AEI prepress abstract  -  DOI:

Impact of farming non-indigenous scallop Argopecten irradians on the benthic ecosystem functioning: a case-study in Laizhou Bay, China

Qian Huang*, Sergej Olenin, Song Sun, Marleen De Troch


ABSTRACT: ABSTRACT: The farming of non-indigenous scallop Argopecten irradians in coastal waters generates large amounts of biodeposits that potentially change the trophic pathways and quality of benthic food web at lower trophic level such as meiobenthos. To understand the trophic link between faecal pellets of bay scallop and meiobenthos in aquaculture area, we investigated the resource use of harpacticoid copepods and nematodes inside and outside three bay scallop farms in Laizhou Bay (Bohai Sea, China), using natural abundance of stable carbon and nitrogen isotopes together with fatty acid profiling. Faeces were found to be the most enriched in δ15N compared to other food sources which made it traceable. The enriched δ15N in several meiobenthos at the farms together with the mixing model results indicated that faeces could be a new food source for most of the harpacticoid copepods and some nematodes. The quantities and the pathways of assimilation differed between the copepod families depending on their feeding behaviors and the receiving environment. Furthermore, with higher levels of polyunsaturated fatty acids (PUFA), in particular docosahexaenoic acid (DHA), the dominant copepod family Canuellidae that abundantly consumed scallop faeces had a higher nutritious quality compared with those in the control sites. This non-indigenous scallop aquaculture provided a food source directly and indirectly consumed by meiobenthos underneath the scallop farms and improved the quality of lower consumers.