Removing vessels from the water for biofouling treatment has the potential to introduce mobile non-indigenous marine species     

Ashley D.M. Coutts  Joseph P. Valentine  Adam Davey 《Marine pollution bulletin》2010,60(9):1533-1540

Vessels found contaminated with biofouling non-indigenous marine species are predominantly removed from the water and treated in vessel maintenance facilities (i.e., slipways, travel lifts and dry-docks). Using pre-fouled settlement plates to simulate a vessel’s removal from the water for treatment, we demonstrate that a range of mobile organisms (including non-indigenous marine species) may be lost to the marine environment as a consequence of this process. We also determined that different levels of biofouling (primary, secondary and tertiary) and emersion durations (0.5, 5 and 15 min) affected the abundance and composition of mobile taxa lost to the marine environment. Primary biofouling plates lost 3.2% of total animals, secondary plates lost 19.8% and tertiary plates lost 8.2%, while hanging duration had only minor effects. The results suggest that removing vessels contaminated with biofouling non-indigenous marine species from the water for treatment may not be as biosecure as is currently recognised.  相似文献   

Palynomorph distribution in Recent offshore sediments along two traverses off South West Africa     

R.J. Davey  J. Rogers 《Marine Geology》1975,18(4):213-225

Dinocysts and sporomorphs are recorded from eleven Recent sedimentary samples in two traverses from South West Africa. The dinocyst assemblages are dominated by Spiniferites ramosus ramosus and Operculodinium centrocarpum, although other species are usually present particularly in the more offshore samples. The occurrences of scolecodonts and microforaminifers are also noted, together with the relative abundance of amorphous organic matter. The hydrology and phytoplankton content of this region and the sedimentary composition of the samples are described in detail and then related to the palynomorph content of the bottom sediments. The palynologic conclusions confirm earlier suggestions that the abundance and type of palynomorphs in sediments are governed by a number of complex and interacting factors. Water turbulence, distance from shore, availability and proximity to a river effluence are all extremely important in this respect; upwelling is of particular importance in the region studied.  相似文献   

Stages in the life history of Mytilicola intestinalis Steuer, a copepod parasite of Mytilus edulis (L.), and the effect of temperature on their rates of development     

Gee  J. M.; Davey  J. T. 《ICES Journal of Marine Science》1986,42(3):254-264

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Gravity measurements over Burdwood Bank     

F. J. Davey 《Marine Geophysical Researches》1972,1(4):428-435

Gravity measurements in the South Atlantic Ocean over Burdwood Bank show a large negative gravity anomaly extending along its northern edge. An interpretation of the gravity data has been made based on the seismic refraction measurements of Ludwig et al. (1968) and shows that the negative gravity anomaly can be largely attributed to a basin containing low density sediments about 8 km thick. The crustal sections constructed also indicate that the crust increases in thickness from about 20 km under Burdwood Bank to about 30 km under the Falkland Islands platform.  相似文献   

Responses of <Emphasis Type="Italic">Spartina alterniflora</Emphasis> to Multiple Stressors: Changing Precipitation Patterns,Accelerated Sea Level Rise,and Nutrient Enrichment     

Alana Hanson  Roxanne Johnson  Cathleen Wigand  Autumn Oczkowski  Earl Davey  Erin Markham 《Estuaries and Coasts》2016,39(5):1376-1385

Coastal wetlands, well recognized for their ecosystem services, have faced many threats throughout the USA and elsewhere. While managers require good information on the net impact of these combined stressors on wetlands, little such information exists. We conducted a 4-month mesocosm study to analyze the multiple stressor effects of precipitation changes, sea level rise, and eutrophication on the salt marsh plant Spartina alterniflora. Pots containing plants in an organic soil matrix were positioned in tanks and received Narragansett Bay (RI, USA) water. The study simulated three precipitation levels (ambient daily rain, biweekly storm, and drought), three levels of tidal inundations (high (15 cm below mean high water (MHW)), mean (MHW), and low (15 cm above MHW)), and two nutrient enrichment levels (unenriched and nutrient-enriched bay water). Our results demonstrate that storm and drought stressors led to significantly less above- and belowground biomass than those in ambient rain conditions. Plants that were flooded at high inundation had less belowground biomass, fine roots, and shoots. Nutrients had no detectable effect on aboveground biomass, but the enriched pots had higher stem counts and more fine roots than unenriched pots, in addition to greater CO₂ emission rates; however, the unenriched pots had significantly more coarse roots and rhizomes, which help to build peat in organogenic marshes. These results suggest that multiple stressors of altered precipitation, sea level rise, and nutrient enrichment would lead to reduced marsh sustainability.  相似文献   

Three-dimensional lateral crustal thickening in continental oblique collision: an example from the Southern Alps, New Zealand     

Muriel Gerbault  Fred Davey  Stuart Henrys 《Geophysical Journal International》2002,150(3):770-779

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The structure of the South Fiji basin     

F.J. Davey 《Tectonophysics》1982,87(1-4)

New magnetic, seismic and bathymetric data show that the South Fiji basin is a structurally complex marginal basin. A gap in the identifiable magnetic anomaly lineations exist over the central part of the basin and prevents the unequivocal linking of the anomaly lineations (anomalies 7A to 12) associated with the ridgc-ridge-ridge triple junction in the north with an apparent single spreading centre of the same age in the south. This gap, which makes a detailed synthesis of the historical development of the basin difficult, may arise from post-spreading intraplate tectonics. If symmetric spreading is assumed, part of the oceanic lithosphere formed during the Oligocene episode of seafloor spreading has subsequently been consumed, presumably by subduction westward under Three Kings rise.  相似文献   

The Antarctic margin and its possible hydrocarbon potential     

F.J. Davey 《Tectonophysics》1985,114(1-4)

Geological and geophysical data over the Antarctic margin are reviewed to define those areas where thick sedimentary sequences occur which may have potential to source hydrocarbons. Where possible, the Waples-Lopatin model has been used to calculate whether the degree of maturation of the sediments is sufficient for hydrocarbons to have been generated.Significant sedimentary sequences occur along the continental margins of Wilkes Land, western Dronning Maud Land, Antarctic Peninsula and Ellsworth Land and, as basins or troughs, on the continental shelf of Prydz Bay, Weddell Sea and Ross Sea. Maturation assessments are possible for western Dronning Maud Land, eastern Weddell Sea, western Antarctic Peninsula, Ellsworth Land and Ross Sea regions. Within the great limitations of the data, only western Weddell Sea and Ross Sea basins have maturation values sufficient for the generation of hydrocarbons.  相似文献   

Three-dimensional lithospheric deformation and gravity anomalies associated with oblique continental collision in South Island, New Zealand     

Martin Scherwath  Tim Stern  Fred Davey  Rob Davies 《Geophysical Journal International》2006,167(2):906-916

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Groundwater flow patterns in the San Luis Valley,Colorado, USA revisited: an evaluation of solute and isotopic data     

Alan L. Mayo  Allen Davey  David Christiansen 《Hydrogeology Journal》2007,15(2):383-408

Groundwater systems in the San Luis Valley, Colorado, USA have been re-evaluated by an analysis of solute and isotopic data. Existing stream, spring, and groundwater samples have been augmented with 154 solute and isotopic samples. Based on geochemical stratification, three groundwater regimes have been identified within 1,200 m of the surface: unconfined, upper active confined, and lower active confined with maximum TDS concentrations of 35,000, 3,500 and 600 mg/L, respectively. The elevated TDS of northern valley unconfined and upper active confined systems result from mineral dissolution, ion exchange and methanogenesis of organic and evaporate lake sediments deposited in an ancient lake, herein designated as Lake Sipapu. Chemical evolutions along flow paths were modeled with NETPATH. Groundwater ages, and δ¹³C, δ²H and δ¹⁸O compositions and distributions, suggest that mountain front recharge is the principle recharge mechanism for the upper and lower confined aquifers with travel times in the northern valley of more than 20,000 and 30,000 ¹⁴C years, respectively. Southern valley confined aquifer travel times are 5,000 ¹⁴C years or less. The unconfined aquifer contains appreciable modern recharge water and the contribution of confined aquifer water to the unconfined aquifer does not exceed 20%.  相似文献