La science doit reprendre son véritable rôle et s'établir comme
premier gardien des océans.
Nous devrions tous surveiller les relations entre les changements
climatiques, les courants océaniques et les pêches parce que les
poissons eux-mêmes pourraient bien s'avérer être l'espèce
Il est plus important que jamais de tenir compte de facteurs comme les
changements climatiques avant que nous soyons obligés de faire appel à
une gestion de crise.
Et quand la prévention n'est plus une alternative possible, nous
devons être prêts à prendre les mesures nécessaires pour préserver
les espèces menacées quels qu'en soient les coûts.
Climate change, Ocean
Currents and Fisheries
I write this article, I see the headline for CBC News (dated Wed, 09 Apr 2003) which reads:
“Super-cold water still lead suspect in cod
die-off: St. John’s - Water temperatures in the
Newfoundland bay where a massive cod kill occurred are the coldest
measured in decades.”
The obvious factor brought into play by
ocean currents and climate change would be temperature changes.
In any scientific research, this is a basic parameter and its
impact on a species can be quite dramatic in determining size,
reproduction, and survival.
Temperature is also a major factor in the occurrence of HABs (Harmful
Algal Blooms), which heavily impact areas used by the shellfish
industry. In the case of Domoic Acid in 1987, the effect on the
industry was devastating, as a great deal of damage control had to be
applied when the toxin caused human fatalities.
Temperature is not the only factor, as climate changes affecting
ocean currents could cause upwelling and gyres, shifting salinity and
phytoplankton distribution. Monitoring these and other factors will
provide the knowledge necessary to determine what has happened in the
past; however, to proceed to the next step requires another tool,
modeling. With the power of today’s computer technology, it is
possible to predict different scenarios based on these changing
parameters. Though there is a degree of certainty, it is the
unpredictability of each species which makes it impossible to
determine what will happen. The combinations resulting from the links
between the different fisheries and numerous variables begs caution as
we interpret the results. As for the factors we can control, in the
case of climate change, the ever obvious reduction in the use of
fossil fuels, and, in the case of the fishery, safe limits with regard
Climate changes are the target of very extensive research being
carried out by various departments, including government agencies,
universities, and focus groups. The cause and effect are all to be viewed under a microscope until we
1) the implications to the human species; and
2) what we can do about it.
The area with the greatest flexibility for input would be the
implications to the human species. Here we would find the impact of
climate change on our oceans and that resource so precious to humans,
Warm surface water cools as it flows into the North Atlantic, releasing heat to the atmosphere and eventually
(image: David Suzuki Foundation)
As many species previously ignored by industry are now being taken
from the oceans, we must not only monitor the impacts of climate
change on them, but the effects compounded by each new fishery. This
increase in fisheries lowers the tolerance for stress due to global
warming on any of these species, which now include rockweed (ascophyllum
nodosum), sea cucumbers (cucumaria frondosa), and sea urchins (strongylocentrotus
The reason for concern may require a short history lesson and a few
equations. Both are products of some very basic principles that must
be adhered to if we are to remain a successful species on this planet.
The equation for the survival of a fishery must
For a sustainable fishery the equation might
For a fishery in trouble the equation
With the realization that we are fishing at a very high capacity
(efficiency, above and beyond), comes the understanding that today’s
fishery (for many species) is a fragile commodity. Hence the
importance of at least monitoring any activity which might have a
negative impact on either the species or the industry.
It is possible to impact one and not the other. If the species
suffers and the industry continues, it may be a few years before
realization sets in that the fishery must adjust accordingly. This is
a worst case scenario for the species.
An example in which the industry may be impacted but not the
species would be a temperature change resulting in the species
abandoning an area and moving beyond the range of the fishery. Here
the changes would be to the local ecosystem,
and everyone knows, a missing link could have severe repercussions,
perhaps starting a chain reaction.
Conceivably the price of having such a productive (demanding) fishery
is “constant vigilance”. As each link in the food chain becomes a
target, it becomes more vital than ever to account for other factors
such as climate changes affecting our oceans before we need crisis management. Whatever leads to a shift in any
fishery toward “Output>Input”, we will need to understand. If and when such a shift occurs, we will need to be
ready. When prevention of a crisis is no longer an option, we must be
willing to take the steps necessary to preserve
the species, whatever the cost.
Science must take the leading role and establish itself as the true
stewards/ caretakers of our oceans. The math is clear, if the fishery
is a function of the species, then the fishery can only exist if
the species exists! There can be no room for compromise knowing
this equation may not be reversible! The
links between any climate change, ocean currents and the fishery will
all bear watching while the indicator species may very well be the
For a more in depth look at this subject I would recommend viewing
the research done by Dr. Fred Page and his scientific team at the
Biological Station in St. Andrews, N.B. Their work on ocean
currents and modeling may well be a reference point for things to
come. The HABs and phytoplankton monitoring/study is the long-term
project of Jennifer Martin, also at the Biological Station in St. Andrews.
Percy, J.A. Whither the Weather? Fundy Issues #18 (BoFEP),