In 2015 the Marine Ecology lab. (Eriksson Lab. at the Groningen Institute for Evolutionary Life Sciences [GELIFES], University of Groningen, The Netherlands); tested the effect of different intertidal bioengineering bivalve habitats on the sediment community. We did this by adding different small scale (0.5 by 0.5 m) bivalve assemblages to the intertidal; the treatments included blue mussel reefs, cockle beds, dead shell assemblages, different types of fencing a to protect the bivalves from bird and crab predation; and fencing controls to test for fence effects. We measured effects on sediment conditions (OM, cohesion, erosion), diatom community composition and development (species composition based on cell counts and biovolume, chlorophyll a concentrations), and infauna abundance. The field experiment in the intertidal ran from 30 April to 10 June 2015 and complementary field samples were collected around a natural blue mussel bed on the same tidal flat on 7 October 2015 (N 53.489, E 6.230 degrees).

Type of experiment: Biomanipulation; blue mussels were added to a tidal flat to test the effect of reefs on the diatom community. The experiment compared effects of adding mussels with not adding mussels to a bare sediment tidal flat. The experiment included two fence treatments (predation protection from birds [rope fence] and birds + crabs [plastic fence]), that were manipulated in a factorial design with the mussel additions. The experiment also included an unmanipulated control (no mussel additions; no fence around the plots) to be able to test for procedural fence effects. Start of experiment: 30 April 2015 End of experiment: 10 June 2015 (this is the time we took the samples)---Unmanipulated Control: C Bare flat + Rope fence: CB Bare flat + Plastic fence: FMussel additions + Rope fence: MMussel additions + Plastic fence: MF