Fish and shellfish husbandry requires well trained aquatic animal health managers. Traditionally, these non-DVM persons have been academically trained in aquaculture, fish biology or microbiology. Their focus has been and continues to be infectious diseases and to a limited extent non-infectious disease processes. These persons usually have at least a BS, but most have a MSc or PhD. After formal academic studies, they are frequently placed in a practical situation that encourages them to broaden their fish medicine training to include epidemiology and actual health management. These individuals fill an important niche in a continually developing industry.

The U.S. aquaculture industry has matured considerably since its inception. Along with that maturation, has come a changed production environment with new demands. Various regulatory requirements are pushing aquaculture in directions not contemplated, even five years ago. Are the fish health professionals of today trained to meet these new challenges? The answer is, yes and no. This presentation will address the suitability of training for the non-veterinarian to meet the demands of aquaculture. At the same time, I would like to address some potential veterinary role in aquatic animal (fish and shellfish) husbandry.

Situation

Aquaculture continues to be the most rapidly expanding agriculture industry in the U.S. The expansion is occurring in the commercial sector and the bulk of this production is directed towards human food production. Public hatcheries, very important in the past for technology development, are still important for the wild fisheries resources of today, but no longer necessarily provide the technologic aquaculture leadership. Today, commercial catfish, trout, tilapia and striped bass producers (to name a few) provide the leadership. The requirements for the commercial sector are considerably different than for public fish production. Commercially, fish are raised at considerably higher rearing densities and with significant financial restraints compared to public sector fisheries. Commercial aqua-culturists must be profitable or they will be out of business. Fish health requirements take on a considerably different flavor as a consequence.

At the same time, regulatory requirements can be substantial. The aquaculture industry evolved during a time when the Food, Drug and Cosmetic Act was loosely applied to fish production. The FDA has subsequently instituted considerable scrutiny of the aquaculture industry. Today several compounds widely used in aquaculture are not labeled for that specific use. Concerns about food safety are raised. Food safety issues require demonstrable safe drug use. Hence, there is considerable interest in quality assurance programs. Drug and chemical use, as well as general effluent quality, can have a significant environmental impact. State and federal water quality regulatory agencies are increasingly concerned. Within this context, fish health management must occur. It may be that the chemical tools used in the past are no longer viable and alternatives must be developed.

While the bulk of aquaculture is directed towards fish destined for immediate human consumption, an important segment produces fish for stocking in lakes, rivers and streams. These fish are transported alive within a state or between states. Since they are alive, significant fish health conditions must be met and these fish must be certified specific pathogen free. This is particularly true for the salmonid industry but can apply to other aquatic species as well. The certification program is mandated by state fish and game authorities and most often relies on diagnostic tests suggested by the American Fisheries Society - Fish Health Section (AFS-FHS) in their Blue Book. The AFS-FHS also certifies individuals as Fish Health Inspectors or Fish Pathologists who are technically qualified to conduct pathogen status certifications. Most individuals certified to date are non-veterinarians and received their training at schools of fisheries, aquaculture or microbiology.

Non-DVM Training

The non-veterinary fish health professional receives considerably diverse academic training. This training very well prepares the fish health professional for research or for the detection of pathogens. The technical aspects of testing for infectious agents are well established. The AFS-FHS has played an important role in developing the diagnostic tests. Non-infections diseases, at least those that are characterized, are also readily diagnosed by the non-DVM. American Fisheries Society - Fish Health Section Fish Pathologist or Fish Health Inspector certifications further demonstrates the adequacy of their diagnostic abilities. FHS professional certification requires considerable academic training including courses in fisheries science, finfish and/or shellfish health, bacteriology, parasitology, virology, mycology, pathology, epidemiology, immunology, histopathology and toxicology. Other public health courses are often taken as well. Three years professional experience and an examination is required for fish pathologist certification. Certification as an inspector, while not as academically rigorous, requires at least three years professional experience as a fish health inspector. Most training allows the non-DVM fish health manager to readily integrate this information with fish biology, physiology and limnology to develop effective management plans. The success of aquaculture to date speaks well of these individuals.

The non-DVM MSc or PhD is also well prepared to conduct fish health research in their particular specialty. Much of today's fish health research is carried out by these non-DVM professionals. These persons are frequently employed by the U.S.F.W.S., veterinary colleges or other academic institutions.

Where the non-DVM fish health manager may need greater depth is the integration of specific diagnostic data with epidemiology and food safety to develop the best treatment or fish health management plan. Economic information must also be integrated to develop various fish health maintenance practices. Considerable experience must be gained before the non-DVM health manager can consistently implement effective herd (school) health practices within the financial constraints of current aqua-cultural practices. Of course, the same comments apply to the veterinarian involved in fish medicine as well.

Additionally, the non-DVM practitioner is not currently trained in pharmacology, food safety or environmental safety. All increasingly important aspects of fish health management and aquatic animal production, particularly for the food animal producer.

Unfortunately, the science of fish health management or medicine is', in many respects, still in its infancy. The tools the fish health practitioner has available are limited. Diagnostically, we are limited to searching for infectious agents and fairly limited environmental analyses. Serologic analyses, including actual physiologic determinations are generally not helpful because of extensive stock (school) variation and the great sensitivity of fish to stress resulting from sampling. Even if environmental parameters are implicated as a confounding factor, the ability of the fish health manager to manipulate the environment in commercial production situations is limited because of physical or financial constraints. The economic advantage of integrated fish health management needs to be demonstrated before commercial producers will implement them.

Additionally, the fish health practitioner is limited in the therapeutic tools available. Over-the-counter drugs and water treatments are extensively used but there are very few of these specifically labeled for aquaculture use. Extra-label drug use, under commercial food fish production conditions, has very limited value because many fish diseases are treated by medicated feeds.

For example, should a different antibiotic be deemed more appropriate than an over-the-counter drug, the veterinarian still cannot administer it because it must be in feed. Extra-label drug use policy does not permit medicated feeds. Further, it is questionable if the commercial fish producer would want to use an extra-label drug because of drug residue concerns. Veterinary prescription or judgment does not ensure drug residue absence. There is particular concern that since fish are so different from their terrestrial counterparts they would not metabolize pharmacologic agents the same. Clearly, both veterinary and non- veterinary based health management is hampered by the lack of tools and scientifically credible information.

Future

There remains considerable opportunity for the non-DVM and DVM fish health specialist. Changing federal requirements may de-emphasize some opportunities for the non-DVM. These federal requirements include food safety and fish health or pathogen free certification regulations. This is an evolving area so it is difficult to predict the outcome. There is a great need for cost-effective fish health management techniques to be developed. These management tools must account for environmental and food safety factors. The non-DVM can be well trained to diagnose and treat the known fish diseases but these diseases are generally due to infectious agents. The state of aquaculture technology and the lack of economic incentive for extensive preventive measures hamper veterinary involvement in aquatic animal medicine. In many respects, the aquaculture industry parallels the poultry industry perhaps 30-50 years ago.

Because of current restraints to fish health management there is great need for research and development. New tools and knowledge must be generated to meet the needs of aquaculture. Hopefully the non-DVM and DVM can combine their efforts. Both groups offer important insights.