Kelp Mapping Guidebook

Download the Kelp Mapping Guidebook (pdf)

Reshitnyk, L., Saccomanno, V., Bell, T.W., Cavanaugh, K.C. (2023). Mapping Canopy-Forming Kelps in the Northeast Pacific: A Guidebook for Decision-Makers and Practitioners. The Hakai Institute, Heriot Bay, BC, Canada. doi: 10.21966/7ze4-x883

Summary excerpt:

Surface canopy-forming kelps (Order: Laminariales) provide the foundation for coastal marine ecosystems that are recognized for their ecological and economic value as well as their cultural importance to First Nations. (Kobluk et al., 2021, Wernberg et al., 2019; Holbrook et al., 1990; Dayton, 1972). Along the coastlines of Northeast Pacific, giant kelp (Macrocystis pyrifera) and bull kelp (Nereocystis luetkeana) form beds and forests that are naturally dynamic and threatened by both local and global stressors. Tools are needed by many groups and organizations to reliably track changes in kelp presence, distribution, abundance, and health at different spatial scales. Optical remote sensing is a powerful tool to monitor canopy-forming kelps that float at the ocean’s surface (Gendall et al., 2023; Cavanaugh et al., 2021; Bell et al., 2020; Schroeder et al., 2019; Cavanaugh et al., 2011; Jensen et al., 1980) and the availability of imagery collected by remote sensing tools has increased dramatically in recent years. However, the optical remote sensing platform used (e.g., drones, planes or satellites) must match management objectives and be appropriate for a given area’s unique constraints. The challenges that someone in Alaska faces for mapping kelp are likely quite different from those faced by someone mapping kelp in California (see examples in Cavanaugh et al., 2021).

This guidebook provides an overview of optical remote sensing as it relates to mapping giant kelp and bull kelp. We describe optical remote sensing platforms and sensors pertinent to mapping and monitoring attributes of bull kelp and giant kelp beds — kelp presence/absence, density, species, and health. Recommendations found in this guidebook can also reasonably be applied to other floating, emergent canopy forming kelp species (i.e., other species that float at the ocean’s surface). This guidebook provides monitoring guidance via infographics developed by an international community of kelp remote sensing experts (see box below). We illustrate a user-friendly framework based on the latest remote sensing science for matching a kelp monitoring objective(s) to the desired spatial scale and environmental setting.

The goal of this guidebook is to help you select the best remote sensing tools and data for your science and/ or management directives related to mapping emergent kelp canopies.