Clearance rates of Cerastoderma edule under increasing current velocity |
| |
Authors: | S Fernandes P Sobral L van Duren |
| |
Institution: | 1. IMAR-FCT/UNL Instituto do Mar, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal;2. Netherlands Institute of Ecology (NIOO-KNAW), Centre for Estuarine and Marine Ecology, Korringaweg 7, 4401 NT Yerseke, The Netherlands |
| |
Abstract: | Estimates of clearance rates (CR) of Cerastoderma edule (300 ind. m−2) as a function of free-stream current velocity (U) (from 5 to 40 cm s−1) were compared between a small annular (60 l) and a large racetrack (8850 l) flume with different hydrodynamic conditions. Results showed that the flumes differ considerably in their hydrodynamic characteristics. The relationship between CR and U is different in the two flume tanks, however there appears to be a straightforward unimodal trend between CR and shear velocity (U*). It was found that the cockles themselves influence the benthic boundary layer (BBL) characteristics, by causing steeper velocity gradients and increasing the mixing over the cockle bed compared to bare sediment. This provides new evidence on how endobenthic organisms can affect the BBL. However, the influence of CR on U* could not be quantified because these parameters have interactive effects that cannot be dissociated. |
| |
Keywords: | Benthic boundary layer Cerastoderma edule Clearance rates Annular and racetrack flumes Shear velocity |
本文献已被 ScienceDirect 等数据库收录! |
|