Stock Structure Analysis of Unicorn leatherjacket, <i>Aluterus monoceros </i>(Linnaeus, 1758) (Tetraodontiformes: Monacanthidae) from Indian Coastal Waters

Aquatic organisms and pathogens may become major threats to the coastal and marine environment when introduced into a region beyond their natural distributions through ballast water (BW). Coastal currents induced by tides and winds, especially ebb currents, may facilitate the spread of these marine organisms along nearshore and inshore areas. Numerical modelling of hydrodynamics is an effective tool to track the dispersion of these organisms in the receiving water body through BW release. Particle transport models can be used to track the advection and dispersion of these organisms. Alternatively, the difference in salinity of the BW and coastal waters can be used as a tracer to estimate the dispersion pattern. Tides and winds present in the region at the time of BW release are responsible for the dispersal of the particles present in BW discharge. Based on advection and dispersion processes, the transport of the marine organisms present in the BW can be studied using numerical models. Numerical modelling studies were carried out using the 2-D hydrodynamic model MIKE21 HD, to understand the pattern of BW dispersion at select bioregions along the east and west coasts of India. Mangalore Port located along the west coast in Bioregion-I (CIO-I) and Chennai Port on the east coast in Bioregion-II (CIO-II) were selected for the modelling study. Results obtained from ballast water dispersion modelling studies will be useful for developing and assisting port-based ballast water management programmes for CIO-I and CIO-II regions. The currents are predominantly tide driven near the ports situated along the west coast and the circulation exhibited reversals associated with the tidal currents. However, along the east coast of India, the particles largely followed coastal currents - advected either southward or northward under the influence of prevailing coastal currents in the offshore region and tidal reversals showed had less impact. This information proved useful for determining suitable locations for BW discharge and monitoring points for field sampling in connection with BW release.

Due to the continuous interface dynamics amongst tectonic, fluvial, coastal and aeolian geomorphic processes, the coastal zones always remain dynamically active with resultant morphological changes like land building and land loss activities. Such morphological changes along the coasts do also control the environment of the coastal systems. In this connection, the east coast of India is unique with complex tectonic and geomorphic processes and the resultant dynamically changing coastal morphologies. Amongst various local processes like wind, wave, tides and the eddies, the regional component of the littoral current is one of the dynamic processes along the east coast of India which move northerly from Cape Comorin in the south to West Bengal coast / Sundarbans in the north during the non-northeast monsoon months (Mar–Oct). These again move southerly all along the east coast of India from the West Bengal coast in the north to Cape Comorin in the south during the northeast monsoon months (Nov-Feb). These currents cause sediment dump in the current ward side and the coastal erosion in the current shadow side when the littoral currents are obstructed by promontories or manmade projections all along the east coast of India. In this connection, detailed mapping of the shorelines and there from the spatial estimation of the erosion/deposition was carried out for the Vedaranniyam region using the satellite Infra-Red & Near Infra-Red data for the years 1972, 1997, 2004, 2006, 2009, 2016, 2018 and 2022. Infrared band of Landsat data was used to demarcate the land–water boundary. In infrared region water bodies exhibit the darker tone with smooth texture to absorption and at the same time, due to heterogeneity, the land portion showing the coarser texture with varying reflectance. This is very much helpful in delineating land–water boundary in general. These showed that the land has grown by an average area of 1.27 km2 in fifty years from 1972 to 2022 in the central Vedaranniyam nose region. Whereas, there observed the land loss or erosion on the northern and southern parts of Vedaranniyam. Keeping this as the base value, the areal extent of land growth was visualised for every 500 years viz. 2500, 3000, 3500, 4000 AD and so on. This indicated that, under the prevailing littoral current dynamics and the seabed topography observed from GEBCO data in between the Vedaranniyam nose (India) and Jaffna peninsula (Sri Lanka), the land will get connected by a land bridge between the both in another 10,000 or 12,000 years. Such land bridging may also lead to the formation of a protected sea in between Vedaranniyam—Jaffna sector in the north and Ramanathapuram—Rameswaram—Thalaimannar sector in the south.This may also end up with the formation of a land in due course of time in such a protected sea due the sediment dump from the rivers of the southernmost part of Tamil Nadu.

A new approach to classify oral-nasal balance disorders based on instrumental measurements was developed based on linear discriminant analysis (LDA) of nasalance scores of simulated oral-nasal balance disorders by de Boer and Bressmann. The current study aimed to apply the newly developed functions to clinical data to investigate the applicability of this new approach. Retrospective diagnostic accuracy study. Tertiary university hospital. Fifty-five Dutch-speaking Flemish children (age 4-12 years) with normal (n = 20), hypernasal (n = 18), hyponasal (n = 12), or mixed nasality (n = 5). Nasalance scores of an oral and a nasal text were used to calculate 3 sets of LDA function scores. Predicted classification was consecutively based on the function values of the group centroids originally determined by de Boer and Bressmann and adapted LDA functions and group centroids based on clinical data. Discriminatory power of the linear discriminant formulas. Based on the original LDA functions, 56% of the speech samples matched the perceptual classification. Applying a correction factor for age and language differences resulted in a 67% correct classification, although 83% of the hyponasal samples were ranked as "normal resonance." Rederivation of the LDA functions based on current clinical data resulted in an 80% correct classification. The new approach of classifying oral-nasal balance disorders based on a combination of nasalance scores was promising. However, further clinical research is needed to refine the LDA functions and group centroids before clinical application is possible.

Algal blooms have been documented along the west and east coasts of India. A review of bloom occurrences in Indian waters from 1908 to 2009 points out that a total of 101 cases have been reported. A comparison of the bloom cases reported before and after the 1950s reveals that there is an increase in the number of bloom occurrences. The reports of algal blooms indicate their predominance along the west coast of India especially the southern part. Majority of the blooms reported along the west coast of India are caused by dinoflagellates, whereas diatom blooms prevail along the east coast. There have been 39 causative species responsible for blooms, of which Noctiluca scintillans and Trichodesmium erythraeum are the most common. Reporting of massive fish mortality in Indian waters has been associated with the blooming of Cochlodinium polykrikoides, Karenia brevis, Karenia mikimotoi, N. scintillans, T. erythraeum, Trichodesmiumthiebautii and Chattonella marina. Most of the blooms occurred during withdrawal of the south-west monsoon and pre-monsoon period. In Indian waters, this process is mainly influenced by seasonal upwelling and monsoonal forcing that causes high riverine discharge resulting in nutrient-enriched waters that provides a competitive edge for blooming of phytoplankton species.

Our examination of net phytoplankton collected from coastal localities in Odisha on the east coast of India, including Chilka Lake, Chandrabhaga Beach and Puri, in December 2015, revealed the overwhelming dominance of Thalassiosira mala, a gelatinous colony-forming, potentially harmful, marine planktonic diatom. The large numbers of cells allowed us to observe details of the cingulum not previously reported. The epicingulum is composed of four open bands including an areolated valvocopula, an areolated copula and two non-areolated pleurae. The immature hypocingulum includes at least two bands. Openings of alternate bands are arranged in a dextral pattern. Based on previous reports from the west coast and our current findings, Thalassiosira mala appears to be a common, widely distributed primary producer in Indian coastal waters. The presence of morphologically similar species, especially those <20 μm in diameter, underscores the importance of reliable species-level taxonomy using appropriate techniques for meaningful ecological and biogeographic considerations and for monitoring potentially harmful algae in India’s economically important coastal waters. Published reports suggest that Thalassiosira mala is widely distributed in temperate and tropical waters, present in 26 of 232 ecoregions and 18 of 62 provinces recognized in a recent classification of coastal marine ecoregions.

The process of upwelling/sinking and associated sea level variations are seen as a response of coastal ocean to pure wind stress forcing. Further,precipitation and monsoonal floods, apart from the marine meteorological parameters, are expected to influence the sea level fluctuations along the coast. This study comprises determining the sea level from the various parameters together with the pure wind stress forcing, which is compared with the observed cycle. However, it is found that there is considerable difference between the computations and observations. This suggests that the sea level is dependent not just on the local forcing alone, but also on the induced background circulation as well. For example, the sea level changes along the east coast of India, particularly the northern region, are more sensitive to freshwater discharge from various rivers joining the Bay of Bengal. This is due to more frequently occurring pre- and postmonsoon cyclonic storms and the associated surges in the Bay of Bengal as compared to the Arabian Sea. Hence the salinity effects are particularly important in the coastal waters off the east coast of India during monsoon months (June-September). For the west coast of India, however, it is expected that the large-scale coastal circulation may play a role in determining sea level changes in addition to other forcings. The salinity effects are negligible along the west coast in the absence of any major river systems that join the Arabian Sea. The local advection currents caused by the offshore directed freshwater discharge from various estuaries joining the coastal bay also seemed to influence the sea level. In order to elucidate the essential dynamics involved and to study the effect of the remote forcing, a three-dimensional baroclinic, nonlinear numerical model is used with appropriate open boundary conditions. The local effect of the current has been incorporated in the west coast model by means of opening a channel at Cochin through which the rainwater is carried away to the model ocean. The low saline plume, cascading from north along the east cost of India, has been incorporated in the east coast model through a proper forcing applied at the northern boundary of the model. With the inclusion of these remote forcings in the models, the disagreement between the simulations and the observations is minimized.

Submarine Groundwater Discharge (SGD) is one of the main external nutrient sources to the coastal waters. The concentrations of nutrients in groundwaters are a few folds higher than that of adjacent coastal waters; therefore, SGD enhances nutrients levels in the coastal waters and influences coastal biota. In order to examine the spatial and seasonal variability in nutrient concentrations and exchange to the coastal waters, groundwater samples were collected at ~ 90 locations along the Indian coast during the wet and dry seasons. This study revealed that dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphates (DIP) and urea were found to be high during the dry than wet period. Higher concentrations of DIN and DIP were observed during both wet and dry periods in the groundwater along the east than the west coast of India. The State-wise mean amount of fertilizer used during Kharif (wet) and Rabi (dry) period in each Indian State showed significant correlation with mean concentrations of DIN and urea. The observed linear relationship of DIN with bacterial respiration and inverse relationship with DO saturation and ammonium in groundwater suggested that decomposition of organic matter and nitrification contributed to the DIN pool in the groundwater. The mean rate of SGD fluxes varied between 1.6 × 104 m3/day and 1.75 × 1011 m3/day in the Indian coastal region. The annual mean SGD flux of DIN and DIP was estimated to be 0.103 ± 0.02 and 0.021 ± 0.01 Tg (1 Tg = 1012 g) to the western coastal Bay of Bengal (east coast of India) and 0.06 ± 0.03 and 0.015 ± 0.01 Tg/y to the eastern coastal Arabian Sea (west coast of India) respectively. The estimated SGD flux of DIN and DIP to the Indian coastal waters amounted to 0.163 ± 0.04 and 0.036 ± 0.02 Tg/y respectively, and it is almost close to that of nutrients discharged by rivers (0.22 ± 0.05 and 0.11 ± 0.03 Tg/y respectively). Among the external sources of nitrogen and phosphorus, such as river discharge, atmospheric deposition, the contribution by SGD is highly significant in the Bay of Bengal (30 and 17% respectively) than in the case of Arabian Sea (24 and 25% respectively).

In this paper, a novel hybrid dimension reduction technique for classification is proposed based on the hybrid analysis of principal component analysis (PCA) and linear discriminant analysis (LDA). LDA is known for capturing the most discriminant features of the data in the projected space while PCA is known for preserving the most descriptive ones after projection. Our hybrid technique integrates discriminant and descriptive information and finds a richer set of alternatives beyond LDA and PCA in a 2-D parametric space, which fits a specific classification task and data distribution better. Theoretical study shows that our technique also alleviates the singularity problem of scatter matrix, which is caused by small training set, and increases the effective dimension of the projected subspace. In order to find the hybrid features adaptively and avoid exhaustive parameter searching, we further propose a boosted hybrid analysis method that incorporates a nonlinear boosting process to enhance a set of hybrid classifiers and combine them into a more accurate one. Compared with the other techniques that aim at combining PCA and LDA, our approaches are novel because our method finds alternatives to LDA and PCA in a 2-D parameter space and the boosting process provides enhancement and robust combination of the classifiers. Extensive experiments are conducted on benchmark and real image databases to compare our proposed methods with the state-of-the-art linear and nonlinear discriminant analysis techniques. The results show the superior performance of our hybrid analysis methods

Improved PCA + LDA Applies to Gastric Cancer Image Classification Process

Using linear discriminant analysis (LDA) of bulk lake sediment geochemical data to reconstruct lateglacial climate changes in the South Carpathian Mountains

Diagnosis and monitoring of hepatocellular carcinoma in Hepatitis C virus patients using attenuated total reflection Fourier transform infrared spectroscopy

Quantitative estimates of the vertical structure and the spatial gradients of aerosol extinction coefficients have been made from airborne lidar measurements across the coastline into offshore oceanic regions along the east and west coasts of India. The vertical structure revealed the presence of strong, elevated aerosol layers in the altitude region of ∼2−4 km, well above the atmospheric boundary layer (ABL). Horizontal gradients also showed a vertical structure, being sharp with the e−1 scaling distance (D0H) as small as ∼150 km in the well‐mixed regions mostly under the influence of local source effects. Above the ABL, where local effects are subdued, the gradients were much shallower (∼600–800 km); nevertheless, they were steep compared to the value of ∼1500−2500 km reported for columnar AOD during winter. The gradients of these elevated layers were steeper over the east coast of India than over the west coast. Near‐simultaneous radio sonde (Vaisala, Inc., Finland) ascents made over the northern Bay of Bengal showed the presence of convectively unstable regions, first from surface to ∼750–1000 m and the other extending from 1750 to 3000 m separated by a stable region in between. These can act as a conduit for the advection of aerosols and favor the transport of continental aerosols in the higher levels (&gt;2 km) into the oceans without entering the marine boundary layer below. Large spatial gradient in aerosol optical and hence radiative impacts between the coastal landmass and the adjacent oceans within a short distance of &lt;300 km (even at an altitude of 3 km) during summer and the premonsoon is of significance to the regional climate.

Two species of ark shells i.e., Anadara consociata (E.A. Smith, 1885) and Anadara troscheli (Dunker, 1882) reported for the first time from Indian waters. These two species were identified based on the collections from different surveys along east coast of India and specimens of National Zoological Collections of Marine Aquarium and Regional Centre, Zoological Survey of India, Digha. Overall eleven species of subfamily Anadarinae of family Arcidae are presented in the current paper. The taxonomic compilation of the eleven species is done with specimens available in the study localities. A key of the eleven species is presented here for future references. These two species are overlooked with related species during the earlier studies from this region.

An annotated checklist of the marine brachyuran crabs occurring in India is compiled from published literature and augmented by collections between 2005 and 2015. A total of 910 species belonging to 361 genera and 62 families are herein listed from Indian waters. Specimens representing 130 species were obtained from Gujarat state during 2005 and 2015, of which 23 are new records to Gujarat state and two species are reported for the first time from the west coast of India. The highest number of species were recorded from the Andaman and Nicobar islands (588 species) while the smallest number were from Goa and Karnataka state (82 species). The records indicate that the east coast of India, with 803 species, is more diverse than the west coast, which has 446 species.

An annotated checklist of hermit crabs (Crustacea, Decapoda, Anomura) of Indian waters with three new records