Mumbai Coast Research Articles

Microplastic Pollution in the Marine Ecosystem: A Study of Seawater and Fish Samples from Bhaucha Dhakka and Versova Beach, Mumbai Coast

The prevalence of microplastics in our environment is well recognized, but the deep extent of its impact on ecosystems is unknown. This study investigates the prevalence of microplastics in seawater and three species (Bombay duck, Silver Pomfret, and Indian prawn) of commercially available marine fish from the Mumbai suburbs. The investigation found microplastics in both water and fish samples, with an average concentration of 20 ± 14.8 MPs/L and 42 ± 14.8 MPs/L in two water samples from Versova Beach and Bhaucha Dhakka selected for the study. And 70 ± 10, 36 ± 08, and 23 ± 09 MPs/L respectively in three fish species. The highest concentrations were found in water samples from Bhaucha Dhakka and Bombay duck (Harpadon nehereus) from Bhaucha dhakka. The discovery of microplastics in fish tissues raises concerns about their potentially harmful impact on fish health and the implications for human consumption.

Integration of machine learning and remote sensing for assessing the change detection of mangrove forests along the Mumbai coast

Integration of machine learning and remote sensing for assessing the change detection of mangrove forests along the Mumbai coast

Natural light driven plastic leaching effects on carbon chemistry in the tropical coastal waters of eastern Arabian sea: An experimental study

This study examined the effects of solar light driven plastic degradation on carbon chemistry in the coastal waters of eastern Arabian Sea along the west coast of India. The research was conducted through experimental incubations exposed to natural sunlight at multiple locations between December 2023–February 2024. Photodegradation induced a significant pH decrease (up to 0.38 ± 0.02) between controls and plastic incubations ranging from 8.17 ± 0.01 to 7.54 ± 0.02 with the highest variation in the Mumbai coast ranging from 8.13 ± 0.01 to 7.75 ± 0.03. pH variations are primarily caused by the leaching of organic acids and CO2 release during solar irradiated incubation. Plastic leaching due to natural light irradiation and subsequent changes in the water chemistry is of prime significance with dissolved organic carbon (DOC) leaching of 0.002–0.03% of plastic weight into the coastal waters. Our estimations suggest 15–75 metric tonnes (MT) of DOC release per year by plastic pollution in the eastern Arabian Sea coastal waters. Further, the fluorescent dissolved organic matter (FDOM) fragmentation, a part of DOC, may act as an organic source of synthetic contaminants and would promote heterotrophic microbial action in the coastal waters. Photodegradation of plastic and the interaction of natural DOC and plastic-derived DOC resulted in longer wavelengths FDOM, which may affect the penetration of photosynthetically active radiation in the water column, thereby impacting primary production. Finally, future research work focussing on the role of plastic pollution in coastal ocean acidification and vice-versa is essential and will be increasingly intense in the upcoming decades.

Diet characteristics of tidal creek-associated fishes of the northeastern Arabian Sea with special reference to microplastic ingestion

The present study assessed the diet characteristics, trophic guild structure, and microplastics (MPs) ingestion by a group of fish sourced from the tidal creeks of the Mumbai coast along the Eastern Arabian Sea. The diet patterns were characterized using gastro-somatic index (GaSI), relative length of gut (RGL), diet overlap (α), diet breadth (Bi), and relative abundance of food items (%IOP), with a special emphasis on MPs contamination. The findings revealed that teleost and shrimps are the most preferred food items for these species. Whereas MPs contribute 5.50% of the total diet composition of the selected fishes. Additionally, we tried to find out the influence of fish size and dietary attributes on MP ingestion, identifying trophic level as a significant factor influencing contamination levels. Using the Polymer Hazard Index (PHI), the potential risks posed by MPs in fish samples were assessed, revealing notable discrepancies among polymers. For instance, polyvinyl chloride showed the highest PHI score of 198.75 and a hazard score reaching the highest risk category (IV), indicating substantial environmental risk. In summary, our findings highlight the impact of fish diet characteristics on MPs contamination and the varying levels of MP risks along the Mumbai coast, categorized according to polymer type from low to high risk.

Length-weight Relationship and Relative Condition Factor of Paratrypauchen microcephalus (Bleeker, 1860) along the Mumbai Coast

Length-weight Relationship and Relative Condition Factor of Paratrypauchen microcephalus (Bleeker, 1860) along the Mumbai Coast

Biometric Characteristic Study of Green Lipped Mussel, Perna viridis (Linnaeus, 1758) From Malad Creek, Mumbai, India

Biometric Studies are essential to understand the growth rate of the species which helps understand the growth patterns, reproduction rate and population distribution of the species. Growth patterns of molluscs help in evaluating their production potential and energy flows through populations and their distribution. Perna viridis (Linnaeus, 1758) commonly known as the green-lipped mussel or the Asian green mussel belongs to the family Mytilidae. It is distributed along the Indo-Pacific region. They are attached to the rocky substratum along the coast, in the intertidal region. The Biometric Analysis and Length-Weight Relationship study was carried out on Perna viridis (Linnaeus, 1758) to understand their growth rate and population distribution through the Coast of Mumbai. A total of 100 samples were used in this study. The correlation between the Total Weight of the Shell with the organism (WSO) to the Shell Length (SL), Shell Width (SW) and Shell Height (SH) and the correlation between the Soft Tissue Weight of the Organism (WO) to the Shell Length (SL), Shell Width (SW) and Shell Height (SH) gave an idea about the growth factors. The Relative Condition Factor was determined by equation W = aLb. The b values of each correlation showed negative allometric growth with p value to be p<.001 with same significance in Pearson Correlation test. The Relative Condition Factor of WSO-SW and WSO-SL was observed to be above 1 indicating good growth conditions. Thus, biometric studies are a useful tool in study of Perna viridis (Linnaeus 1758) biology, physiology, ecology, growth potential, stock assessment, genetics and breeding of Perna viridis (Linnaeus, 1758).

Antimicrobial activity with special reference to antimycobacterial activity of the coral, Junceella delicata (Grasshoff,1999) collected from Madh island, West coast of Mumbai, India

Antimicrobial activity with special reference to antimycobacterial activity of the coral, Junceella delicata (Grasshoff,1999) collected from Madh island, West coast of Mumbai, India

Identification and Microscopic Classification of Microplastics in Beach Sediment Sample at Dadar Chowpatty

The current study involves the design of a feasible solution for cleaning beach sediments off microplastics. The results of this study will help spread awareness about this micro-menace threatening our societies. It also focuses on otherwise neglected and invisible aspects of plastic pollution. These findings may open up new avenues for research in this area. The long-term impacts of this study may involve the conservation of food quality in fisheries and ecosystems along the coast of Mumbai. During sampling, it was observed that the Dadar Beach was relatively less polluted or disturbed. Albeit having a beach that looks clean and does not look like has a plastic pollution issue, the study results clearly indicate exactly the opposite. The results show that various microplastic particles were identified across the length of the beach and that transect 1, which is shielded by rock reclamation debris, is less affected by active wave action and shows a lower density of microplastics than transect 2, which is readily subjected to active wave action. Based on the major microplastics found in sand, the presence of filaments and disintegration in large quantities, along with foam, can be attributed to fishing activities occurring in nearby oceans, along with some washed off disintegrated plastics whose source cannot be identified.

Identification of potential breeding ground of flathead grey mullet, Mugil cephalus (Linnaeus, 1758), along the Mumbai coast, India, for ecological monitoring and conservation strategies.

Identifying the breeding grounds of fishes is crucial for the sustainable management of fisheries resources. The present study is aimed at identifying the potential breeding ground of Mugil cephalus along the estuary of the North Mumbai coast. A total of 1197 specimens of M. cephalus, including 546 eggs, 271 larvae, 235 juveniles, and 235 adults, were collected from four sampling stations in the Karanja estuary between January to October 2022. Water quality parameters, plankton dynamics in the estuary, and the reproductive and feeding biology of M. cephalus were also examined. The eggs, larvae, juveniles, and adults were identified using traditional morpho-meristic and DNA barcoding techniques. The results revealed a potential spawning ground of M. cephalus in the Karanja estuary. The results of reproductive biology also confirmed the occurrence of matured fishes during May-July. The abundance of eggs and larvae at the estuary's mouth and the presence of juveniles and mature individuals of M. cephalus dominantly in the Karanja estuary from May to July infer the presence of a spawning site. It is also recorded that M. cephalus spawn in higher salinity (35 ppt) and seawater temperature (33 °C) where the hatching of offspring takes place successfully. This study emphasizes the significance of DNA barcoding in guiding routine monitoring surveys and demonstrates its usefulness when combined with these techniques in identifying fish spawning grounds. The study findings will serve as baseline information to develop effective conservation and management strategies and protect the ideal spawning stock.

Recent Foraminifera from the coast of Mumbai, India: distribution and ecology

Foraminifera have been used in biostratigraphy and paleoenvironmental research. They are useful environmental indicators for monitoring the marine environment. Intertidal sediment samples were analysed for their diversity in relation to physicochemical parameters and sediment characteristics along the Mumbai coast of India. Thirty-five species were found, divided into five orders and 18 families. The orders Rotaliida and Miliolida were identified to be dominant. Foraminifera were observed to be inversely related to sand particle size in relation to sediment and physicochemical parameters of water. Canonical correlation analysis explained the relationship between species abundance and water physicochemical parameters.

GIS Mapping of Marine Litter Along Recreational Beaches of Mumbai Coast, Maharashtra

GIS Mapping of Marine Litter Along Recreational Beaches of Mumbai Coast, Maharashtra

Anthropogenic litter on sandy beaches in Mumbai Coast, India: a baseline assessment for better management

Anthropogenic litter on sandy beaches in Mumbai Coast, India: a baseline assessment for better management

Awareness, perception and adaptation strategies of fisher community towards marine plastic pollution along Mumbai coast, Maharashtra, India

Plastic pollution in Indian beaches has reached almost unmanageable proportions and practically no documentation available on the views, occurrence and adaptation methods of the coastal communities exposed to plastic discards in Indian beaches and fishing grounds. This study attempted to fill this gap. The 5-point Likert scale was used to determine the awareness level, perceptions and attitude of respondents towards plastic pollution among the sampled fishers of Versova, Mumbai. Indices to measure these parameters were developed. The results revealed that the respondents were knowledgeable about the ill effects of plastic pollution on the environment. Easy availability (48%), substitutability (26%) and low cost (16%) of plastics were the reasons expressed by respondents for its rampant use in fishing. The perception index scores were found to be highest (1) for “juvenile destruction” and lowest for “damage to crafts and gear” (0). Strategies that provide incentives for change, assured government support, along with environmental awareness and community led management measures are necessary to address this menace. If plastic production and availability is reduced, availability of biodegradable substitutes is increased and information through various media sources reaches the unreached from time to time, it will go a long way to reduce marine plastic pollution. Keywords: Coastal communities, Fishers, Fishing grounds, Indian beaches, Likert scale, Perception index score, Plastic discards

Mangrove ecology and species distribution along the Gorai Creek of Mumbai coast, Maharashtra, India

The extensive mangrove forest of Gorai Creek, Mumbai coast, has recently seen substantial deterioration. The results of a study on mangrove diversity conducted in Gorai Creek on the Mumbai coast from June 2017 to May 2018 are presented here. During the course of the study, twelve species of mangroves from five families and eight genera were identified in each of the three study locations along the creek. Avicennia marina accounted for 13.44% of the Gorai creek marshes, confirming its predominance. Sonneratia alba, Avicennia officinalis, Rhizophora apiculata, Bruguiera cylindrica, Kandelia candel, and Acanthus ilicifolius are among the mangrove species found in the estuarine embayment, with other species strewn around. A diverse range of species, including endangered migratory birds and herpetofauna, can be found in these mangrove environments. Mangroves have been observed to have narrowed in density with time, and it is critical to begin conservation efforts as speedily as humanly possible.

Analysis of reproductive patterns of Sardinella longiceps (Valenciennes, 1847) from the Mumbai Sea, Maharashtra, India

In developing countries, management of fisheries resources is directly or indirectly dependent on fish reproductive biology & conservation of the breeding grounds. Indian Oil Sardine fishery is a commercially important pelagic fishery along the coast of Mumbai. A Ganado-somatic index value of females was maximum (8.20) in September and minimum (0.38) in January. For males, the maximum Gonado-somatic index was 8.36 in September and the minimum 0.29 in February. Based on sex ratios month-wise, females were slightly more dominant in all months. There is a significant difference in the length-wise distribution of sexes, with a large number of females in higher length groups. Females attain the length at first maturity at 166.5 mm, and matured ovaries were seen in September and October, with a maximum percentage in September. It is estimated that the absolute fecundity ranged between 28,860 and 52,646, and the relative fecundity ranged between 450 and 684 number eggs per gram of fish weight.

The Molecular Characterization and Phylogenetic Reconstruction of Penaeid Shrimps from Mumbai Coast, Maharashtra

The commercial Penaeid shrimp Fenneropenaeus indicus H. Milne-Edwards, 1837, Parapenaeopsis stylifera H. Milne-Edwards, 1837 and Solenocera crassicornis H. Milne-Edwards, 1837 were collected to estimate phylogenetic relationships and taxonomic status amongst other members of Family Penaeidae from Fishing Area 51. The present results suggest that Fenneropenaeus indicus, Parapenaeopsis stylifera and Solenocera crassicornis from different locations or countries from Fishing Area 51 belong to the same genetic population. This study revealed the identification of shrimp species based on the molecular approach using mitochondrial COI gene marker. Sequence of Penaeid shrimps, Fenneropenaeus indicus (MK488093), Parapenaeopsis stylifera (MH724294) and Solenocera crassicornis (MK511444) from Mumbai, western coast of Maharashtra were published in NCBI. This result will be useful for obtaining the intraspecific and interspecific genetic distance, genetic biodiversity of the population structure and for the conservation and management of these resources. P. stylifera and S. crassicornis shows close relation with each other and F. indicus form different clade.

Microplastic pollution in coastal ecosystem off Mumbai coast, India

Microplastics (MPs) are anthropogenic pollutants which can adsorb toxic substances from surrounding water and absorb into the fish body. During the present study, MPs were observed in water, sediment, and gastrointestinal tracts of marine biota samples collected from the coastal waters of Mumbai, India. The mean abundances of MPs recorded in water samples 372 ± 143 items/liter and 9630 ± 2947 items/kg dry weight (DW) in sediment samples. The mean abundance of MPs in pelagic fish species varied from 6.74 ± 2.74 to 9.12 ± 3.57 items/individual and in the demersal species the values ranged from 5.62 ± 2.27 to 6.6 ± 2.98 items/individual. Shape-wise, four type of MPs were observed in the surface waters, sediments and all studied species, predominantly fibers, followed by fragments, pellets/beads, and films. Seven different colors of MPs (red, blue, black, translucent, brown, green, and yellow) were observed from studied samples. MPs of size below 250 μm formed the dominant size in the surface water, sediments, and biota samples except Bombay duck and Malabar sole fish. Based on Raman spectroscopy analysis, eleven types of plastic polymers identified from all studied samples. Thus, presence of MPs in studied biota indicates the transfer of MPs through interlinked food chain/web to higher trophic levels and the occurrence of MPs in the fish gut underlines the necessity of more studies on processing interventions for reducing the microplastic contamination in fish for human consumption.

Isolation and Partial Purification of Bioactive Compounds from Sponge Sigmadocia Fibulata (Schmidt) Collected from West Coast of Mumbai, India

The sponge Sigmadocia fibulata (Schmidt) was collected during low tides from West Coast of Mumbai. Crude extract was obtained by taking 10 gram of sponge samples in10 ml of methanol. The preparative TLC (Thin Layer Chromatography) was performed by using Toluene: Ethyl acetate: Diethylamine (7:2:1) (v/v). The isolated compounds were subjected to GC-MS and FTIR analysis. The structural properties of bio active compounds were determined.From the structural determination it was confirmed that S. fibulata contains bioactive compounds as Triacontanoic acid, methyl ester – (Skin irritant), Hexadecanoic acid, 2- hydroxyl- (hydroxymethyl) ethyl ester – (Fatty acid, Metabolite and Irritant) and 2-Nitro-1, 3-bis-oclyoxy-benzene, (A natural product found in Neolitsea daibuensis. It has a role as a plant metabolite and an algal metabolite). From their biological properties it was confirmed that S. fibulata contains bio active compound, which has biomedical and pharmaceutical properties.

Rock characterisation for a road tunnel in Mumbai (India)

The Mumbai Coastal Road is a freeway currently being constructed along the western coast of Mumbai. A key element of this route is a twin-bore tunnel with total length of about 3km (a 2km TBM-excavated central section, plus cut-and-cover ramps at both ends). The tunnel alignment underpasses Malabar Hill and then runs under Chowpatty Beach for most of its length. The central section is located below the sea level with ground covers ranging from a maximum of 70m at Malabar Hill to less than 15m under Chowpatty Beach. Each bore, excavated by Tunnel Boring Machine (TBM), has an internal dimeter of 11m and includes a section with a horizontal radius of curvature tighter than 400m. This paper describes (i) the desk studies and the geological survey which provided the basis for an additional ground investigation plan, (ii) the results of the additional boreholes, in situ test and laboratory test, (iii) the overall characterisation of the rock mass (and of the overlying soils) based on the entire set of old and new data. The rock characterisation provided the fundamental information for the TBM type selection, and for the design of all the underground works. The launching chamber and the first part of the TBM drive are located within a Basaltic lava flow, while the second part of the alignment is set in Volcanic Breccia underlying the fine-grained soils and made ground of Chowpatty Beach.

TIME SERIES ANALYSIS OF URBANISATION IMPACT ON THE TEMPERATURE VARIATIONS OFF MUMBAI COAST

Abstract. Urbanisation is an ever-evolving, complicated continuous process distinct from its surroundings, having the tendency to create a micro-scale system with characteristic local environmental conditions. Large-scale urbanization near the coasts has a definite impact on the coastal processes due to dynamic interactions of the coastal waters with the urban atmospheric, hydrological and anthropogenic residues. This study focuses on understanding the contribution of immediate atmospheric variations due to urbanization on surface temperature of coastal waters along the Mumbai coast. Different meteorological and air quality parameters such as Air Temperature (AT), Land Surface Temperature (LST), Precipitation (P), Relative Humidity (RH), Wind Speed (WS) and Aerosol Optical Depth (AOD) collectively were used as determinants of local urban climatic environment; to analyse and understand the impact of urbanization on Sea Surface Temperature (SST) representing coastal system. ERA5 Reanalysis meteorological data and MODIS satellite data products were used to extract information of the said parameters for a period of 20 years and time-series analysis was performed for each using Mann-Kendall method to establish their trend. Harmonic regression using Autoregressive Integrated Moving Average (ARIMA) and Neural Network Autoregression (NNAR) were used to model the existing and forecast the future trend of SST which showed an increasing trend with comparatively better representation by NNAR (RMSE 0.4 – 0.7 K). Further, a polynomial multiple regression model was built to correlate the influence of all urban climatic parameters with SST, which clearly indicated positive forcing of local climate variation on the coastal waters with an R2 value of 0.93.