onwards.

During the last 20 years, there has been a shifting of mass nesting site towards the north Orissa Coast, owing to gradual change of beach profiles in the Gahirmatha Coast. The newly formed Island is called the “Nasi Island” where mass nesting continued from 1990 onwards.

Shifting of Gahirmatha mass Shifting of Gahirmatha mass nesting sitenesting site

Shifting of Gahirmatha mass Shifting of Gahirmatha mass nesting sitenesting site

1970’s: Satabhaya-Ekakula

1975-89: Gahirmatha-Ekakula

1990-2000: Nasi Island

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Shoreline changes in Gahirmatha

The beach erosion and accretion are regular annual phenomena. In May 1989, a cyclonic storm swept across the Gahirmatha coast and fragmented the mass nesting beach. However, currently due to the heavy erosion of this region, the width of the beach is reduced. The shoreline change appears to be the main causative factor for shifting of nesting site of olive ridley turtles in the Gahirmatha coast.

DATA

Toposheet (SOI) 1972 IRS 1D LISS-III 1998

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Comparative data of beach width in Gahirmatha coast

An analysis of the data on the width of the beach available for nesting An analysis of the data on the width of the beach available for nesting in Gahirmatha Coast during 1972 vis-à-vis 1998, presented in the table in Gahirmatha Coast during 1972 vis-à-vis 1998, presented in the table (based on Survey of India Toposheet - 1972 & IRS 1D LISS III 1998), (based on Survey of India Toposheet - 1972 & IRS 1D LISS III 1998), would reveal a decline in the width at Satabhaya, Gahirmatha and would reveal a decline in the width at Satabhaya, Gahirmatha and Habalikhati. However, in Ekakula and Ekakulanasi, an increase in the Habalikhati. However, in Ekakula and Ekakulanasi, an increase in the area was evident. The changes in the beach width due to erosion may area was evident. The changes in the beach width due to erosion may be attributed as one of the reasons for shifting of nesting site.be attributed as one of the reasons for shifting of nesting site.

Name of the placeName of the place 19721972 19981998

SatabhayaSatabhaya 375 m375 m 198 m198 m

GahirmathaGahirmatha 405 m405 m 101 m101 m

HabalikhatiHabalikhati 756 m756 m 159 m159 m

EkakulaEkakula 70 m70 m 123 m123 m

Barrier IslandBarrier Island 4 sq. km4 sq. km 5 sq. km5 sq. km

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TemperatureTemperature plays an important role in the nesting Temperature plays an important role in the nesting behaviour and incubation of hatching process of sea behaviour and incubation of hatching process of sea turtles. The average monthly air temperature data (in turtles. The average monthly air temperature data (in o o

C)C) in Gahirmatha for 1995 and 1998 are given in the in Gahirmatha for 1995 and 1998 are given in the table.table.

Month 1995 1998

Min o C Max o C Min o C Max o C

January 14.6 25.9 16.9 27.8

February 18.9 31.7 19.1 31.3

March 22.6 34.3 23.1 34.0

April 25.9 38.5 25.5 36.4

May 27.2 35.4 27.7 38.6

June 27.4 34.0 28.7 36.5

July 26.7 32.1 26.9 33.9

August 26.7 32.5 27.0 32.8

September

26.8 30.9 26.0 32.8

October 24.7 30.9 26.0 32.2

November

20.9 28.8 22.4 30.6

December

16.4 29.0 15.9 29.1

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Rainfall

In the present study In the present study (1998) the minimum (1998) the minimum average rainfall of average rainfall of 3.0 mm was 3.0 mm was observed in January observed in January and a maximum and a maximum average rainfall of average rainfall of 318 mm in 318 mm in September. The September. The average rainfall data average rainfall data (in mm) for 1995 (in mm) for 1995 and 1998 are given and 1998 are given in table.in table.

In the present study In the present study (1998) the minimum (1998) the minimum average rainfall of average rainfall of 3.0 mm was 3.0 mm was observed in January observed in January and a maximum and a maximum average rainfall of average rainfall of 318 mm in 318 mm in September. The September. The average rainfall data average rainfall data (in mm) for 1995 (in mm) for 1995 and 1998 are given and 1998 are given in table.in table.

MonthMonthMonthMonth 1995 1995 1995 1995 1991998 8

1991998 8 JanuaryJanuaryJanuaryJanuary 5.05.05.05.0 3.03.03.03.0

FebruaryFebruaryFebruaryFebruary 40404040 9.09.09.09.0

MarchMarchMarchMarch 29292929 117117117117

AprilAprilAprilApril 16161616 93939393

MayMayMayMay 228228228228 15151515

JuneJuneJuneJune 154154154154 101101101101

JulyJulyJulyJuly 140140140140 137137137137

AugustAugustAugustAugust 293293293293 228228228228

SeptembSeptembererSeptembSeptemberer

202202202202 318318318318

October October October October 229229229229 273273273273

NovembeNovember r NovembeNovember r

261261261261 100100100100

DecembeDecember r DecembeDecember r

---- ----

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Humidity

Humidity is important Humidity is important for inducing the for inducing the nesting activity and nesting activity and building of nests by building of nests by the turtles. In the the turtles. In the present study, the present study, the humidity value was humidity value was observed to range observed to range from 64% to 87% from 64% to 87% during 1998 in the during 1998 in the Gahirmatha coast. Gahirmatha coast. The average monthly The average monthly humidity values (in %) humidity values (in %) recorded are given in recorded are given in the table.the table.

Month

1995 1998

08.30 hrs 17.30 hrs 8.30 hrs 17.30 hrs

January 75 63 80 67

February 81 64 82 64

March 73 58 78 64

April 71 61 77 65

May 79 73 73 67

June 82 81 78 73

July 86 78 84 81

August 87 81 87 84

September 87 84 86 81

October 83 85 84 85

November 82 79 81 78

December 81 72 78 67

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Hydrological ParametersPhysico-chemical parameters were studied during May 98, Nov. 98, and May 1999 in six locations viz., Maipura river, Maipura estuary, Maipura (seaside), Wheeler island, Dhamra river and Ekakula (seaside) region of Gahirmatha coast.

Salinity

D O

SPM

Nitrite

Nitrate

Phosphate

Click on individual parameters for more details.

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SalinitySalinityThe overall salinity ranged from 12.5 to 33.37 ppt during 1998-99. Lower salinity values were recorded during monsoon and post-monsoon period. Seasonal and station-wise salinity values (in ppt.) are given below.

 Station Station

Season (Month)Season (Month)

May-98May-98

Nov-98Nov-98 May-99May-99

Maipura riverMaipura river 16.2416.24 12.512.5 13.6913.69

Maipura estuaryMaipura estuary 16.6316.63 15.7515.75 32.4332.43

Maipura (seaside)Maipura (seaside)

-- 21.1421.14 31.9831.98

Dhamra riverDhamra river 9.859.85 -- --

Wheeler IslandWheeler Island 28.6328.63 14.9914.99 32.5432.54

Ekakula (seaside)Ekakula (seaside)

-- 20.8720.87 33.3733.37

MainMain

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Dissolved OxygenDissolved OxygenThe Dissolved Oxygen (DO) is an indicator of health of water quality. It ranged from 6.9 mg/l to 12.9 mg/l at Wheeler Island (seaside). Seasonal and station-wise DO values (in mg/l) are given below.

  StationStation

  StationStation

Season (Month)Season (Month)Season (Month)Season (Month)

May-May-9898May-May-9898

Nov-98Nov-98Nov-98Nov-98 May9May999May9May999

Maipura riverMaipura riverMaipura riverMaipura river 11.611.611.611.6 12.512.512.512.5 9.29.29.29.2

Maipura estuaryMaipura estuaryMaipura estuaryMaipura estuary 10.410.410.410.4 8.88.88.88.8 11.611.611.611.6

Maipura (seaside)Maipura (seaside)Maipura (seaside)Maipura (seaside) ---- 10.410.410.410.4 9.89.89.89.8

Dhamra riverDhamra riverDhamra riverDhamra river 7.47.47.47.4 ---- ----

Wheeler IslandWheeler IslandWheeler IslandWheeler Island 12.912.912.912.9 7.47.47.47.4 6.96.96.96.9

Ekakula (seaside)Ekakula (seaside)Ekakula (seaside)Ekakula (seaside) ---- 11.211.211.211.2 9.89.89.89.8

MainMain

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Suspended MatterSuspended MatterSuspended matter varied from 4.80 mg/l at seaside of Ekakula to 230.71 mg/l at Wheeler Island. In summer, suspended solids are generally higher when compared to other seasons. The Table shows Suspended Matter in Gahirmatha coastal waters during 1998-99.

  StationStation

  StationStation

Season (Month)Season (Month)Season (Month)Season (Month)

May-98May-98May-98May-98 Nov-98Nov-98Nov-98Nov-98 May-99May-99May-99May-99

Maipura riverMaipura riverMaipura riverMaipura river 24.224.224.224.2 15.8215.8215.8215.82 68.9568.9568.9568.95

Maipura estuaryMaipura estuaryMaipura estuaryMaipura estuary 23.123.123.123.1 61.3261.3261.3261.32 87.2687.2687.2687.26

Maipura (seaside)Maipura (seaside)Maipura (seaside)Maipura (seaside) ---- 15.9215.9215.9215.92 66.3266.3266.3266.32

Dhamra riverDhamra riverDhamra riverDhamra river 34.034.034.034.0 ---- ----

Wheeler IslandWheeler IslandWheeler IslandWheeler Island 75.375.375.375.3 230.71230.71230.71230.71 93.2293.2293.2293.22

Ekakula (seaside)Ekakula (seaside)Ekakula (seaside)Ekakula (seaside) ---- 4.804.804.804.80 64.7764.7764.7764.77

MainMain

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NitriteNitrite

Nitrite content in Gahirmatha coastal waters varied from 0.08 mol/l (at Ekakula) to 12.9 mol/l (at Maipura estuary), as detailed below.

StationStation StationStation

Season (Month)Season (Month)Season (Month)Season (Month)

May-May-9898May-May-9898

Nov-Nov-9898Nov-Nov-9898

May-99May-99May-99May-99

Maipura riverMaipura riverMaipura riverMaipura river 0.640.640.640.64 3.143.143.143.14 0.490.490.490.49

Maipura estuaryMaipura estuaryMaipura estuaryMaipura estuary 0.400.400.400.40 5.995.995.995.99 12.912.912.912.9

Maipura Maipura (seaside)(seaside)Maipura Maipura (seaside)(seaside)

---- 1.451.451.451.45 0.360.360.360.36

Dhamra riverDhamra riverDhamra riverDhamra river 4.854.854.854.85 ---- ----

Wheeler IslandWheeler IslandWheeler IslandWheeler Island 1.371.371.371.37 5.425.425.425.42 0.840.840.840.84

Ekakula (seaside)Ekakula (seaside)Ekakula (seaside)Ekakula (seaside) ---- 0.080.080.080.08 0.100.100.100.10

MainMain

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NitrateNitrateNitrate content in Maipura river varied from 0.10 mol/l to 5.57 mol/l. It was higher in river/estuarine zone as compared to neritic zone. The details are given below.

StationStation StationStation

Season (Month)Season (Month)Season (Month)Season (Month)

May-98May-98May-98May-98 Nov-98Nov-98Nov-98Nov-98 May-99May-99May-99May-99

Maipura riverMaipura riverMaipura riverMaipura river 0.10 0.10 0.10 0.10 5.575.575.575.57 0.240.240.240.24

Maipura estuaryMaipura estuaryMaipura estuaryMaipura estuary 0.210.210.210.21 1.801.801.801.80 1.141.141.141.14

Maipura Maipura (seaside)(seaside)Maipura Maipura (seaside)(seaside)

---- 0.740.740.740.74 0.420.420.420.42

Dhamra riverDhamra riverDhamra riverDhamra river 0.400.400.400.40 ---- ----

Wheeler IslandWheeler IslandWheeler IslandWheeler Island 0.200.200.200.20 1.891.891.891.89 0.180.180.180.18

Ekakula Ekakula (seaside)(seaside)Ekakula Ekakula (seaside)(seaside)

---- 0.160.160.160.16 0.940.940.940.94

MainMain

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PhosphatePhosphatePhosphate content in Gahirmatha coast varied from 0.33 mol/l (at Maipura-seaside) to 2.11 mol/l (Dhamra river). The details are given below.

   StationStation   StationStation

Season (Month)Season (Month)Season (Month)Season (Month)

May-98May-98May-98May-98 Nov-98Nov-98Nov-98Nov-98 May-May-9999May-May-9999

Maipura riverMaipura riverMaipura riverMaipura river 0.920.920.920.92 0.630.630.630.63 0.490.490.490.49

Maipura estuaryMaipura estuaryMaipura estuaryMaipura estuary 1.401.401.401.40 0.540.540.540.54 0.880.880.880.88

Maipura Maipura (seaside)(seaside)Maipura Maipura (seaside)(seaside)

---- 0.330.330.330.33 0.880.880.880.88

Dhamra riverDhamra riverDhamra riverDhamra river 2.112.112.112.11 ---- ----

Wheeler IslandWheeler IslandWheeler IslandWheeler Island 1.331.331.331.33 1.961.961.961.96 1.81.81.81.8

Ekakula Ekakula (seaside)(seaside)Ekakula Ekakula (seaside)(seaside)

---- 0.580.580.580.58 0.880.880.880.88

MainMain

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Distribution of marine organisms in Gahirmatha coast during 1998-99

In the present study (1998-99), 207 species of marine organisms were recorded in the estuarine and neritic zones of Gahirmatha coast.

DATA

Phytoplankton Zooplankton Benthos

(No. of species)

Click on individual group.

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GroupGroup No. of No. of speciesspecies

PhytoplanktonPhytoplankton

Bacillariophyceae

Dinophyceae

Chlorophycea

Cyanophyceae

Euglenozoa

Prymnesiophycea

Xanthophyceae

95

10

4

4

1

1

1

ZooplanktonZooplankton

Hydrozoa

Polychaeta

Crustacea

Polyhymenophora

Sagittoidea

Tentaculata

Thaliacea

Gastropoda

Appendicularia

2

2

19

2

3

1

1

1

1

GroupGroup No. of No. of speciesspecies

BenthosBenthos

Annelida

Arthropoda

Mollusca

Pisces

Turtle

15

5

8

26

4

Marine Organisms recorded in Gahirmatha Coast (1998-99)

Overall

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PhytoplanktonPhytoplanktonIn the present study (1998-99), In the present study (1998-99), 116 species of phytoplankton 116 species of phytoplankton were recorded (95 species of were recorded (95 species of Bacillariophyceae, 10 species of Bacillariophyceae, 10 species of Dinophyceae, 4 species each of Dinophyceae, 4 species each of Chlorophyceae, Cyanophyceae Chlorophyceae, Cyanophyceae and one species each of and one species each of Euglenophyceae, Euglenophyceae, Prymneziophyceae and Prymneziophyceae and Xanthophyceae). The maximum Xanthophyceae). The maximum diversity of phytoplankton was diversity of phytoplankton was recorded during December 1998. recorded during December 1998. The maximum density of The maximum density of phytoplankton recorded was phytoplankton recorded was 75.000/m75.000/m33 in Wheeler Island and in Wheeler Island and 71,600/m71,600/m33 in Maipura River. The in Maipura River. The density of phytoplankton was density of phytoplankton was found to be higher in the found to be higher in the estuarine zone than in the neritic estuarine zone than in the neritic zone.zone.Overall

Euglenophyceae

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In the present study (1998-99), 18 zooplankton groups were identified in Gahirmatha coast. Totally 32 species of zooplankton were recorded. They are 19 species of crustacea, 3 species of sagittoidea, two species each of polyhymenophora, polychaeta, hydrozoa and one species each of appendicularia, thaliacea and tentaculata. The zooplankton density was found to be higher in the estuarine zone compared to neritic zone. The maximum number of species was observed in the post monsoon. The density of zooplankton ranged from 49 to 2904 numbers/m3.

In the present study (1998-99), 18 zooplankton groups were identified in Gahirmatha coast. Totally 32 species of zooplankton were recorded. They are 19 species of crustacea, 3 species of sagittoidea, two species each of polyhymenophora, polychaeta, hydrozoa and one species each of appendicularia, thaliacea and tentaculata. The zooplankton density was found to be higher in the estuarine zone compared to neritic zone. The maximum number of species was observed in the post monsoon. The density of zooplankton ranged from 49 to 2904 numbers/m3.

ZooplanktonZooplankton

Overall

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BenthosIn the present study (1998-99) totally 29 species of benthic organisms were recorded (15 species of annelida, 5 species of arthropoda, 8 species of mollusca and one species of chordata). The maximum number of benthic organisms was recorded during post-monsoon period.

Overall

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In Orissa, the mangroves extend from Balasore coast to Puri coast covering an area of 211 sq. km., of which 161 sq. km. is in and around the Gahirmatha coastal region. Around Dhamra mouth, the mangroves exist in very dense patches. The Bhitarkanika sanctuary, a part of the Gahirmatha coast, is located between 20° 4’–20° 8’ N latitude and 86° 45’ E – 87° 50’ longitude covering an area of 672 sq. km.

In Orissa, the mangroves extend from Balasore coast to Puri coast covering an area of 211 sq. km., of which 161 sq. km. is in and around the Gahirmatha coastal region. Around Dhamra mouth, the mangroves exist in very dense patches. The Bhitarkanika sanctuary, a part of the Gahirmatha coast, is located between 20° 4’–20° 8’ N latitude and 86° 45’ E – 87° 50’ longitude covering an area of 672 sq. km.

Mangroves

Species Species compositioncomposition

Mangroves

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Mangrove species compositionMangrove species composition

14 species of mangroves are found in the Gahirmatha coastal region. They are:14 species of mangroves are found in the Gahirmatha coastal region. They are:

Derris scandensBruguiera gymnorrhizaBruguiera sexangulaBruguiera parvifloraBruguiera cylindricaCeriops decendraCeriops tagal.

Avicennia albaAvicennia officinalisAvicennia marinaLumnitzera racemosaExoecaria agallochaXylocarpus granatum X. mokongensi

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Major Threats

Indiscriminate fishing by trawlers in nearshore and offshore coastal waters, without TED.Indiscriminate fishing by trawlers in nearshore and offshore coastal waters, without TED.

The females of the second arribada dig up pits in the same stretches of the beach especially in the “core” area which overlap with the first mass nesting severely damaging the earlier nests as well as the hatchlings.

The females of the second arribada dig up pits in the same stretches of the beach especially in the “core” area which overlap with the first mass nesting severely damaging the earlier nests as well as the hatchlings.

Beach erosion, damage by predators, human interference and change in the land use pattern of coastal areas.Beach erosion, damage by predators, human interference and change in the land use pattern of coastal areas.

ICMAM-PD

Indiscriminate fishing by trawlers in nearshore and offshore coastal waters, without TED.Indiscriminate fishing by trawlers in nearshore and offshore coastal waters, without TED.

The females of the second arribada dig up pits in the same stretches of the beach especially in the “core” area which overlap with the first mass nesting severely damaging the earlier nests as well as the hatchlings.

The females of the second arribada dig up pits in the same stretches of the beach especially in the “core” area which overlap with the first mass nesting severely damaging the earlier nests as well as the hatchlings.

Beach erosion, damage by predators, human interference and change in the land use pattern of coastal areas.Beach erosion, damage by predators, human interference and change in the land use pattern of coastal areas.

Major Threats

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Indiscriminate fishing by trawlers in nearshore and offshore coastal waters, without TED.Indiscriminate fishing by trawlers in nearshore and offshore coastal waters, without TED.

The females of the second arribada dig up pits in the same stretches of the beach especially in the “core” area which overlap with the first mass nesting severely damaging the earlier nests as well as the hatchlings.

The females of the second arribada dig up pits in the same stretches of the beach especially in the “core” area which overlap with the first mass nesting severely damaging the earlier nests as well as the hatchlings.

Beach erosion, damage by predators, human interference and change in the land use pattern of coastal areas.Beach erosion, damage by predators, human interference and change in the land use pattern of coastal areas.

Major Threats

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Turtles as Incidental catches Turtles as Incidental catches Turtles as Incidental catches Turtles as Incidental catches

Decayed adult specimens and young ones were found along the Gahirmatha beach during the nesting season. This could be a part of incidental catch from fishing gears operated from mechanised and other fishing craft.

Decayed adult specimens and young ones were found along the Gahirmatha beach during the nesting season. This could be a part of incidental catch from fishing gears operated from mechanised and other fishing craft.

(Source: Kar and Dash 1990, Silas et. al 1984-85, Pandav et. al 1994, Pandav and Choudhury 1999 and Das 2001.)

Year No. of dead turtles recorded

1990-91 2,810

1991-92 2,315

1993-94 5,282

1994-95 3,250

1997-98 13,575

1998-99 30,000

1999-2000 20,000

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Suggestion for turtle conservation Suggestion for turtle conservation Strict enforcement of Orissa Marine Fishing Regulation Act 1982 Strict enforcement of Orissa Marine Fishing Regulation Act 1982

and Rules 1983, which prohibit any kind of mechanised fishing and Rules 1983, which prohibit any kind of mechanised fishing within 5 km of the shore along Orissa coast for reducing the within 5 km of the shore along Orissa coast for reducing the mortality of sea turtles. mortality of sea turtles.

Use of Turtle Excluder Devices (TED) in the 3000 trawlers Use of Turtle Excluder Devices (TED) in the 3000 trawlers operating off Orissa coast to minimize turtle mortality.operating off Orissa coast to minimize turtle mortality.

PProtection of nesting grounds and aquatic habitats by minimising rotection of nesting grounds and aquatic habitats by minimising human intervention/interference in the nesting area.human intervention/interference in the nesting area.

Creation of facilities for nesting, incubation, hatching and Creation of facilities for nesting, incubation, hatching and protection of the hatchlings along the beach.protection of the hatchlings along the beach.

National and international coordination of conservation strategies.National and international coordination of conservation strategies.

Creation of awareness among local people on conservation of Creation of awareness among local people on conservation of turtles and its nesting grounds, through informal education, turtles and its nesting grounds, through informal education, training, extension and media.training, extension and media.

Carrying out studies on the causative factors responsible for Carrying out studies on the causative factors responsible for change in beach profile, which lead to shifting of nesting grounds change in beach profile, which lead to shifting of nesting grounds and for planning corrective measures.and for planning corrective measures.

ConclusioConclusionnThe Information System The Information System

developed for Gahirmatha developed for Gahirmatha using remote sensing and GIS using remote sensing and GIS has demonstrated that these has demonstrated that these tools could be effectively used tools could be effectively used for monitoring and managing for monitoring and managing the breeding and nesting the breeding and nesting grounds of olive ridley turtles grounds of olive ridley turtles in Gahirmatha coast and their in Gahirmatha coast and their conservation.conservation.

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