Terms of Reference
Carrying Capacity for Shellfish Aquaculture with Reference to Mussel Aquaculture in Malpeque Bay, Prince Edward Island
Regional Science Peer Review – Gulf Region
October 8 and 9, 2014
Moncton, New Brunswick
Chairperson: Gérald Chaput (DFO Gulf Region)
Context
Shellfish (mussel, oyster) aquaculture is an expanding industry in Atlantic Canada and particularly in the bays of Prince Edward Island. There is growing interest to expand the industry. In Atlantic Canada, shellfish (mussel and oyster) aquaculture production occurs in sheltered, generally shallow bays. The productive capacity of a bay for shellfish aquaculture is determined by many factors including the hydrodynamics of the bay and input of nutrients. There is considered to be a limit to the production (biomass) that can be extracted from an area due to competition for the limiting resource, the primary trophic level.
Carrying capacity was identified as an Environmental and Socio-economic Component of Concern (ECC) in the development of the Replacement Class Screening Report for water column oyster aquaculture in New Brunswick. Carrying capacity was not defined in this report. In its simplest form, it can refer to the total standing stock biomass of a species or species groups that can be supported by the resources available in a defined area. The amendments to the Fisheries Act refer to protecting productivity to ensure sustainability of fisheries for commercial, recreational and aboriginal (CRA) use. Ideally, the question of carrying capacity would consider all the CRA fishery components of the ecosystem and the fish that support them. In the absence of sufficient information to do so, the use of proxies for productivity and carrying capacity could be considered. One possible proxy for assessing carrying capacity is the depletion of suspended food particles because it provides an assessment of the potential growth rates or condition of the shellfish in culture and wild grazers.
Requests have been made to increase the leases and the production of mussels in Malpeque Bay, Prince Edward Island. DFO Aquaculture Management has asked for advice on how much expansion could occur without exceeding the carrying capacity of the bay. The bay management plan for Malpeque Bay is expected to be finalized in 2015. Decisions on extending leases in Malpeque Bay and other areas will be made based in part on this advice.
Objectives
DFO Science will consider the following questions:
- How to define production and ecological carrying capacity,
- How to estimate production and ecological carrying capacity
- What are the indicators that could be used to establish the carrying capacity of a bay, and to determine if the carrying capacity has been exceeded?
- Specific to Malpeque Bay, what is the current level of cultivated mussel biomass, would increasing acreage by 1,456 acres impact the production of existing mussel farms, and are there any indications that the production or ecological capacity is already attained for some regions of Malpeque?
Expected Publications
- Science Advisory Report
- Proceedings
- Research Document(s)
Participation
The issue of carrying capacity for shellfish aquaculture is relevant to other DFO regions. The advice provided for the Gulf Region request may have precedent for other assessments and advice.
- Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, Ecosystems and Fisheries Management) from Gulf, Maritimes, Quebec, Pacific
- Academia
- Invited experts
Notice
Participation to CSAS peer review meetings is by invitation only.
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