Wednesday, December 28, 2011

Kadapalem and Gollakommu salt marshes

Avicennia marina forest in the swamps of Kadapalem

Fiddler crab seen in the mangrove swamps of Kadapalem

Students and teachers of Otturu High school addressed by this blogger about the need for conservation of mangroves

I explored the coast of Bogole mandal at Chippaleru, a brackish water stream for mangroves. I came across with patches of mangroves at two places, Kadapalem and Gollakommu. These are very minor swamps where very little mangrove diversity is seen.
  • Mandal : Bogole
  • Co-ordinates : 14048123.4411N, 80004156.7611E
  • Date of visit : 30-07-2011
There salt marshes are adjacent to Chippaleru, a brackish water creek which flows from west to east and merges with Bay of Bengal after branching off into a few smaller creeks.
Mangroves are sparingly distributed in an area of about 10 acres. There is extensive invasion of Prosopis chilensis into the salt marshes.

True mangroves:
1. Avicennia marina : not exceeding 5-6 tall, sparingly distributed, full of flowers and fruits.
2. A. officinalis : only two plants are noticed, but very robust, 5-6 ft tall, flowering just began.

Mangrove associates:
1. Sesuvium portulacastrum: flowering.
2. Suaeda nudiflora: flowering.
3. S. maritima: flowering.
4. Ipomoea pes-caprae : no flowers.
5. Salicornia brachiata : no flowers.
6. Sarcolobus carinatus: Asclepiadaceae, no flowers

There is a Mandal Parishad Primary School, about 3 km from the above swamps, at Tatichetlapalem (Venkateswarapuram) in Bogole mandal. There are 73 students and 3 full-fledged teachers. After completing the field visit, this school was visited and the students and teachers were addressed about mangroves, their importance to mankind and the need for their conservation. Live specimens were shown to the students and explained with the help of a poster. Pamphlets on the need for conservation of mangroves were distributed to the teachers for disseminating the information contained therein to the local stake holders and others concerned.

Lakshmipuram of Annagaripalem mangrove swamps

Gaint trees of Rhizophora mucronata

Sesuvium portulacastrum & Suaeda nudiflora

As part of my study on mangroves of Nellore district, I happened to visit Lakshmipuram of Annagaripalem in Kavali mandal. It is here we find the tallest trees of Rhizophora mucronata which are extended over a large area. Artrhocnemum indicum & Sesuvium portulacastrum are two mangrove associates which have spread over a large area in these swamps.
  • Mandal : Kavali
  • Coordinates : 14049125.9411N, 80004137.3411E
  • Date of visit : 27-7-2011
The swamps of the above location are about 1 km to the east of Lakshmipuram, a fishermen hamlet in Annagaripalem panchayat of Kavali mandal. In order to reach these swamps one has to cross the Buckingham canal. The entire area to the east of Buckingham canal is heavily invaded with Prosopis chilensis , which has extended farther into the salt marshes.

True mangroves:
a. Avicennia marina : about 6-7 ft tall, very dense, in full bloom, there are fruits here and there.
b. Rhizophora mucronata : in flowering. In entire Nellore district, it is here we find the tallest and most robust R. mucranata trees. About 5 such trees have come together giving the appearance of a single tree. They occupy an area of about 150 ft X 2 ft, and a height of 15 -18 ft.

They are at the fringe of a creek, full of water round the year. Besides, there are 21 smaller trees R. mucranata ranging from 6-10 ft in height.

Lakshmipuram mangrove swamps are dominated by A. marina with dense growth. The extent of the mangrove swamp is about 18000 sq. meters.

Mangrove associates:
1. Acanthus ilicifolius : sparse in number, in flowering.
2. Sesuvium portulacastrum: dense growth, no flowers.
3. Artrhocnemum indicum : dense growth, no flowers.
These two mangrove associates have spread in a mixed pattern occupying an area of about 2 hectares.
4. Suaeda nudiflora: flowering.

Lakshmipuram is predominantly a fishermen hamlet. Most of the dwellers are engaged in fishing in the creeks and in the sea, about 1 km away. Some of them are engaged as laborers in the prawn culture ponds which are hardly a km away from the hamlet.

There is a Mandal Parishad School with a student strength of 30 and two full-fledged teachers. After completing the field visit the school was visited and the students and teachers were addressed about mangroves, their significance and the need for their conservation. Live plant specimens collected were shown and explained with the help of poster. Pamphlets on the need for conservation of mangroves were distributed to the teachers for disseminating the information contained therein to the local stake holders and others concerned.

Mangrove swamps of Dugarajapatnam & Kondurupalem

Fishermen at Konduru estuary

Konduru estuary
Dugarajapatnam in Vakadu mandal was once a sea port. Here the mangroves are very stunted and degraded. Much of the mangrove swamps are now converted into shrimp ponds.

Kondurupalem is one of the mouths of the Pulicat Lake in Nellore district, the other being Pudirayaduruvu. Here also there is not any diversity of mangroves. Even the mangroves present here are very much stunted due to the non-availability of fresh water.

1. Dugarajapatnam (Vakadu mandal)

Location : 13059100.9711 N, 80009121.3911E

The village is a accessible from Mallam and is about 25 km from the latter. There is Buckingham canal at Dugarajapatnam. It is very shallow here. When we cross Buckingham canal we find mangrove swamp. Avicennia marina is the only mangrove found here and it is stunted, 4-5 ft tall.

4. Kondurupalem (Konduru estuary)

Coordinates : 13059111.2111 N, 80009147.4711E

This is one of the two mouths of Pulicat Lake to Bay of Bengal. The Kondurupalem estuary has a few mudflats where mangroves are found.

True mangroves:
1. Avicennia marina - 6-8 ft tall, no flowers
2. Excoecaria agallocha- 10 ft tall, no flowers

Mangroves associate:
Sesuvium portulacastrum, no flowers

salinity: 45 ppt.
Water Temperature : 280C

Peddathota and Chinnathota mangrove wetlands

Excoecaria agallocha

Aegiceras corniculatum

Chinnathota & Peddathota are mangrove swamps supported by Pulicat Lake in Vakadu mandal of Nellore district. They form a vast mangrove forest in this part of Pulicat lake. Here we find true mangroves like Lumnitzera racemosa & Aegiceras corniculatum with a robust growth. On the whole here we find a very thick mangrove forest over a length of about 2 km.
  • Mandal : Vakadu
  • Date of visit : 23.3.2011
1. Peddathota :
This mangrove swamp is on the northern fringe of Pulicat Lake in Vakadu mandal. Peddathota is about 100 m. from a metal road. The following mangroves are recorded.

True mangroves:

1. Aegiceras corniculatum: 12-15 ft tall, flowering
2. Excoecaria agallocha : 8-10 ft tall, flowering
3. Avicennia marina: 8-12 ft tall, not in flowering

Here we find pure Aegiceras communities. The trees are very dense, the tallest being 12-15 ft tall.

Other flora:
1. Calamus rotang(associated with Aegiceras and Excoecaria) Family Arecaceae
2. Centella asiatica(L.) Urban: Family Apiaceae, flowering
3. Bacopa monnieri (L) Pennel Family Scrophulariaceae, flowering

There are Casuarina plantations beside the mangrove belt.

Salinity: 25 ppt
Water Temperature : 270C

2. Chinnathota:
It is also close to a metal road on the northern fringe of Pulicat Lake in Vakadu mandal. In fact, there is no demarcating line between Peddathota and Chinnathota.

True mangroves:

1. Lumnitzera racemosa : 13-15 ft tall, flowering
2. Aegiceras corniculatum : 10-12 ft tall, flowering
3. Excoecaria agallacha : 18- 20 ft tall, flowering

There is virtually no difference in the mangrove flora composition of Peddathota and Chinnathota, except that the mangroves are denser at Chinnathota. In Chinnathota it is a mixed community of Lumnitzera and Excoecaria trees.

Mangrove associate:
Fimbristylis ferruginea Family Cyperaceae, flowering

Other flora:
1. Calamus rotang
2. Manilkara hexandra (Roxb) Dub, Family Sapotaceae, no flowers

Salinity: 28 ppt
Water Temperature : 280C

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 - 13048l06.1211N, 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 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.

Tuesday, December 27, 2011

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 : 140141.16-8.911-14015l01.2511N, 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 14O 45’N and longitudes 80O 05’ to 80O 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 : 26OC

At the second station R. mucronata are dominant
Water salinity : 20 ppt
Dissolved oxygen: 07.6
ater temperature: 27OC.

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.