CAHS Research: 2010-2011 field research season

Dr. Hammell led the research efforts of both the AVC Centre for Aquatic Health Sciences (AVC CAHS) and the international OIE Collaborative Centre for Aquatic Epidemiology and Risk Assessment of Aquatic Animal Diseases (ERAAAD).

During this period, the AVC CAHS team of 2 Research Scientists and 12 technicians delivered several established research programs in aquaculture health for the Atlantic region. In addition, Dr. Hammell led an initiative to develop  international projects within the OIE Collaborating Centre.

1) Expansion of integrated sea lice management program in late 2010 and summer 2011 seasons

The research group led by Dr. Hammell has unparalleled credibility for delivering evidence-based health management research to finfish aquaculture sites throughout Atlantic Canada. Based on our earlier work on the emergence of resistance of sea lice (a crustacean parasite of Atlantic salmon) to Emamectin Benzoate (EMB), we played a pivotal role in assessing other products used as bath treatments in which there is direct exposure of the parasite to the chemical. Although all of the treatments expecting to be registered in Canada are already in use, some for more than a decade, in other salmon-producing countries (e.g. Norway, Scotland), Canadian studies on the effects are required for their emergency release and eventual registration process.

Following on our key monitoring of AlphamaxÒ (Deltamethrin) in late 2009, we led the group that did detailed counting of sea lice stages (there are 11 life stages for this species of sea lice and the precise differentiation of the stages in the field is technically challenging) prior to and immediately after treatments. Crucial information regarding efficacy estimates for each grouped stage was provided to industry and regulators to gain temporary access to this product through PMRA (Pest Management Regulatory Agency of Health Canada) and EC (Environment Canada). However, when the temporary permit for Alphamax expired in early 2010, further access was denied for environmental fate concerns, leading the industry to turn to SalmosanÒ (Azamethiphos) and eventually to ParamoveÒ (Hydrogen Peroxide). Each change in treatment chemical also required adjustments to the delivery method. Skirting of cages was abandoned in favour of full tarping and then, as they became available, well-boats. Assessing the efficacy of lice bath treatments required a complex response to ever changing conditions and logistical challenges available through the AVC CAHS. The capability and credibility of AVC CAHS in performing scientifically rigorous assessments of field effectiveness of both Salmosan and Paramove provides third party, evidence-based support when gaining access to new therapeutants.

Dr. Jillian Westcott, a member of the AVC CAHS team, has modified bioassay methods for the new lice treatments adopted in 2009-2011 period. These bioassays require more than 500 lice collected from production sites (primarily in NB, but plans for NL and NS are underway) brought back to AVC and exposed under laboratory conditions to different concentrations of the treatment. This test provides the most reliable evidence for resistance development when analyzed as a trend. Our group has performed bioassays against several sea lice treatments and has done more bioassays than any other group globally over the past 4 years. Based on this wealth of data, industry and regulatory decisions continue to be informed by sound epidemiology.

Dr. Hammell and his team have presented and attended meetings with industry (farmers, veterinarians, and pharmaceutical companies) and regulators (multiple provincial and federal departments). Therapeutic options for 2010-11 were designed around an enhanced research plan supported by evidence-based decision making. This research plan was requested and funded by industry and New Brunswick Dept of Agriculture, Aquaculture, & Fisheries (NBDAAF) with the support of NS, NL, and PE departments responsible for aquaculture. The wide-reaching program consisted of six components with the primary function of providing credible sea lice field efficacy and resistance detection.

The Integrated Sea Lice Management Program (as outlined in 2009-10 report) pursues the following goals:

  • Ensure comparability between sites of valid sea lice count data through: 1- Training of farm staff on sea lice count methods: 2- Verification of sea lice counts by periodic audits (CAHS counter done independently from site counts)
  • Assessment of treatment efficacy using field counts post-treatment compared to pre-treatment counts in two situations:  1- Farm count data submitted to central recording system 2-3rd party counts done on a subset of treatments
  • Assessment of treatment responses at different concentrations under controlled laboratory conditions, including: 1- Bioassays against multiple products, 2- Archiving of sea lice for later diagnostic analysis based on tests developed for resistance
  • Assessment of sea lice risk factors using data collected from sites (such as cage location, depth, fish size, etc) related to sea lice count trends
  • Improved sea lice control options using data-driven models for optimal timing and selection of treatments, using a Decision Support System, based on farm and 3rd party count data submitted to a centralized information system.

Based on the credible and thorough evaluations done by the team led by Dr. Hammell in 2009, the salmon farming industry and provincial governments (primarily NBDAAF but also including the support of NLDFA and NSDFA) requested and funded this integrated program to be initiated.

In close collaboration with Dr. Crawford Revie, Canada Research Chair in Epi-Informatics, the Decision Support System with the many contributing elements (see diagram above) was initiated in 2010. This program represents a further building of our capacity to deliver results with the speed and flexibility required for farmers, veterinarians, and regulators to make science-based decisions on sea lice management.

2) Expansion of the Decision Support System (DSS) for sea lice management in 2010-11

Although the DSS is an essential tool for the industry to provide assurance to regulators, its ultimate goal is to provide timely information on which industry veterinarians and health managers can optimize decisions. Toward this end, our team has consulted with farm company managers and their veterinarians to identify useful information summaries that can inform strategies and direct action on sea lice control. We have also anticipated various key decision factors and constructed automatic reporting structures that streamline management. For example, we have created a “weekly threat report” (see figure below for example) that provides the sea lice change (in absolute numbers) from one week to the next, based on user-selected stages (or multiple stages) and inputted data up to the time of report generation. At the request of industry partners, the automatic generation of the report occurs at 7 am Tuesday because they indicated that they tend to make decisions on which sites to target treatments based on counts done up to the previous Friday (and they require Monday to input data).

We also created multiple graphing methods to examine treatment effect on sea lice changes following bath treatments.

There are many other functions of this system. They include methods for regulators to be assured that sea lice counts are being done and submitted to the DSS without revealing the actual count information. To this end, we developed a site (and company) compliance record for counts and for treatment information.

Lastly, we have developed means to compare at the site, bay management area (BMA), and industry-wide levels the sea lice trends by stage and week. This has proved invaluable to the regulators and industry associations to prove that considerable gains have been made to the management of sea lice since last year.

In 2011, we have initiated two major new areas of activity for the industry: training of farm staff toward a 3 level certification system, and third party audits of sites. These activities have been requested by industry to facilitate more trust in their reporting.

3) Development of international projects within the OIE Collaborating Centre

Based on previous successes and current activities in aquatic epidemiology, Dr. Hammell has led the process of AVC/UPEI becoming only the second Collaborating Centre in an aquatic discipline at the World Organization for Animal Health (OIE), based in Paris. In a partnership with the Norwegian Veterinary Institute, the rigorous process was finalized at the OIE World Assembly in May 2010. Although our designation as the OIE Collaborating Centre for Epidemiology and Risk Assessment of Aquatic Animal Diseases (ERAAAD) provides no automatic funding from the OIE, it does provide recognition of the credibility that the epidemiology groups at AVC, led by AVC Centre for Aquatic Health Sciences, are a global resource. This OIE Collaborating Centre formalizes our network of experts and extends knowledge and expertise to the OIE and its member countries for solving health challenges in aquatic species using evidence-based investigation and epidemiologic techniques.

The specific areas of focus for ERAAAD are evidence-based health management utilizing epidemiology for aquatic health, training (producer & scientist), research (investigations interacting with local vets/producers), and service (supporting policy for farmer & government) in the following areas:

  • Outbreak investigations & risk factor studies
  • Surveillance and diagnostic test evaluation
  • Disease control and clinical field trials
  • Quantitative analytic support for regional and national/international research
  • Decision support tools to deliver evidence-based outcomes to all levels of policy makers
  • Train experts in aquatic epidemiology and evidence-based health management

ERAAAD provides the vehicle to deliver an expanded range of research and training to aquatic food animal production in other areas of the world. In so doing, we continue to build on our recognition as the global leader in this field and further increase the attraction for new graduate students and early career scientists to come to AVC to work on Canadian and international research projects.

Toward this end, several key projects were initiated in 2010-11. Hammell presented at the Aquatic Disease Focal Points meeting for the Americas in Honduras (Nov 2010) and Vietnam (April 2011). In each case, the meeting involves the key decision makers for fish health policy and disease reporting to meet international trade obligations. These representatives for each government’s Chief Veterinary Officer often know very little about aquatic health and so this represents a real opportunity to introduce our expertise and offer to collaborate on research and training in their region. Several key contacts have been made in each location and are likely to lead to further work in the future. While in Vietnam, Hammell visited with a local aquaculture health expert and together toured Pangasius, Cobia, tilapia, shrimp, and barramundi production facilities. Research project discussions are on-going.

The OIE Global Aquatic Health Conference was held in Panama in June 2011 and Hammell attended. Again, it was a successful networking opportunity that generated a request for ERAAAD to assist deliver of a fish health course in Grahamstown, South Africa, in September 2011. Further short courses (particularly in aquatic epidemiology) are being developed to offer aquatic focal points at future meetings. AVC-CAHS and ERAAAD so-sponsored (and organized / presented) the International Aquaculture Biosecurity Conference in Trondheim, Norway, in August 2011. Hammell is also part of a disease surveillance workshop to be held in Adelaide, Australia, in December 2011. These short courses and workshops are not financially profitable (cost-recovery only), but they represent very successful marketing and name-recognition opportunities for ERAAAD and AVC in aquatic epidemiology. They are expected to lead to longer term academic relationships for graduate students and field research in these geographical areas. This also applies to the participation of Hammell in two OIE Ad Hoc groups: Aquatic Disease Surveillance and Aquatic Pathogen Differentiation, in which international policies are developed.