Barcoding sharks
Wellington College teacher Andrea Shaw spent 2006 at NIWA as a New Zealand Science, Mathematics and Technology Teacher Fellow. Her project work included sequencing shark DNA to determine DNA barcodes.
Andrea’s work was part of the ambitious Fish Barcode of Life Initiative (FISH-BOL), an international effort to collect DNA barcodes for all fish species. This will mean that any fish, or part of a fish (such as a fish fillet), can be identified by DNA analysis.
The FISH-BOL project
The Fish Barcode of Life Initiative (FISH-BOL) is one of the Consortium for the Barcode of Life’s (CBOL) major barcoding projects. In May 2009, more than 6,500 fish species had been barcoded out of an estimated 29,112. The project ran for five years.
The Fish-Bol project
Andrea Shaw, a teacher at Wellington College, spent a year at NIWA helping collect and analyse shark DNA as part of a major international research project.
For scientists to compare species across the world, they must all use the same gene. Therefore, all DNA barcoding projects compare the same region of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene.
For further information, see article: The ideal barcoding gene.
Samples of shark DNA
Andrea was comparing shark DNA barcodes. The shark DNA samples come from several sources. A sample can be taken from live sharks using a small, harmless fin clip, or samples can be taken from sharks captured off the New Zealand coast.
Catching sharks
Wellington College teacher Andrea Shaw gets up close and personal with some sharks.
Extracting and sequencing shark DNA
A small sample of flesh is taken from the shark and then DNA is extracted from it. DNA for the CO1 gene is amplified from the sample using polymerase chain reaction (PCR) and checked on a gel. The sample is then sent overseas where it is sequenced. The DNA sequence acts as a unique barcode that can be compared with other species of shark.
Sequencing shark DNA
Sequencing DNA requires several steps: first it must be isolated from the cells, then amplified by PCR, checked using gel electrophoresis, and finally sequenced. Teacher Andrea Shaw became an expert whilst working at NIWA for a year.
Why do we need fish DNA barcodes?
There are a number of benefits for establishing DNA barcodes for all fish species, including:
to conserve fish numbers by helping track fish populations and set fishing quotas
to prove identity and prevent consumer fraud, where high-value fish products are substituted with ones of less value.
Sharks
Sharks are one of the many species being identified by DNA barcoding.
See these videos taken by students on Sequencing shark DNA.
Related content
Discover more about research that has found that the long lifespans and slow reproduction rates of deep-water sharks and rays mean that these species are as vulnerable to overexploitation as whales once were.
