A freeze-corer for simultaneous sampling of benthic macroinvertebrates and bed sediment from shallow streams

This paper describes a new liquid nitrogen freeze-corer for simultaneous sampling of benthic macroinvertebrates and the top 10-15 cm of bed sediment in shallow (< 0.3 m) streams. The corer weighs 12.3 kg and is operated by hand to sample a 0.03 m(2) area of the stream bed. The corer was tested by taking two samples at each of nineteen stream sites with varying bed texture in Yorkshire, UK. The high success rate (35/38) demonstrates the viability of this corer for year-round use in shallow urban and rural streams.