Quigley Jason T, Harper David J
Oceans, Habitat and Enhancement Branch, Fisheries and Oceans Canada, Suite 200, 401 Burrard Street, Vancouver, BC V6C 3S4, Canada.
Environ Manage. 2006 Mar;37(3):336-50. doi: 10.1007/s00267-004-0262-z.
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.
在过去的一个世纪里,北美鱼类栖息地的丧失速度空前。作为回应,加拿大议会颁布了《渔业法》中的栖息地条款。根据这些条款,除非得到加拿大渔业和海洋部(DFO)的授权,并提供具有法律约束力的补偿性栖息地以抵消“对鱼类栖息地的有害改变、破坏或毁坏”(HADD),否则不得发生此类情况。DFO保护目标的指导原则是“鱼类栖息地的生产能力不出现净损失”(NNL)。然而,从未在全国范围内对实现NNL的成效进行过评估。我们调查了加拿大各地的52个栖息地补偿项目,以确定其是否符合《渔业法》第35(2)条授权中的物理、生物和化学要求。生物要求的合规率最低(58%),化学要求的合规率最高(100%)。不同栖息地类型在生物要求的合规情况上存在差异,河岸栖息地的合规情况最差(合规率为19%)。约86%的授权项目所造成的HADD和/或补偿区域比授权的更大或更小。就栖息地面积而言,最大的不合规情况发生在河流栖息地,其中HADD平均比最初授权的大343%。总体而言,67%的补偿项目导致栖息地面积净损失,2%的项目没有净损失,31%的项目实现了栖息地面积净增加。有趣的是,约一半的项目普遍存在可能违反《渔业法》的情况。分析表明,可能违反《渔业法》的频率在各省之间存在差异。加拿大目前实施的为实现NNL而进行的栖息地补偿,充其量只是减缓了栖息地丧失的速度。在缺乏制度变革的情况下,增加授权补偿性栖息地的数量很可能无法扭转这一趋势。为实现加拿大的保护目标,必须加强监测和执法。