Compensatory mitigation is a practice whereby a government agency requires the creation, restoration, enhancement, or preservation of ecological resources to offset unavoidable adverse impacts to environmentally sensitive habitat caused by some form of development. Compensatory wetland mitigation programs have slowed the rate of wetland loss in California and elsewhere, but they have largely failed to offset impacts with a sufficient amount of functional mitigation acreage. In California, more than 90% of the state's historical wetlands have been drained, diked, filled, or dredged over the past 100 years. This report evaluates the success of compensatory wetland mitigation required by the California Coastal Commission between 2012 and 2018. Methods involved reviewing permits and preparing a database to index all compensatory mitigation projects in the study period; locating all available mitigation plans and monitoring reports for those projects; statistically evaluating each project's compliance with performance criteria and "no net loss" policies; and performing a literature review to contextualize these findings. As permitted, the Coastal Commission's compensatory mitigation program appears to have resulted in a net gain of wetlands; however, incomplete monitoring data suggests that the net gain may be lower than reported. Fulfillment of performance criteria was about 70% as reported by annual monitoring reports from 20% of projects. Performance criteria focused mainly on vegetation. Requiring a more diverse range of criteria-including hydrology, soil, and wildlife-based metrics in addition to vegetation-could improve tracking of ecological function. This research also reveals opportunities to improve accountability through technical and procedural reforms, including maintaining a centralized storage system for mitigation monitoring data, requiring that compliance reports be reviewed by technical staff, encouraging clearer descriptions of mitigation requirements, and making compensatory mitigation data more accessible to the public.

Refecting what a new generation of conservation biologists is doing and thinking, this vital and far ranging second edition explores where conservation biology is heading. It challenges many conventions of conservation biology by exposing certain weaknesses of widely accepted principles. Combining contributions from both the school and the new breed of conservation biologists, this insightful text focuses primarily on topics the are integral to the daily activities of conservation biologists. Several chapters address ecosystem restoration and biotic invasions as well as the the mechanics of population viability analyses, which are now a routine facet of conservation efforts. A case history approach is implemented throughout the book, with the use of practical real-world examples. Furthermore, an in-depth look at quantitative analyses is presented, allowing for models and mathematical analyses to pinpoint limitations in existing data and guide research toward those aspects of biology that are most likely to be critical to the dynamics of a species or an ecosystem.