Below‐ground ecosystem engineers enhance biodiversity and function in a polluted ecosystem

Many important ecosystem functions are underpinned by below-ground biodiversity and processes. Marine sediments, one of the most abundant habitats on earth, essential to mineralisation organic matter. However, they increasingly polluted urban activities leading loss provide. While traditional sediment remediation strategies focussed microbial engineering solutions, we propose that reintroduction engineers (bioturbators) is rehabilitate sediments drive recovery their in coastal ecosystems. We tested this notion introducing bioturbators nutrient assess survival, as well capacity oxygenation potential remediate pollution. Polychaete worms Diopatra aciculata clams Katelysia sp. were added mesocosms (ex-situ), also experimental plots in-situ. Potential for was assessed with measures content. All animals survived when introduced showed no evidence sub-lethal effects. Worms oxygenated reduced matter content up 50% The drove shifts receiving communities at all locations increased number taxa location. On other hand, effects variable, showing opposite different sites levels Synthesis applications. Global seafloor becoming degraded novel combine restoration urgently needed return function. Tube-building can stimulate processing proving multiple functional outcomes, but these dependent environment. In areas medium pollution, kick-start a feedback loop whereby bioturbation increases remediation, shifting contributing further recovery. This long-term changes communities, particularly where unvegetated conspicuous.