Acoustic Monitoring

Coastal Acoustic Buoys were deployed at four paired locations between Cattle Point and Pile Point in the summers of 2019 and 2020 to measure ambient noise levels inside and outside of the County’s voluntary No-Go Zone as well as acoustically detect Southern Residents.

To tease apart different drivers of ambient noise in the study area, SMRU Consulting focused on seven different factors: 1) the No-Go Zone, 2) location, 3) day vs night, 4) weekend vs midweek, 5) holiday weekends, 6) year, and 7) commercial fish openings.

In addition to ambient noise, an acoustic boat detector and a 50 kHz detector were used to identify periods when boats were present and depth sounders/fish finders were being used.  These detectors allowed for transiting boats to be differentiated from those engaged in trolling.

To learn about this study and the results please view the video below and check out the report. 

 

SMRU Consulting Acoustic Monitoring Report

The project’s three key data inputs used to inform the planning process included:

1. Identifying high-priority foraging hotspots using whale behavior data from more than 18,000 observations over 19 years.
2. Understanding the acoustic soundscape of high-use areas and how it relates to different boating activities.
3. Understanding the social values and attitudes of local user groups, as well as Tribes.

In addition, information was gathered on recreational and commercial fishing openings to understand the overlap with killer whales’ presence on the westside on the westside of San Juan Island.

Identifying Southern Resident Killer Whale Priority Foraging Areas

Southern resident killer whales are more vulnerable to disturbance while they are feeding than in other activity states. In 2010, Oceans Initiative conducted a study to identify key feeding areas for the Southern Residents as the first step of a systematic conservation planning process to identifying protected areas that would confer the most conservation benefit to the whales while minimizing costs, impacts, and inconvenience on other ocean user communities.

This study is building off this initial effort and has expanded the data available to input into the spatial models from one season to 15, spanning 2003 - 2020. This has been achieved by combining data sources from 7 researchers. 

18,558 whale observations were used for this analysis representing a 14-fold increase in sample size. This study used spatial modeling techniques to determine where the highest probability of whales foraging was along the west side area. 

A summary of this study, the findings, and the important context related to vessel noise and presence impacts on whale foraging behavior is provided below. 

OI SRKW Feeding Final Report 2021.pdf

Preliminary Analysis of Stakeholder Values and Attitudes

Identifying acceptable management alternatives of a common property resource area is complex.  User groups access and impact these areas differently and have diverse opinions about conservation goals and the tradeoffs of management alternatives.   The analysis of user values and opinion of management options included information from seven groups:

• San Juan Island westside residents
• Whale watching tour operators
• Sea kayaking tour operators
• Recreational boaters
• Recreational fishers
• Commercial fishers
• Whale conservation non-profits and advocates

Full report on preliminary results

In addition to user groups, this project is conducting direct consultation with Coast Salish Tribes about the scientific findings and asking for their perspective on possible management options.

Summary of Survey Results

Commercial and Treaty Fishing Openings 

Information for commercial and treaty fishing openings were obtained from WDFW (for chum) and from the Fraser River Panel (for sockeye and pink). 

Data were only selected for purse seine and gill net operations because these are the gear types used off the west side of San Juan Island. There were no openings for sockeye and pink in 2020,  and WDFW only provided the combined (reef net, gill net, and purse seine) openings for 2019. 

This infographic provides a summary of the number of days commercial and treaty fishing was open, and in 2019 a summary of the number of days whales were present on the westside per month compared to the number of days of fishing per month. 

Recreational Fishing Activities

Recreational fishing data were obtained for Area 7 from WDFW for 2016-2019. Not all 2020 data were available at the time of application, so we have not included them in the summaries presented here. 

• Fishing activity was focused in January and during July-September each year. 
• Salmon catches generally peaked in July with an average of 3,535 fish caught per month, during an average of 10,303  angler trips per month. 
• July 2017 saw the highest number of angler trips at 17,268. 
• It is important to note that these data represent the whole of Area 7 which encompasses San Juan County and are not just for the westside area. 
• The number of killer whale days per month peaked during the months July - September, with 2016 and 2018 seeing the most whale days per month during these months. 
• It is important to note that these data represent both Southern Resident and Transient killer whales combined because the majority of boaters and fisheries are unlikely to tell the difference.