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Loss of fish habitat in North America has occurred at an unprecedented rate through the last century. In response, the Canadian
Parliament enacted the habitat provisions of the Fisheries Act. Under these provisions, a “harmful alteration, disruption, or destruction to fish habitat” (HADD) cannot occur unless authorised
by Fisheries and Oceans Canada (DFO), with legally binding compensatory habitat to offset the HADD. The guiding principle
to DFO’s conservation goal is “no net loss of the productive capacity of fish habitats” (NNL). However, performance in achieving
NNL has never been evaluated on a national scale. We investigated 52 habitat compensation projects across Canada to determine
compliance with physical, biological, and chemical requirements of Section 35(2) Fisheries Act authorisations. Biological requirements had the lowest compliance (58%) and chemical requirements the highest (100%). Compliance
with biological requirements differed among habitat categories and was poorest (19% compliance) in riparian habitats. Approximately
86% of authorisations had larger HADD and/or smaller compensation areas than authorised. The largest noncompliance in terms
of habitat area occurred in riverine habitat in which HADDs were, on average, 343% larger than initially authorised. In total,
67% of compensation projects resulted in net losses of habitat area, 2% resulted in no net loss, and 31% achieved a net gain
in habitat area. Interestingly, probable violations of the Fisheries Act were prevalent at half of the projects. Analyses indicated that the frequency of probable Fisheries Act violations differed among provinces. Habitat compensation to achieve NNL, as currently implemented in Canada, is at best
only slowing the rate of habitat loss. In all likelihood, increasing the amount of authorised compensatory habitat in the
absence of institutional changes will not reverse this trend. Improvements in monitoring and enforcement are necessary to
move towards achieving Canada’s conservation goals. 相似文献
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Fish habitat loss has been prevalent over the last century in Canada. To prevent further erosion of the resource base and
ensure sustainable development, Fisheries and Oceans Canada enacted the habitat provisions of the Fisheries Act in 1976. In 1986, this was articulated by a policy that a “harmful alteration, disruption, or destruction to fish habitat”
(HADD) cannot occur unless authorised with legally binding compensatory habitat to offset the HADD. Despite Canada’s progressive
conservation policies, the effectiveness of compensation habitat in replicating ecosystem function has never been tested on
a national scale. The effectiveness of habitat compensation projects in achieving no net loss of habitat productivity (NNL)
was evaluated at 16 sites across Canada. Periphyton biomass, invertebrate density, fish biomass, and riparian vegetation density
were used as indicators of habitat productivity. Approximately 63% of projects resulted in net losses in habitat productivity.
These projects were characterised by mean compensation ratios (area gain:area loss) of 0.7:1. Twenty-five percent of projects
achieved NNL and 12% of projects achieved a net gain in habitat productivity. These projects were characterised by mean ratios
of 1.1:1 and 4.8:1, respectively. We demonstrated that artificially increasing ratios to 2:1 was not sufficient to achieve
NNL for all projects. The ability to replicate ecosystem function is clearly limited. Improvements in both compensation science
and institutional approaches are recommended to achieve Canada’s conservation goal. 相似文献
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