Maharashtra Coast Research Articles

Understanding heavy mineral dynamics using magnetic fingerprinting technique: a case study of North Maharashtra Coast, India

Environmental magnetic and grain size measurements were carried out on sand samples collected from nine sand pits along a 20-km coastal stretch of Arnala Beach, North Maharashtra, India. This study sets out to identify the potential heavy (magnetite) mineral-rich sites in a dynamic coastal system and decipher their enrichment processes. Combination of rock-magnetic and grain size data of the sand pits mirrors the differential heavy mineral fluxes along the coast. Two distinct and well-separated bands of magnetite enrichments were identified. The upper magnetite band (UMB) is more pronounced and shows uniform magnetite enrichment representing the present-day beach erosional state. A well-separated lower magnetite band (LMB) had highest magnetite concentration at Vaitarna River mouth and depicts a strong decrease in magnetite content and clastic (mean) grain size away from the river mouth. This suggests that the NW–SE-directed coast-parallel sediment transport in the past played a major role in the formation of magnetite-rich layers of LMB. A non-enriched zone (NEZ) between UMB and LMB is magnetically weak and showed large variations in clastic grain sizes and possibly represents a period of sediment accretion. A strong correlation between magnetite concentration and magnetic grain size was found for all the sand pit samples, with highest magnetic susceptibility values being dominated by coarser magnetic grains. This relationship needs to be further exploited as a potential fingerprint to identify the heavy mineral lag deposits in coastal environments. Our study explores the potential of using environmental magnetism and sedimentological methods to identify the potential areas enriched in heavy (magnetic) minerals and explains the mechanism of their formation.

Trend of gillnet fishery along the Maharashtra coast of India: A case study

In the context of increasing fuel prices in fishing operations, low impact fuel efficient (LIFE) fishing practices such as gillnetting assume significance globally for sustainable development of fisheries. Satpati, which is well known for the dominance of mechanised gillnet fishing is an important marine fishing zone of Maharashtra along the north west coast of India. Considering the relevance of fuel efficient fishing methods, the present study focuses on highlighting the importance of gillnet fishing and to document the several changes that have taken place in the fish catch composition and fishing operations in the gillnet fishery at Satpati during the last few decades. The catch data were collected by fortnightly sampling from the single-day (lobster gillnetting) and multiday (pomfret and seer fish gillnetting) gillnet fishing. Specifications of crafts were recorded in the pre-scheduled questionnaire and by physically sampling the units. The study analysed the catch composition of all the three representative units that revealed a change in the trend of species composition over the years. The contribution of pomfrets to the total marine fish landings of Satpati had reduced from 30% in 1987 to 20% in 2015. This can be mainly attributed to the usage of smaller mesh size and increase in juvenile catch of pomfret over the past few years. In this regard, results of the present study with regard to assessment of the present scenario of the mechanised gillnetter fleet at Satpati would be useful to decision makers for imposing fishing fleet restrictions.

Textural characteristics and morphosedimentary environment of foreshore zone along Ganpatipule, Maharashtra, India

ABSTRACTThe cross-shore profile and the textural distribution of foreshore sediments of Ganpatipule beach along Maharashtra coast covering two annual cycles are examined. Ganpatipule beach depicts erosion and accretion of the berm, reduction and widening of foreshore widths during the monsoon (June–September) and post-monsoon (October–May), respectively with net sediment accretion during the study period due to the changes in the wave characteristics. A direct correlation is observed between the median sediment grain size and beach-face slopes signifying high wave energy ensuing to a gentle to very gentle slope. The sediments are mainly medium grain size, moderately well sorted, bimodal, very fine skewed to very coarse skewed and very platykurtic to very leptokurtic in nature. The binary plots of the textural parameters (mean, skewness, kurtosis, and standard deviation) depicted a characteristic beach environment of deposition. The study shows that the sediment is concentrated in the environment of rolling and bottom suspension. The study on grain size distribution of sediments could be used to assess the wave energy condition prevailing along the coastal area.

Marine engines of wooden trawlers operating along Ratnagiri coast of Maharashtra

A total of 47 wooden trawlers were in operation from Mirkarwada fishing harbour of Ratnagiri of which 98 per cent were wooden trawlers fitted with Ashok Leyland make diesel engines. The length class of wooden trawlers ranged from i.e. .below 40 ft (6%), 40-50 ft (64%), 50- 60 ft (28%) and above 60 (2%) and the horse power of the engines ranged from, below 100 hp (83%), 100-200 hp (15%) and above 200 hp (2%). During the present study, Ashok Leyland (AL- 370, AL-400, AL-402) diesel engine were found to be the most popular and commonly installed marine engine on the wooden trawlers.

Disco fish trawl (137 m) of Ratnagiri, Maharashtra

Trawling is one of the popular fishing methods along the west coast of India. However, there are regional variations in trawl net design, construction and operation. The present study deals with the general characteristics and specifications of fish trawl (137 m) operated along the Ratnagiri coast of Maharashtra. The material used for the fish trawl is HDPE (High density polyethylene) and the knot type used for construction is a single trawl knot. Blue colour netting twine material is normally used having twine diameter of 1.50 mm for construction of netting of wing and belly; while 1.0 mm twine is used for cod end. The mesh size of the cod end section was 18 mm while the upper and lower edge of cod end had 100 meshes in width and 150 meshes in depth.

Design and technical specifications of steel purse seiners operating along Ratnagiri coast of Maharashtra

Recently, steel purse seiners were introduced in Ratnagiri, Maharashtra. The present study was an attempt to document the design and technical aspects of steel purse seiners presently operated from Mirkarwada fishing harbour of Ratnagiri. For the steel purse seiners operating along Ratnagiri coast, overall length was recorded to be 19.55 to 19.85 m, breadth at midship 5.79 m to 6.1 m, depth of vessel 3.1-3.65 m, length of freeboard 1.27 m to 1.50 m, draught 1.82 to 2.14 m and length of keel 16.72 m. The steel purse seiners were fitted with engines having maximum horse power of 350 and the minimum horse power recorded was 175 hp.

Design and technical aspects of bottom fish trawl (64 m) of Ratnagiri, Maharashtra

The present study deals with the design and technical aspects of bottom fish trawl (64 m) locally know as 32 Angali disco dol, operated along the Ratnagiri coast of Maharashtra. The material used for the fish trawl is HDPE (High density polyethylene) and the knot type used for construction is a single trawl knot. Blue colour multifilament netting twine was normally used, having twine diameter of 1.25 mm for construction of netting of wing and square section while 1.00 mm twine was used for the belly, lengthener and cod end section. The mesh size of the wing and square section was 600 mm and gradually reduced down to the cod end section (18 mm). The net was specifically used to catch Ribbonfish, Squid, Croaker, Pomfret etc.

Morphometric Study of Blood Clam, Tegillarca rhombea (Born, 1778)

Morphometric study of blood clam, Tegillarca (Anadara) rhombea was undertaken for the period of twelve months from February 2014 to March 2015 (except June-July) at the Ratnagiri coast of Maharashtra, India. Relationships between shell length (L), shell height (Ht.), shell width (Wd), hinge length (Hg), total weight (Wt.), wet weight (WWt) and dry weight (dWt) were studied in total 1200 blood clams. Linear regressions calculated were Ht=6.068+0.7106 L, Wd=2.938+0.9041 L, Hg=-0.7707+0.6649 L, Log Wt=Log (-2.795)+2.67 Log L, Log Wwt=Log(-1.0834)+1.2395 Log L, Log Dw=Log (-2.16)+1.30 Log L respectively. From the present study, it can be concluded that more or less similar growth pattern was observed in different months though a faster growth rate was observed during postmonsoon due to the recruitment of small sized clams in January, which grew at a faster rate initially and the growth rate decreased afterward as the energy was utilized for gonadal developments and other body functions.

Major and trace element concentrations in the geothermal springs along the west coast of Maharashtra, India

The west coast geothermal province in Maharashtra hosts a number of thermal springs along the 350 km linear stretch. Major and trace element analyses of thermal springs from 15 locations along with groundwater and surface water samples have been studied. The thermal waters had temperatures ranging from 40 to 71 °C, pH from 7.1 to 8.8 and total dissolved solids between 337 and 8698 mg/l. Most of the thermal waters are Na-Ca-Cl or Ca-Na-Cl type except one which is of Na-HCO3 type. The major ion data is comparable over three decades suggesting a mature geothermal system in the west coast. Trace elements concentrations were low in case of some elements such as<0.1 ppb of Ag and Cd, 1–3 ppb of Cr, Zn, Co, Cu, Pb and Ni, whereas elements like Li (19–386 ppb), B (104–1362 ppb), Sr (16–13,560 ppb), Rb (13–220 ppb), Cs (0.75–44 ppb) and Ba (3–2077 ppb) were much higher in concentration. The variations in the trace element concentration in the thermal waters indicate involvement of different rock types although all the thermal emergences are within the Deccan volcanic flows.

On Haematological Characteristics of Blood Clam, Tegillarca rhombea (Born, 1778)

The blood clam Tegillarca (Anadara) rhombea is one of the important bivalves that show the presence of haemoglobin in its blood as against haemocyanin that is present in other bivalves. The haematological characteristics of this clam found along the south west coast of Maharashtra, India were studied from February 2014 to March 2015, excluding June-July 2015 due to heavy monsoon, in randomly selected specimens. The blood showed the presence of red blood corpuscles with round nucleus, white blood corpuscles with kidney bean shaped nucleus and non-nucleated platelets. The average count of RBCs was 1.76 X 109 per ml, WBCs 4.87 X 106 per ml. and platelets were 66 X 108 per µl. Haemoglobin (Hb) was found in the range of 2.03 to 8.87 gdL-1 and seen to be increasing with size. The general trend in the relationship between blood parameters and body size is that the bigger the animal, the higher the values of its haematological parameters.

Exploration of a haloarchaeon, Halostagnicola larsenii, isolated from rock pit sea water, West Coast of Maharashtra, India, for the production of bacteriorhodopsin.

The aim of the present investigation was to isolate haloarchaea from rock pit sea water, West Coast of India and to explore their potential in the production of bacteriorhodopsin (BR) which converts light energy into electrical energy. Haloarchaeal strains were isolated from rock pit sea water samples collected from Rock garden, Malvan, West Coast of India. Based on morphological, physiological and biochemical characteristics, and 16S rRNA gene sequencing, all the 11 strains were identified as Halostagnicola larsenii. All the strains require at least 1·5moll(-1) NaCl for growth; grow optimally in the range of 3·5-5·2moll(-1) NaCl. BR was detected in all the strains ranging from 0·035 to 0·258gl(-1) . All 11 strains showed conversion of light energy into electrical energy in the range of 0·7-44·2mV, when exposed to sunlight. A haloarchaeon, Hst.larsenii is isolated from rock pit sea water and demonstrated to have BR that converted light energy into electrical energy. The present investigation is presumably the first report of the isolation of Hst.larsenii from low salinity environment and its potential in production of BR. The haloarchaeon could be explored for the generation of electrical energy.

Compliance of bag net fishery of Maharashtra coast, India with Article 7 of the FAO Code of Conduct for Responsible Fisheries

The paper presents the results of evaluation of compliance of the bag net fishery of Maharashtra coast, India with the relevant clauses of Article 7 (Fisheries management) of the Code of Conduct for Responsible Fisheries (CCRF). Questionnaire-based approach that covered ten categories of stakeholders responsible wholly or partially for the management of the bag net fishery was used in the present study. Evaluation of the Code revealed an overall compliance level of 67.52%. The study identified the critical areas of low compliance levels that require immediate attention. Though the bag net fishery is the most common and traditional fishery of Maharashtra that supports livelihood of several fishers, there is no specific policy to regulate, develop and ensure sustainability of the bag net fish resources. Therefore the Code could be taken as a reference document to facilitate responsible management of the bag net fishery taking the local conditions into account. The findings of the present study could be used as a diagnostic tool to help in suggesting measures to ensure sustainability of the bag net fishery resources achievable by making amendments to the fisheries policies of the State.

Classification of Tidal Inlets Along the Central West Coast of India

Tidal inlets along the Maharashtra coast on the central west coast of India were classified according to three methods available in the literature. Two classification methods viz., (i) Hydrodynamic classification (Hayes, 1979) and (ii) Classification based on dimensionless parameters (Vu, 2013) used for the classification are compared with the morphological classification of de Vriend et al., (1999). The hydrodynamic classification of Tidal inlets along Maharashtra coast is carried out considering mean annual significant wave height. The classification is also extended considering significant wave heights obtained for South-West monsoon, North-East monsoon and Fair Weather seasons. It has been observed that 74% of the inlets are tide dominated as per morphological classification whereasconsidering annual mean wave heights in Vu (2013) method, 67% of the inlets are wave dominated.

SSC Analysis of South Maharashtra Coast: A Case Study from Vengurla Coastal Region

Suspended sediment transport plays a major role in many coastal, estuarine and offshore engineering applications. The transport of suspended sediment influences the constructions of harbours, constructions of coastal power stations and refineries, safety of offshore platforms and pipelines, erosion and accretion of beaches, quality of the water and many other applications. To understand the suspended sediment transport pattern along South Maharashtra coastal region, a case study was conducted at Vengurla coastal waters. In order to do that, the sea water samples at 6 transects (18 stations) were collected for analysis of suspended sediment concentration (SSC) during pre-monsoon and post-monsoon periods. The results showed that during post monsoon, the SSC pattern at surface, mid and bottom layers having 10-20mg/l, 10-19mg/l and 50-60mg/l respectively. But during the pre-monsoon, the respective layers show 5-20mg/l, 4-15mg/l and 70mg/l of SSC concentration. In addition, Ocean Colour Monitor (OCM) satellite images were analyzed in the same study area to know the SSC distribution pattern. In Vengurla, post-monsoon, the SSC values of surface coastal waters ranging from 5-15mg/l from OCM satellite images and also SSC is compared with OBS 5+ profiles. In this paper, the SSC distribution pattern of both seasons is narrated and the validations of SSC using OCM satellite data are also discussed.

High-heat-producing granites of East Dharwar Craton around Gugi, Karnataka, and their possible influence on the evolution of Rajapur thermal springs, Deccan Volcanic Province, India

BackgroundThe thermal springs of Rajapur situated along the west coast of Maharashtra and parts of high-heat-generating granites of Gugi in Karnataka (India) seem to be genetically related. The present investigation involves quantification of the heat generated by the Gugi Granites using the the U, Th and K contents in the rock samples and probing their possible influence on the evolution of the Rajapur springs, based on the geochemistry of the thermal waters, published Bouguer gravity anomaly data, and the overall geological setup.MethodsFourteen water samples from Rajapur including thermal and groundwater samples were analysed for major ions and five rock samples from the gugi area were analysed for U, Th and K.ResultsRajapur thermal spring is of Na-HCO3 type, while other thermal springs along the west coast are either Na-Cl type or Na-Cl-CO3 type. The stable isotope data of the thermal waters signifies mixing with the ground water. The gravity anomaly data supports the extension of the Gugi Granites below the Deccan Volcanics of the study area.ConclusionsThe present investigation suggests that the Gugi Granites could be the main source of heat for these thermal springs, even though the springs issue through the Deccan volcanic flows.

Description on Tylocephalum salunkhi N. Sp. (Cestoda: Lecanicephalidea) and Study of Conserved Domain across Divergent Phylogenetic Lineages of Class Cestoda

Tylocephalum salunkhi n. sp. cestode parasite of Trygon sephen is described on the basis of type material from Ratnagiri (West Coast of Maharashtra, India). The present worms resemble with Tylocephalum marsupium in having all essential morphological characters. Species having scolex oval, rostellum elongated/rounded, presence of four suckers, mature proglottids are broader than long, testes rounded and excretory canal long tube. But the same differ due to number of testes. Hence, it is new species described.

Factors controlling the distribution of metals in intertidal mudflat sediments of Vaitarna estuary, North Maharashtra coast, India

Sediment cores collected from intertidal mudflats of Vaitarna estuary were investigated for distributions of sediment components, organic carbon, metals (iron, manganese, aluminum, copper, zinc, cobalt, nickel, and lead) in bulk sediments, as well as clay-sized fraction (<2 μm). Sorting of grain size under the influence of varying hydrodynamic energy conditions within Vaitarna estuary was discussed. Index of geoaccumulation indicated different levels of contamination for the studied metals at three locations. Pb and Zn were mainly found to be associated with clay fraction and showed exclusive lithogenic origin. While all the other metals showed signatures of anthropogenic origin in addition to that of lithogenic.

Reproductive biology of Horse mackerel Megalaspis cordyla (Linnaeus, 1758) along Ratnagiri coast of Maharashtra, India

Marine biology,marine ecology,Phytoplankton, marine algae, zooplankton, nekton, benthos, corals and coral reefs, ecology, zoogeography and systematics, primary production and experimental work on ecosystem including energy flow at different trophic levels, population dynamics and theoretical models, recycling of matter, influence of environmental factors on metabolic activity, marine microbiology, mariculture and experimental work on propagation of cultivable species, biology of fishes, marine reptiles, sea birds and mammals, physical, chemical, geological and meteorological features of the environments related to marine biology, marine environmental damage caused by pollution and engineering works, underwater observations, conservation of living resources, modifications in methodology and techniques and development of new apparatus related to marine sciences

Numerical Modeling of Oil Spill Movement along North-West Coast of India Using GNOME

India is located at a very strategic point with respect to the international commercial sea routes with a large amount of crude oil traffic. Hence, the risk of oil spill occurring in the Indian waters is considerably high. In the present paper, forecasting the movement of a possible crude oil spill of 10,000 barrels at a location of latitude 21° 41′ 48.53′ N and longitude 66° 46′ 41.45″ E, intersection point of two ship routes from Kandla port and Bombay port (Kandla port of India to Yanbu port of Saudi Arabia and Bombay port of India to Ras Tanura port of Saudi Arabia) has been carried out using GNOME (General NOAA Operational Modeling Environment) model developed by Hazardous Materials Response Division (HAZMAT) of the National Oceanic and Atmospheric Administration Office of Response and Restoration (NOAA OR&amp;R) of United States government. The governing equations for horizontal diffusion, evaporation, dissolution, dispersion etc, adopted by GNOME have been presented in the paper. The simulation is carried out for month of September 2011. It is found that the spill possibly takes 10 hours to reach Gujarat coast and 15 hours to reach Maharashtra coast. With this available knowledge, appropriate mitigation measures may be adopted before spill reaches the shores.

Depositional environment and geochemical response of mangrove sediments from creeks of northern Maharashtra coast, India

Present study provides results of trace metal distribution in mangrove sediment cores collected from macro-tidal Khonda and Dudh creeks of Northern Maharashtra coast, India. Most of the metals showed significant higher addition in Dudh creek (core DC) as compared to Khonda creek (core KC). However, Khonda creek sediments did show anthropogenic enrichment of Mn, Zn and Ni, while Dudh creek sediments showed anthropogenic enrichment of almost all the studied metals. Large difference in metal concentration between the two creeks was attributed to their proximity to industries. The higher Mn, Zn and Ni content in Khonda creek was mainly attributed to addition from domestic and agricultural wastes. While high deterioration of Dudh creek sediments was the outcome of addition from industrial effluents.