共查询到20条相似文献,搜索用时 31 毫秒
1.
The excessive and unsustainable exploitation of our marine resources has led to the promotion of marine reserves as a fisheries management tool. Marine reserves, areas in which fishing is restricted or prohibited, can offer opportunities for the recovery of exploited stock and fishery enhancement. This study examines the impact of the creation of marine protected areas, from both economic and biological perspectives. The consequences of reserve establishment on the long-run equilibrium fish biomass and fishery catch levels are evaluated. We include reserve size as control variable to maximize catch at equilibrium. A continuous time model is used to simulate the effects of reserve size on fishing catch. Fish movements between the sites is assumed to take place at a faster time scale than the variation of the stock and the change of the fleet size. We take advantage of these two time scales to derive a reduced model governing the dynamics of the total fish stock and the fishing effort. Simulation results suggest that the establishment of a protected marine reserve will always lead to an increase in total fish biomass, an optimal size of a marine reserve can achieve to maximize the catch at equilibrium. 相似文献
2.
《Journal of Molecular Catalysis .B, Enzymatic》2010,67(3-4):241-256
This review is intended to give an account of the knowledge about known enzymes of marine origin described in literature thus stimulating future applications in biocatalysis that these biocatalysts can offer to a large spectra of end-users. The uniqueness of marine biocatalysts is not only based on habitat-related properties such as salt tolerance, hyperthermostability, barophilicity, cold adaptivity, etc. A marine enzyme in fact may carry more, e.g. novel chemical and stereochemical properties. This “chemical biodiversity” increases interest in this field; substrate specificity and affinity are evolved properties linked to the metabolic functions of the enzymes and to ecological asset related to the natural source and this is an important aspect in the bioprospecting for new biocatalysts. The importance of all examples reported should be sufficient to trigger the attention of the biocatalytically oriented scientific community towards marine environment as source of biocatalysts, and this could in turn enhance both new discovery and improvement of marine enzymes. 相似文献
3.
The use of marine parasites as non-intrusive natural tags of their hosts was first broadly applied in fisheries science in the 1940s. Both micro- and macroparasites have been used to assess the status of current stocks of several commercially exploited species of marine animals. Here, Santiago Pascual and Eric Hochberg offer a brief comment on marine parasite tags as a stock assessment methodology, with special reference to cephalopod hosts. 相似文献
4.
JAMES A. BOHNSACK 《Austral ecology》1998,23(3):298-304
Abstract Establishing permanent ‘no-take’ marine reserves, areas where fishing and all other extractive activities are prohibited, is an attractive but under-utilized tool for fisheries management. Marine reserves could potentially deal with many fishery problems that are not effectively addressed by other traditional management measures; they also offer numerous social, economic, and scientific benefits not directly related to fisheries. Limited but growing research has shown beneficial biological and economic effects of marine reserves on fisheries. More research is needed, especially at larger scales, to determine the ideal marine reserve size, number and location necessary to optimize fisheries productivity and resource conservation. Sufficient evidence is available to justify the expanded use of marine reserves in an adaptive approach to fisheries management. 相似文献
5.
Why are there so few evolutionary transitions between aquatic and terrestrial ecosystems? 总被引:3,自引:0,他引:3
GEERAT J. VERMEIJ ROBERT DUDLEY 《Biological journal of the Linnean Society. Linnean Society of London》2000,70(4):541-554
Insects and flowering plants have rarely invaded the sea. Explanations for this have traditionally centered on the unique shortcomings of these groups in the marine environment. We show, however, that transitions among terrestrial, freshwater, and marine environments are infrequent in all major plant and animal clades except tetrapod vertebrates. In general, well-adapted incumbents are at a competitive advantage over would-be invaders from a physically different habitat. Data on the times and places of transition are consistent with our contention that evolutionary transitions among physically different environments are most likely when incumbents in the recipient environment exist in a regime of low-intensity competition and prcdation, as in terrestrial communities of the middle Paleozoic or the land biotas of oceanic islands. Freshwater environments, in which inferred intensities of predation are lower than in most marine and terrestrial environments, offer less biotic resistance to invaders than do communities in the sea or on land. Most invaders respond to novel physical circumstances by shutting down their metabolic machinery, and therefore add to their subordinate status as competitors with active incumbents. Only active tetrapods, particularly those with high and endothermically driven rates of metabolism, have successfully overcome this limitation. 相似文献
6.
Serena Lucrezi Martina Milanese Roberto Danovaro Carlo Cerrano 《Journal of biological education》2018,52(4):391-405
Marine biology is an increasingly preferred study major and career among youth. This is particularly the case of countries with extensive coastlines, such as Italy. In order to understand what exactly is fuelling this trend, and whether it culminates in the successful absorption of marine biologists as valued workforce by society, this study investigated the motivations, satisfaction and career goals of marine biology undergraduate students in Italy. Although it was expected that scientific literacy in formal education plays an important role in motivating marine biology students, the results showed that intrinsic motivations and informal education play a more crucial role. The students consider realistic career options, although these imply having to leave the country. The results of this study were used to make recommendations on the importance of marine and ocean literacy in the formal educational system in Italy, and the general improvement of scientific literacy in formal school education. Recommendations were also made on the potential improvements that can be made by higher education institutions, to better equip marine biologists with the skills required by emerging sectors in society. Finally, considerations were made regarding the dimensioning of supply, offer and marketing of employment opportunities for marine biologists in Italy. 相似文献
7.
Osovitz CJ Hofmann GE 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,147(4):821-827
A new approach toward understanding marine ecosystems has emerged through the integration of ecological physiology and macroecology. This multidisciplinary approach, titled here marine macrophysiology, facilitates unique insight into the foundation of macro-scale ecological patterns, such as biogeographic distributions, via examination of functional attributes of marine organisms across large spatial scales. For example, these broad-scale physiological inquiries confer the ability to directly assess the abundant-center hypothesis (aka Brown's principle) which proposes that species have decreased performance toward their range edges. By extension, the marine macrophysiological perspective also stands to clarify our understanding of more complex macro-scale phenomena such as biological invasions, the design of marine protected areas, and species' responses to global climate change. In this article, we review recent marine macrophysiology research and offer insights into future directions for this emerging field. 相似文献
8.
Molecular Phylogenetic Positions and Ultrastructure of Marine Gregarines (Apicomplexa) Cuspisella ishikariensis n. gen., n. sp. and Loxomorpha cf. harmothoe from Western Pacific scaleworms (Polynoidae)
下载免费PDF全文
![点击此处可从《The Journal of eukaryotic microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Davis Iritani Takeo Horiguchi Kevin C. Wakeman 《The Journal of eukaryotic microbiology》2018,65(5):637-647
Marine gregarines are unicellular parasites of invertebrates commonly found infecting the intestine and coelomic spaces of their hosts. Situated at the base of the apicomplexan tree, marine gregarines offer an opportunity to explore the earliest stages of apicomplexan evolution. Classification of marine gregarines is often based on the morphological traits of the conspicuous feeding stages (trophozoites) in combination with host affiliation and molecular phylogenetic data. Morphological characters of other life stages such as the spore are also used to inform taxonomy when such stages can be found. The reconstruction of gregarine evolutionary history is challenging, due to high levels of intraspecific variation of morphological characters combined with relatively few traits that are taxonomically unambiguous. The current study combined morphological data with a phylogenetic analysis of small subunit rDNA sequences to describe and establish a new genus and species (Cuspisella ishikariensis n. gen., n. sp.) of marine gregarine isolated from the intestine of a polynoid host (Lepidonotus helotypus) collected from Hokkaido, Japan. This new species possesses a set of unusual morphological traits including a spiked attachment apparatus and sits on a long branch on the molecular phylogeny. Furthermore, this study establishes a molecular phylogenetic position for Loxomorpha cf. harmothoe, a previously described marine gregarine, and reveals a new group of gregarines that infect polynoid hosts. 相似文献
9.
公众参与海洋生态修复对我国海洋环境保护与生态安全具有重要意义。利用单边界二分式引导技术评估青岛市居民海洋生态修复偏好,并从内疚和抵抗心理两方面就社会总体偏差与同伴效应对修复偏好的影响机理进行分析,为政府激发公众参与海洋生态修复的积极性提供理论依据与技术指导。结果表明:①青岛市居民平均每年愿意为海洋生态修复捐赠184.386元,考虑属性重要程度结果表明生物数量的改善可显著提高公众海洋生态修复支付意愿,而公众对改善海水水质和海岸环境并未表现出显著差异性偏好。②社会总体偏差和同伴效应均对公众海洋生态修复支付意愿表现出显著正向影响。③社会总体偏差和同伴效应可通过激发受访者的内疚感提高生态修复支付意愿,但也会导致抵抗心理抑制参与积极性;主观规范正向调节社会总体偏差和同伴效应对支付意愿的影响。研究揭示了公众在海洋生态修复中的偏好和竞争性心理对陈述偏好的影响,可为促进公众参与海洋生态修复和提高海洋环境资源价值评估准确性提供参考。 相似文献
10.
Franck Lejzerowicz Philippe Esling Wojciech Majewski Witold Szczuciński Johan Decelle Cyril Obadia Pedro Martinez Arbizu Jan Pawlowski 《Biology letters》2013,9(4)
Deep-sea subsurface sediments are the most important archives of marine biodiversity. Until now, these archives were studied mainly using the microfossil record, disregarding large amounts of DNA accumulated on the deep-sea floor. Accessing ancient DNA (aDNA) molecules preserved down-core would offer unique insights into the history of marine biodiversity, including both fossilized and non-fossilized taxa. Here, we recover aDNA of eukaryotic origin across four cores collected at abyssal depths in the South Atlantic, in up to 32.5 thousand-year-old sediment layers. Our study focuses on Foraminifera and Radiolaria, two major groups of marine microfossils also comprising diverse non-fossilized taxa. We describe their assemblages in down-core sediment layers applying both micropalaeontological and environmental DNA sequencing approaches. Short fragments of the foraminiferal and radiolarian small subunit rRNA gene recovered from sedimentary DNA extracts provide evidence that eukaryotic aDNA is preserved in deep-sea sediments encompassing the last glacial maximum. Most aDNA were assigned to non-fossilized taxa that also dominate in molecular studies of modern environments. Our study reveals the potential of aDNA to better document the evolution of past marine ecosystems and opens new horizons for the development of deep-sea palaeogenomics. 相似文献
11.
Compounds from the sea with actions on the cardiovascular and central nervous systems 总被引:2,自引:0,他引:2
P N Kaul 《Federation proceedings》1981,40(1):10-14
Recent efforts at probing into the oceans have produced evidence that marine invertebrates such as gorgonians and sponges offer a rich reserve of pharmacologically interesting molecules. Our investigations indicate that it is possible to obtain novel compounds both structurally and pharmacologically. For example, autonomium from a sponge is a dual adrenergic combined with cholinergic molecule, with a structure that may be considered a hybrid between a catecholamine and choline. Various terpenoids and indole derivatives from marine organisms have been found to possess activities on the central nervous system. Several peptides from sea anemones are cardiotonic and have initiated a new concept of chemical structure believed to be associated with cardiac activity. A number of closely related halogenated cyclic ethers are good inhibitors of drug metabolism. Thus, there seems little doubt that the sea warrants an extensive chemical and pharmacological examination. 相似文献
12.
Abstract Over the past ten years, federal management authorities for ocean uses and resources have become excessively compartmentalized and complex. In the interest of evaluating the need for a better articulated and organized national ocean program, this article examines the concept of ocean management. It attempts to portray an analytical review approach for assessing current ocean uses and management strategies. It explores the implications of ocean management as they impinge on the federal government's role in an organization for the marine environment. The concept of ocean management is reviewed from three perspectives: (1) an analysis of current conflicts among uses competing for scarce ocean resources; (2) an evaluation of existing programs which are designed to integrate other marine authorities; and (3) a survey of existing legal and administrative authorities that pertain to the marine environment. In light of these perspectives, the authors examine approaches that have been suggested for revising our ocean management system and offer recommendations toward this end. 相似文献
13.
Panchanathan Manivasagan Subramaniyan Bharathiraja Madhappan Santha Moorthy Sudip Mondal Hansu Seo Kang Dae Lee 《Critical reviews in biotechnology》2018,38(5):745-761
In recent years, marine natural pigments have emerged as a powerful alternative in the various fields of food, cosmetic, and pharmaceutical industries because of their excellent biocompatibility, bioavailability, safety, and stability. Marine organisms are recognized as a rich source of natural pigments such as chlorophylls, carotenoids, and phycobiliproteins. Numerous studies have shown that marine natural pigments have considerable medicinal potential and promising applications in human health. In this review, we summarize the marine natural pigments as potential sources for therapeutic applications, including: antioxidant, anticancer, antiangiogenic, anti-obesity, anti-inflammatory activities, drug delivery, photothermal therapy (PTT), photodynamic therapy (PDT), photoacoustic imaging (PAI), and wound healing. Marine natural pigments will offer a better platform for future theranostic applications. 相似文献
14.
Jonathon P. Schuldt Katherine A. McComas Sahara E. Byrne 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2016,371(1689)
As anthropogenic stressors threaten the health of marine ecosystems, there is a need to better understand how the public processes and responds to information about ocean health. Recent studies of public perceptions about ocean issues report high concern but limited knowledge, prompting calls for information campaigns to mobilize public support for ocean restoration policy. Drawing on the literature from communication, psychology and related social science disciplines, we consider a set of social-cognitive challenges that researchers and advocates are likely to encounter when communicating with the public about ocean health and emerging marine diseases—namely, the psychological distance at which ocean issues are construed, the unfamiliarity of aquatic systems to many members of the public and the potential for marine health issues to be interpreted through politicized schemas that encourage motivated reasoning over the dispassionate consideration of scientific evidence. We offer theory-based strategies to help public outreach efforts address these challenges and present data from a recent experiment exploring the role of message framing (emphasizing the public health or environmental consequences of marine disease) in shaping public support for environmental policy. 相似文献
15.
16.
Anastasia Chatzimentor Aggeliki Doxa Stelios Katsanevakis Antonios D. Mazaris 《Global Change Biology》2023,29(7):1809-1821
Rapid anthropogenic climate change is driving threatened biodiversity one step closer to extinction. Effects on native biodiversity are determined by an interplay between species' exposure to climate change and their specific ecological and life-history characteristics that render them even more susceptible. Impacts on biodiversity have already been reported, however, a systematic risk evaluation of threatened marine populations is lacking. Here, we employ a trait-based approach to assess the risk of 90 threatened marine Mediterranean species to climate change, combining species' exposure to increased sea temperature and intrinsic vulnerability. One-quarter of the threatened marine biodiversity of the Mediterranean Sea is predicted to be under elevated levels of climate risk, with various traits identified as key vulnerability traits. High-risk taxa including sea turtles, marine mammals, Anthozoa and Chondrichthyes are highlighted. Climate risk, vulnerability and exposure hotspots are distributed along the Western Mediterranean, Alboran, Aegean, and Adriatic Seas. At each Mediterranean marine ecoregion, 21%–31% of their threatened species have high climate risk. All Mediterranean marine protected areas host threatened species with high risk to climate change, with 90% having a minimum of 4 up to 19 species of high climate risk, making the objective of a climate-smart conservation strategy a crucial task for immediate planning and action. Our findings aspire to offer new insights for systematic, spatially strategic planning and prioritization of vulnerable marine life in the face of accelerating climate change. 相似文献
17.
Marine species offer a tremendous diversity of life histories, physiologies, genetics, behaviors, and biologies, reflecting myriad adaptations to the water environment. Historically, marine vertebrates, particularly fish, have played significant roles in a wide range of disciplines, including environmental toxicology, genetics, developmental biology, and physiology, among others. Much still remains to be learned from these animals, and there is a growing need for new marine models. Models for expression of marine animal genes have been limited to heterologous expression systems. While there is still a great deal to gain from heterologous expression systems, the interactions of genes with one another can best be determined in homologous expression systems where appropriate interactions are possible. This has become particularly important with the development of functional genomics in marine models. These homologous gene expression systems will be key to the use of functional genomics for marine animal molecular physiology and toxicology. 相似文献
18.
DNA Microarrays for Identifying Fishes 总被引:2,自引:1,他引:1
Kochzius M Nölte M Weber H Silkenbeumer N Hjörleifsdottir S Hreggvidsson GO Marteinsson V Kappel K Planes S Tinti F Magoulas A Garcia Vazquez E Turan C Hervet C Campo Falgueras D Antoniou A Landi M Blohm D 《Marine biotechnology (New York, N.Y.)》2008,10(2):207-217
In many cases marine organisms and especially their diverse developmental stages are difficult to identify by morphological characters. DNA-based identification methods offer an analytically powerful addition or even an alternative. In this study, a DNA microarray has been developed to be able to investigate its potential as a tool for the identification of fish species from European seas based on mitochondrial 16S rDNA sequences. Eleven commercially important fish species were selected for a first prototype. Oligonucleotide probes were designed based on the 16S rDNA sequences obtained from 230 individuals of 27 fish species. In addition, more than 1200 sequences of 380 species served as sequence background against which the specificity of the probes was tested in silico. Single target hybridisations with Cy5-labelled, PCR-amplified 16S rDNA fragments from each of the 11 species on microarrays containing the complete set of probes confirmed their suitability. True-positive, fluorescence signals obtained were at least one order of magnitude stronger than false-positive cross-hybridisations. Single nontarget hybridisations resulted in cross-hybridisation signals at approximately 27% of the cases tested, but all of them were at least one order of magnitude lower than true-positive signals. This study demonstrates that the 16S rDNA gene is suitable for designing oligonucleotide probes, which can be used to differentiate 11 fish species. These data are a solid basis for the second step to create a "Fish Chip" for approximately 50 fish species relevant in marine environmental and fisheries research, as well as control of fisheries products. 相似文献
19.
Yan-Hua Hou Song Qin You-Xun Li Fu-Chao Li Huan-Zhang Xia Fang-Qing Zhao 《World journal of microbiology & biotechnology》2006,22(5):525-529
Summary Allophycocyanin is one of the most important marine active peptides. Previous studies suggested that recombinant allophycocyanin
(rAPC) could remarkably inhibit the S-180 carcinoma in mice, indicating its potential pharmaceutical uses. Based on intergeneric
conjugal transfer, heterologous expression of rAPC was first achieved in marine Streptomyces sp. isolate M097 through inserting the apc gene into the thiostrepton-induced vector pIJ8600. The transformation frequency for this system was approximately 10−4 exconjugants/recipient. In the transformed Streptomyces sp. isolate M097, the yield of purified rAPC could amount to about 38 mg/l using a simple purification protocol, and HPLC
analysis showed that the purity of the protein reached about 91.5%. In vitro activity tests also revealed that the purified rAPC had effective scavenging abilities on superoxide and hydroxyl radicals.
This would widen the usefulness of the marine Streptomyces as a host to express the rAPC and to offer industrial strain for the production of rAPC. 相似文献