During the last several years, culture of the blue mussel, Mytilus edulis, has been one of the fastest growing food-related industries in the Atlantic Maritime Provinces and is now rapidly reaching the point of becoming a major marine industry. As the industry grows it is becoming increasingly obvious that the successful culture of mussels, as well as the potential environmental impact of culture activities, is very much dependent on the nature of a number of key environmental conditions at growing sites. This has lead to the opinion, among both private mussel growers and government regulatory agencies, that orderly development of the industry could benefit from a programme in which environmental conditions at growing sites would be monitored on a routine basis The need for an environmental monitoring programme became particularly evident in the late summer of 1986 when a large number of growers experienced severe summer-mortality of market-size mussels and were unable to determine or understand the cause of the mortality, largely because of the lack of basic data on environmental conditions or the condition of the mussels at the time of the mortality. A short while later events in Prince Edward Island associated with the presence of domoic acid further indicated the need for a routine monitoring programme that would provide base-line data useful in attempts to understand the causes of unusual and unexpected events. More recently, a growing concern among many individuals with regard to the potential environmental impact of mussel culture has further emphasized the need to document changes in environmental conditions that may be occurring at growing sites.

In response to the obvious need, and at the request of a number of practicing mussel growers and government agencies, the Acadia Centre for Estuarine Research (ACER) developed a proposal to implement a water quality monitoring programme at a number of growing sites located throughout the Atlantic Maritime provinces. A unique aspect of the proposed programme was that it required the active participation of private mussel growers in collecting data and samples. The participation of growers was considered not only desirable in terms of the training and general educational benefits they would receive, but necessary in order to develop a comprehensive programme at reasonable cost.

The major objectives of the programme, as stated in the original proposal, were: (1) to introduce commercial mussel growers to the environmental factors critical to the successful culture of mussels; (2) to train growers in the techniques for monitoring these variables; (3) to create a facility that would provide expertise in monitoring techniques, sample analyses and data interpretation; and (4) to begin development of a long-term data base that would be useful in explaining seasonal and yearly variations in mussel settlement, growth, and survival and provide a record documenting changes that may be occurring in environmental conditions at growing sites.

The proposal was subsequently jointly funded in the late summer of 1987 by the Nova Scotia Department of Fisheries under the ERDA programme and by the Gulf Region of the Federal Department of Fisheries and Oceans as a Department of Supply and Services contract. A total of twenty sites were scheduled to take part in the monitoring programme; eight in Nova Scotia, eight in Prince Edward Island, three in New Brunswick, and one in Newfoundland.. The programme ended in March, 1989, having lasted approximately nineteen months. This report summarizes the development and results of the monitoring programme. It is divided into three sections. The first provides a brief overview of the design and development of the programme. The second section summarizes the final results and discusses the successes and shortcomings of the programme, and the third section makes suggestions and recommendations that should be considered in establishing future monitoring programmes.