Molecular detection and genotyping of Aphanomyces astaci directly from preserved crayfish samples uncovers the Norwegian crayfish plague disease history.

Aphanomyces astaci causes crayfish plague in European freshwater crayfish, but most historical epizootics lack agent isolation and identification. Although declared as crayfish plague outbreaks by the Norwegian Competent Authorities, only presumptive diagnoses without agent isolation exist from Norwegian epizootics until 2005. Molecular methods now allow both A. astaci detection and genotype determination from preserved samples. We therefore aimed to (1) investigate molecularly if A. astaci was involved in a selection of mass-mortality events in Norwegian noble crayfish populations from 1971 to 2004, and (2) determine the eventually involved A. astaci genotype groups both from these historical and also more recent mass-mortality events. DNA was extracted directly from presumptively infected crayfish tissues, and screened by A. astaci specific qPCR. A representative selection of positive samples was confirmed by ITS-sequencing. Finally, genotype determination was performed with microsatellite markers that distinguish all known A. astaci genotype groups. The molecular examination detected A. astaci in crayfish materials from all examined mass-mortality events. The first event in 1971-1974 was caused by the A. astaci genotype group A, presumably the first genotype group that entered Europe more than 150 years ago. All later outbreaks were caused by the A. astaci genotype group B which was introduced to Europe by importation of signal crayfish in the 1960s. The results suggest that molecular methods can verify the involvement of A. astaci in the vast majority of observed crayfish mass mortalities in Europe whenever preserved materials exist. Moreover, microsatellite genotyping can reveal at least parts of the underlying epidemiology.

Expanding the moral circle: farmed fish as objects of moral concern.

Until recently fish welfare attracted little attention, but international and national legislation and standards of fish welfare are now emerging and an overview of these developments is presented in this study. Whereas animal welfare legislation is based on public morality, animal ethics does not automatically accept public morality as normative and elaborates arguments regarding the way humans should treat animals (referred to as moral standards). In this study we present the most common animal ethics theories. For most of these, sentience is considered a demarcation line for moral concern: if an animal is sentient, then it should be included in the moral circle, i.e. receive moral consideration in its own right and some basic welfare should be ensured. As for fish, research has revealed that the sensory system of teleosts can detect noxious stimuli, and that some kind of phenomenal consciousness, allowing the fish to feel pain, seems to be present. This raises the ethical question as to how much evidence we need in order to act on such indications of fish sentience. A simple risk analysis shows that the probability that fishes can feel pain is not negligible and that if they do indeed experience pain the consequences in terms of the number of suffering individuals are great. We conclude that farmed fish should be given the benefit of the doubt and we should make efforts that their welfare needs are met as well as possible. Finally, the way forward is briefly discussed: efforts must be made to understand what fish welfare means in practical fish farming. This will involve the development of research and education, greater accountability and transparency, compliance with and control of policies, and quality assurance schemes.

OIE involvement in aquatic animal welfare: the need for development of guidelines based on welfare for farming, transport and slaughter purposes in aquatic animals.

Globally there has been increasing agreement that aquatic animals are entitled to certain welfare considerations and standards. This trend will most likely grow stronger in the years to come. The World Animal Health Organisation (OIE) has realised that animal welfare issues are receiving increased public attention by governments as well as non-governmental and consumer organisations. Animal welfare was identified as a priority in the 2001-2005 OIE Strategic Plan. OIE Member Countries decided that the OIE must provide international leadership on animal welfare. Animal protection includes important scientific, ethical, economic and political dimensions and thus a need to establish guidelines in the field of welfare. The OIE established a permanent Working Group on Animal Welfare (2002) to coordinate and manage animal welfare activities. It was indicated that the welfare of animals used in agriculture and aquaculture should be prioritized and that the development of policies and guiding principles on transportation, humane slaughter and killing for disease control purposes was a primary task. Thus, the OIE established two ad hoc Groups to draft the guiding principles on the humane slaughter of fish for human consumption, killing fish for disease control purposes, and land and sea transport based on the generic OIE guiding principles and policies for animal welfare. Below, the scope and development of these Guidelines, the OIE guiding principles for the welfare of aquatic animals as well as the OIE in house procedures for the approval of a set of guidelines to be incorporated into the OIE Aquatic Animal Health Code will be described in more detail.