A Decade of Disappearance: Bull Kelp in the San Juan Islands
A presence/absence comparison of Bull Kelp canopies over a decade in Samish Traditional Territory, San Juan Archipelago, Washington
Depicted here is Samish Traditional Territory.
Samish Department of Natural Resources focuses on preserving, protecting, and enhancing culturally significant natural resources and habitats within this area for current and future generations.
Samish Territory is located in the heart of the Salish Sea.
Samish Traditional Territory location within the United States
Samish Tradition
Since time immemorial, Samish people have lived and prospered on the land and water of the Salish Sea in Washington State. Over time, Samish people have successfully navigated a variety of changes while maintaining a strong connection to the resources, rich lands, and waters of our region. While many of us may have moved away, we are still connected to this place and through it, to each other.
Through our strong connection with the natural world, we are beginning to see changes, such as the disappearance of kelp and in the number of species struggling to survive and adapt.
Our history instructs us as to proper relationship to the land and its resources by teaching us the lessons left for us by our ancestors about both the natural and spiritual worlds and how those worlds cannot be separated. This teaching helps guide our tribal members in their daily lives and offers a unique and irreplaceable system of beliefs, which takes us through the transitions of life from birth to death and beyond.
Samish people were respected for their spiritual strength, as well as their skillful carving of canoes and construction of longhouses. One of those longhouses on the eastern end of Samish Island measured some 1,250 feet in length. In 1847 the Tribe had over 2,000 members, but raids from Northern Tribes and epidemics of measles, small pox, and the ague (flu), reduced the Tribe's population to approximately 150 by the time of the signing of the Point Elliott Treaty. History also tells us that 113 Samish were present at the Treaty grounds at the time of signing in 1855.
Canoes approaching Longhouse on Samish Island
As part of a larger Coast Salish cultural complex the Samish formed a village community, which consisted of several important social groupings. These groupings can be listed as 4 units: the family, the house group, the villages, and the tribe as a whole. Samish tribal members married outside of their groupings, so as to create a network of kinships. These kinships regulated both the internal and external relationships between the families, the house groups, the villages, and the tribe as a whole. The Tribe relied on these relationships during bad times in order to be able to access areas of food and shelter that was not currently in their home territory. Linguistically and culturally, the Tribe is grouped as Coast Salish, speaking a dialect of Coast Salish known as Straits Salish.
The Tribe's traditional territory historically stretched over a wide area, which ranged from the mountain tops of the Cascades westerly along the hills, woodlands, and river deltas, arriving at the far western shores of the San Juan Islands. Samish Traditional Territory provides a backdrop for our history and cultural traditions that remain strong today.
Traditional Ecological Knowledge: Providing Direction to Samish Department of Natural Resources
Samish people have been stewards of the environment in the San Juan Archipelago for hundreds of generations. As ocean people, Samish culture and traditions are intimately tied to resources and places in the Salish Sea. There is a common phrase said among Samish and other Coast Salish People:
"When the tide is out, the table is set!"
Clam Bake
There is not a single beach in Samish Traditional Territory that has not seen the footprints of the ancestors. Honoring traditional ways while preserving cultural use of materials and foods for future generations is a cornerstone that guides the work of Samish DNR.
Cooking salmon using traditional carved Iron Wood
Understanding and planning for the changes in marine ecosystems over time ensures that Samish People will be able to continue utilizing the bountiful natural resources of the Salish Sea that are such an important part of their cultural identity.
The Maiden of Deception Pass: Guardian of Her Samish People
For millennia, kelp has been used by Samish People for such things as fishing and in food preparation. Kelp also plays a significant role in Samish stories such as the Maiden of Deception Pass.
The Maiden of Deception Pass: Ko-Kwal-Alwoot was a beautiful Samish woman. She was gathering seafood one day when a young man from beneath the sea saw her and fell in love. But when this man of the sea asked her father for her hand in marriage, he refused, for fear she would drown. The young man warned Ko-Kwal-Alwoot's father that the seafood would disappear unless she married him. When his warning proved to be true, Ko-Kwal-Alwoot's father granted permission for the marriage. The beautiful woman waded into the sea to join her new husband. Once again the seafood returned and was plentiful. Ko-Kwal-Alwoot returned to her people once a year for four years. Barnacles had grown upon her hands and arms, and her long raven hair turned to Bull Kelp. Chill winds followed wherever she walked, and she seemed to be unhappy out of the sea. Seeing this, Ko-Kwal-Alwoot's people told her she did not need to return to them. And so Ko-Kwal-Alwoot lives eternally underwater, ensuring her land has an abundance of food and pure spring-water. Since that day, she has been Samish Tribe's guiding spirit providing protection as they travel the waters of the ancestors.
The Maiden of Deception Pass
Tracy W. Powell, a local carver from Anacortes, WA carved a 23-foot story pole out of Western Red Cedar, which resides at Rosario Head in Deception Pass.
Bull Kelp throughout the San Juan Islands, Washington
Bull Kelp (Nereocystis luetkeana) canopy forests play an integral role in the Salish Sea. They provide critical habitat for a wide variety of species including ESA listed rockfish and Orca, and other marine wildlife. Yet little data exists to determine overall canopy coverage or trends in Bull Kelp in the San Juan Islands, Washington.
Studies show that between the years of 1912 and 1978, canopy-forming Bull Kelp increased substantially, with the largest relative increases in South and Central Puget Sound, Washington.
However, from 1978 to 2013, there were conspicuous declines in the abundance of floating kelp beds throughout the area. Research by Helen Berry, Washingon DNR's Manager of the Nearshore Habitat Program, suggests a continued decline in bull kelp through 2013 to 2016 in central and south Puget Sound, Washington.
Bull Kelp is found in discrete locations throughout the San Juan archipelago. Beds grow in extreme low tide levels and are attached to bedrock or to large cobbles in the sub-tidal zone, especially in areas of significant water circulation due to wave exposure or currents.
Bull Kelp is protected under the Environmentally Sensitive Areas section of the San Juan County Unified Development Code (SJCC 18.30.110.5) and is listed as a priority habitat type by the US Department of Fish and Wildlife’s Priority Habitats and Species Program. These kelp forests provide critical biogenic habitat for a wide range of species and other ecosystem functions, including primary production and cycling of nitrogen and carbon.
As floating kelp beds continue to diminish in the Salish Sea, concerns for the decline and overall disappearance of pristine spawning and nursery habitats of pacific herring, juvenile rockfish, and other marine wildlife grow ever so quickly.
The Project
The goal of this project is to develop a substantial amount of baseline data that can be used to monitor long-term trends in kelp depletion and accretion throughout the area. In partnership with NOAA and NW Straits Foundation this project will aid kelp recovery efforts throughout the Salish Sea.
Using 2016 6-inch high resolution aerial imagery captured by Pictometry International for San Juan County, WA during June, 2016, at midday when the sun angle was at its highest point to reduce shadows, we visually identified Bull kelp and digitized bull kelp surface canopies within the county. Because the imagery was only for San Juan County, Skagit County Islands were not digitized. By applying this method, we were more accurate than kayak surveys and the data collection process was less time consuming.
Our digitized data was first compared to data computed from a 2006 study by Friends of the San Juans (FOSJ), located in Friday Harbor, San Juan Island, WA. Based on low tide color infrared high resolution imagery, FOSJ performed an image classification to detect Bull kelp surface canopies throughout San Juan County.
Following this comparison, Samish GIS digitized the 2006 imagery used in the FOSJ study and compared it to the FOSJ image classification results and to our digitized 2016 data.
2019 6-inch high resolution aerial imagery captured by Pictometry International for San Juan County during June 2019 was also obtained, digitized, and compared to the 2016 and 2006 digitized datasets.
These comparisons gave us positive and negative change (presence/absence) in Bull kelp canopies over a decade.
The results were astonishing.
Traditional Ecological Knowledge of Bull Kelp in San Juan Islands
Samish DNR gathered Traditional Ecological Knowledge (TEK) from two tribal fishermen who have been fishing this area for decades and have nearly 100 years of combined knowledge of the waters surrounding the San Juan Islands.
A weekend was spent drawing on a nautical chart of Samish Traditional Territory where they remembered seeing Bull Kelp growing up.
To the right is the TEK data from these two tribal fishermen.
Nautical Chart after two tribal fishermen drew where they remembered seeing Bull Kelp from their decades of fishing the waters surrounding the San Juan Islands.
2006 Baseline Bull Kelp Survey Data
In 2006, FOSJ used remote sensing techniques to identify Bull kelp in San Juan County. An image classification was performed based on low tide color infrared high resolution imagery.
This process categorized pixels that reflected a certain band wave understood to be Bull kelp in the water. FOSJ added a 10-foot buffer around the categorized pixels to account for sub-surface kelp not detected in the image classification.
Depicted in the map to the right in pink are the results of the FOSJ 10-foot buffer and where Bull Kelp was identified. 845 acres of kelp were identified using this method.
Samish Digitized 2016 Bull Kelp Survey Data
Using the 2016 0.5 foot high resolution aerial imagery, captured by Pictometry International during May/June of 2016, our GIS Program Manager and an intern, Jason Flowers, digitized Bull kelp found in San Juan County.
Depicted to the right in teal color is the 2016 digitized kelp data. We completed digitizing in April 2018.
Using this method, we identified and digitized 540 acres of Bull Kelp.
2016 Aerial Bull kelp Clarity Example
2016 Aerial Bull kelp located off the southern end of Lopez Island
2016 Aerial Digitized Bull kelp off the southern end of Lopez Island
Comparison of 2006 FOSJ and 2016 Samish Data:
Upon completion of the digitized 2016 Imagery, we compared our findings to the 2006 data.
To the right is the comparison of both Bull kelp datasets and our TEK in San Juan County.
Though we were comparing Bull kelp data acquired by two different methods, our data suggests a 305 acre loss from 2006 to 2016. This is roughly a 36% loss in Bull kelp forest canopy overall in one decade. The table below breaks down the losses in acreage by Island from comparing the Bull kelp data.
2006 and 2016 Kelp Average Differences in the San Juan Islands, Washington
We found that the average loss of Bull kelp between all Islands was approximately 49% with a maximum loss of 77% and a minimum loss of 6%; excluding Matia, Clark, and Barnes Islands, where imagery was too disrupted by surface roughness and sun glare to digitize. Areas with little surface roughness or sun glare were still digitized and added to the overall amount of acres found in the 2016 imagery.
Example of Surface Roughness and Sun Glare that was included in the 2016 Bull Kelp Dataset
Presence/Absence from comparing FOSJ and Samish DNR Bull kelp data: Four Islands within Samish Traditional Territory, San Juan Archipelago, WA.
Stuart Island, San Juan Archipelago, Washington
In 2006, 101.04 acres of Bull kelp was identified surrounding Stuart Island. The 2016 digitized data suggests the number of acres declined to 51.62 acres. That is a loss of 49.42 acres or 49% in just 10 years.
Patos Island, San Juan Archipelago, Washington
In 2006, 15.86 acres of Bull kelp was identified surrounding Patos Island. The 2016 digitized data suggests the number of acres declined to 3.6 acres. That is a loss of 12.26 acres or 77.3% in just 10 years, with most kelp disappearing from the north and northeast side of the island.
Southern Lopez Island, San Juan Archipelago, Washington
In 2006, 222.29 acres of Bull kelp was identified surrounding Lopez Island. The 2016 digitized data suggests the number of acres declined to 138.96 acres. That is a loss of 83.33 acres or 37.5% in just 10 years. Depicted above is the southern end of Lopez Island where most of the Bull Kelp surrounding Lopez is located.
Southern San Juan Island, San Juan Archipelago, Washington
In 2006, 236.82 acres of Bull kelp was identified surround San Juan Island. The 2016 digitized data suggests the number of acres declined to 208.08 acres. That is a loss of 28.74 acres or 12.2% in just 10 years.
Though San Juan Island experienced a loss overall, the southern end of San Juan represents an area of substantial gain from 2006 to 2016. This could be due to the significant water circulation from large wave exposure and dynamic currents in the area.
Comparison of 2006 FOSJ and 2006 Samish Data:
Upon completion of the digitized 2006 Imagery, we compared our findings to the 2006 FOSJ image classification data.
To the right is the comparison of both Bull kelp datasets in San Juan County. The little bits of pink color you see are from the 2006 FOSJ image classification. The light blue is from the 2006 Samish digitized data.
When comparing Samish GIS digitized 2006 data to FOSJ 2006 image classification data, the data suggests a 68 acre difference in Bull kelp mapped between the two methods. This is most likely due to the 10ft buffer that FOSJ added to their image classification. On the map to the right, you can see the pink FOSJ outline surrounding the light blue Samish 2006 digitized data.
2006 FOSJ Total Acreage: 845 Acres
2006 Samish Digitized Acreage: 777 Acres
Difference of just 68 acres.
Comparison of 2006 and 2016 Samish Digitized Data:
To the right is the comparison of both digitized Bull kelp datasets in San Juan County. Light Blue is the Samish 2006 digitized data and light green is the Samish 2016 digitized data.
When comparing Bull kelp extent data acquired by digitizing, our data suggests a 237 acre loss from 2006 to 2016. Bull kelp extent was ~30% smaller in 2016 than in 2006.
Because there was little difference between the 2006 FOSJ image classification and the 2006 Samish digitized dataset, (305 acres and 237 acres, respectively) we chose not to compare Island by Island.
2019 Samish Digitized Data:
Samish then digitized 2019 6-inch resolution imagery of San Juan County captured by Pictometry International.
In the 2019 imagery, only 375 acres of Bull kelp surface canopy extent was mapped.
When comparing the 2019 digitized data to 2016 and 2006, we continue to see the trend of loss.
Compared to 2016, the San Juan County Bull kelp surface canopy extent was ~30.50% smaller in 2019.
Compared to 2006, the San Juan County Bull kelp surface canopy extent was ~51.75% smaller in 2019.
This large difference in mapped Bull kelp surface canopy extent in 2019 could be due to high annual variations that kelp is known to have. As well as, the possibility of higher tides when the aerial dataset was obtained.
However, as you will see below in the kayak surveys section, one of the reference kelp beds Samish kayaks annually, was approximately 50% smaller in 2019 than in 2018. This suggests that the large difference is more related to the high annual variations in kelp rather than tidal influences when the aerials were obtained.
In 2021, the reference kelp bed grew back to approximately 85% of its original size measured in 2018. 2020 kayak surveys were cancelled due to COVID-19.
Bull Kelp Kayaking Surveys
Since 2018, we have monitored Bull kelp beds in the Skagit County portion of the San Juan Islands, by kayak, measuring surface canopy using a field GPS unit. Kayak Surveys are performed within a week of the previous year, at a 2-foot tide, and approximately slack current.
We are currently kayak surveying two reference beds. These beds were selected based on location and ease of access. By collecting this data, we begin building a baseline and establish long-term monitoring to aid in the understanding of the dynamic kelp beds within the San Juan Archipelago.
1st Site: Burrow's Lighthouse Kelp bed, Burrow's Island, Skagit County, San Juan Archipelago
Our 1st site is the Burrow's Lighthouse kelp bed, located off Burrow's Island (Above). Over the past 4 years of surveys, the kelp canopy has remained approximately the same size, showing little to no variation. We will continue monitoring this bed in 2023.
2nd Site: Reef Point, Cypress Island, Skagit County, San Juan Archipelago
Our 2nd site is the Reef Point kelp bed, located off the southern end of Cypress Island. Over the past 4 years of surveys, we have noticed significant changes each year.
2018, 2019, 2021, and 2022 Highlighted Kayak Surveys of Reef Point, Cypress Island, San Juan Archipelago
A closer look
The 2018 survey, indicated in red, measured the Bull kelp canopy to be approximately 17 acres. The 2019 survey, indicated in green, measured Bull kelp canopy at approximately 9 acres, which was about 50% smaller than in 2018. Our 2020 kayak surveys were cancelled due to the COVID-19 pandemic.
During our 2021 survey, indicated in blue, we measured the kelp canopy to be approximately 14.5 acres. (about 15% smaller than its original mapping in 2018)
The 2022 survey, indicated in yellow, measured the canopy to be approximately 8 acres, which is about 45% smaller than the 2021 canopy size and over 52% smaller than the 2018 kayak survey. Though we only have 4 years of kayak surveys completed, the variance in acres over the years and the continuance of measuring less acreage then our original 2018 kayak survey has caught our attention.
We look forward to our 2023 kayak surveys, which will help us form a more complete picture of what is happening at this bed.
Moving Forward
Bull kelp canopy forests play an integral role in the Salish Sea. They provide critical habitat for a wide variety of species including ESA listed rockfish and Orca, and other marine wildlife.
Samish Indian Nation initiated the Bull kelp project to help fill knowledge gaps and develop a substantial amount of baseline data to monitor long-term trends in kelp depletion and accretion throughout the Islands.
Though, there are obstacles to consider when mapping Bull kelp using high-resolution imagery, such as sea roughness, shadows obscuring kelp, tidal exchange during flyovers, and different mapping techniques creating different results, our results from this study still tell a story.
Traditional Ecological Knowledge and analyzing historical imagery suggests that we have lost Bull kelp throughout the San Juan Islands.
We now have:
- Digitized Traditional Ecological Knowledge of kelp throughout Samish Traditional Territory
- 2006 Image Classification with a 10-ft buffer, which highlights the Bull kelp canopy coverage for San Juan County
- 2006 digitized dataset, which highlights the Bull kelp canopy coverage for San Juan County
- 2016 digitized dataset, which highlights the Bull kelp canopy coverage for San Juan County
- 2019 digitized dataset, which highlights the Bull kelp canopy coverage for San Juan County
We will continue to kayak survey Bull kelp throughout the San Juan Islands in 2023 and look deeper into additional local changes in kelp forest canopies within the Salish Sea.
Data generated is shared with project partners to fill knowledge gaps regarding this critical habitat, guide future restoration efforts and play a crucial role in the Rockfish Recovery Plan.
Story Map Created By: Sophia Ammons, Samish Indian Nation GIS Program Manager
Want to learn more about this project and other things Samish is doing to help protect, preserve, and enhance culturally significant natural resources and habitats? Please visit our website or contact: Todd Woodard, Samish Indian Nation Director of Natural Resources
To learn about other StoryMaps and GIS Applications Samish has created, please visit our GIS website below:
This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement PA-01J27601 to the Northwest Indian Fisheries Commission. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
