Amphipods (H. plumulosa) for laboratory experiments were collected
at the same location. Sediment containing amphipods was placed
into a 19 L bucket filled with seawater. The contents were swirled by
hand, causing any amphipods in the sediment to swim up into the
water column. The water was then decanted onto a 500 μm sieve and
any resulting amphipods were collected. In the laboratory, the amphipods
were kept in aerated natural seawater under conditions described
above, and fed green algae (Ulva spp. and Enteromorpha spp.).