Replace or repair damaged anti-predator nets around aquaculture systems

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • One study evaluated the effects on marine mammals of replacing anti-predator nets around aquaculture systems. The study was in the North Atlantic Ocean (USA).





  • Human-wildlife conflict (1 study): One site comparison study in the North Atlantic Ocean found that replacing anti-predator nets more frequently at salmon farms resulted in fewer salmon losses to harbour seal predation.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A site comparison study in 2001–2003 of 26 Atlantic salmon Salmo salar farms in the western North Atlantic Ocean, off the coast of Maine, USA (Nelson et al. 2006) found that farms that replaced anti-predator nets more frequently had fewer fish losses to Western Atlantic harbour seal Phoca vitulina concolor predation than those that replaced nets less frequently. Farms that replaced anti-predator nets more than once/year reported fewer losses of fish to seal predation than farms that replaced anti-predator nets once/year or less (data reported as statistical model results). Twenty-two farms replaced anti-predator nets more than once/year. Four farms replaced nets once/year or less. Farm managers were sent annual questionnaires in 2001–2003. Data were collected on methods used to deter predators and estimated numbers of fish lost or damaged due to seal predation.

    Study and other actions tested
Please cite as:

Berthinussen, A., Smith, R.K. and Sutherland, W.J. (2021) Marine and Freshwater Mammal Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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Marine and Freshwater Mammal Conservation

This Action forms part of the Action Synopsis:

Marine and Freshwater Mammal Conservation
Marine and Freshwater Mammal Conservation

Marine and Freshwater Mammal Conservation - Published 2021

Marine and Freshwater Mammal Synopsis

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