Text and photos by Amanda Mintz, SPP EVM Program Coordinator

Brian Bedilion and Rudy Smale compare a water quality test to a color chart.

From a tilapia farm to a wetland plant nursery, the aquaponics house at Stafford Creek Corrections Center has experienced major transformations over the past year. Creating a new program brings many challenges, particularly when we start from scratch with no existing model to imitate. Careful monitoring and teamwork means we can meet those challengers, and constantly improve the system.

What’s in a Name?

We often call our program the EVM, a name that rolls easily off the tongue. But not everyone knows that EVM stands for Emergent Vegetated Mat, or what an Emergent Vegetated Mat even is! To meet this challenge, EVM program technicians receive training in wetland ecology, plant propagation, and aquaponics, and are capable of explaining what we do to anyone who asks.

Technicians learned about the functions of wetlands, such as water holding capacity demonstrated by peat pods, and phytoremediation: the ability for wetland plants to absorb and transform pollutants.

Ecosystem Balance

Our aquaponics system relies on symbioses among fish, bacteria, and plants; for the system to thrive, maintaining optimal water quality is a constant concern. The aquaponics unit is a living system which can, at times, be unpredictable. Technicians monitor water quality daily, looking for changes in dissolved oxygen, ammonia, nitrate, and pH that could indicate a problem. Solutions to an imbalance can be as simple as increasing the water flow to plants, or as complex as adding a new heating system. With time and experience, we have learned how to increase the stability of the system through understanding the specific needs of the living things it supports.

Technicians monitor water quality with aquarium test kits. Occasionally water is taken back to The Evergreen State College‘s laboratory and tested there to make sure the kits are taking accurate readings.

Critter Control

Any nursery will eventually experience a critter invasion. Red-legged frogs and spiders are frequent visitors to the facility, as are less desirable critters like aphids. Technicians use low-impact methods to keep pests at bay, such as manual removal or biodegradable soap. As you can see, our plants are thriving (and the frogs are happy)!

Kent Dillard and Rudy Smale use manual control and biodegradable soap to remove aphids from the mats without harming plants or fish.

Over the next few months, the addition of two new hoop houses will significantly increase our capacity for mat production. We look forward to facing the challenges of expanding the EVM program now that we have a year’s experience under our belts. None of these projects would be possible without the tireless effort of Stafford Creek Corrections Center maintenance mechanics and plumbers, the EVM technicians, the folks at Center for Natural Lands Management and Washington Department of Fish and Wildlife, and all our funders: Washington Department of Corrections, Department of Defense, and the United States Fish and Wildlife Service (with a little help from us at SPP)!

This red-legged frog, lounging on the edge of a coir mat, is a frequent visitor to the aquaponics house!