Understanding the impact of sand extraction on benthic ecosystem functioning: a combination of functional indices and biological trait analysis

• Published in: Frontiers in Marine Science
• Main Authors: Goedefroo, Nanou, Braeckman, Ulrike, Hostens, Kris, Vanaverbeke, Jan, Moens, Tom, De Backer, Annelies
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Frontiers Media SA 2023
• Subjects: Ocean Engineering; Water Science and Technology; Aquatic Science; Global and Planetary Change; Oceanography; North East Atlantic
• Online Access: https://biblio.ugent.be/publication/01HM8WK5F3GPRP5M9VD4JZF40M; http://hdl.handle.net/1854/LU-01HM8WK5F3GPRP5M9VD4JZF40M; https://doi.org/10.3389/fmars.2023.1268999; https://biblio.ugent.be/publication/01HM8WK5F3GPRP5M9VD4JZF40M/file/01HM8WNP8P3FWKYV5X6K37CFWM

<jats:p>Marine aggregates have been intensively extracted in the North-East Atlantic over the past decades. This study aimed to assess the effect of sand extraction on benthic ecosystem functioning using a combination of biological traits and functional indices (the bioturbation (BP<jats:sub>c</jats:sub>) and irrigation potential (IP<jats:sub>c</jats:sub>) and secondary production (SP<jats:sub>c</jats:sub>) of the macrobenthic community). Data on macrobenthos, sediment properties and extraction intensity were collected over a time period of ten years (2010 – 2019) for three coarse sediment extraction areas in the Belgian Part of the North Sea, each with a different extraction regime. Sediment parameters such as the medium sand fraction (250 – 500 µm) and median grain size showed a significant effect on all functional indices. Whilst sand extraction variables only significantly affected secondary production estimates. The secondary production of the macrobenthic community decreased following a high yearly extraction intensity, whereas a high cumulative (10-year period) extraction intensity resulted in a slightly increased secondary production. Species-specific responses revealed that these high cumulative extraction volumes increased the abundance of opportunistic species, which could have contributed to the higher SP<jats:sub>c</jats:sub> values observed in cumulative disturbed areas. Response traits such as tube-living and sessile individuals with a pelagic egg development were positively influenced by a long-term disturbance, an indication of a more disturbance-tolerant community. A short-term disturbance rather seemed to favor a macrobenthic community characterized by a higher burrowing capability. In terms of effect traits, both short- and long-term extraction clearly favored deposit feeders, which can structure organic matter distribution and thus indirectly influence nutrient and oxygen fluxes as well. Future <jats:italic>in ...