Life cycle assessment of a cold weather aquaponic food production system

Global fish consumption is increasing due to growth in the world's population, aligned with changes in human diet preferences. Consequently, environmental impacts due to this consumption increase are raising concerns with respect to fisheries' resource depletion and ecosystem deterioration. Natural fish environments are one of the ecosystems that are in danger of losing their healthy populations and carrying capacity due to anthropogenic activities, such as overfishing, waste emissions, and ecosystem change. One approach for fish production that minimizes waste and damage to ecosystems is tightening nutrient cycles. Aquaponic food production (where fish and plants are grown in a symbiotic system) is a prospective solution to reduce the adverse environmental impacts of food production systems, including nutrient losses and water consumption. A comprehensive cradle-to-gate life cycle assessment utilizing multiple midpoint environmental impact categories (such as eutrophication potential and greenhouse gas emissions) was performed on a case study aquaponic system, which cultivates multiple vegetable species as well as carnivorous hybrid walleye. This provided the opportunity to investigate the environmental impacts of using closed-loop aquaponics in a cold weather setting. The main contributors of the system's environmental impacts were recognized. Heat, electricity, equipment, and fish food contributed to >88% of environmental impacts in all investigated categories. Finally, alternatives using different real-case scenarios (effective space heating, equipment lifespans, fishmeal-free diet, etc.) were proposed and evaluated. This work seeks to inform the discussion as to the environmental considerations of aquaponic food production. [Display omitted] •Heat, electricity, equipment, and fish food are the environmental impact hotspots.•Heat is the main contributor to 7 out of 10 investigated impact indicators.•Fishmeal-free diet does not guarantee less impacts compared to fishmeal containing.•Lifetime equipment use causes a relatively significant drop in associated impacts. .•Significant reduction in electricity use impacts is achieved by coal replacement.