Regime shifts in Artic terrestrial hydrology manifested from impacts of climate warning

Anthropogenic warming in the Arctic is causing hydrological cycle intensification and permafrost thaw, with implications for flows of water, carbon, and energy from terrestrial biomes to coastal zones. To better understand the likely impacts of these changes, we used a hydrology model driven by meteorological data from atmospheric reanalysis and two global climate models for the period 1980–2100. The hydrology model accounts for soil freeze–thaw processes and was applied across the pan-Arctic drainage basin. The simulations point to greater changes over northernmost areas of the basin underlain by permafrost and to the western Arctic. An acceleration of simulated river discharge over the recent past is commensurate with trends drawn from observations and reported in other studies. Between early-century (2000–2019) and late-century (2080–2099) periods, the model simulations indicate an increase in annual total runoff of 17 %–25 %, while the proportion of runoff emanating from subsurface pathways is projected to increase by 13 %–30 %, with the largest changes noted in summer and autumn and across areas with permafrost. Most notably, runoff contributions to river discharge shift to northern parts of the Arctic Basin that contain greater amounts of soil carbon. Each season sees an increase in subsurface runoff; spring is the only season where surface runoff dominates the rise in total runoff, and summer experiences a decline in total runoff despite an increase in the subsurface component. The greater changes that are seen in areas where permafrost exists support the notion that increased soil thaw is shifting hydrological contributions to more subsurface flow. The manifestations of warming, hydrological cycle intensification, and permafrost thaw will impact Arctic terrestrial and coastal environments through altered river flows and the materials they transport

Enzymes of Ammonia Assimilation in Fungi: An Overview

Nitrogen is a major element found in many of the simple compounds and nearly all of the complex macromolecules of living cells. Nitrogen can be obtained either from organic source or inorganic source but ultimately it is converted into ammonia and glutamate. Ammonia is the preferred   source of nitrogen. The assimilation of ammonia into glutamate and glutamine plays a central role in the nitrogen metabolism of all organisms. Glutamate dehydrogenase (GDH), Glutamate synthase (GOGAT), and glutamine synthetase (GS) are the key enzymes involved in ammonia assimilation. The specific steps in these pathways vary with the organism, but in virtually all cells glutamate (85%) and glutamine (15%) serve as the nitrogen donors for biosynthetic reactions. In fungi lot of work has been carried out on these enzymes from lower fungi to the higher ones and there are differences in the role played by theses enzymes. Thus knowledge of the formation of glutamate and glutamine from various nitrogen sources is crucial to our understanding of cell growth.  In this review an overall view of the elements present in ammonia assimilation especially in fungi will be carried out along with recent developments and concepts

Unusual landing of blue shark

The fishermen of Thoothoor and Thengapattanam are experts in hook and line operations for sharks and conduct multiday distant water shark fishing off Maharashtra and Gujarat coasts at 150-180 km from shore. Large-sized elasmobranchs caught here are landed in southern India, where the meat is saltdried and sold for domestic consumption. Blue sharks are not regular contributors to the shark fishery in India and are rarely seen in such large numbers as in the present observation

Dynamics and energy spectra of aperiodic discrete-time quantum walks

We investigate the role of different aperiodic sequences in the dynamics of single quantum particles in discrete space and time. For this we consider three aperiodic sequences, namely, the Fibonacci, Thue-Morse, and Rudin-Shapiro sequences, as examples of tilings the diffraction spectra of which have pure point, singular continuous, and absolutely continuous support, respectively. Our interest is to understand how the order, intrinsically introduced by the deterministic rule used to generate the aperiodic sequences, is reflected in the dynamical properties of the quantum system. For this system we consider a single particle undergoing a discrete-time quantum walk (DTQW), where the aperiodic sequences are used to distribute the coin operations at different lattice positions (inhomogeneous DTQW) or by applying the same coin operation at all lattice sites at a given time but choosing different coin operation at each time step according to the chosen aperiodic sequence (time dependent DTQW). We study the energy spectra and the spreading of an initially localized wave packet for different cases, finding that in the case of Fibonacci and Thue-Morse tilings the system is superdiffusive, whereas in the Rudin-Shapiro case it is strongly subdiffusive. Trying to understand this behavior in terms of the energy spectra, we look at the survival amplitude as a function of time. By means of the echo we present strong evidence that, although the three orderings are very different as evidenced by their diffraction spectra, the energy spectra are all singular continuous except for the inhomogeneous DTQW with the Rudin-Shapiro sequence where it is discrete. This is in agreement with the observed strong localization both in real space and in the Hilbert space. Our paper is particularly interesting because quantum walks can be engineered in laboratories by means of ultracold gases or in optical waveguides, and therefore would be a perfect playground to study singular continuous energy spectra in a completely controlled quantum setup

Biology of some important Demersal Fishery Resources In: ICAR Sponsored Winter School on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation, 1-21 December 2018, Kochi.

Global total capture fishery production in 2014 was 93.4 million tonnes, of which 81.5 million tonnes from marine waters and 11.9 million tonnes from inland waters. Total capture production in marine waters was 81.5 million tonnes in 2014, a slight increase on the previous two years (SOFIA, 2016). The marine fish landings from the coast of the main land of India in 2017 was estimated as 3.83 million tonnes (t) showing an increase of 5.6% compared to in 2016. Landings in all the maritime states except Tamil Nadu increased in 2017. Highest landings was along the Gujarat coast (7.86 lakh t; 20.5%), followed by Tamil Nadu, Kerala and Karnataka with 6.55 lakh t (17.1%), 5.85 lakh t (15.3%) and 5.48 lakh t (14.3%). Percentage increase was high in Goa (64%), West Bengal (33%), Maharashtra (30%) and Kerala (12%). Along the Indian coast demersal finfishes form one of the major components in the marine fish landings. Demersal fish groups such as the sharks. groupers. snappers. threadfins, pormfrets and Indian halibut are commercially valuable and contribute substantially to the economy of Indian marine fisheries. Some of these groups, especially of largesize, are targeted by the fishermen by using different craft and gear combinations. However, several other demersal finfishes are not targeted, but are landed as bycatch by shrimp trawlers

Forecasting species distributions : correlation does not equal causation

This research was funded by the U.S. Department of the Interior Northeast Climate Adaptation Science Center, which is managed by the U.S. Geological Survey National Climate Adaptation Science Center. Additional funding was provided by T-2- 3R grants for Nongame Species Monitoring and Management through the New Hampshire Fish and Game Department and E-1- 25 grants for Investigations and Population Recovery through the Vermont Fish and Wildlife Department.Aim Identifying the mechanisms influencing species' distributions is critical for accurate climate change forecasts. However, current approaches are limited by correlative models that cannot distinguish between direct and indirect effects. Location New Hampshire and Vermont, USA. Methods Using causal and correlational models and new theory on range limits, we compared current (2014?2019) and future (2080s) distributions of ecologically important mammalian carnivores and competitors along range limits in the northeastern US under two global climate models (GCMs) and a high-emission scenario (RCP8.5) of projected snow and forest biomass change. Results Our hypothesis that causal models of climate-mediated competition would result in different distribution predictions than correlational models, both in the current and future periods, was well-supported by our results; however, these patterns were prominent only for species pairs that exhibited strong interactions. The causal model predicted the current distribution of Canada lynx (Lynx canadensis) more accurately, likely because it incorporated the influence of competitive interactions mediated by snow with the closely related bobcat (Lynx rufus). Both modeling frameworks predicted an overall decline in lynx occurrence in the central high-elevation regions and increased occurrence in the northeastern region in the 2080s due to changes in land use that provided optimal habitat. However, these losses and gains were less substantial in the causal model due to the inclusion of an indirect buffering effect of snow on lynx. Main conclusions Our comparative analysis indicates that a causal framework, steeped in ecological theory, can be used to generate spatially explicit predictions of species distributions. This approach can be used to disentangle correlated predictors that have previously hampered understanding of range limits and species' response to climate change.Publisher PDFPeer reviewe

Demersal Fishes - Life History Studies and Resource Assessment of fishes In: ICAR Sponsored Winter School on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation, 1-21 December 2018, Kochi.

Demersal fishes are those, which are bottom dwelling fishes and fishes that are close to the sea bottom. Demersal fisheries have been a major source of human nutrition and commerce for thousands of years. Main objective of the demersal fishery is nothing but human consumption. Compared with pelagic resources like mackerel and sardine, the demersal fishes are relatively large and high value species. Since the fishes are mostly associated with sea bottom, these are also known as ground-fish fisheries. Deep-water fisheries are mostly featured by some of their major characteristics like slow growth, longevity, and low reproductive output that may be the reasons for the low sustainability towards the high level of fishing pressure. The intensity of fishing activity throughout the world, including demersal fisheries, has increased rapidly over the past century, with more fishing vessels, greater engine power, better fishing gear, and improved navigational aids. Many demersal fisheries are now overexploited and all are in need of careful assessment and management if they are to provide a sustainable harvest

ICAR-CMFRI Winterschool on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation

The application of scientific knowledge for the development of the fishing industry lies in an intimate knowledge of the biology of fishes. Without proper knowledge of the life, habits and behaviour of fishes, it would not be possible to plan, control and manage the fisheries resources in a satisfactory manner. The importance of knowledge of the natural history and ecology of organisms affecting the particular fishery cannot be overestimated. Such knowledge is largely the basis for fishery regulation. It also helps in determining the need to improve a given environment and in the required direction. Marine fisheries comprise of capture and management offish and other commercially important organisms found in the seas. Effectively combining fisheries management and biodiversity conservation for both human and ecosystem well being is the central challenge of modern fishery governance. At the global level, the aims of fisheries management and of biodiversity conservation are,respectively, framed by the 1982 Law of the Sea Convention (LOSC) and the 1992 Convention on Biological Diversity (CBD) and related implementation instruments(such as the 1995 United Nations Fish Stocks Agreement, the 1995 Code of Conduct for Responsible Fisheries, and the 1995 Jakarta Mandate on Marine and Coastal Biological Diversity), each with its own sets of requirements. While this field is predominantly of the capture type, culture of certain marine organisms is also possible.In both cases, basic knowledge on the biology of fishes or other organisms of economic importance is necessary. Most conservation efforts are based on scientific management tools, which in turn rely on sound biological data and derivations from the same for farming the management recommendations. A wide array of techniques are used by fishery biologists to study fishes and these biological inputs used are further used to effectively manage the fisheries

Stomach Content Analysis Techniques in Fishes In: ICAR Sponsored Winter School on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation, 1-21 December 2018, Kochi.

In Ichthyology, fish ecology & fisheries resource management, the information on diet & food habits are valuable in the decision-making process related to natural resources (Kido, 1996). Fish gut content analysis provides an important insight into feeding patterns & quantitative assessment of feeding habits is an important aspect of fisheries management. Fish diet represents an integration of many important ecological components that includes behaviour, condition, habitat use, energy intake & inter & intra-specific interactions, etc. A valid description of fish diets & feeding habits also provides the basis for understanding trophic interactions in aquatic food webs. Conceptually, trophic relations of fishes begin with the food & feeding habits & gut content analysis can be used to evaluate the habitat preferences, prey selection, effects of ontogeny & developing conservation strategies (Chipps & Garvey 2007). A food habit study might be conducted to investigate the most frequently consumed prey or to determine the relative importance of different food types to fish nutrition & to quantify the ingestion rate of individual food types. All such questions demands information on fish diets & requires different approaches in how one collects & analyzes data. In summary, gut content analysis is used in the understanding of many aspects of fish ecology on individual, population & ecosystem levels. It helps us to study & elucidate specific problems of interactions, evolution, speciation, invasions & fishery management nature protection. As a result, stomach content studies could be incorporated into a variety of different research objectives. Consequently, the study of the gut content is not only way to know the diet but also superior source of information on many aspects of fish biology & ecology