On the dynamics of oceanographic surface moorings     

Mark A. Grosenbaugh 《Ocean Engineering》1996,23(1):7-25

An analytical model is proposed for predicting the dynamics of instrumented oceanographic surface moorings made up of a combination of wire rope and compliant synthetic rope. The model simplifies the problem by treating only the vertical motion of the buoy and the longitudinal motion of the mooring line and attached instruments. It is demonstrated using full-scale experimental data and numerical simulations, that the simplified model captures all of the important dynamic effects and gives accurate predictions of the dynamic tension at the top of the mooring line. The model shows that the total mass and damping of the instruments and wire rope that make up the stiff upper half of the mooring are the major sources of the dynamic tension. Damping of the instruments becomes a significant factor in larger sea states, especially near the peak frequency of the wave spectrum. Elastic stretching of the wire and synthetic rope make up approximately 10% of the total response. This is based on a coefficient of friction equal to 0.003 which fits the experimental data best.  相似文献   

Research challenges at the land–sea interface     

Drew M. Talley  Elizabeth W. North  Andrew R. Juhl  David A. Timothy  Daniel Conde  Jody F. C. deBrouwer  Cheryl A. Brown  Linda M. Campbell  Tobias Garstecki  Catherine J. Hall  Filip J. R. Meysman  David M. Nemerson  Pedro W. Souza Filho  Robert J. Wood 《Estuarine, Coastal and Shelf Science》2003,58(4):699

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Effects of pulsed nutrient inputs on phytoplankton assemblage structure and blooms in an enclosed coastal area   总被引：6，自引：0，他引：6  

Sofie Spatharis  George Tsirtsis  Daniel B. Danielidis  Thang Do Chi  David Mouillot   《Estuarine, Coastal and Shelf Science》2007,73(3-4):807-815

The response of phytoplankton assemblage structure to terrestrial nutrient inputs was examined for the Gulf of Kalloni in the Northern Aegean Sea, a productive semi-enclosed coastal marine ecosystem. The study was focused on a typical annual cycle, and emphasis was placed on the comparative analysis between blooms developing after significant nutrient inputs from the watershed, and naturally occurring blooms. Baseline information was collected on a monthly basis from a network of stations located in the oligotrophic open sea and the interior and more productive part of the embayment. Intensive sampling was also carried out along a gradient in the vicinity of a river which was the most important source of freshwater and nutrient input for the Gulf. Phytoplankton assemblage structure was analyzed from 188 samples using diversity indices (Shannon and Average Taxonomic Distinctness), multivariate plotting methods (NMDS), multivariate statistics (PERMANOVA), and canonical correspondence analysis (CCA). Three characteristic assemblages were recognized: (1) an autumn assemblage developed under nutrient depleted conditions, having low diversity due to the dominance of two small diatoms, (2) a winter bloom of the potentially toxic species Pseudo-nitzschia calliantha occurring immediately after a nutrient peak and characterized by very low diversity, and (3) a naturally occurring early summer bloom of centric diatoms with relatively high diversity. The results of the study support the view that moderate nutrient inputs may have a beneficial effect on the functioning of coastal ecosystems, stimulating the taxonomic diversity through the growth of different taxonomic groups and taxa. On the other hand, a sudden pulse of high nutrient concentrations may greatly affect the natural succession of organisms, have a negative effect on the diversity through the dominance of a single species, and can increase the possibility of a harmful algal bloom development.  相似文献   

Nutrient and plankton dynamics in an intermittently closed/open lagoon, Smiths Lake, south-eastern Australia: An ecological model     

Jason D. Everett  Mark E. Baird  Iain M. Suthers 《Estuarine, Coastal and Shelf Science》2007,72(4):690-702

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Accelerated relative sea-level rise and rapid coastal erosion:: testing a causal relationship for the Louisiana barrier islands   总被引：1，自引：0，他引：1  

Jeffrey H. List  Asbury H. Sallenger Jr.  Mark E. Hansen  Bruce E. Jaffe 《Marine Geology》1997,140(3-4):347-365

The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s, 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium criterion; this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus, in terms of the Bruun approach, relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.  相似文献   

The Ah receptor in marine animals: phylogenetic distribution and relationship to cytochrome P4501A inducibility     

Mark E. Hahn  Alan Poland  Ed Glover  John J. Stegeman 《Marine environmental research》1992,34(1-4)

In mammals, the induction of cytochrome P4501A forms by chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and halogenated biphenyls is under control of a soluble protein known as the Ah (aromatic hydrocarbon) receptor. Little is known about the presence and properties of the Ah receptor in other vertebrate and invertebrate species. In these studies, we sought evidence for an Ah receptor in the liver or liver-equivalent of 20 species of marine and freshwater animals, using the photoaffinity ligand 2-azido-3-[¹²⁵I] iodo-7,8-dibromodibenzo-p-dioxin (N₃[¹²⁵I]Br₂DD). Specific labeling of cytosolic proteins by N₃[¹²⁵I]Br₂DD was observed in seven species of teleost and elasmobranch fish, in PLHC-I fish hepatoma cells, and in beluga whales. No specifically labeled proteins were found in cytosol from two species of agnathan fish nor in any of nine invertebrate species representing eight classes of four phyla. The presence or absence of specifically labeled polypeptides corresponds with the inducibility of cytochrome P4501A and sensitivity to the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related planar halogenated aromatic hydrocarbons in many of these groups. Thus, Ah receptor function may have arisen early invertebrate evolution and has been conserved from elasmobranch and teleost fish to mammals.  相似文献   

Industry participation in stock assessment: the New Zealand SNA1 snapper (Pagrus auratus) fishery     

Mark N. Maunder  Paul J. Starr   《Marine Policy》2002,26(6)

We describe industry funded contributions to the assessment of the SNA1 snapper (Pagrus auratus) fishery during the 1990s and discuss the advantages and disadvantages of industry funded research. We also provide background on the history of fisheries management in New Zealand, on the current assessment and management processes, and on the SNA1 snapper fishery. In the SNA1 fishery, the contributions of industry and the cooperation with Government scientists has resulted in high quality assessments. In our opinion, the advantages of industry funded research out weigh the disadvantages and suggest that industry funded assessments are highly desirable and should be an integral part of any management system.  相似文献   

Standardized measures of relative abundance based on modelling log (c.p.u.e.), and their application to Pacific ocean perch (Sebastes alutus)     

Kimura  Daniel K. 《ICES Journal of Marine Science》1981,39(3):211-218

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French marine technology policy : Industrializing ocean depths     

Daniel Spagni  Luke Georghiou  Michael Gibbons 《Marine Policy》1985,9(4):280-291

This paper outlines the structure of the institutions involved in scientific and technological development in France. It points to new trends in French marine policy, and gives details of the country's offshore petroleum technology and nodule mining.  相似文献   

Multi-proxy evidence of long-term changes in ecosystem structure in a Danish marine estuary, linked to increased nutrient loading   总被引：3，自引：0，他引：3  

Marianne Ellegaard  Annemarie L. Clarke  Nina Reuss  Simon Drew  Kaarina Weckstrm  Stephen Juggins  N. John Anderson  Daniel J. Conley 《Estuarine, Coastal and Shelf Science》2006,68(3-4):567

This paper presents a study of changes in eutrophication over the past 100 years in a fertile estuary. The Danish estuary Mariager Fjord is a long, narrow sill-fjord with a permanently anoxic basin. In 1997 anoxia spread from the basin to the entire inner estuary, killing almost all eukaryotes and prompting debate on the causes. This paper reports a multi-proxy survey of ²¹⁰Pb-dated sediment cores from the anoxic basin. Analyses of diatoms, dinoflagellates, pigments and geochemical proxies were used to determine changes in ecosystem structure over the past 100 years. The aim was to establish ‘base-line conditions’, for management purposes, of the biological structure prior to 1900, and to examine possible causes of changes observed. Geochemical proxies total nitrogen (TN), total carbon (TC) and biogenic silica (BSi) were consistently high throughout the sediment record. Increased concentrations of pigments and natural isotopes (δ¹³C, δ¹⁵N) suggested increasing production and nutrient loading. The main changes in the biological proxies occurred between 1915 and the 1940s, and indicated that the estuary has been somewhat eutrophic since 1900, but that the eutrophication process increased over the past 100 years. A reconstruction of TN concentration by a diatom-based transfer function supports this interpretation, with inferred TN ca. 1900 around 60 μmol l⁻¹, and an increase in TN concentration over the past century to ca. 130 μmol l⁻¹ by 1995. Inferred TN decreased to ca. 100 μmol l⁻¹ by 2001, similar to present day monitoring data.  相似文献