Unformatted text preview: in age-structure of Gulf cod
under commercial exploitation
Abundance of age classes (millions) M7.30
BIO 3115 Université d’Ottawa / University of Ottawa 2012 M7.15 BIO 3115 Conservation Biology Consequences of exploitation III:
changes in spatial distribution Exploitation can result in
changes in the spatial
populations to leave areas
of optimal habitat for
areas of marginal habitat.
This change in spatial
distribution may itself
High density area,
viability, as growth rate is
reduced in sub-optimal
habitat. Low density area,
low exploitation M7.31
BIO 3115 Université d’Ottawa / University of Ottawa 2012 Harvest-induced changes in
spatial distribution of Gulf cod.
Percentage of total stock biomass in regions east of 4T M7.32
BIO 3115 Université d’Ottawa / University of Ottawa 2012 M7.16 BIO 3115 Conservation Biology Consequences of overexploitation
IV: exploitive transference 35000
Annual harvest (kg) as stocks of one species
become overexploited, effort
turns to the harvest of other
species, thereby simply
transferring the risk.
E.g. on lower Saskatchewan
River, as sturgeon stocks
were depleted, commerc...
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