By Elizabeth Trudel, Staff Writer
The Department of Environmental Science and Policy has installed elaborate aquaponics systems in the basement greenhouse of Bailey Hall. This was created to promote sustainability and clean water research, while also engaging students in essential hands-on applied science.
Robert Sanford, the head of the Environmental Science Department states, “The aquaponics greenhouse research project was built specifically for student use.” Over the course of the 2017-2018 school year, environmental science students have been working on aquaponics research alongside Dr. Karen Wilson, particularly in the research and analytical methods course she taught in the fall. Although the aquaponics research has been the main focus of the class, the department is currently seeking small aquaponics projects to integrate into future environmental science and policy courses.
In August of 2017, the greenhouse aquaponics project was kick-started with a generous $25,000 donation from Poland Spring/Nestlé Waters North America and support from the Maine EPSCOR project SEANET, a network of interdisciplinary researchers along the coast of Maine to help advance sustainable ecological aquaculture.
The aquaponics systems were built in the summer of 2017 and consist of two 250-gallon setups, each with a 150-gallon fish tank attached to a “swirl tank” to filter fish waste, connected to an 18-square-foot grow bed. The systems also include two 45-gallon fish tanks attached to two 4-square-foot grow beds.
The grow beds contain clay pebbles rather than dirt. Sanford explains that clay pebbles are effective in retaining moisture which is important as they are trying to collectively maximize the efficiency of the water supply. They are also porous and light-weight, which improves the aeration to the root systems of the plants and they also improve drainage which prevents rotting and promotes healthy root-systems.
Sanford explains that the setup uses blue nile tilapia fish which are originally from Africa. The fish were infants when the project started and have since matured significantly in size. Sophomore Environmental Science major, Kayla Curtis, states, “The most interesting part about the aquaponics research project this far has been watching the fish and plants grow bigger and stronger everyday.”
Sanford states that the fish are fed fish-food to produce ammonia-rich waste, which accumulates in the water. The effluent-rich water is toxic to the fish in high concentrations, but they’re essential for plant growth, so the wastewater is pumped to the grow beds. The bacteria that is cultured in the grow beds helps to break down impurities, and as a result, nitrogen remains, which is an essential nutrient for plants. The plant roots filter the water which now contains nutrients for the fish and is pumped back down to the fish. The cycle then repeats itself. He explains, “Our ultimate goal is to make the systems as sustainable as possible.” He expresses that aquaponics research is crucial because it is a potential world food source.
Sanford states that the research project as an opportunity for USM students to gain the skills and knowledge needed to succeed in the ongoing efforts to meet sustainable food needs not only in Maine but also around the world. He expresses that he is excited to see all of the different research experiments that students will be able to conduct over the coming years.