DOI: 10.5061/dryad.5qfttdzd7
title: Density-dependent effects of parasitism on the activity of a benthic engineer species: potential impact on ecosystem functioning

description: While parasitism is a common lifestyle on Earth, its importance for the
 functioning of marine ecosystems has been overlooked for a long time. In
 particular, parasites have significant potential to influence central
 ecological processes through their impacts on hosts that serve as
 ecosystem engineers. Using an ex-situ experimental approach, we explored
 the effects of trematode parasites on the engineering bioturbation
 activity of a common and abundant bivalve along European Atlantic
 soft-bottom coastlines, the peppery furrow shell Scrobicularia plana, as
 well as knock-on effects for nutrient exchanges at the sediment-water
 interface. Trematodes negatively impacted the host’s ability to transport
 sediment particles and solutes in a density-dependent way with parasite
 burden explaining 22–31% of the inter-individual variability. This could
 be explained by parasitism impairing the bivalve physiological state and
 ability to burrow as we observed a decrease in the condition index and the
 burrowing depth of the bivalves with an increase in the number of
 parasites they host. In contrast, the influence of S. plana on benthic
 biogeochemical fluxes did not vary significantly according to parasitic
 burden over a short time scale. Here, we focused on the effects of
 trematode parasites on the sole behaviour of S. plana and thus excluded
 other macrofaunal organisms. We should next test whether trematodes
 modulate the structure and functioning of benthic communities dominated by
 S. plana to better understand and quantify the engineering role of
 parasites in soft-bottom coastal environments.
description: # Density-dependent effects of parasitism on the activity of a benthic
 engineer species: potential impact on ecosystem functioning
 This data set encompasses
 two .csv files, namely "dataset_coefficient_OIKOS_Dairain.csv"
 and "dataset_profils_bromide_luminophore_OIKOS_Dairain.csv". ##
 Description of the data and file structure ### **File
 "dataset\_coefficient\_OIKOS\_Dairain.csv"** In this file, the
 reader will find values for different coefficients determined for each
 bivalve. Below are the details of the different column names: *
 "sample": name of the sample * "site": where the
 bivalve has been collected. * "bivalve": control vs. with
 bivalve. Control experimental units did not contain any bivalve. *
 "replicat": replicate number * "Parvatrema_minutum":
 infection with the parasite Parvatrema minutum (yes vs no vs NA = not
 applicable for when there was no bivalve) *
 "Sum_metacercaria_Himasthla": total number of metacercariae of
 the Himasthla genus in the bivalve (NA = not applicable for when there was
 no bivalve) * "Wet_weight_flesh_mg": wet weight of the bivalve
 flesh in mg (NA = not applicable for when there was no bivalve) *
 "Dry_weight_flesh_mg": flesh dry weight of the bivalve in mg (NA
 = not applicable for when there was no bivalve) *
 "AFDW_flesh_mg": ash-free dry weight of the bivalve's flesh
 in mg (NA = not applicable for when there was no bivalve) *
 "Dry_weight_shell_g" : dry weight of the bivalve's shell in
 g (NA = not applicable for when there was no bivalve) *
 "Db_conveyor": biodiffusion rate Db (cm2 y-1) *
 "vb_conveyor": vb rates (cm2 y-1) *
 "Maximal_Penetration_Depth_99_luminophore_cm": maximal
 penetration depth of luminophores in the sediment column (cm) *
 "Penetration_depth_bromide_cm": maximal penetration depth of
 bromide in the sediment column (cm) * "Alpha_per_year" :
 non-local exchange coefficient of bioirrigation (y-1) *
 "Nitrites_µmol/m2/min" : Flux of nitrites at the sediment-water
 interface (µmol/m2/min) * "Nitrates_µmol/m2/min": Flux of
 nitrates at the sediment-water interface (µmol/m2/min) *
 "Phosphates_µmol/m2/min": Flux of phosphates at the
 sediment-water interface (µmol/m2/min) *
 "Silicates_µmol/m2/min": Flux of silicates at the sediment-water
 interface (µmol/m2/min) * "Ammonium_µmol/m2/min": Flux of
 nitrites at the sediment-water interface (µmol/m2/min) *
 "Oxygene_mmol/m2/d": Flux of oxygene at the sediment-water
 interface (mmol/m2/min) (NA: data not available) ### **File
 "dataset\_profils\_bromide\_luminophore\_OIKOS\_Dairain.csv"**
 In this file, the reader will find values for concentration of bromides
 and luminophores at different depht in the sediment column for each
 sample. It will allow to plot vertical distribution of the two tracers in
 the sediment column for each sample. Below are the details of the
 different column names: * "site": where the bivalve has been
 collected. * "bivalve": control vs. with bivalve. Control
 experimental units did not contain any bivalve. * "replicat":
 replicat number * "Parvatrema_minutum": infection with the
 parasite Parvatrema minutum (yes vs no) * "Depth_cm": depth in
 the sediment column (cm) * "Concentration_bromide_µM":
 concentration of bromide (µM) * "Relative_abundance_luminophore"
 : relative abundance of luminophore (for each sample, the total abundance
 equals 1).