Performing Department
Biology
Non Technical Summary
Aquaponic practices in small and mid-scale systems have often low revenue because fish production is suboptimal compared to plant production. Therefore, there is a need to find new commercial fish culture models that integrate with established plant cultures in aquaponic systems and maximize the profitability of mid and small-scale aquaponic systems. Our exploratory seed project aims to identify novel fish models that can lead to new lines of production in aquaponics. Thus, we will characterize the reproductive output and optimized welfare parameters of green swordtail and of fathead minnow cultures in a small-scale and mid-scale basil aquaponic set-up. We additionally propose extension activities to advance the connection between academia and local farmers (e.g., design of a new aquaponic courses directed to increase the aquaponics taskforce). This proposal is included in the Program Area Agriculture Economics and Rural Communities and directly fits the Program Area Priority of Small and Medium-Sized Farms. Our long-term aim is to develop and adopt new fish culture models that assist farmers in the establishment of aquaponics strategies and technologies that will enhance economic sustainability and competitiveness in the farm market. This will be achieved by addressing the need of 1) create opportunities for new markets in aquaponics systems 2) promote novel fish culture as a source of revenue in aquaponics systems 3) develop effective strategies to aid in the development of research, education and extension/outreach programs that meet the needs of underserved small and medium-sized farmers and ranchers.
Animal Health Component
40%
Research Effort Categories
Basic
20%
Applied
40%
Developmental
40%
Goals / Objectives
ObjectivesOur long-term goal is to develop the culture of two novel aquaponics fish species and determine the optimal input of macronutrient derived from plant fertilizer that maximizes these fish welfare. The overarching hypothesis of this proposal is that K and Fe can affect hormonal output during fish sexual reproduction reducing reproductive yield and fish welfare. Our experiments will answer the following experimental aims: (1) Characterization of reproductive output of green swordtail (Xiphophorus helleri). in a small-scale and mid-scale basil aquaponic set-up; and (2) Characterization of reproductive output of fathead minnow (Pimephales promelas) in a mid-scale and large-scale basil aquaponic set-up. We also have an educational and extension third aim that will focus in the design a new aquaponic course and stablish connections with the local farmer community.
Project Methods
AIM #1. Characterization of reproductive output of green swordtail (Xiphophorus helleri) in a small-scale and mid-scale basil aquaponic set-up. Small-scale experiments: We will co-cultivate basil with green swordtail for 3 months. The experiments will be conducted in spring in four aquaponic units located in the green house of TXST. The green house has partial control of temperature and a retractable semi-translucent ceiling cover to prevent direct sunlight. Each aquaponic unit contains a 500L fish tank, a biofilter tank, a mixing tank, a plant tank with a floating bed of 160x122x40 cm (63x48x15 inch) with a surface area of 1.9 m2 (20.7 ft2) hosting 24 plants/ bed, a submersible sump pump of capacity 1 HP and ball valves to regulate the water flow (Fig.1). The water pumps will be continuously recirculating water. Coconut coir will be used as the medium in the plant bed to anchor plants. We will culture and harvest basil 3 times during the experiment. Green swordtails will be stocked at a density of 50 individuals per tank (15 males, 35 females) and fed daily with swordtail pellets (Hikari micro pellets) supplemented with black fly larvae (3% w/w). We produce our own black fly larvae in our TXST greenhouse. Adult fish will be hosted in a 1 m3 basket with mesh walls located inside the tank, thus when juveniles are born can escape the basket and avoid predation from parents. Swordtail pregnancy last 1 month and the embryonal sac have embryos at different stages of development. Thus, one single female can have dozens of fish in 3 months.Due to the fast growth of basil, we will plant and harvest two generations of plants during the experiment. Preliminary experiments showed a nutritional deficit in our basil crops in the aquaponic system. Thus, once a week, two units will have plants leaves sprayed with fertilizer containing knowns amounts of Fe, K and two units will be sprayed with water.We will monitor daily for water quality and environmental conditions including temperature and humidity, water temperature, pH, dissolved oxygen [DO], water ammonia, nitrites, nitrates, and alkalinity. We will take weekly water samples (from the different sections of the aquaponics system), adult fish samples, juvenile fish samples and basil leave samples. Moreover, we will quantify reproductive output in fish, and yield basil production weekly. To quantify the flow of nutrients in water fish and plants we will measure chlorophyll of the basil leaves, nitrogen (N), potassium (K), calcium (Ca), magnesium, (Mg), phosphorus (P) and sulfur (S) and seven trace elements (chlorine (Cl), iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu) and molybdenum (Mo) of the fish food, leaves, water, and waste by variety of sensors; as well as X-ray fluorescent (XRF) analyzer technique developed at Dr. Asiabanpour lab or using chromatography lab services in TXST. Additionally, fish and water samples will be extracted and analyzed for steroid metabolomics profile to asses reproductive and stress status. For that fish will be homogenized with ethanol 70%, centrifuged, and supernatant evaporated and reconstituted with phosphate buffer. Water and tissue extracts will be extracted by solid phase extraction methods using a C18 Seppac [33]. Extracts will be stored in methanol until analysis by the LC-MS in the Metabolomics and Small Molecules center at NC State University [9]. This technique allows to measure up to 15 different steroids in 80 samples per run. The steroids to be measured are estradiol-17β, testosterone, 11-ketotestosterone, 17α,20ß-dihydroxy-4-pregnen-3-one, androstenedione, cortisol, pregnenolone, progesterone and other related progestogens. The PI used these methods in the past and feels confident with this technique. We will analyze statistical differences between treatments for different variables with ANOVA using GraphPad Prism 9.0 software (San Diego, CA, USA). The PI and co-PI will coordinate with the master's student on the development and sampling of this experiment at TXST.Mid-scale experiments. These experiments will be repeated in the mid-scale aquaponics set up in SFCC. The mid-scale system at SFCC has a 500ft2 dome greenhouse also operates a year-round aquaponics system on campus with goldfish and koi.The TXST master student will displace for 3 summer months to Santa Fe and will perform these experiments supervised by R.. Shultz. During this time the master's student will learn several techniques in aquaponics under the supervision of R. Shultz and will also be exposed to the different extension programs that SFCC has developed with the local communities.AIM #2. Characterization of reproductive output of minnows in a mid-scale and large-scale basil aquaponic set-up. We will perform, in the second year fall in TXST and summer at SFCC, the same experiments detailed in aim 1, but replacing the swordfish by fathead minnows. The main difference will be that minnows will be stocked at 20 females: 20 males per tank. Also, instead of baskets we will introduce floating spawning mats. Eggs from floating mats will be collected and hatched embryos will be cultured in 500L fish tanks in Dr. Huertas fish laboratory.AIM 3#. Development of a virtual aquaponics course with a practical laboratory and build of farmers connections. The Pi and coPI will design a 3 credit aquaponic course that can be taught virtually during the spring semester. This course can be added as an elective class to the biology, agriculture and engineering programs or offered as a formative course for anyone interested. The course will be composed of several modules, each one of them taught by a different PI. The TXST master sand SFCC student will design and perform outreach activities directed to local farmers (e.g., farm visits, in which we will facilitate information of aquaponics courses and record information to build a database of local farmers) both in Texas and New Mexico.