Indian Journal of Marine Sciences

  ISSN: 0379-5136  CODEN : IJMNBF]

(www. niscair.res.in)

 

VOLUME 31

NUMBER 4

DECEMBER 2002

 

CONTENTS

 

Papers

 

 

 

Calibration of a finite element surge prediction model for the east coast of India
G. Latha, E. P. Rama Rao & R. Mahadevan

265-270

 

Tidal and non-tidal sea level variations at two adjacent ports on the southwest
coast of India
K. Srivinas & P. K. Dinesh Kumar

271-282

 

Wave transmission and reflection for two rows of perforated hollow piles
Subba Rao, Kiran G. Shirlal & N. B. S. Rao

283-289

 

Study of sediment movement and coastal processes along Mangalore coast
(southwest coast of India) using satellite imageries
K. M. Santosh, H. R. V. Reddy, Prakash Chauhan & R. K. Sarangi

290-294

 

Textural and trace elemental distribution in sediments of the Beypore estuary
(SW coast of India) and adjoining innershelf
M. N. Muraleedharan Nair & K. K. Ramachandran

295-304

 

Sulphated galactans of marine red alga Laurencia spp. (Rhodomelaceae,
Rhodophyta) from the west coast of India
A. K. Siddhanta, A. M. Goswami, M. Shanmugam, K. H. Mody,
B. K. Ramavat & O. P. Mairh

305-309

 

Composition and distribution of epigrowth fauna in Visakhapatnam harbor,
east coast of India
C. Jayaprada

310-314

 

Distribution of Recent benthic Ostracoda off Karikkattukuppam (near Chennai), southwest coast of India
S. P. Mohan, G. Ravi , S. M. Hussain & N.Rajeshwara Rao

315-320

 

Imposex in rock whelks Thais and Ocenebra species (Mollusca, Neogastropoda,
Muricidae) from Gujarat coast
A. Tewari, C. Raghunathan, H. V. Joshi & Yasmin Khambhaty

321-328

 

 

(Contd….)


 

Gill net selectivity studies for fishing frigate tuna, Auxis thazard Lacepede
(Perciformes/Scombridae) in Thoothukkudi (Tuticorin) waters, southeast coast of India
D. Jude, N. Neethiselvan, P. Gopalakrishnan & G. Sugumar

329-333

 

Short Communications

 

 

Effect of ultraviolet – B radiation on biochemical composition of three Ulva species (Chlorophyta) from southeast coast of India
K. Eswaran, M. Ganesan, C. Periyasamy & P. V. Subba Rao

334-336

 

Toxicity of Hg (II) to prawns Penaeus monodon and Penaeus indicus (Crustacea: Penaeidae) from Rushikulya estuary, Bay of Bengal
Snehalata Das & B. K. Sahu

337-339

Annual Index

341-358

 

 

 

 

 

 

Abstracts of the Papers

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 265-270

 

Calibration of a finite element surge prediction model for the east coast of India

G. Latha*, E.P. Rama Rao* & R. Mahadevan

Real time simulation of storm surges using numerical models requires calibration and validation of the model before being used for operational forecasts. The main objective of this paper is to present the calibration studies carried out on an operational level storm surge prediction model developed at NIOT using finite element method. The primary requirement for calibration of surge prediction model is the actual data on bathymetry, past cyclones and the observed surges. The bathymetric contours along the shelf of east coast of India were digitized from the hydrographic charts and the data on cyclones which crossed the east coast of India for the past fifty years were collected from India Meteorological Department. The sensitivity studies showed that the wind stress coefficient is the key sensitive parameter for the model and so the model is calibrated for this parameter. The surge simulations using the calibrated parameter compare very well with the observed surges and illustrate the predictive capability of the model.

 

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 271-282

 

Tidal and non-tidal sea level variations at two adjacent ports on the
southwest coast of India

*K. Srinivas & P. K. Dinesh Kumar

Analysis of sea level data collected at two adjacent ports (Cochin and Beypore) on the southwest coast of India has been made to understand tidal and non-tidal variations. Amplitudes of the tidal harmonic constituents showed that M2 is maximum, followed by K1, for both the stations. A large spring-neap variation and monthly variation in the semi-diurnal forcing was seen at both the sites. The Form Numbers indicated that the tides are of a mixed and predominantly semi-diurnal type. Amplitudes of most of the tidal constituents are slightly larger at Beypore than at Cochin. The sea level variation is dominated by tidal signals at both the stations. Seasonal variation of the amplitudes of the most important harmonic constituents namely O1, K1, M2 and S2 are presented. The mean spring and neap tidal ranges exhibited a higher degree of variability (over the seasonal cycle) at Beypore than at Cochin. The annual cycles of non-tidal sea level at both the sites were similar, with most conspicuous changes during June and July at Beypore, caused by summer monsoonal river discharge. The annual cycles of atmospheric pressure at both the sites were remarkably similar. The atmospheric pressure is not an important controlling factor on sea level at both the sites. Analysis of the sea level series pertaining to the premonsoon season indicated that Cochin marginally leads Beypore, suggesting the propagation of coastal trapped waves from south to north. The cross-correlograms of the atmospheric pressure time series for the premonsoon and summer monsoon seasons between Cochin and Beypore suggest the mesoscale nature of the atmospheric pressure system.

 

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 283-289

 

 

Wave transmission and reflection for two rows of perforated hollow piles

Subba Rao, Kiran G. Shirlal & N.B.S.Rao

 

A laboratory investigation on perforated hollow piles in two rows was conducted in a two dimensional regular wave flume to study the wave transmission and reflection characteristics. The influence of incident wave steepness, relative clear spacing between the piles and rows of piles on transmission co-efficient and reflection co-efficient have been investigated. The effect of staggering of piles in the rows on both transmission and reflection co-efficients was also studied. The present study has revealed that for perforated pile groups incident wave steepness, relative clear spacing between the piles, relative clear spacing between the rows of piles influence both transmission and reflection co-efficients. Staggering of piles reduces reflection from the perforated piles. Perforated piles have smaller transmission and reflection co-efficient values compared to that of non-perforated piles at lower wave steepness.

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 290-294

 

Study of sediment movement and coastal processes along Mangalore coast (southwest coast of India) using satellite imageries

K. M. Santosh*, H. R. V. Reddy1 ,Prakash Chauhan & R.K.Sarangi

Satellite imagery on IRS-1C (LISS-3) of south Karnataka coast shows mid portion of Nethravathi river was dry with lot of sediment depositions and end portion of Gurupur was found to be dry. Whereas IRS-1D(LISS3) of 10th November,1999 both Nethravathi and Gurupur rivers any prevailing dry conditions could not be observed. IRS-P4(OCM) false colour coded (FCC) imageries on suspended sediment concentrations pertaining to south Karnataka coast from October, 2000 to February, 2001 were closely examined for tracing suspended sediment movement. Maximum river runoff could be seen in October and turbidity current was observed from November to February. Least suspended sediment concentration was observed in February. In-situ data on suspended sediment concentration off Mangalore varied between 1 and 84 mg/l throughout the study period and showed temporal oscillations. Low tide periods recorded maximum concentration of SSC which justifies its transportation by Nethravathi and Gurupur rivers. Extinction coefficient showed linear relationship with SSC in coastal stations. Beach profiles showed occurrence of severe erosion during southwest monsoon periods.

 

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 295-304

Textural and trace elemental distribution in sediments of the Beypore estuary
(SW coast of India) and adjoining innershelf

M.N. Muraleedharan Nair & K.K.Ramachandran

The Beypore estuary, situated in Kerala along the southwest coast of India, receives large volumes of untreated/partially treated industrial effluents, municipal sewage and wastes. Concentrations of trace elements (Mn, Cr, Zn, Ni, Cu, Pb and Co) in 52 surficial sediment samples collected from the Chaliyar River, the Beypore estuary and the adjoining innershelf region are presented here. Textural characteristics, major elements and total organic carbon (TOC) content of the sediments have substantial influence on the elemental distribution. Significant variations in the concentrations of Mn, Cr, Zn, Ni, Cu, Pb and Co were observed in riverine and estuarine sediments whereas except for Mn, the variations are not so pronounced in the innershelf region. Both silt and clay show high positive loadings with all the elements in the estuarine region. However, in the innershelf sediments, the trace elements show better affinity with clay fraction than silt. TOC has significant positive correlation with trace elements in both estuarine and innershelf sediments. Trace elements are also associated with Fe, Al and Mn. Finer fractions and TOC played a major role in the distribution and retention of trace elements in the sediments. Except Cu, all the other trace elements showed considerable enrichment beyond st. 13 (downstream of effluent discharge point from the rayons factory), indicating the effect of industrial effluents on their incorporation in the sediments. Estuarine input has a profound influence on the trace metal flux in the immediate vicinity of the adjoining innershelf.

.

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 305-309

 

Sulphated galactans of marine red alga Laurencia spp.
(Rhodomelaceae, Rhodophyta) from the west coast of India

A. K. Siddhanta*, A. M. Goswami, M. Shanmugam, K. H. Mody, B. K. Ramavat & O. P. Mairh

Sulphated galactans were isolated from four different species of Laurencia (L. papillosa, L. cruciata,
L. pedicularioides, L. majuscula) from Indian waters. The crude sulphated polysaccharide (SPS) extracts contained ash
(16-18%), moisture (14-18%), sugar (44-53%), sulphate (12-18%), protein (2-6%), 3,6-anhydrogalactose (14-27%) and uronic acid (4-9%). Crude extracts were chromatoghaphed on DEAE cellulose column and major fractions (0.5 M NaCl fraction) were characterized by GC-MS and 13C-NMR studies. Agarose-2-sulphate unit was identified in all the four polysaccharides samples. Laurencia papillosa, L. cruciata and L. pedicularioides SPS were found to be of similar type having 2-O-methy-3,6-anhydro-L-galactose and agaran 6
¢-sulphate (porphyran) units. Agarobiose and agarose-6-sulphate were detected in L. majuscula. Identification and chemical nature of these sulphated polysaccharides in the Laurencia spp. of Indian waters are of chemotaxonomic significance in view of their potential applications as agaroid.

 

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 310-314

Composition and distribution of epigrowth fauna in Visakhapatnam harbor,
east coast of India

C. Jayaprada

Biological examination of epigrowth fauna on concrete underwater structures and shell settled on made structures was carried out at three selected stations in Visakhapatnam harbor (latitude 17 °14' 34" N and longitude 83 °17¢ 45¢¢E) during low tide for a period of three months. The study revealed changes in the composition and distribution of epigrowth fauna at inner harbor (st.1), outer harbor (st.3) and an intermediate location in between these two (st.2). The number of species was high at seaward station (20, st.3) when compared to st.1 (8); whereas the overall population showed gradual decrease seawards (3,890 no / 50 ml at st.1 – 2,267 no / 50 ml at st.3). Based on the Pearson coefficient, two distinct groups were identified among the fauna, such as Corophium – Polydora group (seaward stations) and Capitella-Mytilopsis group (inner harbor). The strong correlation between organisms and the abiotic factors (salinity, dissolved oxygen and pH) was found to be the decisive factor for the spatial distribution of epigrowth fauna.

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 315-320

 

Distribution of Recent benthic Ostracoda off Karikkattukuppam (near Chennai), southeast coast of India

S. P. Mohan, G. Ravi & S. M. Hussain*,and N. Rajeshwara Rao

To perceive the spatial and temporal distribution and ecology of Recent benthic Ostracoda, 56 inner shelf sediment and 60 bottom water samples were collected from the Bay of Bengal, off Karikkattukuppam, Tamil Nadu, starting from October 1995 to July 1996. Living and total (living + dead) population sizes were determined. Temporally, both living and total population sizes were found to be more during April, followed by July, which may be attributed to high temperature, salinity and dissolved oxygen of the bottom water, high calcium carbonate and low organic matter content of the sediments. The most congenial substrate for better thriving of the fauna was found to be silty-sand. The optimum ecological conditions for the abundance of standing crop of 8 persistent taxa of the study are presented.

 

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 321-328

Imposex in rock whelks Thais and Ocenebra species
(Mollusca, Neogastropoda, Muricidae) from Gujarat coast

A. Tewari, C. Raghunathan, H. V. Joshi & Yasmin Khambhaty

Imposex in Thais bufo, T. rudolphi, T. tissoti and Ocenebra bombayana was observed from Saurashtra coast of Gujarat. The maximum percentage of imposex out of total sample size (44.80 and 46.55%) were observed at Porbandar in T. bufo and T. rudolphi respectively while T. tissoti and O. bombayana at Mahuva showed 10.29 and 9.72% of imposex respectively. The percentage conversion of potential females to imposex was minimum at Diu and maximum at Porbandar. The number of ships operated from Porbandar and Diu directly correlated with severity of CPFII and percentage of imposex at these places. The results indicate that severity of imposex in T. rudolphi could be utilized as a bioindicator of TBT contamination in the marine environment. The Relative Penis Size Index(RPSI) ranged from 3.24 at Veraval to 16.50 at Porbandar in T. bufo while in T. rudolphi it ranged from 44.26 at Okha and 55.96 at Veraval. It was 21.19 and 14.26 for
T. tissoti and O. bombayana respectively. The results indicate that RPSI may not be a foolproof indicator of severity of imposex in these organisms. Therefore a new index has been developed which is termed as Conversion of Potential Females to Imposex Index (CPFII) to calculate the potential females of a given area of a population. It seems the causative agents in seawater is neither toxic nor growth inhibitory at all the places of study but it interferes with the reproductive mechanisms and morphogenesis in these four species. The imposex in these organisms and its relation to TBT concentration in the marine environment is discussed.

 

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 329-333

Gill net selectivity studies for fishing frigate tuna, Auxis thazard Lacepede
(Perciformes/Scombridae) in Thoothukkudi(Tuticorin)waters,
southeast coast of India*

D. Jude, N. Neethiselvan†, P. Gopalakrishnan & G. Sugumar

Auxis thazard form commercial fishery in Thoothukkudi coastal waters from June to October in big meshed drift gill nets with the mesh size ranging from 60 to 100 mm. The fishery is mainly constituted by the length group 275-500 mm. The present study deals with the estimation of mesh size to capture the commercially significant length group (326-400 mm) of A. thazard and its enmeshing pattern in gill nets with two different mesh sizes. The optimum mesh size for the exploitation of the commercial significant size group of A. thazard from Thoothukkudi coastal waters is estimated as 84 mm. As the length at first maturity of this species in Thoothukkudi coast varied from 300 to 310 mm, the nets with proposed mesh size would reduce growth and recruitment over fishing of A. thazard in this coast and allow for spawning before first capture. Though the big meshed drift gill net fishery of Thoothukkudi coast is multi species oriented, the study emphasises the need to regulate the mesh size of the nets based on the type of fishes that form fishery and fishing seasons. It is recommended to conduct big meshed gill net fishing from June to October with the nets having the mesh size of 84 mm,as A.thazard is the major contributor to the big meshed gill net catch during this season. The use of gill nets with the 60 mm-mesh size should be banned during this season, as this would result in capturing of juveniles of A.thazard leading to growth overfishing.

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 334-336

Effect of ultraviolet-B radiation on biochemical composition of three Ulva species (Chlorophyta) from southeast coast of India

*K. Eswaran, M. Ganesan, C. Periyasamy & P.V. Subba Rao

The young plants of Ulva fasciata, U. reticulata and U. lactuca were subjected to UV–B (320-280 nm) radiation for 30, 60, 90, 120, 150 and 180 min. The changes in chlorophylls, carotenoids, protein, nitrate contents and reductase activities were studied. Compared to control, in UV exposed plants both pigments and protein concentrations were significantly decreased. The magnitude of such decrease was higher in Ulva lactuca than in other two species. In contrast to this in vitro nitrate reductase activity was more severely affected in Ulva reticulata. The experiments clearly showed that the UV (A & B)-B radiation has a strong inhibitory effects on biochemical properties in all three Ulva species. However,  the rate of inhibition is dependent on the duration of exposure of plants to UV (A & B)-B radiation.

Indian Journal of Marine Sciences

Vol. 31(4), December 2002, pp. 337-339

 

Toxicity of Hg (II) to prawns Penaeus monodon and Penaeus indicus
(Crustacea: Penaeidae) from Rushikulya estuary, Bay of Bengal

                                                                                Snehalata Das & B. K. Sahu

Penaeid prawns belonging to size 35-55 mm TL and 55-75 mm TL were exposed to the five concentrations of Hg (II) in salinities 5, 15, and 25 ‰. The values of LC50 with 95 % confidence limit for 96 hours were 0.036 (0.032-0.041) and 0.042 (0.036-0.044) mg l-1 for large size groups of P. monodon and P. indicus respectively. The LC50 decreased with increase of time period. Small size groups were more sensitive to mercury at lower salinities while large size groups were more tolerant at high salinities. Penaeus monodon was more sensitive to mercury than P. indicus at each salinity. Threshold limit for P. monodon and P. indicus was 0.016 and 0.024 mg l-1 respectively.