Impact and recovery of water quality in a river with salmon aquaculture

Abstract

Freshwater aquaculture can have negative impacts on chemical, physical and biological water quality. To contextualise the impact that these activities may have, a case study site in Ireland was monitored for 1 year. The study aims were to investigate the impact of freshwater aquaculture on water quality (biological, physical, and chemical) and the degree of the impact and recovery in water quality, within 1000 m downstream of a salmon smolt hatchery. The hatchery was monitored, at four locations (upstream, 10, 100, and 1,000 m downstream of the discharge point). Data on macroinvertebrate, macrophyte, hydromorphology and chemical characteristics were collected. Results for the physical monitoring indicated no significant changes in hydromorphology between up and downstream sites. Chemical water quality did decrease downstream in terms of nitrogen (N) and phosphorus (P). The greatest concentrations in N and P were found at 1000 m though it is likely additional contributions from agriculture impacted this site. Dissolved oxygen was steady throughout the monitoring campaign with a 13% variance between upstream and downstream locations. Changes in biological indices were statistically significant for taxa at all downstream sites. There were positive trends which indicated a degree of recovery in biotic indices.

Horticulture Irrigation Systems and Aquaculture Water Usage: A Perspective for the Use of Aquaponics to Generate a Sustainable Water Footprint

“…Nevertheless, life cycle assessment strategies are essential for sustainable fish production and to generate positive ecological footprint [122108]. There has been a variability of investigations about life cycle assessment and the quantification of sustainability in aquaculture food production [119], especially in comparison to the production of other animals (beef, chicken, pork) [106], but the life cycle assessment methods are presently not capable to measure the interactions between the natural aquatic environment and aquaculture food production [122].…”

Horticultural Irrigation Systems and Aquacultural Water Usage: A Perspective for the Use of Aquaponics to Generate a Sustainable Water Footprint

“…Nevertheless, life cycle assessment strategies are essential for sustainable fish production and to generate a positive ecological footprint [108,121]. There has been variability in investigations about life cycle assessments and the quantification of sustainability in aquacultural food production [118], especially in comparison to the production of other animals (cows, chicken, and pigs) [106], but the life cycle assessment methods are presently not capable of measuring the interactions between the natural aquatic environment and aquacultural food production [121].…”