Dredged material disposal site monitoring across England and Wales: results of sampling under SLAB5 (2008-09)

The data and scientific findings of the dredged material disposal site sampling around the England and Wales coast during 2008 under SLAB5 are presented. The background, issues and impact hypotheses pertaining to each site are also detailed. During 2008, a total of 8 disposal sites were sampled with a further site investigated by modelling the likely fate of disposed material at different tidal states. Parameters monitored varied across sites (governed by the specific issues and subsequent impact hypotheses for each) included multibeam and sidescan sonar acoustic techniques, sediment particle size assessments, sediment organic carbon and nitrogen, macrofaunal communities, sediment profile imagery (SPI), and the assessment of a range of sediment contaminants including tributyl tin (TBT), polycyclic aromatic hydrocarbons (PAHs), organohalogens (e.g., pesticides, flame retardants) and trace metals. The results of such sampling and analyses are presented in this report in terms of whether observations are aligned with those expected for that particular site, and, where possible, temporal comparisons are made to give an indication of whether changes are showing positive or negative trends with respect to the parameters monitored. This report, therefore,helps provide an insight as to whether a particular site should be the subject of sampling in successive years.