Streaming Media
Presentation Abstract
Bull kelp (Nereocystis luetkeana) is an important primary producer that plays a foundational role in the marine nearshore ecosystems of Puget Sound. Evidence of significant declines in bull kelp forests in this region has motivated efforts to establish region-wide long-term monitoring programs for this critical species. As part of this drive, the Washington State Department of Natural Resources (DNR) has been testing a series of aerial imaging platforms to detect and map the distribution of bull kelp to complement existing monitoring protocols. In 2020, DNR began surveying floating bull kelp canopies in Puget Sound using RGB and multispectral Unmanned Aerial Vehicles (UAVs), as well as low-cost RGB and near-infrared sensors carried by fixed wing aircraft. We have conducted surveys at five diverse kelp forest sites using three different imaging platforms, and additional surveys at many other sites with one or two methods, representing a range of potential trade-offs. Surveys conducted at sites in North Puget Sound were done so in partnership with county Marine Resource Committees through the Northwest Straits Commission, which involved community science efforts from volunteers. Orthomosaics (large format image products) generated from our aerial surveys were georeferenced, analyzed using a supervised object-based random forest classifier, and assessed against technician-verified stratified random accuracy assessment points. From these final classified results, we generated map layers of the floating bull kelp canopy at each site and developed derived metrics to describe each kelp bed including canopy area, overall bed area, and canopy percent cover. Our findings demonstrate the comparative strengths and limitations of each aerial imaging platform with regard to cost, kelp canopy detection capability, resolution, and spatial coverage. These findings enable us to make recommendations for the most appropriate use for each platform with regard to bull kelp canopy mapping in Puget Sound.
Session Title
Kelp Monitoring - Collaboration & Technology
Conference Track
SSE9: Nearshore
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-traditionals-334
Start Date
26-4-2022 11:30 AM
End Date
26-4-2022 1:00 PM
Genre/Form
conference proceedings; presentations (communicative events)
Subjects – Topical (LCSH)
Nereocystis luetkeana--Washington (State)--Puget Sound; Kelps--Monitoring--Washington (State)--Puget Sound; Drone aircraft in remote sensing; Environmental monitoring--Washington (State)--Puget Sound--Remote sensing
Geographic Coverage
Puget Sound (Wash.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons
Assessing the viability of mapping bull kelp in Puget Sound using aerial imaging platforms
Bull kelp (Nereocystis luetkeana) is an important primary producer that plays a foundational role in the marine nearshore ecosystems of Puget Sound. Evidence of significant declines in bull kelp forests in this region has motivated efforts to establish region-wide long-term monitoring programs for this critical species. As part of this drive, the Washington State Department of Natural Resources (DNR) has been testing a series of aerial imaging platforms to detect and map the distribution of bull kelp to complement existing monitoring protocols. In 2020, DNR began surveying floating bull kelp canopies in Puget Sound using RGB and multispectral Unmanned Aerial Vehicles (UAVs), as well as low-cost RGB and near-infrared sensors carried by fixed wing aircraft. We have conducted surveys at five diverse kelp forest sites using three different imaging platforms, and additional surveys at many other sites with one or two methods, representing a range of potential trade-offs. Surveys conducted at sites in North Puget Sound were done so in partnership with county Marine Resource Committees through the Northwest Straits Commission, which involved community science efforts from volunteers. Orthomosaics (large format image products) generated from our aerial surveys were georeferenced, analyzed using a supervised object-based random forest classifier, and assessed against technician-verified stratified random accuracy assessment points. From these final classified results, we generated map layers of the floating bull kelp canopy at each site and developed derived metrics to describe each kelp bed including canopy area, overall bed area, and canopy percent cover. Our findings demonstrate the comparative strengths and limitations of each aerial imaging platform with regard to cost, kelp canopy detection capability, resolution, and spatial coverage. These findings enable us to make recommendations for the most appropriate use for each platform with regard to bull kelp canopy mapping in Puget Sound.
