Table 2.

Sampling protocols used to assess plastic debris loads in urban runoff by the Algalita Marine Research Foundation. Water-based samples are collected upstream of debris booms, above the influence of the tidal prism.

habitat sampledcollection devicenet aperture (m)mesh size (mm)
surface; mid-streammanta trawl0.9 × 0.150.33
surface, edgehand net0.46 × 0.250.5 or 0.8
mid-waterweighted net0.46 × 0.250.33
bed loadstreambed sampler0.15 × 0.150.33
bottom sedimentsscoop15 l bucketa
  • aFifteen litres of bottom sediments are collected to a depth of 100 mm; in cement-lined canals, samples are collected where the concrete bottom terminates and natural bottom begins.