Sediment reworking by the burrowing polychaete Hediste diversicolor modulated by environmental and biological factors across the temperate North Atlantic. A tribute to Gaston Desrosiers

Particle mixing and irrigation of the seabed by benthic fauna (bioturbation) have major impacts on ecosystem functions such as remineralization organic matter sediment-water exchange. As a tribute to Prof. Gaston Desrosiers Nereis Park association, eighteen laboratories carried out collaborative experiment acquire global snapshot particle reworking polychaete Hediste diversicolor at 16 sites surrounding Northern Atlantic. Organisms soft sediments were collected during May – July different geographical locations and, using common laboratory protocol, particulate fluorescent tracers (‘luminophores’) used quantify transport over 10-day period. was quantified maximum penetration depth (MPD), diffusive coefficients (Db), non-local (r). Non-local (reflecting centimeter scale steps) ranged from 0.4 15 yr?1, not correlated across with any measured biological (biomass, biovolume) or environmental parameters (temperature, grain size, matter). Maximum depths (MPD) averaged ~10.7 cm (6.5–14.5 cm), similar average bioturbation inferred short-lived radiochemical tracers. MPD also measures size (individual biomass), but increased decreased temperature. Biodiffusion (Db) inversely individual biomass (size) directly temperature range (Q10 ~ 1.7; 5–21 °C). The data comparable in magnitude rates reported for localized H. populations confirmed some all correlations between sediment variables found previous studies. results imply that activities species single location can be generally extrapolated conditions.