Sea cucumber conservation in Palk Bay and Gulf of Mannar, India "An evaluation of the current conservation measures on sea cucumber stocks in Palk Bay and Gulf of Mannar of India"

Sea cucumber fishery and trade were one of the top non-finfish income streams for the coastal people of Palk Bay and Gulf of Mannar in the South East coast of India. As there was no regulation to control the fishery, there was a concern on decline in sea cucumber populations. In order to conserve the over-exploited stocks, the Ministry of Environment, Forestry and Climate Change, Government of India banned the fishery and trade of sea cucumbers by including them under Wild Life Protection Act 1972 since 2001. The enforcement of a blanket ban of sea cucumber fishing over the last 14 years might have helped in reviving their populations; at the same time, the ban would possibly had a social and economic impact on scores of people, who were dependent on the sea cucumber fishery. To understand the situation, the Bay of Bengal Large Marine Ecosystem (BOBLME) project approved a short term project to Central Marine Fisheries Research Institute (India). The project was intended to understand the sea cucumber stocks and implications of the ban on the livelihood of fishers in Palk Bay and Gulf of Mannar. The purpose of the project was also to suggest management options for conservation and sustainable use of sea cucumber resources

Status of sea cucumber resources and impact of fishing ban on the livelihood of fishers in Gulf of Mannar and Palk Bay

The sea cucumbers constitute an important part of non-fish income source for thousands of fishers along Gulf of Mannar and Palk Bay of south east coast of India. The fishery which is more than thousand years old was introduced by the Chinese stationed at Ramanathapuram, for preparing a dried sea cucumber product Beche-de-mer. The sea cucumber fishery in Gulf of Mannar and Palk Bay was artisanal in nature and consisted of fishermen who were good divers, the processors who acted as middlemen and the exporters. The sea cucumbers were chiefly collected by skin diving to a depth of 1.5 to 6.0 m in the shallow seas using nonmechanised country crafts. They were also caught as by-catch in trawlers locally known as Thallu madi (an indigenous modified trawler operating on wind power in shallow waters), besides the Chanku madi and Attai madi which were operated in deeper coastal waters

Spontaneous cecal perforation secondary to acute fulminant gastroenteritis: report of a rare case

Acute gastroenteritis and food poisoning are the two common diagnoses considered when two or more family members present with vomiting, diarrhea, and abdominal pain. Acute fulminant gastroenteritis is usually seen in immunocompromised patients and is associated with significant morbidity and mortality. We report a 15-year-old boy who presented with acute onset abdominal pain, vomiting, and diarrhea, along with three other family members. He developed abdominal distension and signs of hollow viscus perforation after 3 days; by that time he had developed  respiratory distress requiring ventilatory assistance. During laparotomy, a 1-cm cecal perforation with feculent peritoneal contamination was noted. Limited ileocolic resection and ileostomy was performed and ileostomy closure was carried out at 6 weeks. This case is being reported to highlight the unusual presentation of fulminant gastroenteritis, leading to spontaneous cecal perforation.Keywords: acute gastroenteritis, fulminant gastroenteritis, spontaneous cecal perforatio

An overview of beach morphodynamic classification along the beaches between Ovari and Kanyakumari, Southern Tamilnadu coast, India

Beach morphology relates the mutual adjustment between topography and fluid dynamics. The morphological makeup of beach systems is not accidental because the arrangement and association of forms occur in an organized contextual space and time. Since the classification derived by Wright and Short (1983) obtained from the analysis of the evolution in a number of Southern Tamilnadu beach sites, beach systems are comprehended in terms of three-dimensional morphodynamic models that include quantitative parameters (wave breaking height, sediment fall velocity, wave period and beach slope) and boundary conditions for definable form-processes association (e.g. presence or absence of bars as well as its type). This has lead to the classification of beaches into three main categories relating the beach state observations with the physical forcing (Short, 1999) dissipative, intermediate (from the intermediate-dissipative domain to the intermediate-reflective domain) and reflective modes. Morphodynamic classification of beach types was based on the equations of Wright & Short (1984) (Dimensionless fall velocity – Dean Parameter).Морфология берега отражает взаимное влияние топографии и динамики жидкости. При этом морфологическое строение береговых систем не является случайным, а определяется распределением и пространственно-временным взаимодействием береговых форм. Начиная с классификации, предложенной Райтом и Шортом (1983), основанной на анализе эволюции нескольких участков пляжа Южного берега Тамилнаду, пляжные системы рассматриваются в рамках трехмерных морфодинамических моделей, включающих количественные характеристики (высоту обрушения волн, скорость образования осадков, волновой период и уклон пляжа) и граничные условия для определенных взаимосвязей береговой динамики (т. е. наличие или отсутствие баров и их тип). Это привело к подразделению пляжей на три основные категории в соответствии с их поведением по отношению к внешним силам (Шорт, 1999) – рассеивающие, промежуточные (от промежуточно-рассеивающих до промежуточно-отражающих вариантов) и отражающие. Морфодинамическая классификация типов пляжей основана на уравнениях Райта и Шорта, 1984 (безразмерная скорость осадкообразования – параметр Дина).Морфологія берега відображає взаємний вплив топографії та динаміки рідини. При цьому морфологічна будова берегових систем не є випадковою, а визначається розподілом і просторово-часовою взаємодією берегових форм. Починаючи з класифікації, запропонованої Райтом та Шортом (1983), заснованої на аналізі еволюції декількох ділянок пляжу Південного берега Тамілнаду, пляжні системи розглядаються в рамках тривимірних морфодинамічних моделей, які включають кількісні характеристики (висоту обвалення хвиль, швидкість утворення опадів, хвильовий період та ухил пляжу) та граничні умови для певних взаємозв'язків берегової динаміки (тобто наявність або відсутність барів і їх тип). Це призвело до підрозділу пляжів на три основні категорії відповідно до їхньої поведінки відносно фізичних сил (Шорт, 1999) – розсіюючі, проміжні (від проміжно-розсіюючих до проміжно-відбиваючих варіантів) і відбиваючі. Морфодинамічна класифікація типів пляжів заснована на рівнянні Райта та Шорта, 1984 (безрозмірна швидкість осадоутворювання – параметр Діна)

An overview of beach morphodynamic classification along the beaches between Ovari and Kanyakumari, Southern Tamilnadu coast, India

Beach morphology relates the mutual adjustment between topography and fluid dynamics. The morphological makeup of beach systems is not accidental because the arrangement and association of forms occur in an organized contextual space and time. Since the classification derived by Wright and Short (1983) obtained from the analysis of the evolution in a number of Southern Tamilnadu beach sites, beach systems are comprehended in terms of three-dimensional morphodynamic models that include quantitative parameters (wave breaking height, sediment fall velocity, wave period and beach slope) and boundary conditions for definable form-processes association (e.g. presence or absence of bars as well as its type). This has lead to the classification of beaches into three main categories relating the beach state observations with the physical forcing (Short, 1999) dissipative, intermediate (from the intermediate-dissipative domain to the intermediate-reflective domain) and reflective modes. Morphodynamic classification of beach types was based on the equations of Wright & Short (1984) (Dimensionless fall velocity – Dean Parameter).Морфология берега отражает взаимное влияние топографии и динамики жидкости. При этом морфологическое строение береговых систем не является случайным, а определяется распределением и пространственно-временным взаимодействием береговых форм. Начиная с классификации, предложенной Райтом и Шортом (1983), основанной на анализе эволюции нескольких участков пляжа Южного берега Тамилнаду, пляжные системы рассматриваются в рамках трехмерных морфодинамических моделей, включающих количественные характеристики (высоту обрушения волн, скорость образования осадков, волновой период и уклон пляжа) и граничные условия для определенных взаимосвязей береговой динамики (т. е. наличие или отсутствие баров и их тип). Это привело к подразделению пляжей на три основные категории в соответствии с их поведением по отношению к внешним силам (Шорт, 1999) – рассеивающие, промежуточные (от промежуточно-рассеивающих до промежуточно-отражающих вариантов) и отражающие. Морфодинамическая классификация типов пляжей основана на уравнениях Райта и Шорта, 1984 (безразмерная скорость осадкообразования – параметр Дина).Морфологія берега відображає взаємний вплив топографії та динаміки рідини. При цьому морфологічна будова берегових систем не є випадковою, а визначається розподілом і просторово-часовою взаємодією берегових форм. Починаючи з класифікації, запропонованої Райтом та Шортом (1983), заснованої на аналізі еволюції декількох ділянок пляжу Південного берега Тамілнаду, пляжні системи розглядаються в рамках тривимірних морфодинамічних моделей, які включають кількісні характеристики (висоту обвалення хвиль, швидкість утворення опадів, хвильовий період та ухил пляжу) та граничні умови для певних взаємозв'язків берегової динаміки (тобто наявність або відсутність барів і їх тип). Це призвело до підрозділу пляжів на три основні категорії відповідно до їхньої поведінки відносно фізичних сил (Шорт, 1999) – розсіюючі, проміжні (від проміжно-розсіюючих до проміжно-відбиваючих варіантів) і відбиваючі. Морфодинамічна класифікація типів пляжів заснована на рівнянні Райта та Шорта, 1984 (безрозмірна швидкість осадоутворювання – параметр Діна)

Socio-economic Impact of Sea cucumber Conservation in Palk Bay and Gulf of Mannar Region of Tamil Nadu

Sea cucumber is one of the important marine resources and its fishery is a source of income to coastal communities. It contributes to poverty alleviation for more than three million fishers globally. The indiscriminate exploitation for this lucrative trade would have resulted in overexploitation leading to endangering of the species in the wild. The blanket ban on collection and trade on sea cucumber in India was imposed during 2002 by listing this organism in Schedule I category of the Wildlife Protection Act of 1972. The present study aimed to analyze and understand the impacts of listing on the conservation of sea cucumber resources in the wild and on the livelihood of the fishers. The enforcement of ban has affected the livelihood of thousands of fishermen families involved in sea cucumber fishing. There was a loss in their regular income as they were not able to do other fishing activities due to lack of capacity for investment. The fishers opined that they want the ban to be lifted at least for a few commercially important species. They are agreeable to follow regulatory measures like size restriction on fishing of undersized sea cucumbers, exclusion of breeding stock from fishing, restraining from use of destructive gears, exclusive fishing ban period for stock replenishment, sea ranching and stock enhancement programmes for conservation of the resource through participatory co-management principles

Spatial variations in the population characteristics of sea cucumber resources in Gulf of Mannar and Palk Bay, south-east coast of India

The lack of data on population abundance, biomass and basic biological parameters of most of the sea cucumber species from Indian waters is a fundamental barrier to impose suitable management measures on these resources. A study was conducted to ascertain the sea cucumber population characteristics in two geographically distinct ecosystems (Gulf of Mannar and Palk Bay) along the south-east coast of India. The stock status of sea cucumber population was assessed both by trawl and dive surveys following standard methods on a random basis. Comparatively, a higher average density of total sea cucumbers was estimated in the Gulf of Mannar (3853±152.3 nos. ha-1) than in Palk Bay (2428.5±504.6 nos. ha-1). The species diversity, average length and weight of individual species were also higher in the Gulf of Mannar. The present study indicated significant variation in status and structure of sea cucumber resources in these two ecosystems. Hence the study warrants the emphasis of ecosystem-based management in formulating conservation measures of these resources in Indian waters

Groundwater shapes sediment biogeochemistry and microbial diversity in a submerged Great Lake sinkhole

For a large part of earth’s history, cyanobacterial mats thrived in lowâ oxygen conditions, yet our understanding of their ecological functioning is limited. Extant cyanobacterial mats provide windows into the putative functioning of ancient ecosystems, and they continue to mediate biogeochemical transformations and nutrient transport across the sedimentâ water interface in modern ecosystems. The structure and function of benthic mats are shaped by biogeochemical processes in underlying sediments. A modern cyanobacterial mat system in a submerged sinkhole of Lake Huron (LH) provides a unique opportunity to explore such sedimentâ mat interactions. In the Middle Island Sinkhole (MIS), seeping groundwater establishes a lowâ oxygen, sulfidic environment in which a microbial mat dominated by Phormidium and Planktothrix that is capable of both anoxygenic and oxygenic photosynthesis, as well as chemosynthesis, thrives. We explored the coupled microbial community composition and biogeochemical functioning of organicâ rich, sulfidic sediments underlying the surface mat. Microbial communities were diverse and vertically stratified to 12 cm sediment depth. In contrast to previous studies, which used lowâ throughput or shotgun metagenomic approaches, our highâ throughput 16S rRNA gene sequencing approach revealed extensive diversity. This diversity was present within microbial groups, including putative sulfateâ reducing taxa of Deltaproteobacteria, some of which exhibited differential abundance patterns in the mats and with depth in the underlying sediments. The biological and geochemical conditions in the MIS were distinctly different from those in typical LH sediments of comparable depth. We found evidence for active cycling of sulfur, methane, and nutrients leading to high concentrations of sulfide, ammonium, and phosphorus in sediments underlying cyanobacterial mats. Indicators of nutrient availability were significantly related to MIS microbial community composition, while LH communities were also shaped by indicators of subsurface groundwater influence. These results show that interactions between the mats and sediments are crucial for sustaining this hot spot of biological diversity and biogeochemical cycling.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136330/1/gbi12215_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136330/2/gbi12215.pd

Evidence for hydrogen oxidation and metabolic plasticity in widespread deep-sea sulfur-oxidizing bacteria

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 110 (2013): 330-335, doi:10.1073/pnas.1215340110.Hydrothermal vents are a well-known source of energy that powers chemosynthesis in the deep sea. Recent work suggests that microbial chemosynthesis is also surprisingly pervasive throughout the dark oceans, serving as a significant CO2 sink even at sites far-removed from vents. Ammonia and sulfur have been identified as potential electron donors for this chemosynthesis, but they do not fully account for measured rates of dark primary production in the pelagic water column. Here we use metagenomic and metatranscriptomic analyses to show that deep-sea populations of the SUP05 group of uncultured sulfur oxidizing Gammaproteobacteria, which are abundant in widespread and diverse marine environments, contain and highly express genes encoding group 1 Ni-Fe hydrogenase enzymes for H2 oxidation. Reconstruction of near-complete genomes of two co-occurring SUP05 populations in hydrothermal plumes and deep waters of the Gulf of California enabled detailed population-specific metatranscriptomic analyses, revealing dynamic patterns of gene content and transcript abundance. SUP05 transcripts for genes involved in H2 and sulfur oxidation are most abundant in hydrothermal plumes where these electron donors are enriched. In contrast, a second hydrogenase has more abundant transcripts in background deep sea samples. Coupled with results from a bioenergetic model that suggest that H2 oxidation can contribute significantly to the SUP05 energy budget, these findings reveal the potential importance of H2 as a key energy source in the deep ocean. This study also highlights the genomic plasticity of SUP05, which enables this widely distributed group to optimize its energy metabolism (electron donor and acceptor) to local geochemical conditions.This project is funded in part by the Gordon and Betty Moore Foundation and the National Science Foundation (OCE 1029242)

Ultrafast all-optical switching in a silicon-nanocrystal-based silicon slot waveguide at telecom wavelengths

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technica editing by the publisher. To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.htmlWe demonstrate experimentally all-optical switching on a silicon chip at telecom wavelengths. The switching device comprises a compact ring resonator formed by horizontal silicon slot waveguides filled with highly nonlinear silicon nanocrystals in silica. When pumping at power levels about 100 mW using 10 ps pulses, more than 50% modulation depth is observed at the switch output. The switch performs about I order of magnitude faster than previous approaches on silicon and is fully fabricated using complementary metal oxide semiconductor technologies.The work was financially supported by the EU through project PHOLOGIC (FP6-IST-NMP-017158).Martínez Abietar, AJ.; Blasco Solbes, J.; Sanchis Kilders, P.; Galan Conejos, JV.; García-Rupérez, J.; Jordana, E.; Gautier, P.... (2010). Ultrafast all-optical switching in a silicon-nanocrystal-based silicon slot waveguide at telecom wavelengths. Nano Letters. 10(4):1506-1511. doi:10.1021/nl9041017S1506151110