The impact on the macrobenthic community of different types of rake, manual (MR), hydraulic (HR), and conveyor (CR) rake, was studied on subtidal flats in the Sacca di Goro. Two sets of experiments, on sandy and muddy bottoms, were undertaken in summer 2004: the experimental protocol required that six, parallel waylines for both MR and HR were raked by a shellfish farmer; areas comprised between parallel waylines were considered as controls. Due to operative constraints, the impact of CR was assessed on a 800 m-distant, deeper sand flat. Sampling design followed a two-way ANOVA layout with treatments and time as factors. Changes in the benthic community were apparent in the raked plots immediately after treatments, but recolonization by small infaunal species was relatively rapid. While the effects of MR and HR were comparable, CR had an higher deleterious effect on the macrofaunal community. In order to discourage the use of CR, clam fishermen should be allowed to equip their boats with HR gears identical to that used in this study
A comparison of the effect of different types of clam rakes on non-target, subtidal benthic fauna
MUNARI, Cristina;MISTRI, Michele
2006
Abstract
The impact on the macrobenthic community of different types of rake, manual (MR), hydraulic (HR), and conveyor (CR) rake, was studied on subtidal flats in the Sacca di Goro. Two sets of experiments, on sandy and muddy bottoms, were undertaken in summer 2004: the experimental protocol required that six, parallel waylines for both MR and HR were raked by a shellfish farmer; areas comprised between parallel waylines were considered as controls. Due to operative constraints, the impact of CR was assessed on a 800 m-distant, deeper sand flat. Sampling design followed a two-way ANOVA layout with treatments and time as factors. Changes in the benthic community were apparent in the raked plots immediately after treatments, but recolonization by small infaunal species was relatively rapid. While the effects of MR and HR were comparable, CR had an higher deleterious effect on the macrofaunal community. In order to discourage the use of CR, clam fishermen should be allowed to equip their boats with HR gears identical to that used in this studyI documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
