Tuna CSI: Forensic Traceability Technology & Incentivising DNA Data Collection
Traceability is the ability to trace a product through a supply chain. In the seafood industry, if undertaken, it is mostly achieved through paper. However regardless of the method of tracking, verification is critical should the aim be a certification for management practices, food safety or sustainability. Mass balance is one technique used to make sure the outputs match the inputs, but when a paper exercise, falsification of documents can occur.
With so much illegal fishing and fraud, a number of forensic techniques have been used to make sure that what is on the license and on the label is what is inside the packaging. Techniques that use genetic signatures, DNA, or environmental signatures such as the micro-chemistry of the ear bones of fish, can detect what species, what population, and what region the seafood originates from. These forensic techniques give more teeth to compliance — something critical to have because there is no point investing in policing if you cannot get a conviction.
During my post-graduate research at the Tsukiji Fish Market in Tokyo I took blood spot DNA samples from a range of tuna using a special paper developed by Prof. Leigh Burgoyne of Flinders University. The paper, known as FTA cards, allowed for easy collection and storage of DNA, and the data used for tuna genome research as a basis for loci selection for genetic diversity studies and breeding programs.
As my Tsukiji research was coming to an end, researchers and the industry in Australia began collecting DNA samples of Southern bluefin tuna. Over the period 2006 to 2010 tissue samples from 5,755 adults caught on the spawning grounds, and from 7,448 3-year-old juveniles caught in the Great Australian Bight were collected as an effort to detect what are known as Parent Offspring Pairs (POPs). The premise behind POPs analysis is the more related tuna you find, the smaller the population, just like you find more related people in a village, and the more unrelated tuna you find, the larger the population of tuna, just like a city. The results estimated the Southern bluefin tuna population to be substantially higher than previous estimates.
Along with this ground breaking research came the capacity to identify individual tuna from one another via differences in the DNA on what are known as micro-satellite markers. Therefore, along with the ability to store the DNA of individual tuna on FTA cards, if we could trace individually numbered whole tuna, loins, blocks, fillets through supply chains, we could feasibly link an individual piece of tuna sushi to the individual tuna it came from.
So in 2010, in Singapore, we commenced an internal project we dubbed Tuna CSI (crime scene investigation). With a container of -60C whole frozen Southern bluefin tuna, all individually tagged and reported to the Commission to the Conservation of Southern Bluefin Tuna (CCSBT), we brought in Japanese experts on tuna processing. Together we developed a numbering system for every possible product sold from a sashimi grade tuna, thus enabling us to track a product such as a 200g fillet of the belly, a chin, or a cheek back to each individual tuna and forward to each buyer.
To confirm the ability to track back to an individual tuna from a piece of tuna sushi, we took FTA cards with blood spot samples, and the tail cuts of the tuna used to provide the blood, to the CSIRO laboratories in Tasmania to see if they could match the cards and the tail cuts correctly. Using 8 loci, the lab were able to correctly match all six tail cut samples (biopsies) with the six FTA blood spot cards.
Thus, if it were a regulatory requirement that each tuna be numbered and a DNA sample recorded at capture or processing, and that the individual tuna number had to accompany each tuna or tuna product through a supply chain, an inspector in London say, could go into a sushi restaurant and take a sample of tuna and ask the chef for the number of the fish it came from. Then, the inspector could run a DNA analysis of the piece of tuna, request a similar analysis from the FTA card in storage in the country of origin or processing, and check to see if they match. If they do, the supply chain has not been broken, if they don’t, possible fraud has been committed, and if so, the chances of a conviction much higher.
Up and till recently though the cost and time taken to capture, store and analyse DNA has been prohibitive. However, in the near future, with the cost of the technology and time for analysis continually coming down, and with governments interested in preventing fraud and ensuring fish populations are being sustainably managed, and fish farmers interested in protecting their brand and selecting broodstock that grow faster and produce better quality, the uses and value of the DNA data is on the way up.
As a result, projects like the one above at Conservation X Labs to build a DNA Barcoder could soon provide rapid, non-destructive, cost effective DNA analysis to meet the aforementioned demand for the data. Although, as with many similar technologies, it can be the business model, or the lack there of, that can be the barrier to adoption. Especially if it has to be applied at one end of a supply chain and the value extracted at the other end, and if fragmentation of said supply chains is a barrier to cost and value sharing. This is where the blockchain and token ecosystems like Fishcoin could come into their own with proof-of-stake and incentives moving through supply chains. Where a fish farmer could collect DNA data, and a processor collects yield and quality data, and where they both benefit from having forensic traceability, brand protection, and better quality fish to supply a wholesaler who gives them tokens in return.
