RESUMEN
The ecological quality status (EcoQS) of Vellar and Uppanar estuaries (Southeast coast of India) has been monitored monthly, using a combination of foraminiferal (Foram Stress Index: FSI and exp(H'bc) indices and abiotic (Pollution Load Index: PLI, Dissolved Oxygen: DO, and Total Organic Carbon: TOC) parameters. The Uppanar Estuary shows relatively higher values of PLI and TOC and lower DO values than Vellar Estuary. The highest value of TOC and PLI are recorded during the monsoon season. These variations are well mirrored by the change in exp(H'bc) and FSI. The lowest values of exp(H'bc) are observed with the monsoon season and could be ascribed by an overall reduction of salinity, and to the highest level of TOC and PLI in response to enhanced river discharge. The FSI also exhibits great variability with significant higher values in the Vellar Estuary than in the Uppanar Estuary. The EcoQS evaluated by a combination of pollution- (i.e., PLI, TOC and DO) and foraminiferal-based [i.e., FSI and exp(H'bc)] indices are highly consistent (73.4%). The most frequent disagreement among indices is mostly associated to Uppanar Estuary and, particularly, in the inner stations. This difference might be related to a time-lag response of benthic foraminifera in terms of diversity and assemblages' compositions as well as of the pollution indicators in response to enhanced riverine input. This study further supports the application of foraminiferal-based indices in EcoQS assessment in transitional environments including tropical Indian estuaries. It also fills the gap of knowledge by providing a seasonal perspective on the variation of EcoQS based on a monthly-scale sampling.
Asunto(s)
Monitoreo del Ambiente , Estuarios , Foraminíferos , India , Estaciones del AñoRESUMEN
Multivariate pollution degree indices were utilized to evaluate the environmental condition of the Uppanar and Vellar estuaries. The Trophic Index (TRIX) indicates a state of "moderate eutrophication" with a value of 4.92, while the Trophic State Index (TSI) ranged from 40.3 to 57.2, categorizing the trophic states from "oligotrophic" to "eutrophic". The Comprehensive Pollution Index (CPI) showed a range of 0.13 to 0.94, classifying pollution levels from "unpolluted" to "slightly polluted". The study revealed that the Uppanar and Vellar estuaries underwent seasonal variations, transitioning from an oligotrophic state during the post-monsoon and summer periods to a eutrophic state in the pre-monsoon and monsoon seasons. The application of multivariate statistical tools allowed the identification of pollution indicator species to assess the estuarine systems. The insights gained from this study can be valuable for assessing other ecosystems facing similar anthropogenic activities, providing a basis for informed management and conservation strategies.
Asunto(s)
Monitoreo del Ambiente , Estuarios , Eutrofización , Ecosistema , Estaciones del Año , Análisis Multivariante , Animales , Contaminación del Agua/estadística & datos numéricosRESUMEN
The solitary entoproct species, Loxosomella diopatricola is recorded from the Bay of Bengal, southeastern coast of India. The species was found on the eunicid polychaete Diopatra sp. collected from depth of 15 m. Loxosomella diopatricola is a medium-sized species with average body length up to 396 m, eight tentacles and oval in calyx shape. The Loxosomella diopatricola was first time recorded in India. A list of all Loxosomella species associated with polychaetes is given.
Asunto(s)
Bahías , Poliquetos , Animales , IndiaRESUMEN
We report herein three epibiotic associations between peritrich ciliate protozoans and polychaete worms, as observed in Tamilnadu, southeastern coast of India. Epibiont ciliates Epistylis sp.1 were found all over the integument of individuals of the terebellid polychaete Terebella sp., collected from Vellar estuary. Epistylis sp.2 ciliates were observed attached to Namalycastis abiuma polychaetes, on both sides of parapodia. Cothurnia sp. ciliates were found on anterior most paleae and hooks of Sabellaria sp. polychaetes, both latter associations from material from the Uppanar estuary. Those epibiont/basibiont associations are all new to science and discussed herein, together with a review on the previous reports of epibiont ciliate protozoans in Indian waters.
Asunto(s)
Anélidos , Cilióforos , Oligohimenóforos , Poliquetos , Animales , IndiaRESUMEN
The changes in physico-chemical and rheological properties of kithul starch by the impact of energetic neutral nitrogen atoms produced by the glow discharge air plasma with novel technique were analysed. Here, treatment was carried out at different power levels (5â¯W & 15â¯W) and treatment time (30â¯min & 60â¯min). Decrease in amylose and moisture content and increase in swelling index and solubility of plasma treated kithul starch were observed. Fourier transform infrared spectra of plasma treated starch showed variation in the peaks corresponding to CH2 and OH groups. Relative crystallinity significantly (pâ¯≤â¯0.05) decreased after plasma treatment. Scanning electron microscopy showed severe damages on the starch granular surface by the effect of energetic neutral nitrogen atoms. Pasting properties increased and thermal properties showed significant (pâ¯≤â¯0.05) changes after plasma treatment. Storage modulus (G') and loss modulus (Gâ³) reduced at higher levels of plasma power and it indicated to its weak gel formation.