Date: Apr 13, 2016 Author: Mary Catherine O'Connor Source: IOT Journal (
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Oyster farming is still living in the Dark Ages, and Daniel Ward says he wants to bring it into the 21st century. The entrepreneur and researcher is working with Verizon on a pilot project at Ward Aquafarms, his 10-acre aquaculture operation in Megansett Harbor, on Massachusetts' Cape Code, aimed at improving the traceability of his oyster harvest.
"Aquaculture is pretty rudimentary compared to terrestrial agriculture," says Ward, who, in addition to running Ward Aquafarms since 2011, serves as a research fellow at the Marine Biology Laboratory in nearby Woods Hole. "The condition of soil, its nutrients, how much moisture is needed--that is all driven by data," he says, referring to terrestrial farming practices. But oyster farmers, he adds, "just set things in water and see what happens."
Oyster cages sitting on a dock, post-harvest, seen through Mobotix camera
When oysters are ready to harvest, they are pulled from the water, boxed up and sent up the supply chain. But because they are shipped and often consumed while they are still alive, oysters pose a human health danger if they are not properly chilled from the time of harvest and at each step in their transit, up until the point of consumption. Vibrio vulnificus and Vibrio parahaemolyticus--bacteria that can be found in the seawater where oysters live--may be present in raw oysters in quantities high enough to cause illness. Warm temperatures during the shipment process may cause the amount of Vibrio bacteria inside oysters to increase to dangerous levels.
For that reason, tracking temperatures at harvest, and as oysters move through the supply chain, is important--but Ward says it is a manual process, carried out with pen and paper. "I write the date, time and temperature of the water when I harvest and pass that along to the wholesaler," he explains. The wholesaler and any logistics providers that handle the oysters from the point of harvest until when they reach the consumer must also add temperature data to this record.
Vibrio bacteria exist naturally in marine waters around the world. Oysters accumulate these bacteria as they filter water while feeding. The bacteria multiply when the water is warm, and oysters harvested from warmer regions and seasons, therefore, often have high levels of these bacteria. To make temperature tracking more reliable, easier and precise at the point of harvest, Ward has installed a cloud-connected thermal radiometry sensor at the oyster farm.
The sensor, made by German manufacturer Mobotix AG, is integrated into a camera that generates dual side-by-side images: both conventional and thermal video. The camera is mounted on a dock in the bay, Ward explains, in a position enabling it to capture images of workers pulling the cages containing the mature oysters from the water. The time and date appear on the conventional video images, while the thermal image shows a temperature profile. The camera continues to track the temperature while the oysters are pulled from the cages and prepared for shipment inside mesh bags, thereby generating a more complete temperature profile than just the water temperature at the time of harvest. The camera transmits this data to the Verizon ThingSpace IoT platform via a cellular modem, and the data is stored in the cloud and can be referenced la
Should consumers report illness due to consuming oysters, representatives from the U.S. Food and Drug Administration's National Shellfish Sanitation Program (NSSP), or a local or state-level affiliate, contact the grower and all supply chain partners to inquire about the shipment's temperature history, in order to compile a complete view of that history. "With all shellfish," Ward states, "the goal is to reduce the temperature to 45 degrees Fahrenheit [7.2 degrees Celsius] as soon as possible after harvest and keep it there until it reaches the final consumer." State agencies set the amount of time by which shellfish must be brought to 45 degrees Fahrenheit post-harvest, Ward says; some states mandate that this occur within one hour, while others give a five-hour window.
"The Vibrio bacteria growth rate follows an exponential growth curve with increasing temperature," he explains. "If [a shipment] sits on a truck at 60 degrees on a cloudy day in May, it may be many hours or days before the bacteria can grow to a density which would cause sickness. However, if the oysters sit on the back of a hot truck at 90 degrees on a sunny day in July, the bacteria could proliferate within hours to a level which may cause sickness."
According to Ward, the government can take up to 45 days to complete the tracking process, from the day that a batch of oysters is harvested until the time that an outbreak of illness is attributed to that batch. "So if oysters harvested in mid-June end up being traced back to an illness, the oyster farm might not be made aware of this until late August," he explains. And at that point, the farm might be required to close while the investigation is conducted. "If the cause of the problem can't be determined, it always falls back on the farm," he says. "And no one wants to buy oysters from a farm that has been closed in the past due to health concerns."
That is why Ward plans to build on the use of the thermal radiometry sensor integrated in the camera by adding temperature-tracking tags to each bag into which the oysters are placed after being harvested and cleaned. Verizon representatives will bring the tags--which will transmit temperature data to the ThingSpace platform via its cellular network--to Ward's aquafarm later this month.
Exactly how many will be used and for how long are unknowns at this time. A representative from Verizon says the company is still busily testing and developing the sensor tags, and she could not specify the sensor manufacturers with which Verizon is working.
Ward's goal is for the tags to eventually replace the manual farm-to-fork record-keeping process currently used to track oysters' temperatures. For the pilot, however, he will first evaluate whether the technology works and how easily he, other supply chain partners and eventually the NSSP will be able to access each shipment's temperature history from ThingSpace. If the technology appears to work as promised, the next step will be to work out the economics and determine how tag cost--also an unknown at this time, Ward says--will be either spread across the supply chain or bore by consumers. "Will consumers pay a premium for oysters if they know they're less likely to make them sick? I think so," he says.
