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D. Pandiaraja

Bio: D. Pandiaraja is an academic researcher from Thiagarajar College. The author has contributed to research in topics: Kappaphycus alvarezii & Water quality. The author has an hindex of 4, co-authored 14 publications receiving 145 citations.

Papers
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Journal Article
TL;DR: The findings disprove all arguments and misapprehensions reported earlier about this species as coral-friendly and as a safe candidate for mariculture for the production of carrageenan under wild conditions in the Gulf of Mannar.
Abstract: Kappaphycus alvarezii (Doty) Doty (Rhodophyta: Solieriaceae) is a Philippine-derived macroalga introduced into the Gulf of Mannar Marine Biosphere Reserve, South India for mariculture in 2000. Here we report its bioinvasion on branching corals (Acropora sp.) in the Kurusadai Island. Qualitative data collected using underwater photography clearly indicated its invasion and establishment on live and dead corals as well as coral rubbles and pavements. It specifically invaded Acropora sp. as monospecific beds with extraordinary phenotypic plasticity in the form of thallus, thickness of its major axis and lateral branching. It shows remarkable shadowing and smothering effects over the coral colonies. The primary and secondary branches are much reduced in the invaded algal colonies. Quantitative data on its live cover on corals and biomass production are also reported. These observations are discussed with available limited information on bioinvasion of K. alvarezii on coral reefs. Our findings disprove all arguments and misapprehensions reported earlier about this species as coral-friendly and as a safe candidate for mariculture for the production of carrageenan under wild conditions in the Gulf of Mannar. Our observations underscore the need for urgent reconsideration of its cultivation in a biologically diverse ecosystem, the Gulf of Mannar.

83 citations

Journal ArticleDOI
TL;DR: It is shown here that generalized KdV equations are characterized by Euler–Painleve equations, and a plethora of exact, explicit similarity solutions are found which include inverse of hypergeometric function.

23 citations

Journal Article
TL;DR: The unsuccessful attempt and negative impact of the eradication programme of K. alvarezii, a commercially important red alga being intentionally introduced in marine waters worldwide for the production of kappa carrageenan, is detailed.
Abstract: Kappaphycus alvarezii is a commercially important red alga being intentionally introduced in marine waters worldwide for the production of kappa carrageenan. Its introduction into the Gulf of Mannar Biosphere Reserve during the 1990s and its subsequent escape from cultivation sites have paved the way for its invasion into the coral reef ecosystem of Kurusadai Island. Since the report of its invasion in 2008, removal of K. alvarezii from the reefs has been started by means of manual removal (hand plucking). This article details the unsuccessful attempt and negative impact of the eradication programme. Regrowth of K. alvarezii from removal points and drifting broken fragments resulting during removal have led to further establishment in the reef environment. Variation in the morphology of K. alvarezii populations after their removal has been observed. A significant reduction in the cover of coral and native algae due to the increase in abundance of K. alvarezii was evident from the study. The need for immediate scientific control measures to eradicate the invasive alga is discussed.

22 citations

Journal ArticleDOI
TL;DR: Chandrasekaran et al. as discussed by the authors reported that K. alvarezii is capable of invading species of non-branching corals as reported in Hawaii for Montipora capitata and Porites compressa.
Abstract: The Gulf of Mannar (GoM), India, includes 21 coral islands (8 N; 79 E), covers an area of 10,500 sq. km and supports 94 species of corals belonging to 37 genera. Kappaphycus alvarezii, a Philippine-derived rhodophyte, has been introduced into the GoM for commercial cultivation in 2002. The ecological threat from this invasive alga to coral species in GoM was first indicated by Pereira and Verlecar (2005). After 6 years of its introduction, its bioinvasion on branching corals (Acropora species) in the Kurusadai island (9 15¢N; 79 12¢E) of GoM was reported in 2008 (Chandrasekaran et al. 2008). Consequently, commercial cultivation of this invasive alga was prohibited. A mechanical removal programme started in 2009 by the State Government at the invaded site could not deliver expected results. Thus, this alga enjoys a freedom of unrestricted spread and aggressive growth in GoM, predominantly on species of Acropora. On 28 April 2010, during our routine sampling visit at Kurusadai Island, unusual appearance of K. alvarezii, on the cup coral, Turbinaria sp. was observed (Fig. 1a). The space between the plates of Turbinaria sp. provides an ideal settlement surface for K. alvarezii, which protect them from the wave action and favour the profuse growth of secondary branches of K. alvarezii between the plates (Fig. 1b) in contrast to the smothering effect on the top of coral plates (Fig. 1c). This finding shows that K. alvarezii is capable of invading species of nonbranching corals as reported in Hawaii for Montipora capitata and Porites compressa (Conklin and Smith 2005). Therefore, perhaps this is the first report from India on bioinvasion of K. alvarezii on a non-branching coral (Turbinaria sp.) in the GoM.

18 citations

Journal ArticleDOI
TL;DR: Ali and Futehally as discussed by the authors have shown that birds are ideal bioindicators and useful models for studying a variety of environmental problems and they are often common denizens of the ecosystem and they have been considere3d as indicator species of inhabited areas.
Abstract: Avian community is an important component of an ecosystem. Birds are playing a major role in the environment as pollinators. Birds might live on this earth even if there were no human beings, but human beings cannot live without bird. Birds are an integral part of the whole system of life on this earth (Ali and Futehally, 2008). Birds are ideal bioindicators and useful models for studying a variety of environmental problems (Newton and Anim, 1995). They are often common denizens of the ecosystem and they have been considere3d as indicator species of inhabited areas (Blair, 1999). Many species of birds respond to small changes in habitat structure and composition, therefore they serve as good indicators of changes in the environment (Robert, 1932).

2 citations


Cited by
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Journal ArticleDOI
TL;DR: To the best of our knowledge, there is only one application of mathematical modelling to face recognition as mentioned in this paper, and it is a face recognition problem that scarcely clamoured for attention before the computer age but, having surfaced, has attracted the attention of some fine minds.
Abstract: to be done in this area. Face recognition is a problem that scarcely clamoured for attention before the computer age but, having surfaced, has involved a wide range of techniques and has attracted the attention of some fine minds (David Mumford was a Fields Medallist in 1974). This singular application of mathematical modelling to a messy applied problem of obvious utility and importance but with no unique solution is a pretty one to share with students: perhaps, returning to the source of our opening quotation, we may invert Duncan's earlier observation, 'There is an art to find the mind's construction in the face!'.

3,015 citations

Book ChapterDOI
01 Jan 2011
TL;DR: Algal-dominated tropical reefs may represent alternative stable states that are resistant to shifts back to coral domination due to the strength and persistence of ecological processes that stabilize the algal state.
Abstract: Benthic macroalgae, or “seaweeds,” are key members of coral reef communities that provide vital ecological functions such as stabilization of reef structure, production of tropical sands, nutrient retention and recycling, primary production, and trophic support. Macroalgae of an astonishing range of diversity, abundance, and morphological form provide these equally diverse ecological functions. Marine macroalgae are a functional rather than phylogenetic group comprised of members from two Kingdoms and at least four major Phyla. Structurally, coral reef macroalgae range from simple chains of prokaryotic cells to upright vine-like rockweeds with complex internal structures analogous to vascular plants. There is abundant evidence that the historical state of coral reef algal communities was dominance by encrusting and turf-forming macroalgae, yet over the last few decades upright and more fleshy macroalgae have proliferated across all areas and zones of reefs with increasing frequency and abundance. Ecological processes that sustain these shifts from coral- to algal-dominated tropical reefs include increases in open suitable substrate due to coral mortality, anthropogenic increases in nutrient supply, reductions in herbivory due to disease and overfishing, and the proliferation of algae with chemical defenses against herbivory. These shifts are likely to be accelerated and the algal state stabilized by the impacts of invasive species and climate change. Thus, algal-dominated tropical reefs may represent alternative stable states that are resistant to shifts back to coral domination due to the strength and persistence of ecological processes that stabilize the algal state.

124 citations

Journal ArticleDOI
TL;DR: The present review focuses on Kappaphycus farming techniques through the application of biotechnological tools, ecological interactions with endemic ecosystems, future K. alvarezii farming potentials in Asia, Africa, and the Pacific, andThe challenges for prospective farmers, i.e., low raw material market value, diseases, grazing, etc.
Abstract: Commercial cultivation of the red alga Kappaphycus alvarezii (Doty) Doty has been satisfying the demand of the carrageenan industry for more than 40 years. For the past four decades, this species has been globally introduced to many maritime countries for experimental and commercial cultivation as a sustainable alternate livelihood for coastal villagers. Accompanying the introduction is an increasing concern over the species effects on the biodiversity of endemic ecosystems. The introductions of non-endemic cultivars have resulted in the adaptation of quarantine procedures to minimize bioinvasions of additional invasive species. The present review focuses on Kappaphycus farming techniques through the application of biotechnological tools, ecological interactions with endemic ecosystems, future K. alvarezii farming potentials in Asia, Africa, and the Pacific, and the challenges for prospective farmers, i.e., low raw material market value, diseases, grazing, etc. The introduction of Kappaphycus cultivation to tropical countries will continue due to the high production values realized, coastal villages searching for alternative livelihoods, and the increased global industrial demand for carrageenan.

106 citations

Journal ArticleDOI
TL;DR: A meta-analysis reveals that the presence of exotic species has a modest but significantly negative impact on the ecological properties of native marine communities and identifies the exotic species that exert the most harmful effects.
Abstract: Exotic species are a growing global ecological threat; however, their overall effects are insufficiently understood. While some exotic species are implicated in many species extinctions, others can provide benefits to the recipient communities. Here, we performed a meta-analysis to quantify and synthesize the ecological effects of 76 exotic marine species (about 6% of the listed exotics) on ten variables in marine communities. These species caused an overall significant, but modest in magnitude (as indicated by a mean effect size of g < 0.2), decrease in ecological variables. Marine primary producers and predators were the most disruptive trophic groups of the exotic species. Approximately 10% (that is, 2 out of 19) of the exotic species assessed in at least three independent studies had significant impacts on native species. Separating the innocuous from the disruptive exotic species provides a basis for triage efforts to control the marine exotic species that have the most impact, thereby helping to meet Aichi Biodiversity Target 9 of the Convention on Biological Diversity.

106 citations

Journal ArticleDOI
TL;DR: Neighbor-joining analyses were congruent in their separation of Eucheuma and Kappaphycus, and the resulting clusters were consistent with those revealed for global comparisons with the mitochondrial cox2-3 spacer and GenBank data.
Abstract: A paucity of diagnostic morphological characters for identification and high morphological plasticity within the genera Eucheuma and Kappaphycus has led to confusion about the distributions and spread of three introduced eucheumoid species in Hawaii. Entities previously identified as E. denticulatum, K. alvarezii, and K. striatum have had profound negative effects on Oahu’s coral reef ecosystems. The use of molecular tools to aid identification of algal species has been promising in other morphologically challenging taxa. We used three molecular markers (partial nuclear 28S rRNA, partial plastid 23S rRNA, and mitochondrial 5′ COI) and followed a DNA barcoding-like approach to identify Eucheuma and Kappaphycus samples from Hawaii. Neighbor-joining analyses were congruent in their separation of Eucheuma and Kappaphycus, and the resulting clusters were consistent with those revealed for global comparisons with the mitochondrial cox2-3 spacer and GenBank data. Based on these results, new insights were revealed into the distribution of these groups in Hawaii.

92 citations