Report - Agence canadienne d'évaluation environnementale

Impacts on the natural environment
Fish habitats in the St. Lawrence River
In the river, the construction of a jetty would cause the permanent loss of nearly
1.1 ha of fish habitat, including approximately 1.08 ha in the intertidal zone 1 and
0.02 ha in the sublittoral zone 2 . Fisheries and Oceans Canada believes that this would
constitute a destruction of fish habitat under the Fisheries Act. The habitat that would
be destroyed presents an average to high vulnerability. In the lower half of the
intertidal space 3 , dense aquatic-grass beds are present, serving various biological
functions for several fish species (DQ5.1, p. 1 to 4).
According to Fisheries and Oceans Canada, backfill work, pile driving and use of
barges could cause an increase in suspended matter (SM) in water and an increase
in underwater noise level. The proponent created a model of the noise produced by
the pile-driving work. Based on the results, these would risk injuring the fish located
within a radius of approximately 10 m around each pile and this, for about one hour
per day for the duration of the work. Fry and juveniles would be most likely to be
affected by pile driving. However, Fisheries and Oceans Canada believes that
appropriate mitigation measures such as restriction periods would decrease the risks
of fish injuries during pile driving.
The increase in SM and underwater noise could also harm the migration of fish such
as the American shad, the Atlantic sturgeon and the American eel, as well as rainbow
smelt larvae, given their high concentration in the area under study during
summertime. However, since the proponent has planned a work break between
7 p.m. and 7 a.m., Fisheries and Oceans Canada believes that nocturnal migratory
species will suffer less disruption. If night-work was to be carried out, Fisheries and
Oceans Canada believes that the proponent should set restriction periods to ensure
fish crossings, in particular of the American shad and the Atlantic sturgeon. Lastly,
pumping water from the St. Lawrence River for hydrostatic tests and for fire hydrants
and potable water needs, as well as pumping ballast water by the LNG tankers, would
risk causing the pumping of larvae and juvenile fish, including the rainbow smelt
(DQ5.1, p. 2 and 3).
♦ Recommendation 25 — The Panel recommends that, additional measures be taken
when a spawning area for the rainbow smelt is present in the jetty area in order to
avoid disrupting the species, to the satisfaction of Fisheries and Oceans Canada and
the ministère des Ressources naturelles et de la Faune.
1. Below the mean higher high water level.
2. Used to describe the underwater level corresponding to the distribution of permanently immersed animal and
plant species or species that tolerate a short immersion.
3. Region located between mean high and mean low tide levels.
214 Rabaska Project – Implementation of an LNG Terminal and Related Infrastructure