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| Identifier |
uch.biology.phd//2005koulouri |
| Title |
Επίδραση των συρομένων αλιευτικών εργαλείων στην μακροπανίδα του βενθικού διαχωριστικού στρώματος |
| Alternative Title |
Bottom fishing gear effects on benthic boundary layer macrofanna |
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Author
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Κουλούρη, Παναγιώτα
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Thesis advisor
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Ελευθερίου, Αναστάσιος
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| Abstract |
The use of bottom fishing gears in the fishing grounds of the continental shelf and upper margin, where most fishing activities are concentrated, can cause long-term and large scale perturbations to the marine ecosystem and alter the composition and the biogeochemical processes of the surface sediments, patterns of biodiversity, functioning and productivity of both benthic and pelagic systems. The aim of this study was to investigate the benthic boundary layer macrofauna in the continental shelf of Heraklion Bay (Crete, Greece) as well as bottom fishing gear effects on this particular macrofauna. Sampling of these often highly mobile animals, which live on or very close to the sediment-water interface where the passage of bottom fishing gears takes place- is not easy. Even the combined use of all the classical types of sampling gears gives no adequate assessment of the composition of the benthic boundary layer macrofauna of soft bottoms. A new sampling device has been constructed (Towed Trawl Simulator Sledge version 2, TTSS2) to simulate the disturbance of the seabed caused by the passage of otter trawl groundropes over the sediment surface. The device has been used both to simulate the event and to collect simultaneously the small macrofaunal organisms found in the plume of the sediments thus disturbed. A welldefined and distinct fauna (mainly Crustacea), which was found in the plume of resuspended sediment behind the groundrope, consists of small-sized epibenthic and hyperbenthic animals (<20 mm) as well as meso- and macro-zooplanktonic organisms (>0.5 mm). Most of these organisms also perform, with varying amplitude, intensity and regularity, seasonal or daily vertical migrations above the seabed. Despite the fact that the benthic boundary layer macrofauna collected by the TTSS2 remains intact, the exposure and stress of these organisms may increase their vulnerability to predators.
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| Language |
Greek |
| Subject |
Βενθικό διαχωριστικό στρώμα; Αλιευτικά εργαλεία, Επίδραση Συρόμενων; Υπερβένθος; Μηχανότρατες; Ψάρια, Βενθοπελαγικά; Στομαχικό περιεχόμενο; Υφαλοκρηπίδα, Ηπειρωτική; Τεχνολογία, Θαλάσσια |
| Issue date |
2005-02-09 |
| Collection
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School/Department--School of Sciences and Engineering--Department of Biology--Doctoral theses
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Type of Work--Doctoral theses
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| Views |
553 |
Επίδραση των συρομένων αλιευτικών εργαλείων στην μακροπανίδα του βενθικού διαχωριστικού στρώματος
