Technical Manager: Gillian Annett, DAERA-NI

The NMBAQC has now developed external tests for various Water Framework Directive (WFD) quality elements, in addition to the marine benthic macroinvertebrates scheme it has run traditionally. One of these quality elements is macroalgae. Trials were run, and a formal exercise is now being advertised. The exercises may be used as training exercises or for assessment of analytical performance. All scheme participants have a unique laboratory code for confidentiality.

The macroalgae component has two modules, one for rockyshore algal identification and one for opportunistic macroalgae/seagrass percentage cover and biomass.

Module 1 Rockyshore Macroalgae Identification

Ring Test (RM-RT)

A photographic ring test of twenty specimens will be sent out to participating laboratories on a disc. 

The test will comprise a range of taxa, some of which may be from the Reduced Species List used for Water Framework Directive monitoring. There will be up to five photographs of each taxon and some habitat information. Taxa included may come from anywhere across the UK and Ireland. Participants should identify the species from the photographs and information given. Results of ring tests will be circulated in a bulletin along with comments on noted identification issues. Full instructions will be given to participants with the exercise. A report will be circulated once all results have been evaluated.

N.B. multiple individuals within a laboratory can participate and send in separate lists.

Module 2  Opportunistic Macroalgae/Seagrass Percentage Cover and Biomass

Macroalgae & Seagrass Percentage Cover Ring Test (OMC-RT)   

This exercise will comprise 15 photographs of quadrats of macroalgal blooms and 15 photographs of quadrats of seagrass beds; these will be sent out to participating laboratories on a disc. The photographs will cover different levels of % cover. Participants will assess the percentage cover within quadrats using their normal method of estimation. Full instructions will be given to participants with the exercise. Results will be circulated in a bulletin along with commentary where any significant discrepancies or issues arise. A report will be circulated once all results have been evaluated and Z-scores calculated. 

N.B. multiple individuals within a laboratory can participate and send in separate lists.

Biomass ring test for macroalgae only (OMB-RT)

Three mock algal samples will be circulated to each participating laboratory. Please note that each test can only be done once within each laboratory. Tests will be made up of synthetic materials to mimic algal samples, as it is impractical to send out live material due to the risks of deterioration and non-reproducibility among participants. The mock algal samples will be mixed with sediment and possibly other materials; participants should rinse the samples and remove excess water using their normal procedures. The samples are then weighed both wet and air dried. Full instructions will be given to participants with the exercise. Results will be compared with the original dry weights to give an assessment of the efficacy of participants' sample processing. Results will be circulated in a bulletin along with commentary where any significant discrepancies or issues arise.