The Hassayampa River is the source of groundwater that maintains one of the largest aquifers in Arizona making aquaculture and agriculture possible. The aquifer water is of critical importance and bares directly on the underlying reason why West Valley Farms was established in the Gila Basin, Arizona. Aquifer water has a saline content of 1.6-5.5 PPT (parts per thousand), i.e., 1.6-5.5 grams per thousand grams of solution. It is also worth noting that water flows through what an earthen filter and effectively microbe free until pumped to the surface.
Finding sustainably farmed shrimp requires looking at factors like water quality and what the shrimp get fed. As a basic rule, U.S. farmed shrimp are considered a “good alternative” by Seafood Watch because federal and state laws regulate water quality. U.S. farms also use 30 percent less feed for shrimp than most overseas processors. Feeding shrimp less yet higher-quality feed means a more efficient and healthier food production.
Post-larvae are purchased from a hatchery that certifies they are specific pathogen free (SPF). They are shipped to Arizona in oxygenated 30 PPT water. If directly placed into low salinity water they will not survive due to osmotic shock, therefore they must undergo a process of acclimation.
Over a period of `30 days the 30 PPT water in which the PLs arrived is slowly diluted with aquifer water until the water in which the shrimp are thriving is isotonic with the aquifer water. In addition, during this 30-day acclimation period the Pls are fed a series of diets that change rapidly over the acclimation period. Water quality, i.e., measurement of ammonia, nitrites and nitrates, are performed daily. And at the same time the salinity is slowly reduced to that of the aquifer water.
Ponds having been filled, the PLs that have transitioned to juvenile shrimp are now ready to be seeded into the 25 ponds available this year. A sample of each juvenile population Is netted and an average weight is calculated for the shrimp population. Based on pond area, shrimp are seeded at concentrations ranging from 20 to 80 shrimp per square meter.
Shrimp are fed twice a day with the diet listed to the right. Pond water measurements of ammonia, nitrites, nitrates, temperature and dissolved oxygen levels are performed daily.
Harvesting commences when shrimp reach desired size, generally not <2.5 months. Larger sizes being more desirable, partial harvests can be carried out from 2.5 to as long as 5.5 months. Partial harvests mean the pond biomass is reduced and the remaining shrimp grow to a larger size.
All ponds are sloped to the center along the linear axis. In addition, the ponds are sloped along the linear axis towards a screened off pit area. The effect is when the water is lowered and the screen is removed the shrimp are concentrated. A large diameter flexible hose connected to a fish pump is then lowered into the water and the shrimp are pumped to a dewatering conveyor machine. The dewatered shrimp coming of the end of the conveyor belt are dropped into a perforated basket tub liner containing 4oC fresh water in which a polyphenol oxidase inhibitor is suspended and allowed to reside for ~10 minutes with agitation.
After treatment the basket containing the shrimp is removed from the tank and transferred to another tank containing of 4oC fresh water. The suspended shrimp are stirred to remove any detritus and water is allowed to drain from the tank and shaved ice is layered over the shrimp before being transferred to the processing center.
When the desired amount of shrimp has been removed from the pond, water from the aquifer is used to restore the desired pond depth and grow out of the remaining shrimp can continue.
Freshly harvested shrimp are transported to the processing center along with a log of the time of harvest, the pond number, etc. On arrival tubs of shrimp are moved to a quarantine area in the processing center. The manager of the processing center at this point makes a decision as to how the shrimp are to be processed.
Samples of shrimp produced by Process 1-4 will be removed for each batch and sent for microbiological assay. Results will be correlated with harvested batch.
A barcode will be assigned to each harvested batch of shrimp and read at each process step. An additional code will be added for processed shrimp indicating date of harvest, date of process, and date of storage. When shipped to client a code encompassing shipping date, client contact info will be correlated with the above for West Valley Farms.
These steps will allow full traceability back to farm. Why is traceability so important?
- More Efficient Farms. With detailed data- and analytics-based records for each step along the supply chain, shrimp farms and production facilities can streamline operations, thereby increasing production volumes. Traceability can increase operational efficiency through record keeping, but that works only if farms take action accordingly.
- Sustainable Production. With traceability, retailers can eliminate producers for their unsustainable practices by refraining from buying, and retailers along with consumers can reward producers for their sustainable practices by paying price premiums. And traceability enables precise tracking of production locations.
- Improved Logistics. Transportation routes can be analyzed and optimized, minimizing food waste during transport and maximizing the ability to deliver fresh products.
- Sustainable Access to Markets. Buyers, especially those in sophisticated markets, will increasingly demand traceable products and eventually drop suppliers and markets that are not fully transparent and that represent a sustained reputational risk. Import authorities are establishing reporting and record-keeping requirements for imports of certain seafood products to prevent illegal, unreported, and unregulated and misrepresented seafood from entering their markets.
- Brand Enhancement. Traceability secures the brand image and can be used as a key marketing differentiator when other claims cannot be validated.
- Opportunity for Premium Pricing. Some consumers are willing to pay a premium for traceable food products, making traceability a market differentiator. To spread the wealth along the supply chain, some technology providers, for example, are working to develop ways to share the rewards with upstream players through token currencies and other incentives. To achieve these benefits, every player in the supply chain must participate and share trusted data with multiple stakeholders. Shielding supply chain data in modern value chains challenges the trust of those purchasing products and calls into question the reliability of companies that are perceived to have something to hide. Middlemen pose a major challenge: their movements are hard to track, and virtually no records of their operations exist. To avoid losing significance or, worse, posing an obstacle to more efficient farms.