Benthic Fauna Identification and Sediment Particle size Analysis

Tender description

At present a requirement exists for the taxonomic identification of marine benthic fauna and sediment particle size analysis from samples collected in shallow waters of the Irish Sea in summer of 2016 all in one Lot. a. In summer of 2016 the Marine Institute completed a benthic survey of shallow water (<10m) soft sediment habitats in the north west Irish sea from Dundalk Bay south to Balbriggan in order to assess the effects of hydraulic dredging for razor clams on benthos and sediments. Samples were taken with a 0.1m2 Day Grab in muddy sand, sandy mud and fine sand sediments. All samples were washed on a 1mm sieve to remove sediments. Retained fauna were preserved in 4% buffered formalin and later transferred to 70% ethanol for preservation. Fauna are dominated by polychaetes and bivalves. A sample of sediment was taken from each grab and frozen. Images of sample content can be seen in Appendix 3. Samples are largely devoid of sediment but have some residual shell material. Sorting time is expected to be minimal. Samples to be analysed: a. Fauna: 213 samples. Identification of all fauna to species level where possible. b. Sediment: 213 samples. Analysis should produce particle size distribution data by wet sieving or laser diffraction or a combination of both. Tenderers should specify methods and a rationale for proposed methods. Raw data for each faunal sample and each sediment sample should be provided.