Seasonal, Mortality, and Tidal Effects on Marine Mammal Abundance and Diversity in San Juan Channel Fall 2015
Presentation Abstract
The San Juan Archipelago (SJA) is a dynamic ecosystem that supports a variety of resident and transient marine mammals. As the Salish Sea and the SJA have extensive cultural and economic ties with marine mammals, it is important to have comprehensive studies on population status throughout different seasons. This fall featured continuing shifts to lower abundance and a more diverse community composition that began in 2014. The three most abundant species for fall 2015 were harbor seals (2.8/km²), steller sea lions (1.96/km²), and harbor porpoises (0.6/km²); however, these were some of the lowest densities in recent history. In addition, six other species of marine mammals were recorded on transect that have not been observed previously from Pelagic Ecosystem Function (PEF) apprentices. This may be related to anomalously warm oceanic conditions. Although mortality does not seem to correlate with low abundance of harbor seals, more detailed analysis should be conducted in future research. Additional studies on fine temporal scales of tidal phases and current speeds and marine mammal abundance found species-specific relationships with tidal phase and current speed. Harbor porpoises aggregated in larger numbers after peak current speed than before while steller sea lions and harbor seals showed different preferences for current speeds.
Session Title
General species and food webs
Conference Track
Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Start Date
2016 12:00 AM
End Date
2016 12:00 AM
Location
2016SSEC
Type of Presentation
Poster
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Marine mammal populations--Environmental aspects--Washington (State)--San Juan Islands; Marine mammal populations--Monitoring--Washington (State)--San Juan Islands
Geographic Coverage
Salish Sea (B.C. and Wash.); San Juan Islands (Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Seasonal, Mortality, and Tidal Effects on Marine Mammal Abundance and Diversity in San Juan Channel Fall 2015
2016SSEC
The San Juan Archipelago (SJA) is a dynamic ecosystem that supports a variety of resident and transient marine mammals. As the Salish Sea and the SJA have extensive cultural and economic ties with marine mammals, it is important to have comprehensive studies on population status throughout different seasons. This fall featured continuing shifts to lower abundance and a more diverse community composition that began in 2014. The three most abundant species for fall 2015 were harbor seals (2.8/km²), steller sea lions (1.96/km²), and harbor porpoises (0.6/km²); however, these were some of the lowest densities in recent history. In addition, six other species of marine mammals were recorded on transect that have not been observed previously from Pelagic Ecosystem Function (PEF) apprentices. This may be related to anomalously warm oceanic conditions. Although mortality does not seem to correlate with low abundance of harbor seals, more detailed analysis should be conducted in future research. Additional studies on fine temporal scales of tidal phases and current speeds and marine mammal abundance found species-specific relationships with tidal phase and current speed. Harbor porpoises aggregated in larger numbers after peak current speed than before while steller sea lions and harbor seals showed different preferences for current speeds.
