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THE VALUE OF ECOSYSTEM MODELING
QUESTIONS ADDRESSED DATA CONCLUSIONS
How has the environment of the
Salish Sea changed in the last 50
years, and why?
How do anthropogenic impacts
interact with environmental changes
in the Salish Sea?
How has predation, competition, and
habitat changed in the last 50 years?
What are the impacts on juvenile
salmon, particularly for Chinook and
Coho Salmon?
Huge amounts of environmental,
biological, ecological and fisheries
data collated and derived from the
Strait of Georgia Data Centre and
other databases. Data include the PSF
Citizen Science data set, as well as
many long- term data sets such as the
DFO Juvenile Salmon Trawl data, the
Strait of Georgia Zooplankton dataset,
catches of salmon and release of
salmon from hatcheries in the
Salish Sea.
Model development is ongoing.
While previous studies have evaluated short-term productivity
patterns for the Salish Sea, there have so far only been
correlative studies to evaluate the relationship between
long-term changes in environment and the productivity
of higher trophic levels organisms (notably salmon) in the
Strait of Georgia ecosystem. However, many studies have
shown that changes in primary production (phytoplankton)
can be amplified through the food web — a 10-20% change
in primary production can lead to a 40-80% change higher
up in the food web, perhaps years later. This modelling
program aims to represent such changes and to examine
if this has occurred in the Strait of Georgia.
A group of scientists within the University of British Columbia
has taken on the task of evaluating such long-term trends
as part of the Salish Sea Marine Survival Project (SSMSP).
The group has learned a great deal from reconstructing
ecosystem history using complex food web models for about
50 other ecosystems around the world. They concluded that
if you wish to replicate historic trends, you need to understand:
the interactions in the food web, including how predator and
prey impact each other and over time, how primary (phyto-
plankton) and secondary (zooplankton) productivity is driven
by atmospheric and oceanic conditions, and how human and
habitat impacts have changed with time.
A core aspect of this research is that it requires long-term
data. So, while the SSMSP research is to a large extent focused
on the present, this ecosystem modelling (along with the
SSMSP data centre, www.sogdatacentre.ca) must gather
extensive past data also. But such historic information
is sporadic at best, making it necessary to rely on data analysis
and synthesis to fill in the blanks. Or in other words: we need
computer models to reconstruct the past, back to when
marine survival of salmon smolts was higher.
SUMMARY OF THE GOALS OF THE SSMSP ECOSYSTEM MODELING PROGRAM
