Stress and welfare in ornamental fishes: what can be learned from aquaculture?

Abstract

The ornamental fish trade is estimated to handle up to 1·5 billion fishes. Transportation and handling of fishes imposes a range of stressors that can result in mortality at rates of up to 73%. These rates vary hugely, however, and can be as low as 2%, because they are generally estimated rather than based on experimental work. Given the numbers of ornamental fishes traded, any of the estimated mortality rates potentially incur significant financial losses and serious welfare issues. Industry bodies, such as the Ornamental Aquatic Trade Association (OATA), have established standards and codes of best practice for handling fishes, but little scientific research has been conducted to understand the links between stress, health and welfare in ornamental species. In aquaculture, many of the same stressors occur as those in the ornamental trade, including poor water quality, handling, transportation, confinement, poor social and physical environment and disease and in this sector directed research and some resulting interventions have resulted in improved welfare standards. This review considers the concept of welfare in fishes and evaluates reported rates of mortality in the ornamental trade. It assesses how the stress response can be quantified and used as a welfare indicator in fishes. It then analyses whether lessons from aquaculture can be usefully applied to the ornamental fish industry to improve welfare. Finally, this analysis is used to suggest how future research might be directed to help improve welfare in the ornamental trade.

Wild caught ornamental fish: a perspective from the UK ornamental aquatic industry on the sustainability of aquatic organisms and livelihoods

“…, Ornamental Fish International, Animal Transport Association). Organisations, such as OATA, lay down comprehensive codes of conduct or charters and promote high standards (Stevens et al ., ). The members of such trade associations must meet set criteria and agree to adhere to these codes of conduct and charters.…”

“…As noted by Stevens et al . () however, membership of such trade associations is not compulsory. In terms of the UK ornamental aquatic industry, OATA estimates that approximately 50% of the industry are members.…”

Shade as enrichment: testing preferences for shelter in two model fish species

“…This is important not only for the broad variety of fish used as model species in biomedical, physiological and behavioural research (Ashley, ; Browman et al ., ; Huntingford et al ., ; Sneddon et al ., ; Williams et al ., ) and may also be useful for ornamental fish in captivity worldwide ((Ploeg et al ., ); see also Stevens et al . ()).…”

Measuring cortisol, the major stress hormone in fishes

“…In aquaculture, effects of changes in rearing conditions on cortisol titres have been intensively investigated, notably as related to the type of feed supplied (Sadoul et al, ), effects of water recirculation (Colson et al, ), or stocking density (McKenzie et al, ; Vijayan & Leatherland, ). Recently, a desire to measure cortisol without stressing animals has led to the development of non‐invasive methods to collect and measure the hormone (Huntingford et al, ; Mormède et al, ; Stevens et al, ). These methods also help to comply with fish welfare recommendations.…”