Ecosystem services benefits of coral reefs along a biological condition gradient to inform local management

Ecosystem restoration aims to recover integrity of degraded ecosystems while providing ecosystem services that humans want and need. To effectively achieve this, methods are needed to assess levels of restored biological condition needed to achieve desired beneficial uses; identify ecosystem attributes of high value where restoration might be targeted; and communicate potential benefits of restoration to gain public support. The Ecosystem Services Gradient (ESG) framework parallels the Biological Condition Gradient (BCG) as a rational and consistent means for describing the range of potential condition, from highest quality to severely degraded. Steps to building an ESG include: i) identifying relevant ecosystem services, ii) identifying metrics to quantify ecosystem services, iii) using monitoring data to numerically describe levels of ecosystem services from worst to best available, and iv) evaluating potential co-occuring benefits or tradeoffs across ecosystem services under changing condition. An ESG was developed for coral reefs of Puerto Rico and the US Virgin Islands to complement recently developed BCGs characterizing reef benthic habitats and reef fish. We quantified measures of reef ecosystem services for thirteen different types of beneficiaries, including snorkelers and coastal property owners, from available coral reef monitoring and biophysical data. We evaluated relationships between potential ecosystem services provisioning and levels of biological condition, including the potential for tradeoffs between attributes of high biological integrity and attributes desired for human uses. The paired BCG and ESG approach supports a better understanding of reef condition and associated benefits to local communities, supporting local management actions to protect and restore reefs.