Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Tipo de estudo
Intervalo de ano de publicação
1.
Mar Pollut Bull ; 165: 112088, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33561712

RESUMO

This is the first study to comprehend copper (Cu)-dynamics in a monsoon fed Indian estuarine system (the Mandovi estuary from the central west coast of India). Distribution and speciation of Cu in estuarine sediment, pore water, suspended particulate matter (SPM) and water column was used to understand geochemical cycling of Cu in the estuary. Geochemical fractionation study reveals that sedimentary organic carbon (Corg) was the major hosting phase for non-residual Cu in the sediments. Experimental analysis and chemical speciation modelling suggests that leaching of sedimentary Cu2+, CuCO3 and a fraction of Cu-Corg complexes increased Cu-concentrations in the pore water towards the downstream of the estuary. Dissolved Cu concentration in overlying water column was observed to increase with increasing Cu concentrations in the pore water. This study suggests that chemical speciation of sedimentary Cu play key role in controlling its distribution and dynamics in the tropical estuarine system during dry period.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Cobre , Monitoramento Ambiental , Índia , Estações do Ano , Poluentes Químicos da Água/análise
2.
Chemosphere ; 270: 129359, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33434694

RESUMO

The present study exhibits the occurrence of MPs in different matrices (water, sediment and biota) from the Sal estuary, Goa, situated on the central west coast of India. The average numbers of MPs in the water column and sediment were 48 ± 19 MP particles/L (MPs/L) and 3950 ± 930 MP particles/kg (MPs/kg), respectively. In shellfish (whole soft tissue), the average concentrations of MPs were 4 ± 2 (Crassostrea sp.), 3.2 ± 1.8 (Perna viridis) and 0.7 ± 0.3 (Paphia malbarica) MPs/g body weight (bw), respectively. The highest MPs were recorded in finfish (gastro-intestinal tract) (Mugil cephalus)7.8 ± 4, followed by (Gerres filamentosus) 5.3 ± 4.9, (Arius jella) 4.6 ± 2.6, and (Etroplus suratensis)1.4 ± 0.3 MP/g bw. MP fibres were predominant in all matrices. Interestingly, a dominance of small sized (10-300 µm) MPs was recorded in biota. Among the 37 polymer types identified by µ-FTIR, the most prevalent ones were, polyacrylamide (PAM) , polyacetylene, ethylene vinyl alcohol (EVOH), polyvinyl chloride (PVC) and polyamide (nylon). Notably, the polymers dominant in the gut of finfish and in whole shellfish were equally prominent in sediment and the water column. This study highlights the presence of MPs in commercially important shellfish and finfish samples from the Sal estuary. This study clearly shows the presence of MPs in various types of marine organisms in the Sal estuary. As shellfish is locally consumed as a delicacy and plays a major role in the seafood industry, the MPs may pose a hazard for human health. There is also an ecological risk as MPs are also found in water and sediment and in the digestive tract of finfish.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Humanos , Índia , Plásticos , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise
3.
Zootaxa ; 4890(3): zootaxa.4890.3.3, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33311117

RESUMO

Epibiosis is a common phenomenon, found in different taxa of aquatic animals. This relationship could occur as hyperepibiosis, when a basibiont being also an epibiont, providing a stable substrate for the hypersymbiont. Here we reported a ciliate-bryozoan-crustacean hyperepibiosis in Mandovi River mouth, Goa, West coast of India. We provided descriptions and characterization of the crab Atergatis sp., serving as basibiont for the bryozoan Triticella pedicellata (Alder, 1857), in turn colonized with (hyperepibionts) the ciliates Paracineta saifulae (Mereschkowsky, 1877) and Cothurnia ceramicola Kahl, 1933. Paracineta saifulae and Cothurnia ceramicola are reported here for first time from the Indian Ocean.


Assuntos
Braquiúros , Briozoários , Cilióforos , Animais , Índia
4.
Artigo em Inglês | MEDLINE | ID: mdl-33140282

RESUMO

The bacterial diversity associated with eroding sponges belonging to the Cliona viridis species complex is scarcely known. Cliona thomasi described from the West Coast of India is a new introduction to the viridis species complex. In this study, we determined the bacterial diversity associated with C. thomasi using next-generation sequencing. The results revealed the dominance of Proteobacteria followed by Cyanobacteria, Actinobacteria and Firmicutes. Among Proteobacteria, the Alphaproteobacteria were found to be the most dominant class. Furthermore, at the genus level, Rhodothalassium were highly abundant followed by Endozoicomonas in sponge samples. The beta-diversity and species richness measures showed remarkably lower diversity in Cliona thomasi than the ambient environment. The determined lower bacterial diversity in C. thomasi than the environmental samples, thus, categorized it as a low microbial abundance (LMA). Functional annotation of the C. thomasi-associated bacterial community indicates their possible role in photo-autotrophy, aerobic nitrification, coupling of sulphate reduction and sulphide oxidization. The present study unveils the bacterial diversity in bioeroding C. thomasi, which is a crucial step to determine the functions of the sponge holobiont in coral reef ecosystem.

5.
Mar Pollut Bull ; 155: 111190, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32469789

RESUMO

Globally, coral reefs have drastically degraded due to local and global environmental stressors. Concurrently, coral reef tourism is rapidly growing in developing economies, which is one of many anthropogenic stressors impacting reefs. At the Malvan Marine Sanctuary, a Marine Protected Area (MPA) on the West coast of India, we investigated the impact of recreational diving on the reef from 2016 to 2019. To evaluate the diver's underwater behavior, a novel approach was used, wherein the video-log broadcasting website www.youtube.com was perused. Evidential proof substantiates heavy physical damage to corals because of recreational diving activity, which may lead to the collapse of coral habitat if it continues unabated. This resource depletion ironically elevates the economy of dependents averting consequences due to lost corals, thus making this a 'tragedy' for corals which are not meant to be 'commons'. The study asserts need for proactive conservation efforts with stringent implementation and restoration initiatives in this MPA.


Assuntos
Antozoários , Mergulho , Animais , Conservação dos Recursos Naturais , Recifes de Corais , Índia
6.
Zootaxa ; 4695(4): zootaxa.4695.4.5, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31719343

RESUMO

The article deals with the report of 5 suctorians viz. Lecanophryella satyanandani (Santhakumari, 1986), Paracineta karunakarani Santhakumari, 1986, Ephelota gemmipara (Hertwig, 1876), Acineta foetida Maupas, 1881 and Pelagacineta sp. on marine pelagic ostracods Cypridina dentata (Müller, 1906) from new localities of the Arabian Sea. Diagnostic characters of Paracineta karunakarani are emended. Ephelota gemmipara (Hertwig, 1876) and Acineta foetida Maupas, 1881 are reported here for the first time on planktonic marine ostracods. Pelagacineta sp. is reported for the first time as epibiont on ostracods and from the Indian Ocean.


Assuntos
Cilióforos , Crustáceos , Animais , Oceano Índico , Plâncton
7.
Zootaxa ; 4612(4): zootaxa.4612.4.2, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31717038

RESUMO

The article presents a review of the literature on known representatives of the genus Lecanophryella containing general characteristics of the members of this genus, information on morphology and data on distribution. Diagnostic characters of L. satyanandani is emended based on material collected from a new locality. A new species, Lecanophryella indica as epibiont on the body surface of cyclopoid copepod from the Zuari estuary, west coast of India is also described.


Assuntos
Cilióforos , Copépodes , Animais , Índia
8.
Mar Pollut Bull ; 149: 110504, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421562

RESUMO

Globally, coral reefs are degrading rapidly due to the combined impact of wide-scale anthropogenic activities and climate change. Similarly, coral reefs in India are facing an existential threat because of intensified environmental degradation, which challenges reef ecosystem resilience and socio-ecological stability. Recently, Govt. of India has taken up the 'SagarMala Programme' aiming to increase its port capacity by the expansion of existing ports, construction of several new ports and allied infrastructure development by 2025. Synergistic impact of coastal development coupled with the on-going environmental changes is deemed to accelerate coral reef degradation in Indian reefs. Therefore, the present article aims to highlight the urgency of positive intervention and initiation of long-term holistic coral reef restoration program as an active reef management tool. Along with conventional management practices, reef restoration program could curtail further reef degradation and will ensure the persistence of Indian coral reefs and the services they provide.


Assuntos
Antozoários/crescimento & desenvolvimento , Conservação dos Recursos Naturais/métodos , Recifes de Corais , Animais , Mudança Climática , Índia
9.
Sci Total Environ ; 668: 592-601, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-30856569

RESUMO

Sedimentary organic matter (SOM) plays an important role in hosting and reducing HgII in marine/estuarine sediment. This study provides a better understanding on the influence of nature of SOM, in regulating sedimentary mercury (Hg) and elemental mercury (Hg0) distribution, and speciation in the Zuari and Mandovi Estuaries that are representative of monsoon fed tropical estuaries, located in the central west coast of India. Salinity of the overlying water column controlled the physical and chemical characteristics of SOM in the estuarine systems. The high molecular weight (MW) SOM dominated at the mid and upstream (low salinity region) of the estuaries, whereas, the low MW SOM prevailed at the downstream (high salinity region). Sediment Hg showed more affinity towards the SOM of high MW. Increasing MW of SOM increased total sedimentary HgT in both the estuaries. SOM with low MW in the estuarine sediment displayed a negative relationship with the sediment Hg concentration. Distribution of Hg0 concentration in the estuarine sediment suggests that reduction of HgII in presence low MW SOM was a dominant process. It was also found that distribution and speciation of Hg0 in the estuarine sediment depends on the quantity, quality of the SOM, and the total sediment Hg loading. This study demonstrated that the competition between Hg-SOM complexation and HgII reduction by SOM controls HgII/Hg0 distribution in tropical estuarine sediment systems.

10.
Environ Monit Assess ; 173(1-4): 65-78, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20213062

RESUMO

Natural disturbances along with human interference make the tropical estuaries amongst the most disturbed areas globally. In spite of this, information on the seasonal variability of macrofauna from tropical estuaries is few. Temporal variability of macrofaunal community from Mormugao Bay, Zuari estuary, on the west coast of India was examined from 2003 to 2004 at seven stations. Environmental variability was assessed through physicochemical parameters of water and sediment. The changes in macrobenthic community were assessed using abundance, biomass and species diversity indices. The environmental parameters showed a significant seasonal variation influenced by monsoonal changes. The changes in the environmental conditions brought about variation in the macrobenthic community. Macrofaunal abundance, biomass and species diversity were the highest during post-monsoon influenced by recruitment. In monsoon, the macrobenthic community was dominated by polychaetes (92.17%), whereas bivalves dominated during the post-monsoon (57.7%). The macrofauna showed drastic decline during the stable pre-monsoon season, a period when the highest abundance of fauna is observed in the tropical estuary. Therefore, the macrobenthic community in the area did not follow the seasonal trend generally observed in a tropical estuary. Further, the community during pre-monsoon season was dominated by the opportunistic polychaete species indicating a possible influence of harbour activities in structuring the benthic community of the area.


Assuntos
Monitoramento Ambiental/métodos , Invertebrados , Animais , Biodiversidade , Índia , Poliquetos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...