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Costas Dounas Ian Davies George Triantafyllou Panayota Koulouri George Petihakis Christos Arvanitidis George Sourlatzis Anastasios Eleftheriou 《Continental Shelf Research》2007
Disturbance of the seabed resulting from bottom trawling affects ecosystem processes, such as the rate and magnitude of nutrient regeneration. The potential responses of the plankton community arising from such effects can be modelled, provided that reliable data on the effects on nutrient fluxes are available. In a north Cretan outer continental shelf and upper slope fishing ground (Heraklion Bay, Crete, Eastern Mediterranean) we applied a new field instrument which can simulate the passage of trawl groundropes across the sea floor and made direct seasonal measurements of the rate of dissolved and particulate nutrient releases resulting from seabed disturbance. These observational data were then integrated in a 3D ecosystem model. Results revealed that bottom trawling may trigger off considerable productivity pulses, in addition to pulses from the natural seasonal cycle. 相似文献
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S. E. Poulos C. G. Dounas G. Alexandrakis P. Koulouri P. Drakopoulos 《Environmental Geology》2009,58(4):843-857
The present study investigates the distribution of trace metals (Zn, Hg, Cd, Cu, and Pb), as indicators of pollution, in the
surficial offshore shelf sediments along the northern coast of Heraklion Prefecture (Crete, Mediterranean Sea). The concentrations
and the spatial distribution of the different trace metals, in relation to the sedimentological characteristics and the water
circulation pattern of the entire continental shelf, are associated with human inshore sources of pollutants located along
the coastline of the study area. Although the trace metal concentrations measured are higher than the background values, they
are not considered to be dangerous to human health, as they are lower than the standard values given by the World Health Organisation,
with only a few localised exceptions. Furthermore, results reveal the important role of local hydrodynamism that moves fine-grained
material and associated trace metals offshore (seawards to wave breaking zone) and then transports them eastwards by entrapping
them in the prevailing offshore shelf-water circulation. 相似文献
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