Aquaculture for all

Can drones help to reduce oyster mortality?

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A $1 million project that aims reduces losses in the shellfish aquaculture industry through the use of unmanned vehicles is underway at North Carolina State University.

Unmanned vehicles could be used to ensure that oyster farmers avoid bacterial hotspots

The researchers plan to use small fleets of unmanned vehicles to monitor water quality in areas that are difficult and dangerous for people to access.

It’s a step, they say, that could help the state’s shellfish farming sector grow into a $100-million-a-year industry by 2030.

The researchers say the project will provide valuable data to inform management decisions that are key to unlocking sustainable growth of nearshore production of shellfish in North Carolina and beyond.

The four-year project was funded in late 2020 by a $1 million grant from the US Department of Agriculture’s National Institute for Food and Agriculture through the multiagency National Robotics Initiative 2.0.

It is being led by Sierra Young, an assistant professor in the Department of Biological and Agricultural Engineering. She says that the team is focusing on water quality because it has important implications for the safety of consumers’ food and for producers’ profitability.

Bacteria and other pollutants carried by stormwater into the ocean can cause nearshore producers to halt their harvests temporarily, until the bacteria reach safe levels. These closures are estimated to cost producers 25 percent of their average annual income.

“We hope to automate water testing and sample collection by creating a data-driven process that makes the window (of closure) as small as it needs to be,” Young explained in a press release issued by North Carolina State University.

The researchers plan to develop computer models that let them know which areas of an operation are most likely to become bacterial hotspots – places “where we can predict there might be higher levels of bacteria or other water-quality parameters of interest, such as dissolved oxygen or pH,” Young said.

Within those hotspots, the robots will use sensor probes to measure conditions, and they’ll take samples that can be returned for laboratory analysis.

“We’re looking to not just have robots that autonomously monitor the same area over and over,” Young says, “but we are integrating that water quality modelling with robot path planning to direct the robots to the most important and informative areas within a shellfish growing area.

“The idea is to get the most value out of a single deployment, especially when the number of water samples the robots can take is limited,” she says.

The researchers will also be looking at ways they can have unmanned surface vehicles (USVs) moving along the water communicate and work with unmanned aerial vehicles (UAVs), or drones. UAVs could, for example, be used to scout areas and let the USVs know where conditions might be unsafe to enter, and the USVs, or drone ships, could be used as landing and docking stations for the UAVs to expand the survey area.

The researchers plan to initially test their system in local lakes and ponds as well as at NC State and the university’s Marine Aquaculture Research Center in Carteret County. Full-scale testing will also occur in commercial oyster-growing areas.

“We’re designing our autonomous robot fleet to generate water quality data not only to inform management decisions in real-time but also to improve bacteria load forecasts and predictions,” Young says. “Our long-term goal is to get this information – and ultimately these robotic tools – in the hands of growers to help mitigate production and income loss due to shellfish mortality and unanticipated closures.”

A longer version of this story was originally published in NCSU’s College of Agriculture and Life Sciences News.