Zooplankton studies in Coringa Estuary of AP

ICEPWCH-2010Department of ZoologyBangalore UniversityPresentation by : 

ICEPWCH-2010Department of ZoologyBangalore UniversityPresentation by P.ANIL KUMAR P. R. Govt. College(A) KAKINADA, A.P

Slide 2: 

The Influence of hydrographic features and Physico-Chemical factors on the distribution of ZOOPLANKTON in River back waters of CORINGA MANGROVES, KAKINADA BAY ANDHRA PRADESH, INDIA

Slide 3: 

General Introduction Description of the study area Hydrographical features of the study area Zooplankton characteristics Discussion and conclusions References

Slide 4: 

Mangrove habitat is a two way system. During floods it gets inundated and retains the nutrients basing on the sediment characteristics and quality of river discharge. During tidal influx it gets submerged and enables the sediment to trap the elements from the sea and contribute to the enrichment by leaching through the sediments. The meroplankton populations survive in the mangrove successfully and serve as “SEEDS” for subsequent recolonisation.

Slide 5: 

The Indo-Pacific region has luxuriant mangroves. In India the total area of Mangroves is estimated to be 6,740 Km2 (about 7% of the world mangrove vegetation). In the vicinity of Kakinada the mangrove vegetation extends to an area of 316 Km2 around different tributaries of river Godavari. Between 1994-2000, Andhra University and the Indo-Belgium Project studied the zooplankton in the Kakinada mangroves.

Slide 6: 

The present study emphasises ... Role of zooplankton in the mangrove Diversity of zooplankton populations Productivity of the zooplankton Hydrographical features’ influence Role of zooplankton in the transfer of energy

Slide 7: 

GENERAL INTRODUCTION Mangrove ecosystems are self sustaining coastal landscape units that have resulted after long-term of geo-morphological process having close interaction with the surrounding aquatic environment. The most important function of mangrove communities is providing food and shelter for fin fish and shell fish. Since the mangrove leaf contains comparatively indigestible cellulose, lignin and wax-like secretions, few animals eat it. (Heald and odum, 1970).

Slide 8: 

The complex aerial root system provides shelter for many commercial and shell fish, particularly in the predator-prone stages of juvenile stages (Felician 1962, Austin 1971). The mangrove environments maintain the equilibrium between the terrestrial and aquatic ecosystems, with regards to physico-chemical and biological aspects. Along the physical process of maintaining the equilibrium, there exists an intricate biochemical process where energy transfer occurs through different trophic levels in the mangrove community.

Slide 9: 

The energy transfer through biochemical process involves the phytoplankton, mangrove vegetation, zooplankton, fishes, benthic community and microbial organisms. In this process, the zooplankton act as secondary producers. They assimilate the plant energy from the phytoplankton and transfer it into animal protein at secondary level. This process of transformation and translocation of energy is useful to understand the food chain, which is characteristic of the ecosystem.

Slide 10: 

Studies on zooplankton distribution and seasonal variations in the mangrove ecosystems throws light on the nutrient cycles, energy transfer and the fishery potential of the area. In the mangrove regions of India, Shanmugam (1986), Sambasivam (1985) from the Pitchavaram Mangroves of Tamil Nadu; Baidy and Chowdhury (1985) from the Sundarbans; Goswami (1992) from Goa; Sreenivas & Chandra Mohan(1999) from Kakinada have made significant contributions.

Slide 11: 

While studying the mangrove ecosystem, the surrounding estuarine environment can’t be isolated. Thus these two dynamic ecosystems are naturally independent and present a complex situation, difficult to understand in certain aspects of biological production. The studies relating to the zooplankton of estuaries has been widely dealt with, since the estuaries are known to be highly productive where juvenile stages of many benthic and nektonic forms spend a part of their life.

Slide 12: 

Some of the major estuaries in the Indian Peninsula are those of Ganga, Hoogly, Matlah stystem (Sunderban Mangroves) of West Bengal. The Mahanadi of Orissa, Bahuda estauary, the Godavari and Krishna of Andhra Pradesh (Coringa Mangroves and Nagayalanka and Etimoga mangrove regions). The Cauvery, Vellar – Coleron estuarine complex (Pitchavaram & Mutupet mangroves) of Tamil Nadu. The Narmada and Tapati of Gujarath.

Slide 13: 

The minor estuaries which are important in faunal diversity are Vamsadhara, Champavathi and Gosthani of Andhra Pradesh, Adyar, Pambar, Kotha Kavi, Vaigai, Palaiyar and Malathur of Tamilnadu. The present study is an attempt to present a detailed account of the zooplankton of the Coringa river of Coringa wild life sanctuary.

Slide 14: 

Materials and Methods . Location Two stations were selected along the course of Coringa river with in the brackish water segment.

Slide 15: 

Station – I The station I is located about 2 km. towards interior from the Kakinada Bay and where it receives nutrient water along with detritus from the surrounding mangrove environment. The Vegetation on either side of Coringa canal is dominated by Rhizophods, Excoicaria and Sonneratia spp . Location of the station I is Lat N. 16 53.68d’, Long E. 82 21.450.

Slide 16: 

Station – II This station is further inside about 4 km. away from the Bay toward intensive and represents the fag end of the region where tidal effect is felt, beyond which complete fresh water conditions prevail. Location of station II Lat N 16.50 160’, Long E 82 04 55’.

Slide 17: 

The stations were selected in such a way that each was represents a unique characteristics with regard to physico-chemical and biological features. The station I is more dynamic in the sense that tidal influence is more, where as station – II experience fresh water dominant conditions during most part of the year.

Slide 18: 

HYDROGRAPHICAL FEATURES OF THE STUDY AREA In the estuaries the hydrographical conditions are highly dynamic, they in turn limit the biota there. The biotic and abiotic interactions leads to establishment of characteristic communities which signifies certain endemism .

Slide 20: 

Monthly samples were collected at the selected two stations along the course of Coringa river from Jan. 09 to June ’09 for a period of six months which includes two biological seasons, i.e., Postmonsoon and summer seasons.

Slide 21: 

. METHODS ADOPTED TO STUDY ZOOPLANKTONS Monthly surface zooplankton samples were made out at the selected two stations in the Coringa river. Surface zooplankton samples were collected by employing a 120  m mesh sized net of 40 cm diameter.

Slide 22: 

As soon as the net was hauled the contents in the cod end collector of the net were gently transferred in to a clean polyethylene container and fixed with 5% formaldehyde solution. In the laboratory biomass was measured by the displacement method (UNESCO 1968, WICKSTEAD, 1965) and expressed as ml-m-3

Slide 23: 

For the enumeration of Zooplankton aliquot method was employed (Wickstead, 1965), where the total sampled was sub sampled and 10 ml. aliquot, was taken into a petridish provided with a grid, and the major groups of zooplankton were enumerated according to the illustrations given by Wickstead (1965).

Slide 24: 

Prior to the sub sampling larger forms like Hydromedusae, Siphonophores were separated from the sample and counted separately. Zooplankton numerical abundance was expressed as no/m3. Wet weight and dry weight of zooplanktons were determined to evaluate quantitative distribution during Jan. – June, 2009.

Slide 25: 

THE STUDY AREA The river Godavari is the second largest river in India (1530 Kms) with a drainage area of about 2,90,000 Km2. Its normal run off is about 4,60,316 million cusec meters. Before opening in to the Bay of Bengal, it divides into Gowtami Godavari and Vashista Godavari. The mangrove of Gawtami Godavari spreads over 316 Km2. It further divides into two at Yanam, as Coringa and Gowtami proper, which meet the sea at Kothapalem and Bhiravapalem, respectively.

Slide 26: 

The Coringa Canal travels about 26 km from Nellapalli (Yanam) and meets the Kakinada Bay. Annual flooding of the river during the monsoon is a characteristic feature. The brackish water conditions turn into marine habitat during this season. When the fresh water discharge ceases, the populations experience extreme variations in temperature and salinity with increasing turbidity. They exhibit interesting adaptive features for their survival and breeding.

Slide 27: 

Station – I Lat N. 160 53.68d’ Long E. 820 21.450 Station – II Lat N 16.50 160’. Long E 820 04 55’ Each of the stations represents unique characteristics with regard to physico-chemical and biological features. The station-I is more dynamic with higher tidal influence. Station-II has mostly fresh water dominant conditions.

Slide 28: 

HYDROGRAPHICAL FEATURES The biotic and abiotic interactions leads to establishment of characteristic communities which signifies certain endemism. Standard techniques were employed for collection and estimation of various parameters.

Slide 29: 

Standard techniques were employed for collection and estimation of various parameters (APHA, 1998). Different hydrographical parameters were estimated by adopting the following methods.

Slide 30: 

Different hydrographical parameters were estimated by adopting the following methods. Depth : Measured by using a sounding lead of 5lb Salinity : Knudsen’s method Turbidity : Nephlo turbidity method PH : Digital, PH meter Dissolved Oxygen : Winklers method Temp : 2O C sensitive thermometer. Monthly samples collected at the two stations in the Coringa river from Jan ’08 to June ’08 for a period of six months which includes two biological seasons, i.e., Pre- monsoon, and Monson seasons.

Slide 31: 

RESULTS Station – I Depth : Between 3.2 mtrs. and 4.0 mtrs. Turbidity: Between 22 -58 NTU PH : Between 6.9- 7.2 Salinity: Between 4.67x 10-3 to 27.23 x10-3 DO2: Between 3.42 ml/l to 4.85ml/l. Temp. : (surface) 28oC - 32.4 o (atmospheric) 29oC - 34.2o C.

Slide 32: 

RESULTS Station – II Depth : Between 2.0 mtrs and 4.9 mtrs. Turbidity: Between 18-83 NTU PH : Between 6.8- 7.2 Salinity: Between 0x10-3and 18.46 x10-3 DO2: Between 2.6ml/l to 5.3ml/l. Temp.: (surface) 26.4oC - 30.2o C, (atmospheric)27o C - 32.4 o C.

Slide 33: 

Station I: Biomass: The zooplankton biomass at the station I varied between 0.30 ml.m-3 and 2.14 ml.m-3 with a mean of 1.0 ml.m-3. Numerical abundance: Zooplankton numerical abundance at the station I varied between 11543 no.m-3 to a maximum of 56430 no.m-3 with a mean of 30513 no.m-3. Copepods: Copepods constitute the bulk of the plankton at the present station the abundance of the copepods ranged from aminimum of 9899 no.m-3 to a maximum of 37002 no.m-3 with a mean of 18827 no.m-3. .

Slide 34: 

Decapod Larvae: The decapod larval abundance varied between 799 no.m-3 and 2880 no.m-3 with a mean of 1854 no.m-3. Chaetognaths: The abundance of the chaetognaths varied between 186 no.m-3 and 959 no.m-3 with a mean of 652 no.m-3. Lucifers: The abundance of the lucifres varied between 16 no.m-3 and 1610 no.m-3 with a mean of 426 no.m-3. Gastropod Veligers: The abundance of the gastropod veligers ranged from a minimum of 252 no.m-3 to a maximum of 12588 no.m-3 with a mean of 5456 no.m-3.

Slide 35: 

Polychaete larvae: The polychaete larval abundance varied between 121 no.m-3 and 12588 no.m-3 with a mean of 340 no.m-3. Bivalve veligers: The bivalve veligers abundance varied between 330 no.m-3 and 5322 no.m-3 with a mean of 2679 no.m-3. Appendicularians: Abundance of the appendicularians varied between 59 no.m-3 and 67 no.m-3 with a mean of 63 no.m-3. Ostracods: The abundance of Ostracods ranged between 43 no.m-3 and 178 no.m-3 with a mean of 129 no.m-3.

Slide 36: 

Cladocerns: Cladocern abundance varied between 47 no.m-3 and 165 no.m-3 with a mean of 109 no.m-3. The miscellaneous groups includes hydromedusae, ctenophores, siphonophores and other larger planktonic groups

Slide 37: 

Station II Biomass: Zooplankton biomass varied between 0.44 ml.m-3 and 1.08 ml.m-3 with a mean of 0.69 ml.m-3. Numerical abundance: Zooplankton numerical abundance varied between 11294 no.m-3 and 31993 no.m-3 with a mean of 22298 no.m-3. Copepods: Copepods’ abundance of the copepods ranged from a minimum of 9063 no.m-3 to a maximum of 24531 no.m-3 with a mean of 14867 no.m-3.

Slide 38: 

Decapod Larvae: The decapod larval abundance varied between 526 no.m-3 and 6351 no.m-3 with a mean of 2256 no.m-3. Chaetognaths: The abundance of the chaetognaths varied between 49 no.m-3 and 172 no.m-3 with a mean of 81 no.m-3. Lucifers: The abundance of the lucifres varied between 79no.m-3 and 326 no.m-3 with a mean of 188 no.m-3. Gastropod Veligers: The abundance of the gastropod veligers ranged from a minimum of 767 no.m-3 to a maximum of 8980 no.m-3 with a mean of 2754 no.m-3.

Slide 39: 

Polychaete larvae: The polychaete larval abundance varied between 43 no.m-3 and 120 no.m-3 with a mean of 69 no.m-3. Bivalve veligers: The bivalve veligers abundance varied between 167no.m-3 and 3556 no.m-3 with a mean of 1597 no.m-3. Ostracods: The abundance of Ostracods ranged between 67 no.m-3 and 254 no.m-3 with a mean of 142no.m-3. Cladocerns: Cladocern abundance varied between 100 no.m-3 and 156 no.m-3 with a mean of 134 no.m-3.

Slide 40: 

Amphipods: Since this station is fresh water dominant station freh water amphipod abundance was noticed, which varied between 28 no.m-3 and 134 no.m-3 with a mean of 82 no.m-3. The miscellaneous groups includes hydromedusae, ctenophores, siphonophores and other larger planktonic groups.

Slide 41: 

DISCUSSION AND GENERAL CONCLUSION The present study has been undertaken to understand the zooplankton distribution and production in this complex environment. The organisms dwelling in this complex environment acquires certain morphological and physiological adaptations which are of interest for any biologist.

Slide 42: 

The results revealed that the mangrove areas support high zooplankton populations. The zooplankton population was mostly dominated by copepods ranging between 53% - 83% of total populations. Estuarine environments exhibited wide range of fluctuations in physical and chemical factors in both time and space demanding considerable physiological and behavioral plasticity in the Organisms which colonize them.

Slide 43: 

In the present study crustacean larvae constituted a very important component of the zooplankton of the area throughout the year represented by larvae of decopods, Stomatopods, Cirrepids and Copepods. Influence of salinity over the plankton populations was noticed in the Coringa mangrove area. Goswami (1973) from the Laccadives reported that due to the shallowness of the lagoon the zooplankton biomass was comparatively high, where planktonic groups like copepoda, decapoda, amphipoda, chaetognatha, mysidalea and fish eggs and larvae dominated

Slide 44: 

Saha (1975) from the Hooghly estuary reported that the zooplankton abundance showed two annual peaks of abundance one in November, February and other during June-July periods. The monsoon months was generally poorest for zooplankton production. Salinity and temperature play an important role in the production of plankton in the different regions of the estuary, since the estuary being shallow practically no longitudinal temperature gradient and vertical thermal stratification could be noticed (Gopala Krishnan, 1968).

Slide 45: 

Similar observations were made in the present study also. Higher abundance of Zooplankton populations during the post monsoon (winter) (Jan, Feb) may be due to the movement of several marine and fresh water populations into the estuarine area. The spawning season of many species of commercially important fishes also coincides with the post monsoon period. (Gopala Krishna 1968).

Slide 46: 

The bivalve larvae recorded from January to May and gastropod larvae were abundant during February, March, and April. Except during the monsoon disturbance a definite relation ship exists between salinity and temperature, and plankton abundance. Though salinity and temperature decrease with the onset of rains minor up and down fluctuations with conspicuous upward trend was noticed during March to May The interaction of the prevailing physico - chemical parameters are responsible for spatial difference in abundance and diversity of zooplankton.

Slide 47: 

Hence it may be concluded that the Meroplankton composition is more at the selected two stations. Among the two stations, station I which is near the confluence of river Coringa with the Kakinada bay is having highly dynamic environment in the sense that the hydrographical parameters fluctuations are very high due to the tidal influence . Similarly the station II which is located at the upper reach of the river Coringa is prone to the anthropogenic influence, and it is fresh water dominant station.

Slide 48: 

Seasonal distribution of major taxa of Zooplankton. Copepoda: Copepods by their sheer abundance and diversity constitute the most important group in any zooplankton community (Madhu pratap1978) In the present study also Copepods dominated the collection with peaks of abundance in the month of January at station-I and February at Station-II respectively.

Slide 49: 

SUMMARY Considerable work has been done with regard to Zooplankton in estuaries around Indian coast. In the vicinity of mangroves their role seems to be different and their qualitative and quantitative aspects also show great variation. The Coringa river where the present investigations have been undertaken exhibited wide fluctuations in the Zooplankton distribution. The Coringa wild life sanctuary is a complex bio diversity zone in the vicinity of Kakinada bay.

Slide 50: 

The results of present study revealed that though Wildlife Act is there, there exists lot of anthropogenic activity in the mangrove area. Regarding the variation in the numerical abundance of Zooplankton it is observed that salinity is the limiting factor. The role of Zooplankton is very important in the sense that they act as the “Transformers” of the primary production to the tertiary production in an ecosystem..

Slide 51: 

The leaching activity of mangroves leaves of the Coringa reserve forest makes the system highly productive, which in turn supports a good number of meroplankton. Hence it is vivid that the stations I & II support maximum number of meroplankton at any given point of time. Similarly mangroves are the nursery grounds for the many of the shell and fin fishes dwelling in the near by marine area

Slide 52: 

The larval development takes place in the mangrove areas and in due course the juveniles migrate towards the Bay. The characteristic feature of the mangrove area is the presence of an environment suitable for the Meroplankton survivalance in terms of food that is present in the form of organic matter and detritus. The predator problem also gets minimized due to the sheltered environment of dense mangrove vegetation. Physical stress from the tides and currents gets reduced because of the smaller creeks which are farther away from the influence of tides and waves.

Slide 53: 

The numerical abundance and biomass of zooplankton in the area during the study period showed two peaks of abundance one in January – February and another in May. The numerical abundance and biomass of zooplankton was high and it showed seasonal patterns. Large scale conversion of mangrove areas for brackish water fish and shrimp ponds has not only rapidly depleted the valuable resources but also impaired the ecological balance in the estuarine ecosystem where mangroves are generally located.

Slide 54: 

The present study is a baseline study, further studies may throw light on the significance of Coringa river and the Coringa wild life sanctuary in the Kakinada Bay and Godavari estuarine environment complex.