Modelling the size selectivities of a trawl codend and an associated square mesh panel   总被引：8，自引：1，他引：8  

Zuur  G.; Fryer  R. J.; Ferro  R. S. T.; Tokai  T. 《ICES Journal of Marine Science》2001,58(3):657-671

  相似文献   

Separating species using a horizontal panel in the Scottish North Sea whitefish trawl fishery     

Ferro  R. S. T.; Jones  E. G.; Kynoch  R. J.; Fryer  R. J.; Buckett  B-E. 《ICES Journal of Marine Science》2007,64(8):1543-1550

  相似文献   

The power of a contaminant monitoring programme to detect linear trends and incidents     

Fryer  R. J.; Nicholson  M. D. 《ICES Journal of Marine Science》1993,50(2):161-168

  相似文献   

Experimental method for quantifying resistance to the opening of netting panels   总被引：1，自引：0，他引：1  

Sala  A.; O'Neill  F. G.; Buglioni  G.; Lucchetti  A.; Palumbo  V.; Fryer  R. J. 《ICES Journal of Marine Science》2007,64(8):1573-1578

  相似文献   

On the quality of North Sea cod stock forecasts     

Cook  R. M.; Kunzlik  P. A.; Fryer  R. J. 《ICES Journal of Marine Science》1991,48(1):1-13

  相似文献   

Moon morphology,interpretations based on lunar orbiter photography | P.H. Schultz, 1976. University of Texas Press,Austin, London, 626 pp., £24.50     

R.J. Fryer 《Earth》1977,13(2):219

  相似文献   

Petrogenesis and paleotectonic history of the Wild Bight Group,an Ordovician rifted island arc in central Newfoundland   总被引：1，自引：0，他引：1  

H. Scott Swinden  G. A. Jenner  B. J. Fryer  J. Hertogen  J. C. Roddick 《Contributions to Mineralogy and Petrology》1990,105(2):219-241

The Wild Bight Group (WBG) is a sequence of early and middle Ordovician volcanic, subvolcanic and epiclastic rocks, part of the Dunnage Tectonostratigraphic Zone of the Newfoundland Appalachians. A detailed geochemical and Nd-isotopic study of the volcanic and subvolcanic rocks has been carried out to determine the geochemical characteristics of the rocks, interpret their palcotectonic environments and constrain their petrogenetic history. The lower and central stratigraphic levels of the WBG contain mafic volcanic rocks with island-arc geochemical signatures, including LREE-enriched are tholeiites with _Nd(t) =-0.1 to +2.2 (type A-I), LREE-depleted arc tholeiites with _Nd(t) =+5.6 to +7.1 (type A-II) and an unusual suite of strongly incompatible-element depleted tholeiites in which _Nd(t) ranges from-0.9 to +4.6 and is negatively correlated with¹⁴⁷Sm/¹⁴⁴Nd (type A-III). High-silica, low-K rhyolites occur locally in the central part of the stratigraphy, associated with mafic rocks of arc affinity, and have _Nd(t) =+4.7 to +5.4. The upper stratigraphic levels of the WBG dominantly contain rocks with non-arc geochemical signatures, including alkalic basalts with _Nd(t) =+4.6 to +5.5 (type N-I), strongly LREE- and incompatible element-enriched tholeiites that are transitional between alkalic and non-alkalic rocks with _Nd(t) =+4.4 to +7.0 (type N-II) and rocks with flat to slightly LREE-enriched patterns and _Nd(t) =+5.1 to +7.4 (type N-III). Rocks with non-arc and arc signatures are locally interbedded near the stratigraphic type of the WBG. Nd-isotopic data in the type A-I and A-II rocks are generally compatible with mixing/partial melting models involving depleted mantle, variably contaminated by a subducted crustally-derived sediment. The petrogenesis of type A-III rocks must involve source mixing and multi-stage partial melting, but the details are not clear. The geochemistry and Nd isotope data for types N-I, N-II and N-III rocks are compatible with petrogenetic models involving variable partial melting of a source similar to that postulated for modern oceanic island basalts. Comparison of the WBG with modern analogues suggests a 3-stage developmental model: stage 1) island-arc volcanism (eruption of type mafic volcancs); stage 2) arc-rifting (continued eruption of type A-I, A-I, eruption of types A-II and A-III mafic volcanics and high-silica, low-K rhyolites); and stage 3) back-arc basin volcanism (continued minor eruption of type A-I basalts, eruption of types N-I, N-II, N-III basalts). Stages 1 and 2 volcanism involved partial melting of subduction contaminated mantle, while stage 3 volcanism utilized depleted-mantle sources not affected by the subducting slab. This model provides a basis for interpreting coeval sequences in central Newfoundland and a comparative framework for some early Paleozoic oceanic volcanic sequences elsewhere in the Appalachian orogen.  相似文献   

Back to the future: reflections and directions of South African marine bioinvasion research     

ME Alexander  CA Simon  CL Griffiths  K Peters  S Sibanda  S Miza 《African Journal of Marine Science》2016,38(1):141-144

Biological invasions continue to increase around the world, with impacts on many coastal marine systems. Here we review the South African marine invasion literature which, despite the field being relatively new, has grown to have significant presence in both the local and international arenas. Of the 79 papers reviewed, 70% focused on the establishment and spread of alien species, with modes of transport and introduction largely overlooked. An emphasis was also apparent towards field studies, in particular survey work, with few experimental studies. The overwhelming majority of papers focused on a single species, the Mediterranean mussel Mytilus galloprovincialis, reflecting the scale of this invasion and the tractable nature of rocky shores as study systems. With the exception of this one species, the impacts of marine alien species have rarely been quantified. We suggest that future research extends the taxonomic coverage of present work and develops a better understanding of the mechanisms of introduction, establishment and spread of marine alien species. Through an experimental approach, the drivers of altered ecological patterns and processes resulting from invasions should be addressed, providing insight into associated impacts. This approach will maintain the local applicability and international relevance of South African marine invasion research.  相似文献   

The development of the subduction channel and “turning on” of slab-to-mantle material exchanges at the start of subduction: insights from eruptive serpentinites (IODP Exp 366) from the forearc of the Mariana subduction system     

Jeffrey G. Ryan  Raymond Johnston  P. Fryer  C.G. Wheat  T. Williams 《《地质学报》英文版》2018,92(Z1):167-167

  相似文献   

ERRORS IN DEPTH DETERMINATION CAUSED BY WAVES IN THROUGH-WATER PHOTOGRAMMETRY   总被引：1，自引：0，他引：1  

J. G. Fryer  H. T. Kniest 《The Photogrammetric Record》1985,11(66):745-753

The determination of depths in shallow water from aerial platforms will become increasingly important as exploitation of coastal resources intensifies. Until a theoretical study of the errors in depth which could be reasonably expected from two-media photogrammetry was made by Okamoto in 1982, there was little relevant literature apart from some isolated case studies. This paper examines the magnitude and distribution of errors in depth caused by the presence of waves on the water surface. The effects of random errors of observational measurement, in combination with waves, are assessed. A conclusion is reached that the traditional method of underwater depth calculation should be modified when the scale of the two media photography is greater than 1:4000.  相似文献