This week
we have shifted our focus from that of the production of shellfish in Newfoundland and other provinces in Canada , to that of finfish. Finfish
include a wide variety of marine and freshwater species that are farmed across Canada with
special recognition given to Salmon, Trout and Steelhead Trout. We will focus on comparing the production of
finfish in Newfoundland to the rest of Canada to grant
insight into the role our province plays nationally. We will take a specific
species of particular importance to Newfoundland
to highlight some of the general conservation impacts. This species is Oncorhynchus mykiss, also known as
the steelhead trout.
With regards to
aquaculture production as a whole, Canada British Columbia Newfoundland
Figure 1: Percentage of Aquaculture Production per Province
in Canada 2009. (Source: Statistics Canada
More specifically we will compare the production of finfish
in Newfoundland to that of the remainder of Canada . Finfish
are evidently a valuable commodity in the Canadian aquaculture industry, as
they accounted for 118,000 tonnes, or three quarters of the total aquaculture
product in 2009 (DFO 2011). 90% of the production of finfish in Canada
was solely Atlantic salmon. In Newfoundland
and the Coast of Bays (Bay d’Espoir) region in
particular, two salmonid species are
considered most valuable; Atlantic Salmon and Steelhead Trout. Steelhead trout
are said to account for approximately 66% of the Bay d’Espoir aquaculture
production (MUN Biology, 2012).
Therefore attention must be focused on the conservation impacts arising
from the farming of this particular salmonid,
so as not to simply classify it as identical to that of the Atlantic salmon. Refer
to Figure 2 and 3 below for a cross comparison of Finfish production in Newfoundland and Canada as a whole.
Figure 2: Aquaculture
Production of Finfish In Canada
Source: Figure 2
taken from DFO 2011
Figure 3: Aquaculture Production of Finfish and Mussels in Newfoundland From 2003-2009
Source: Figure 3 taken from NAIA 2011
Steelhead trout are one of the most
highly valued species in Newfoundland .
For various reasons they are a fairly easy species to farm. They spawn easily, grow quickly and can
withstand a wide range of environmental stressors including temperature variation
from 0-27ºC (FAO, 2012). “According to Fisheries and Oceans Canada steelhead is
farmed in BC, Saskatchewan , Nova
Scotia , New Brunswick , and Newfoundland and Labrador
(DFO 2006b as cited by Winter and Vincent, 2006).” For our purposes we will use
the “University of British Columbia Sustainable Seafood Project ” 2006 to
assess conservation issues which may apply to Newfoundland as well. The current use of
floating net pen and cage aquaculture used to raise steelhead in Newfoundland is not
viewed as sustainable. Concerns that evolve from this form of aquaculture are
water pollution, transmission of pathogens, and escape of farmed fish (Winter
and Vincent, 2006). As we mentioned in previous blogs, the damage that
effluents pose to the environment can be substantial. A more sustainable technique is known as a
freshwater flow-through system. (Figure
4)
Figure 4: Two
types of freshwater flow through layouts.
Water from an adjacent river is usually diverted to flow through raceways
or ponds. (Source: UBC Sustainable Seafood Project.
As one can probably infer from the above diagram, such flow
through systems allow for the removal of effluents which can then be further
treated in settling ponds to decrease impact on farmed trout. Nevertheless
further treatment measures are still required to decrease organic matter and
dissolved solids through filtration systems (Papatryphon et al. 2004 as cited
in Winter and Vincent 2006). Unfortunately, systems such as these are not
currently being used by the aquaculture industry. Thus organic matter and
dissolved solids simply become a problem for the environment surrounding such
freshwater flow through sites. The Newfoundland
site in particular, being located in a large fjord sculpted bay and subject to
large freshwater inflows from the central part of the island, may be subject to
some natural cleansing of cages and pens (NAIA 2011).
As
mentioned in previous blogs aquaculture of carnivorous fish such as steelhead
trout can add stress to wild fish stocks such as anchovy, herring, mackerel
etc. which are used for fish oil and fish meal (Naylor et al. 2000, O’Neill
2006 as cited in Winter and Vincent 2006). Nevertheless, globally there has
been a decrease to less than 50% fish meal being used in trout feed as a result
of incorporating other protein sources such as soy, wheat, maize etc. (Cowx
2006, Moffitt 2003, Paratryphon et al. 2004). Regardless of this current
approach aquaculture’s ability to reduce pressures on wild fish stocks is still
a significant issue.
Overall one
can see that Newfoundland , with its similar
techniques to other countries and especially to its fellow provinces in Canada
faces global conservation issues. In relation to British Columbia and elsewhere in the world,
new filtration techniques must be implemented to decrease the effects of
effluents. Like the rest of Canada ,
Newfoundland aquaculture
operations have significant impacts to assess in the most suitable manner. In a
world where the dependency on high protein species, such as Atlantic Salmon and
Steelhead seems to be anything but waning, ways to produce these species
effectively and safely are of major concern globally. Ensuring the health and
safety of the environment as well as the consumer are crucial in Newfoundland and
world-wide.
References
DFO (2011).Aquaculture Canada
FAO (2012). Cultured Aquatic
Species Information Programme: Oncorhynchus mykiss. Retrieved from: http://www.fao.org/fishery/culturedspecies/Oncorhynchus_mykiss/en
N.A. (2008, April 5).
Aquaculture in Newfoundland Memorial University
Papatryphon,
E., J. Petit, S.J. Kaushik, and H.M.G. van der Werf. 2004. Environmental impact
assessment of salmonid feeds using Life Cycle Assessment (LCA). Ambio. 33:
316-323.
Statistics Canada (2010). Aquaculture
Statistics 2010. 23-222-x
Winter, L.; Vincent, A. (2006). The University of British Columbia
No comments:
Post a Comment