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Science Response 2011/009

Reconstruction of the Tadoussac and Baie-Ste-Catherine, Quebec, landing docks – Impacts on marine mammals


The existing ferry boats between Tadoussac and Baie-Sainte-Catherine, operating since 1980, have reached the end of their useful life. In 2013, the Société des traversiers du Québec (STQ) will replace these ferries with two new ships of greater capacity. Although slightly larger, the new ferries would be able to operate with the existing infrastructures. However, they would be affected by operational constraints, including the inability to guarantee service during high tide. Therefore, to enable optimal use of the new ferries, the STQ would like to expand one of two access ramps at each of the landing docks.

The reconstruction project of the Tadoussac and Baie-Sainte-Catherine landing docks is not subject to the Canadian Environmental Assessment Act (CEAA) and does not require an authorization pursuant to subsection 35(2) of the Fisheries Act (FA). However, the increase in underwater noise caused by drilling and sawing activities could disturb or harm marine mammals present at the mouth of the Saguenay River, particularly the St. Lawrence beluga.

To ensure that the project will not cause significant impacts to marine mammals, the Fish Habitat Management Division (FHMD) sought, on August 5th, 2011, the cooperation of scientists from the Regional Science Branch, who have expertise on marine mammals in the St. Lawrence Estuary, to obtain their advice on the potential impacts on cetaceans, particularly the St. Lawrence beluga (species at risk).

Considering the short notice (advice required August 26th, 2011 in order not to hinder the beginning of the work), a Science Special Response Process (SSRP) was initiated to provide scientific advice on five specific issues related to this project and its potential impacts on cetaceans:

  1. Are the estimates of noise level generated by the operations and the propagation distances provided by the consultant realistic? Are the estimates provided by the consultant concerning noise reduction by the implementation of mitigation measures (containment and bubble curtain) valid and realistic?
  2. Is it fair to consider that the noise impacts generated by the operations will be mitigated by the fact that the mouth of the Saguenay is a noisy environment because of the significant shipping traffic occurring there?
  3. Will the project, as proposed, prevent any physical damage to belugas? If not, what additional mitigation measures would reduce the risk of physical harm? What if operations do not occur in a confined environment?
  4. Is the project, as proposed, likely to cause disturbance for the beluga? If so, what additional mitigation measures would make the disturbance acceptable? What if operations do not occur in a confined environment?
  5. In the event the project causes disturbance to the beluga despite the implementation of additional mitigation measures, is the anticipated disturbance likely to jeopardize the species’ recovery?

This Science response report stems from the analysis conducted between August 15-18, 2011, under the SSRP on the review of potential impacts on marine mammals by the reconstruction project of the Tadoussac and Baie-Sainte-Catherine landing docks. Three experts in underwater acoustics and in marine mammal behaviour were present. A description of the main aspects of the project, timelines and proposed mitigation measures were presented for consideration in order to formulate this advice.

The proposed reconstruction project of the Tadoussac and Baie-Sainte-Catherine landing docks will occur at the heart of the beluga habitat in the St. Lawrence and Saguenay-St Lawrence Marine Park. Belugas are present there 50% of the time, at least from May to September, to feed or to transit to other frequently attended areas. Minke whales occur there frequently while other marine mammals are present more occasionally. Construction noise associated with the project will be an additional contribution to the high level of noise from the ferries and the ecotourism whale-watching fleet during the construction period, estimated at 20 months. No loud noise such as impulse noise (e.g. piling or sheet pile driving) is scheduled in the project, but noise from non-impulse drilling and other operations will be frequent. The levels and frequencies of these sounds are detectable by marine mammals and fish in the region. Although the risk of causing physical damage to the animals’ internal tissues is low, the noise poses a risk to the health and recovery of the St. Lawrence beluga, a threatened species under the Species at Risk Act (SARA). The operations and mitigation measures proposed by the proponent and additional measures proposed herewith should help minimize the impacts of these operations on the beluga and other marine mammals at the mouth of the Saguenay River.

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