| Summary: | Coho salmon (pnayrhynchus kisutch) declines in the Strait of Georgia, British Columbia
have been attributed to overfishing, marine survival, and habitat loss; however, the relative
impact of each is difficult to ascertain. In many cases of commercial fish population declines,
factors other than fishing are blamed. In British Columbia considerable funding is allocated to
habitat restoration projects; however, if spawners fail to colonize streams, then funding and
effort may be wasted. I investigated the contribution of freshwater habitat loss in the Georgia
and Lower Fraser Basins of British Columbia to a substantial decline in coho salmon abundance
from mid-1970 to 1995. I used land use as an indicator of potential habitat loss and degradation
for an index set of watersheds and measured land use change over four decades using aerial
photos and a Geographic Information System. I compared land use to coho escapement and
coho fry for sixteen watersheds and over three time periods (1955, 1975 and 1995) using linear
regressions. I found no significant relationships between mean coho escapement and land use
for each time period. Land use change over time was not related to the realized rate of
population growth (g) for coho or coho fry. Coho fry abundance was positively related to
proportion old growth in a watershed, and negatively related to proportion urban land use in the
1995 time period. === Science, Faculty of === Zoology, Department of === Graduate
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