What is a Split-Pond Partitioned Aquaculture System (PAS)?

According to the Southern Regional Aquaculture Center, “The Partitioned Aquaculture System (PAS) developed at Clemson University combines the process control advantage of recirculating aquaculture with the lower cost of pond aquaculture.” Since then, scientists at Mississippi State University have begun to modify the original Partitioned Aquaculture System, offering the aquaculture industry a new way to maintain fish crops.

How Does Split-Pond PAS Work?

According to the Southern Regional Aquaculture Center in their article on how the original PAS works, “The PAS superimposes a water velocity field upon the pond, making it possible to reconfigure the pond into separate, controllable compartments for the processes of fish culture, gas exchange, algal growth and waste treatment.” This means that the PAS offers farmers a malleable environment for their fish crops. The PAS is made of a few key features, including system paddlewheels, sluiceways, a fish confinement area and an algal basin.

A “sluiceway” is simply an artificial channel allowing farmers to control the flow of water through the earthen wall between the two areas of their system. In this case, the first area is the larger “fish-confinement area” where the fish live. The second area is the smaller “algal basin” that collects algae separately from the fish’s habitat and allows the production of dissolved oxygen via photosynthesis.

The Split-Pond variety includes a few modifications from the original PAS but maintains the general design and purpose of the original. The first and main difference is the true “split” in its structure that gives it its name. The Global Seafood Alliance defines Split-Pond PAS as being “constructed from existing earthen ponds by splitting into two unequal sections with an earthen levee breached with two sluiceways. One sluiceway is fitted with a large paddlewheel that pumps water out of the fish-confinement area. The other sluiceway is for return flow from the algal basin into the fish-confinement area.”

Why Use a Split-Pond PAS?

Starting in 2003, Craig S. Tucker, Ph.D. and Susan K. Kingsbury studied the Split-Pond PAS system as a modified version of the traditional PAS system designed by Clemson University. The goals for Split Pond PAS are to facilitate feeding, ease of inventory, ease of harvest, health management and protection from predators in an efficient way that lessens the need for management labor. The modified design also allows farmers the ability to control their fish’s environments to a greater extent.

One key reason for using a Split-Pond Partitioned Aquaculture System has to do with dissolved oxygen. The paddlewheels and algal basins both contribute to oxygen regulation in the fish-confinement area. The algal basin can collect algae and produce oxygen via photosynthesis, and the paddlewheels turn over the surface of the water to aerate the tanks.

In comparison to the traditional PAS, the Split-Pond PAS has a smaller algal basin and a significantly larger fish-confinement area. The resulting system size increases the opportunity for stocking fish, allowing farmers to keep a higher number of fish on their farms at a time.

Optimizing Dissolved Oxygen Management with Split-Pond PAS

The Global Seafood Alliance identifies dissolved oxygen requirements as a key design parameter for any Split-Pond PAS. They make note of the algal basin’s inability to create dissolved oxygen via photosynthesis overnight, so the algal basin is closed off overnight, and the ponds are instead aerated using the system’s paddlewheels.

Understanding the dissolved oxygen levels of your Split-Pond PAS system is crucial to the management of any aquaculture habitat. The Aquasend Beacon™ sends real-time data to any device connected to a network. With the Aquasend Beacon™ aquaculture farmers can ensure their system’s oxygen levels are within a healthy range. Having water quality data at your fingertips can reduce labor costs, travel costs and loss of product and offer confidence in the operation of your Split-PAS, traditional PAS or another aquaculture habitat.

To learn more about other aquaculture habitats read our blog, “What is an Aquafarming Tank or Raceway?”

To learn more about the Aquasend Beacon visit our website.