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ABOUT...
ACROSS CANADA
AND...
RESOURCES
FACT SHEET - INTEGRATED AQUACULTURE RESEARCH AT ST. ANDREWS BIOLOGICAL STATION
In the past quarter century, aquaculture in Atlantic Canada has become a major economic activity and force for community and regional development. Blue mussels, sea scallops, oysters, Atlantic salmon, Atlantic halibut, rainbow trout and striped bass are some of the marine species that have been cultivated in Atlantic Canada. Research at Fisheries and Oceans Canada’s St. Andrews Biological Station (SABS) in the late 1970s led to the development of the Atlantic salmon aquaculture industry in the Bay of Fundy. By 2004, production from this new industry was approximately 35 thousand metric tonnes valued at almost $175 million.
Marine aquaculture occurs mainly in the coastal zone, a region that is heavily used by other sectors of society for a variety of industrial and recreational activities. Interactions between the growing aquaculture industry and these groups are inevitable, thus the key to acceptance of coastal aquaculture is mitigating the effects from these interactions. Mitigation can best be achieved through a thorough understanding of the nature of these impacts.
As a result, scientists at the Biological Station have adopted a multi-disciplinary approach to aquaculture research intended to enhance the economic and environmental sustainability of the Canadian aquaculture industry. The following sections provide an overview of current aquaculture research activities.
MARINE FINFISH CULTURE
The commercial marine finfish culture industry in Atlantic Canada is based on Atlantic salmon. The risks inherent on the region’s dependence on the culture of a single species culture have been apparent for years, but the industry has not been able to develop suitable alternative species. Haddock, Atlantic cod, Atlantic halibut and Arctic char have potential, and the remaining biological and technological constraints are being assessed. Recent haddock research has shown that photoperiod (length of exposure to light) and temperature can be manipulated to advance broodstock egg production by up to nine months.
BROODSTOCK MANAGEMENT
Females of some fish species grow faster and mature later than their male counterparts. This is desirable in cultivated species because it can be used to enhance the economic return to growers. Efforts are under way to develop all-female stocks of Atlantic halibut for culture. Researchers are exploring the use of environmental and biochemical factors to manipulate the number of female halibut produced under culture conditions.
The tools of molecular genetics (e.g. DNA finger printing) are being used to identify the pedigree of the cultured Atlantic halibut broodstock maintained in Atlantic Canada. This will help prevent inbreeding and facilitate future programs on genetic selection. High-quality halibut and haddock seedstock from the broodstock program are provided to support collaborative research by university, government and industry scientists.
MOLECULAR BIOLOGY
In recent years, molecular biology has provided aquaculture researchers with powerful tools for enhancing desirable traits and dealing with disease in cultivated organisms. For example, molecular techniques are being used in the production of vaccines that will protect salmon against Infectious Salmon Anemia and cod against nodavirus infection. Similar molecular tools are being used to establish a premium breeding stock of Atlantic cod.
INTEGRATED MULTI-TROPHIC AQUACULTURE (POLYCULTURE)
For the past five years, an internationally acclaimed project involving SABS and the University of New Brunswick has been integrating other cultivated species with Atlantic salmon aquaculture in the Bay of Fundy. The research has focused on growing various organisms from different levels in the food chain (i.e. kelp, a form of seaweed, and blue mussels) alongside Atlantic salmon sea cages. The theory is that the growing of multiple species will provide a more balanced ecosystem approach and a more economically efficient industry. The kelp and mussels are natural consumers of the dissolved nutrients and fine organics and effectively recycle part of this excess production from the salmon that would otherwise be lost to the farmer. Results have shown that growth rates and quality of these species are substantially higher when grown alongside the salmon cages. The study is also showing that the food safety, social acceptance, economic viability and environmental sustainability of this approach are all very encouraging. Ultimately, the goal of the project is to get marine food production industries to naturally evolve to a more sustainable and benign phase.
OCEANOGRAPHY
Oceanography deals with the physical components of the ocean environment (water temperature, salinity and currents) and the linkages between these conditions and the marine ecosystem. Oceanography has broad potential application in the management of coastal marine resources, including fisheries and aquaculture. For example, the salmon aquaculture industry of southwestern New Brunswick (SWNB) is proposing a Performance-Based Management System (PBMS) in which production limits would be determined by the farm’s performance relative to established environmental standards. This requires intensive benthic (bottom) sampling to determine whether monitoring standards (e.g. sediment sulphide levels) are adequate. Water column dissolved oxygen level is another parameter that might be included in a PBMS. Oceanography is also contributing to a process which will likely result in major changes in the Bay Management Area structure of the salmon aquaculture industry of SWNB. The potential for offshore aquaculture is another initiative where oceanography is a major consideration.
ENVIRONMENTAL CHEMISTRY AND TOXICOLOGY
Organic wastes from excess feed and from fish faeces may accumulate in the sediment beneath salmon farms and lead to a reduction in oxygen concentrations in the water column and in the sediment. Research has been carried out to determine how far from farm sites these conditions exist and what effect, if any, this has on organisms that live near aquaculture sites. In addition, certain chemicals used in fish food and as therapeutants in the aquaculture industry may come into contact with other aquatic species in the vicinity of sea cages. The nature, concentration and environmental effects of some of these chemicals have been studied. Controlled experiments in the laboratory have shown that the pesticides and drugs used in aquaculture can affect invertebrates such as lobsters and shrimp. While it remains unclear whether exposure or effects take place in the field, their risk in the environment is judged to be low. On-going monitoring and research will continue to inform management decisions regarding the use of veterinary drugs and pesticides.
HARMFUL ALGAL BLOOMS
Some naturally-occurring marine phytoplankton (minute plant and animal life) produce toxins that can reach harmful concentrations during annual blooms. The interaction of the aquaculture industry on phytoplankton and vice versa has been studied. Recently SABS researchers have responded to aquaculture salmon mortalities caused by harmful algal blooms by identifying the toxin-causing plankton. Training of industry staff in the identification and enumeration of harmful algae is under way. In addition, methods are being developed for predicting the onset of harmful algal blooms.
