Showing papers in "Netherlands Journal of Sea Research in 1979"

TL;DR: The amount of organic matter produced through autotrophic processes in the euphotic zone of the tropical open ocean and available for respiration of autotrophs and heterotrophics was at least 5 to 15 times higher than values derived from the common 14 C method suggested.

TL;DR: Both total biomass and species richness were reduced after the 1979 winter, but the decline was only slight and greatest reductions were observed in areas low in the intertidal.

TL;DR: After an initial decline during some years of low recruitment, total population of adults was found to be stable and population stability will have been enhanced by a long lifespan and an inverse relationship between adult density and rate of recruitment.

TL;DR: An automatic ammonia method has been developed that can be used for samples throughout the salinity range of 0 to 35% S (standard deviation 2.4%).

TL;DR: In this article, the authors studied sediment reworking by Heteromastus filiformis and found that the size distributions of the faecal pellets produced by the population could be used as a measure of the population structure.

TL;DR: At least in lugworms, production of regenerating parts after cropping should be taken into account in studies of food chain transfer, as exerted particularly by flatfish.

TL;DR: In this paper, the authors made estimates for in situ phytoplankton primary production in the Marsdiep tidal inlet area of the western Dutch Wadden Sea using a constant light source.

TL;DR: The macrophyte production and the transport of particulate organic matter between marsh and adjacent estuary have been investigated for a 0.3 km2 salt marsh along the Oosterschelde estuary, The Netherlands and resulted in a net import.

TL;DR: In this article, the boundary between the mud field and the sandy Souther Bight is principally determined by spring tide current velocities, and it is shown that the increase of erosion velocity by consolidation proceeds faster than the increasing of current velocity after slack tide.

TL;DR: The size distributions reflect the multiple origin of the suspended material and the variable conditions of deposition, resuspension and aggregation.

TL;DR: In this article, it is suggested that the lower chlorinated fraction is derived from atmospheric input, which has not been observed in other reports, and PCBs are associated specifically with finer particles.

TL;DR: In this article, natural dissolved fluorescent material was measured in the upper 300 m at stations in the eastern tropical Atlantic Ocean, and lower concentrations of the surface layer are caused by degradation by sunlight of dissolved organic substances, as demonstrated by a laboratory experiment.

TL;DR: A diurnal oxygen rhythm with an amplitude of less than 0.6% of ambient oxygen concentration was measured at 5 stations in the mixed layer of the Atlantic Ocean through the application of a high precision Winkler titration method.

TL;DR: A mechanism which causes the chance of a particle to stick to the mucus covered papillae on the lugworm's proboscis and to be swallowed depends on its surface area; smaller particles have a greater chance than large ones.

TL;DR: In this paper, carbonate, total N, and organic C content, grain size distributions, analyses of Foraminifera, molluscs and pollen, as well as two 14 C data of cores taken in the Witch and Fladen Ground area, were used to supplement earlier interpretations of acoustical reflection records, in an attempt to clarify the Late Pleistocene and Holocene history of the northern North Sea.

TL;DR: Two laboratory systems are described in which the complete cycle of spawning, larval development, and postlarval migration of Arenicola marina were studied and show a larval life in which previous observations on the biology can be integrated.

TL;DR: The spatial and numerical distribution of juvenile and adult lugworm populations on an intertidal mud flat in the western Wadden Sea is described and it is shown that high densities of juvenile worms always occur in places where the numbers of adults are relatively low.

TL;DR: Field observations on the early life history of Arenicola marina L. in tidal areas near Texel between summer 1977 and spring 1978 generally agree with results of laboratory studies of the early development of the species, as reported by Farke & Berghuis (1979).

TL;DR: Production values obtained by 14C measurements of carbon dioxide and dissolved and particulate organic carbon along a section off the African coast chiefly following the parallel of 20°N support observations made by Gieskes, Kraay & Baars and Tijssen during the same programme but with different methods.

TL;DR: In this paper, the effects of filtration and centrifugation on the concentrations of several metals in coastal suspended matter were compared and the resulting data were interpreted in terms of varying contributions of larger and denser bottom derived particles with higher concentrations of K, Fe, Mn, and Al and of smaller and less dense, continuously suspended particles with high concentrations of Cu, Cd, Cr, K and Mg.

TL;DR: Retarded growth, as observed in natural populations of O-group worms on the extensive mud flats as well as on special “nursery” flats is attributed to an insufficient food supply on these flats, though these are characterized by a high input of primary organic matter, locally produced aswell as imported from the adjacent North Sea.

TL;DR: Growth in Arenicola was depressed or absent in cases of food shortage, and in the presence of Nereis ; effects were most serious when both factors go together.

TL;DR: Pumping rates of Arenicola marina are far too low to cause sediment transport, but may be important in transport of soluable matter.

TL;DR: The concentrations of free sulphide in the upper 30 cm of the sediment of a tidal mud flat in the Dutch Wadden Sea were measured periodically during one and a half year as mentioned in this paper.

TL;DR: The distribution of the first intermediate host (Valvata piscinalis) makes the cercariae to be limited to large fresh water bodies, especially in fishers from the IJsselmeer, a freshwater lake, newly formed after closing of the Zuiderzee in 1932.

TL;DR: During 4 years in succession weight frequency distributions of an adult Arenicola marina population in the western Wadden Sea were investigated, oocyte development, spawning and spawning season were studied, and the production by gametes released was calculated.

TL;DR: Curie-point pyrolysis mass spectrometry was used as analytical technique to analyse the organic matter from sediments and concluded that the slow pace of food ingestion points to an ample supply of digestable organic matter for the adult worm.

TL;DR: In this paper, a mixture of 1-0-alk-1-enyl-diacylglcerols and trimethylsilyl ethers was extracted from extractable lipids of Arenicola marina L.