The length of time that farmed animals are exposed to handling practices, such as transport, pre-slaughter, and crowding are very brief when compared against the broader production stages. However, these processes can present equally if not more risks of damage, stress, and mortality. In addition, the handling and transportation of live aquatic animals is often an unavoidable stage in the farming process. Many of the concerns related to handling practices are effectively more acute versions of other factors listed throughout this module, a number of which are more likely to result in severe consequences due to the more sensitive conditions involved (e.g., confined enclosures and potentially rapidly deteriorating water quality involving build-up of CO₂ and ammonia, temperature control, spread of disease, injuries from mishandling etc.).

This video shows some examples of netting fish for husbandry purposes. For each example shown, identify the welfare risks, how they are being managed, and what further steps you think could be taken to ensure best welfare practices. Note there is no audio for this video. (download text description of content)

Crowding of fish prior to management procedures can be one of the most significant stressors to farmed aquatic animals. There are potential decreases in O₂ levels and water quality, along with increased chances of abrasive injuries and stress responses to net capture. It is once again worth noting that there will be a massive variation in water quality parameter requirements between species to ensure their welfare needs are met. In connection to water quality, transport duration (especially for fish transported in closed systems or out of water) is another significant factor.

This video shows some examples of husbandry procedures with juvenile fish. For each example shown, identify the welfare risks, how they are being managed, and what further steps you think could be taken to ensure best welfare practices. Note there is no audio for this video. (download text description of content)

In addition to crowding, practices of pumping, handling, grading, and loading of animals all provide opportunities for damage to the epithelial layer leading to increased risks of infection (due to loss of essential physical and chemical barriers). For many aquatic species, this epithelial layer serves additional roles in osmoregulation and locomotion. Another potential stressor includes fasting pre-transport, followed by exposure to novel environments. Excessive weight loading on fish at the bottom of nets, weighing buckets, or tanks should also be avoided. Where handling is prolonged, sedation may be required to reduce the stress response.

This video shows broodstock rainbow trout being stripped to produce fertillised eggs. Identify the welfare risks, how they are being managed, and what further steps you think could be taken to ensure best welfare practices. Note there is no audio for this video. (download text description of the video content)

Of particular concern during these short-lived events is that exposure to numerous stressors, either simultaneously or in rapid succession, can induce significant physiological stress that can often be mitigated or avoided entirely.  If left unmoderated, these disturbances can all evoke the neuroendocrine stress response, resulting in increased blood cortisol levels which (if kept at high levels over long periods of time) is associated with decreased disease resistance. Staff training therefore plays an integral role in minimising welfare risks posed to the animals during practices where these direct disturbances are unavoidable.