Sriharikota mangrove wetlands

Continuing my work on the mangroves of Nellore district, I visited the Satish Dhawan Space Centre at Sriharikota during March 2011 with their prior permission. There I noticed some mangrove swamps supporting the growth of a few true mangroves.

• Location : Satish Dhawan Space Centre, SHAR, Sriharikota.
• Mandal : Sullurpet
• Date of visit : 21.3.2011
• Co-ordinates : 13⁰38¹34.30¹¹ - 13⁰48^l06.12¹¹N, 80⁰11¹38.75¹¹-80⁰12¹¹49.75¹¹E

Permission was issued by SHAR authorities to enter the forest area. After security clearance the Principal Investigator was allowed into the forest area along with Sri .N. Sreenivasulu Reddy, Horticulturist of SHAR. We went into the forest covering COP area which includes Malipeduvagu, Cholla Doruvu, Chidimoti Kayya swamps. Finally, the adjoining Rayadoruvu was also visited.

COP area (Chandrasi Kuppam Out post)

I. Malipedu vagu:

This is a fairly big pond

The following mangrove associates and other flora were recorded.

1. Pandanus fascicularis Lam.- Pandanaceae, flowering

2. Calamus rotang L – Arecaceae, no flowers

3. Myriostachya wightiana L – Poaceae, flowering

4. Calophyllum inophyllum L - Calophyllaceae

Salinity: 30 ppt

Water Temperature: 27⁰C

II. Cholla doruvu:

This is a very important mangrove swamp in SHAR. It is adjacent to a blacktop road. It is sustained by flood waters. Cholladoruvu has a small, but thick mangrove forest. It has other non-mangrove flora also. Cholladoruvu is a brackish water pond with an opening into the Bay of Bengal.

True mangroves:

1. Avicennia marina 8 – 10 ft tall; No flowers

2. Lumnitzera racemosa Willd, Combretaceae, 15 ft tall; flowering and fruiting

3. Excoecaria agallocha 10-12 ft. tall; flowering

Mangrove associates:

1. Pandanus fascicularis Lam.- Pandanaceae, no flowers

2. Phoenix paludosa Roxb. (Mangrove date palm) Arecaceae, flowering

3. Ipomoea pes-caprae, flowering

4. Caesalpinia crista L. Caesalpinaceae, not in flowering

5. Cassia biflora L. Caesalpinaceae, flowering

Salinity : 30 ppt

Water Temperature : 28⁰C

III. Chudimoti Kayya:

This is a typical mangrove swamp in the sense that it receives fresh water from upstream during monsoon and is close to the sea with mouth opening into the sea. At this time of season, at the last week of March, it has water at the middle of the pond and the periphery is swampy. It has fringe mangroves and is about 50 acres in extent. The water is brackish.

True mangroves:

1. Lumnitzera racemosa: 15- 18 ft. tall, flowering and fruiting

2. Excoecaria agallocha – 15- 18 ft. tall, flowering

It is precisely a thick mixed Lumnitzera – Excoecaria community here at COP area. Both these mangroves are found at the fringe of the pond at Chudimoti kayya.

Mangrove associates:

1. Clerodendrum inerme, Verbenaceae, flowering

2. Ipomoea pes-caprae, Convolvulaceae, flowering

3. Derris indica, Bennet, Fabaceae, 10 ft tall, not in flowering

Other flora:

1. Garcinia spicata (Gamboje) Well, Clusiaceae, no flowers

2. Celosia sinensis (local name: Garika muttivellu), Amaranthaceae, flowering

There are Casuarina plantations very close to the mangrove communities at Cholladoruvu and Chudimoti Kayya. Practically there is no menace of prosopis invasion into the mangrove wetlands here. The soil at the ponds is predominantly light sandy enriched by litter, and a little sediment,

and is quite different from that of other mangrove swamps in the district.

Salinity : 30 ppt

Water Temperature : 28⁰C

Pudirayadoruvu:

Pudirayadoruvu pond is a fenced and barricaded area separating SHAR from the adjoining northern area of Pulicat lake. The water in Pudirayadoruvu pond is highly saline, approaching the salinity of sea water. There are no traces of mangroves here. Pudirayadoruvu is one of the two mouths of Pulicat Lake to the sea, the other being Kondurupalem, on the Andhra Pradesh side of Pulicat Lake. There are thick Casuarina plantations on the northern bank of Pudirayadoruvu, where the coastal village of Nawabpet (Vakadu mandal) is located.

Survey of Krishnapatnam Mangrove Swamps

Invasion of Prosopis into mangrove wetlands

Ceriops decandra

Bruguiera cylindrica

Bruguiera gymnorhiza

My fourth field visit in the study of mangroves of Nellore district is Krishnapatnam where the Kandaleru creek merges with the Bay of Bengal. Here I have noticed two important mud flats, Burada Dibba & Chintala Dibba. At both of these places I found a fairly good mangrove diversity in view of influx of brackish water and fresh water daily.

• Mandal: Muthukuru
• Date of visit 24.02.2011
• Coordinates : 14⁰14¹.16-8.9¹¹-14⁰15^l01.25¹¹N, 80⁰07¹24.35¹¹-80⁰08¹¹01.99¹¹E

Two small islands which are actually broad mudflats, to the south of Krishnapatnam port were surveyed. The stations surveyed are surrounded by backwaters of Bay of Bengal and of Kandaleru creek.

Station 1 : Burada Dibba

This is actually a broad mudflat inundated by high tide everyday and so it is muddy. Mangroves are found at the fringe and interior also, and they are dense. Prosopis is not found, possibly due to daily inundation. Avicennia marina is the dominant species. Bruguiera gymnorrhiza and Ceriops decandra are also represented, but sparsely.

Ture mangroves :

1. Avicennia marina, 8-10 ft tall, with flowers and fruits

2. Ceriops decandra, 4-6 ft tall, with flowers and fruits

3. Bruguiera gymnorhiza (L.) Savigny, Rhizophoraceae, 6-8 ft tall, flowering

4. Excoecaria agallocha, 8-10 ft tall, no flowers

Mangroves associates:

1. Suaeda nudiflora, flowering

2. Clerodendrum inerme, flowering

3. Sesuvium portulacastrum, no flowers

Other flora:

Asparagus racemosus

Salinity: 35 ppt

Dissolved oxygen: 46

Water temperature: 29⁰C

Station 2: Chintala Dibba(Island)

Like Mud island, Chintala Dibba is also a broad mudflat, but a little raised so that it is not subject to daily inundation, except at the periphery. The interior of the mudflat is quite dry. Prosopis is of conspicuous occurrence.

True mangroves:

1. Avicennia marina, 8-10 ft tall, no flowers and fruits

2. Ceriops decandra, 4-8 ft tall, flowering

3. Bruguiera gymnorhiza, 6-9 ft tall, flowering

4. B.cylindrica (L) Bl, 5-6 ft tall, flowering

Mangrove associates:

1. Clerodendron inerme, flowering

2. Thespesia populneoides(Roxb) Koestel, Malvaceae, no flowers

3. Atriplex repens Roth Chenopodiaceae

Other flora:

1. Asystasia gangetica

Salinity : 35 ppt

Dissolved oxygen: 13.8

Water temperature : 28⁰C

Sediment samples were collected for chemical analysis.

Survey of Peddapalem-Ponnapudi (Lakshmipuram, Kottur) Mangrove Wetlands

Sonneratia apetala: Tree & Fruits

Conversion of mangrove wetlands into salt pans
Excoecaria agallocha

<-- Mangroves felled & transported

Furthering my study of mangroves of Nellore district, I undertook a field visit to the Iskapalle lagoon in Vidavalur mandal. Here I found a very vast wetland occupied by mangroves. In this lagoon a fresh water body, Pyderu stream joins the Bay of Bengal. This has resulted in a vast mangrove forrest.

• Panchayat : Ramachandrapuram
• Mandal: Vidavalur
• Date of visit : 21.02.2011
• Coordinates : 14⁰ 40¹07.17¹¹–14⁰45¹11.43¹¹ N, 80⁰05¹38.17¹¹-80⁰09¹08.20¹¹E

What we find at Peddapalem- Ponnapudi in respect mangroves are actually mangroves of the Iskapalli lagoon. The Iskapalli lagoon is a narrow curvilinear brackish water body lying quasi-parallel to the shore line of Bay of Bengal .The lagoon is located at the northeastern part of the Pennar delta near Iskapalli village in Nellore district ,and is separated from the open sea by a 6 km- long and about 6 km-wide shore parallel sandy island, which is known as Kuratipalem island. .On the whole, with a water spread of about 10 miles² (17.75 km²), including the tidal channel formed on the eastern side, the lagoon extends between latitudes 14O 40’ to 14^O 45’N and longitudes 80O 05’ to 80^O 10’ E. Another important aspect of the lagoon is that Pyderu. a 22 – km long rivulet that drains 50 km² area in the northwestern Pennar delta directly empties into the lagoon.

True mangroves:

1. Avicennia marina 6-8 ft tall, no flowering

2. Rhizophora mucronata, 8-12 ft tall, one or two plants in flowering; no fruits.

3. Aegiceras corniculatum(L.) Blanco Myrsinaceae: 5-6 ft tall, flowering, no fruits.

4. Ceriops decandra (Griff) Ding Hou: Rhizophoraceae,5 – 6 ft tall, flowering; no fruits.

5. Excoecaria agallocha 6-8 ft tall, no flowers

6. Sonneratia apetala: No flowers; in fruiting condition. This species has been first identified by me in these swamps and has not been found in any other swamps of Nellore district I have so far visited.

Mangrove associates:

1. Acanthus ilicifolius L. – Acanthaceae, 4-5 ft tall, huge stands in flowering.

2. Aeluropus lagopoides (L.) Trin – Poaceae, flowering.

3. Fimbristylis ferruginea(L.) Vahl - Cyperaceae, flowering.

4. Ipomoea pes-caprae, flowering

5. Sesuvium portulacastrum, no flowers

Overall, the swamp is dominatd by A.marina . However.they are stunted, the tallest tree being not more than 8 ft. Next to A.marina, Acanthus ilicifolius is found in large numbers. A.ilicifolius communities are found at many points around the island. Such pure stands of A.ilicifolius is a rare feature in the mangrove swamps of Nellore district.

Wherever found, Aegiceras corniculatum is invariably associated with A.marina. Acanthus ilicifolius is found exclusiverly alone as pure communities, or associated with A.marina., Rhizophora mucronata is very sparsely distributed. The tallest tree is about 10-12 ft. True mangroves are found all along the fringe of the island and other creeks. In the interior of the island also which is waterlogged , both A.marina and Acanthus ilicifolius are noticed. On the whole, A.marina and other true mangroves are more robust and dense at the fringe of the island than at the boarding ferry point.

The mangrove swamps are reported to be revenue lands. At the periphery of the swamp, there is a mushrooming of salt pans, at East Gogulapalli of Allur mandal. There are also shrimp ponds around the swamp. The brackish water of Pyderu - sea are pumped in to the ponds. There is a lot of fishing activity in the brackish water. The fishermen are conscious of the significance of mangroves. Some of them reported that they venerated the mangroves. In spite of this, there is a lot of felling of A.marina for firewood and fencing. They reported that the fuel of A.marina is superior to mesquite. High tide is reported to prevail up to 11 am and low tide after that time.

Significantly, mesquite is absent anywhere around or in the interior of the Kuratipalem island or at the fringe of the Pyderu stream. It is found only landward along the ferry boarding points. This swamp is superior in terms of extent, diversity, density and robustness of mangroves compared to the three swamps visited so far.

Water and sediment samples are collected at 3 stations quite apart, in the swamp. At the first station where the samples are collected A.marina are dominant.

Water salinity : 21 ppt

Dissolved oxygen: 08.6

Water temperature : 26^OC

At the second station R. mucronata are dominant

Water salinity : 20 ppt

Dissolved oxygen: 07.6

ater temperature: 27^OC.

At the third station called ‘Cheruvu kalva’ both A.marina and R.mucronata are found.

Water salinity: 20 ppt

Dissolved oxygen : 08.5

Water temperature: 270C

Evidently, both salinity and dissolved oxygen are almost uniform throughout the three stations.