SPATIAL FIN-FISHERY SPECIES DIVERSITY OF ULHAS RIVER ESTUARY

Research project, 2005

It was envisaged to determine the reason for decline in the mudskipper fishery during the past decade. The anthropogenic stressors were studied to analyse the impact on the fishery of Boleophthalmus dussumieri (Cuv. & Val.) and their health.

Documentation of biodiversity has become very important aspect scientific studies. Fish diversity of any region has great significance in assessment of that region with reference to environmental conditions. The present study has been carried out to assess the fish diversity at Vaitarna estuary from Dativare Coast to Pargaon. About 32 species have been identified. Actinopterygii was a major class of fishes to be observed. Some Deep sea fishes are also observed in estuarine region. About 8 orders were observed Perciformes was found to be the most observed order. Fish diversity along this region was found to be satisfactory. INTRODUCTION India has a rich biological heritage that qualifies it as one of the mega diversity nations of the world (Gadgil, 1996). Estuaries are the meeting place of freshwater rivers and saltwater from the sea and as such are dynamic environmental conditions (James et al., 2007). Estuaries are areas of physical and biological transition between the land, fresh...

Journal of Media and Communication Studies, 2018

The study aims to establish strategies on how to manage coastal fisheries conflicts and livelihood in Pulicat estuary. This estuary, lying in the east of the Tamil Nadu and Andhra Pradesh States in India, is the second largest brackish water body in India, the first being the Chilika estuary in the State of Odisha. The total area of the estuary is 759 km 2 with many island as part of it. But only 360 km in the southern part is active and the northern part is dormant. The rivers Araniri, Kalangi and Swarnamukhi are the major ones that feed the lagoon. The estuary faces anthropogenic, developmental, industrial and environmental issues threatening not only the livelihood activities of fisherfolk but also the very survival of the estuary. Studies show that the estuary (lake) is shrinking and the depth has decreased from 6 m to 1 m, putting the livelihood of the people at stake. Separate questionnaires were administered to 100 lake fisherfolk and 100 to sea fisherfolk. All were active fisherfolk, aged 18 to 65. And 20 in-depth interviews were also conducted among different stakeholders including members of civil society. There is a huge divide difference between the sea fisherfolk and the lake fisherfolk. There is a social stigma attached to the lake fisherfolk on the basis of caste and economical standards.

The river Subarnarekha, about 460 km in length, originates in the Chotanagpur plateau near Ranchi, traverses through the states of Jharkhand, West Bengal and Orissa before meeting the Bay of Bengal about 1.5 km downstream of Kirtania / Chaumukha. Located in the state of Orissa, the entire estuarine stretch, about 50 km in length from Jaleswar to sea face, constitutes around 10% of the total length of the river. Based on the primary observations on the salinity regime and extent of tide, the Subarnarekha estuary was divided into three zones, viz., (i) Kirtania-Ramnagar (ii) upstream of Ramnagar to Dahamunda and (iii) upstream of Dahamunda to Jaleswar. Information on the piscine fauna of the estuary appears to be scanty. With this in view, a benchmark survey covering the period between April, 2008 and October, 2009 was conducted to evaluate the fish diversity of the Subarnarekha estuary. During the present course of investigations 140 species of fishes belonging to 18 orders and 55 families could be recorded of which estuarine / marine species contributed around 59.29% (excluding species found both in estuarine and transitional zone) and those migrating upstream even to freshwater zone. Perciformes constituted more than 45% of the total fish species recorded.

Study of coastal water quality plays important role in evaluating and determining the pollution status and health of the water. Ulhas river estuary is one of the important water bodies in Thane district. Entire stretch of estuary was arbitrarily divided into three zones. Physical and chemical variables of water were monitored month-wise in the year 2004-2005. In the present study the entire stretch of estuary showed high values of BOD, PO 4 -P, NO 3 -N, Suspended solids and hypoxia suggesting deterioration of the estuary. .

Journal of the Marine Biological Association of India, 2020

The spatial and seasonal variability in finfish availability in the tropical Kali Estuary, in Karwar was studied from January 2017-May 2019 at three stations. A total of 26 species belonging to 9 orders and 20 families were recorded from the Kali Estuary and the order Perciformes with 16 species dominated the group (62%) followed by order Mugilliformes and Pleuronectiformes (8%). Maximum abundance was observed during the pre-monsoon season in all the stations. Excluding Ambassis ambassis which was abundant in all the stations, Caranx ignobilis dominated in all the stations. Truly marine and estuarine species of fishes recorded dominated than the freshwater estuarine ones like Etroplus suratensis, Scatophagus argus, Aplocheilus lineatus. Number of species recorded at each station during the study ranged from 11 to 25 and it was significantly different between stations. The Shannon-Wiener diversity index ranged from 2.0 to 4.6, the minimum in station 1 and maximum in station 3. The seasonal analysis of diversity also showed minimum value during the monsoon season in station 1 and maximum value in station 3. The minimum value (2.2) of Margalef richness index was also recorded in Station 1 during monsoon season and maximum value (4.2) in Station 2. When comparing the relative abundance using Pielou's evenness index (J') the values were in the range of 0.92 to 0.99 which was closer to one, indicating evenness in distribution. There was similarity in species composition according to different seasons except for monsoon season in Station 1. The same pattern was also evident in the MDS plot where seasonal aggregation was observed between the stations. In addition to the diversity studies, the surveys also threw light on the abundance and seasonality of candidate species suitable for mariculture like C. ignobilis, Lutjanus spp., Etroplus spp., etc. Judicious exploitation of the species could help brackishwater fish farmers.

The greatest estuary created by the Gangetic delta in India is the Hooghly estuary. Despite their importance to the estuarine biodiversity, the tidal freshwater areas of this estuary have gained little interest from ecologists. Present study aims to explore the fish diversity with its assemblage pattern and their relationship with physico-chemical parameters from June 2020 to May 2021. There have been identified 118 species in total, from 14 orders and 47 families, with seven (7) being near threatened, fifteen (15) vulnerable, four (4) endangered, and eight (8) not evaluated. Perciformes (29.66%), Cypriniformes (22.88%), and Siluriformes (21.18%) accounted for 73.72% of the overall species count. Station-1 has significantly higher species richness, rarefied richness, and abundance. Station-3 and station-2 followed station-1 respectively. The composition of fish species changed significantly among the stations, as shown by cluster analysis, nMDS (nonmetric multidimensional scaling), ...

International Journal of Creative Research Thoughts, 2023

Ulhas River Estuary and Thane creek are two adjacent brackish water bodies lying in the vicinity of Thane City. These are highly impacted by various anthropogenic activities mainly due to urban, industrial, and reclamation activities. Artisanal fisheries from these water bodies have been under threat for decades. The qualitative fisheries diversity study revealed that the water body has declined further in fisheries catches. Nevertheless, a total of 31 fisheries species were observed in the study. Some species viz. Mystus gulio, Oreochromis mossambicus, and bivalves which were previously reported to be abundant were found to be dwindling in the present scenario. However, species like mullets, crabs, Acetes indicus, shrimps sciaenids, and clupeiformes were abundant in the present study Moreover the marketing and dealing have no proper facilities. The perennial estuarine fish species were high in landings followed by estuarine seasonal species. The marine migratory fish dominated the landing as compared to the riverine migratory species.

Indian Journal of …, 2012

The status of fisheries and seasonal variation in fish diversity in the Kodungallur-Azhikode Estuary (KAE) were investigated. Total annual average fish production in the estuary declined significantly to 908.6 t with average yield of 5.4 kg ha -1 day -1 , when compared to earlier study; where 2747 t was reported. During the present study, 60 species of finfishes (belonging to 34 finfish families), 6 species of penaeid shrimps, 2 species of palaemonid prawns, 2 species of crabs (4 crustacean families), 6 species of bivalves (3 molluscan families) were noticed. Finfishes were the major group that contributed 69.62% of total fishery in the estuary and crustaceans (23.47%), bivalves (6.84%) and oysters (0.07%) also formed good fishery. Many of the fish species in the estuary were observed as threatened (Horabagrus brachysoma, Channa striatus, Channa marulius, Clarias batrachus, Heteropneustes fossilis and Wallago attu). The major fishing gears employed in the estuary were gillnets, cast nets, stake nets, scoop nets, ring nets, traps and Chinese dip nets. Gillnets contributed 45% of the total fish catch. Gillnets also showed highest catch per unit effort (CPUE) of 6.91 kg h -1 followed by cast nets (1.85 kg h -1 ), Chinese dip nets (3.20 kg h -1 ), stake nets (3.05 kg h -1 ), ring nets (1.27 kg h -1 ), hooks and lines (1.35 kg h -1 ) and scoop nets (0.92 kg h -1 ). The study implies that temporal changes in fish landing pattern of the KAE was mainly due to environmental variability, habitat modification and fish migration; under the influence of south-west monsoon and anthropogenic activities in the KAE. Results of the study suggest that spatio-temporal variations in the fish community structure could be an indicator for anthropogenic stress and it should be considered for restoration programmes.

Current Science, 2014

Fish diversity (77 species) in the Aghanashini River estuary of the Indian west coast is linked to variable salinity conditions and zones I, II and III for high, medium and low salinity respectively. Zone I, the junction between Arabian Sea and the estuary, had all species in yearly succession due to freshwater conditions in monsoon to high salinity in pre-monsoon. The medium (zone II) and low (zone III) salinity mid and upstream portions had maximum of 67 and 39 fish species respectively. Maintenance of natural salinity regimes in estuary, among other ecological factors, is critical for its fish diversity.