Cawthron successfully collaborates with organisations around the world in the development of molecular tools for the detection and identification of marine and freshwater organisms. The DNA-based assays support research and commercial monitoring programmes targeting marine and freshwater algae, cyanobacteria, and bioinvasive/pest species that pose a risk to the safety of seafood exports, water quality and biosecurity.
Tools include fluorescent in situ hybridization assays (FISH), a rapid automated system based on the sandwich hybridization assay (SHA), SHA and Quantitative PCR (qPCR).
Recent research projects include:
||Development of FISH assays for neurotoxic micro-algae based on the binding of fluorescently-labelled oligonucleotide probes to the 18S ribosomal RNA of the target species. This assay is also available for seastar (Asterias amurensis) larvae.
||qPCR-based detection is now being trialled for a range of toxic dinoflagellates including the paralytic shellfish toxin (PSP) producers, the Alexandrium group and Gymnodinium catenatum.
||A SHA assay has been developed for fish-killing micro-algae - the main targets currently are the neurotoxin producers Karenia and the raphidophytes. The assay is also being developed for detection of marine pest larvae. Collaboration with Monterey Bay Aquarium Research Institute (MBARI, California) will see their in situ environmental sampling processor deployed in NZ waters with associated DNA probe capability to monitor for toxic algae species and bioinvaders.
||Testing of qPCR probes for the marine bioinvasives species Asterias amurensis (developed by CSIRO, Australia) and Sabella spallanzanii (developed by SARDI) against closely related New Zealand species.
||Detection and enumeration of viable bacteria defined in the IMO standard for ships ballast water, using qPCR methods.
||The development and/or validation of qPCR assays for toxin producing or bloom forming cyanobacterial species.
||Development and validation of PCR and qPCR assay tools for identifying the presence and relative contributions of human and ruminant sources of faecal contamination in coastal catchments and downstream nearshore waters - read more on the Microbial Source Tracking page.