Potential of earth observation (EO) technologies for seagrass ecosystem service assessments

Abstract

Seagrasses are rapidly losing their ability to serve ecosystem services (ESs) with the loss of global biodiversity and coastal habitat degradation over the past few decades. Monitoring ESs is therefore important for tracking subsequent decline or recovery. The development of new Earth Observation (EO) technologies and approaches involved in observing and analyzing data collected from remote sensing (RS) satellite/aircraft would make for a useful application: monitoring and mapping spatial distribution of ESs that seagrasses provide to marine ecosystems and human well-being. Unfortunately, current approaches greatly rely on spatial proxy measures to map distribution of ESs. Many of biophysical parameters are currently detectable by EO instruments, with relevance to ESs. This paper review the capabilities of advanced RS techniques for informing species diversity, growth traits, health condition, ecological processes, and water quality variables linking ESs and describe how these EO products can contribute to ES assessments. Incorporation of both the direct (seagrass extent) and indirect (water related ESs) estimates derived from EO data can now provide more direct estimates of seagrass ecosystem properties (seagrass habitat quality and biodiversity) influencing ESs than the spatial proxies presently in use and they can support in developing more mechanistic models in GIS framework and spatially explicit maps of ESs. The increasing range of EO system and data sets suitable for measuring ES indicators has potential to supporting integrated coastal land use planning. Because each ES indicator and service responds to the environment, there is no ‘one approach fits all’ solution. Selecting EO products, with required resolution to be analyzed will guide to improving mapping efforts. This work also shed lights to sensitize discussion about need of holistic methodologies, challenges, and to motivate an enhanced use of EO-based technology and data. The need for a multidisciplinary project team of ecologists, sociologists, biologists and RS experts has been suggested for proper identification of ES indicators and advanced analysis of EO data. By doing so, we anticipate rapid progress in satellite based ES assessment and characterization of ESs and, in turn, supporting conservation and management of coastal ecosystem.