Lab journal

Thomas Trott, PhD – Friedman Field Station – August 2007




The demanding field day was followed by a labor intensive laboratory processing of collected substrate and macroalgae samples. The goal set for the next three days was to identify and separate all algae so that wet and dry weights of each species could be measured. In addition, all substrate samples were washed through sieves to separate meiofauna from macrofauna. Macrofauna samples were sorted into hard and soft organisms. In all, there were 30 samples to be processed this way, in addition to the 30 samples of macroalgae that needed to be carefully picked over so that no organisms were included in the wet weights. As data was generated, the information was entered into the NaGISA database through filling in a globally used spreadsheet.


Specimens of the different species of macroalgae were pressed as vouchers, and samples were taken for DNA analysis.



With the macroalgae portion of the processing completed, focus was now turned to the macrofaunal samples. Organisms were sorted from sand grains and detritus into phyla, e.g., molluscs, annelids, arthropods, cnidarians, etc. From this initial separation, each phylum was further scrutinized and every animal was identified to the lowest taxon, that being species when possible and the number of each counted. Just as with the vouchers of macroalgae, vouchers of macofauna were also taken, including some for DNA analysis. By performing this inventory, a ‘picture’ of the intertidal and subtidal communities could be reconstructed.

Editor’s note: Data analysis and comparison with historic data will continue in 2007-2008.