Techniques for sampling motile macroinvertebrates associated with Posidonia oceanica seagrass meadows have mainly involved the use of hand-nets and suction samplers or collection by hand.These techniques give unreliable quantitative estimates or have practical difficulties.A large cylindrical saw-rimmed corer was designed and used successfully to obtain quantitative samples of Mugs macroinvertebrates from both foliage and root-rhizome matrix of a Posidonia oceanica meadow in Malta (central Mediterranean).Choice of the appropriate sample unit size was assessed by comparing the relative accuracy, precision and efficiency of three different core diameters: 25 cm, 35 cm and 45 cm.
The results suggest that for comparison of macrofaunal species richness and abundance between different meadows/sites the 25 cm diameter corer is recommended.For surveys aimed at estimating total diversity within Placenta cream a particular site, the 35 cm diameter corer is more appropriate.