A Multilevel Core Sampler Device to Directly Estimate Food Supply Accessible to Waders
Résumé
To understand food webs functioning in intertidal soft-sediments, it is critical to assess the macrobenthic prey fraction accessible to waders. Here we describe a simple core sampler device allowing to directly relating the vertical distribu- tion of macrozoobenthos to waders bill length. Bill length measurements were used as a proxy of probing depth to esti- mate the amount of food supply accessible. Several metal plates can be inserted in the core sampler at different heights according to the bill length data of the studied species. These data are provided in a literature survey. For each species, the bill length variability is then explicitly taken into account in the estimation of food accessibility. The core is trans- parent to check for the quality of the sample. It could also be used to estimate a Benthic Habitat Quality index (BHQ) based on characteristics of the vertical structure of the sediment. This multilevel core is easy to build and to adapt to any studied wader species of the intertidal zone, floodplains or other wetlands. The samples are obtained with the same ef-fort as with usual circular cores leading to the possibility to survey large area. With one core sample, the ecological in-formation that can be achieved at once is threefold: 1) benthic community structure (partitioned in several depths), 2) estimate of the accessible food fraction to waders (range of values) and 3) habitat quality index assessment
Domaines
Océanographie
Origine : Fichiers éditeurs autorisés sur une archive ouverte
