Biofouling management in New Zealand salmon farms: challenges and directions
Thursday, 10 December 2020
Webinar closed, recording available here
Biofouling presents an operational challenge for finfish aquaculture globally, as it adds weight and drag on farm structures and can lead to reduced water flow with associated effects to fish health. Copper-based antifouling coatings are often used to manage fouling on production nets; however, the use of copper can have negative environmental impacts. In New Zealand, the salmon aquaculture industry has moved away from the use of antifouled nets. While there are environmental advantages to not using biocides, untreated nets require regular cleaning to prevent occlusion and associated reduced water flow. Cleaning is generally carried out in situ using specialised high-pressure equipment. As net cleaning is generally undertaken without waste recapture, all biofouling present is released into the pen environment. The exposure of farmed fish to this material is believed to be linked to the development of skin health issues, with fish more vulnerable to pathogens, thermal stress and other factors that can increase mortality.
Lauren Fletcher, Marine Ecologist - Biosecurity and Invasive Species, Cawthron Institute
Dr. Lauren Fletcher is a marine biosecurity scientist at the Cawthron Institute, in New Zealand. Her research interests include the biology, ecology and impacts of marine pests with a particular focus on how these species interact with aquaculture activities. Lauren is currently conducting research investigating the impacts of biofouling in New Zealand’s salmon aquaculture industry. Other areas of interest include the effects of non-indigenous species on coastal ecosystems, novel management tools for marine pests, and benthic ecology more broadly. She also participates in broader projects evaluating marine biosecurity risks to New Zealand, including commercial consulting in the wider biosecurity area.