Record Details
Pacific lamprey Entosphenus tridentatus : integrating traditional ecological knowledge and contemporary values into conservation planning, and stream substrate associations with larval abundance in the Willamette River Basin, Oregon, U.S.A.
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Pacific lamprey Entosphenus tridentatus : integrating traditional ecological knowledge and contemporary values into conservation planning, and stream substrate associations with larval abundance in the Willamette River Basin, Oregon, U.S.A. |
| Names |
Sheoships, Gabe
(creator) Schreck, Carl B. (advisor) |
| Date Issued | 2014-12-12 (iso8601) |
| Note | Graduation date: 2015 |
| Abstract | Pacific lamprey Entosphenus tridentatus is a valuable icon and traditional food source for Indigenous people of western North America. Native Americans have utilized traditional ecological knowledge (TEK) since time immemorial to guide their ways of life, transmitting cultural values and natural history to further generational knowledge. Pacific lamprey are in decline throughout their range, and have historically been disregarded in western science. The Willamette River Basin, Oregon, U.S.A currently supports a traditional harvest location, Willamette Falls, which continues to persist, despite great losses in adjacent basins and remains a harvest stronghold amongst Columbia River Basin Tribes. To further understand Pacific lamprey, we utilized both Indigenous knowledge and western science to gain information that would aid recovery. My first goal was to determine traditional ecological knowledge and the cultural values of Pacific lamprey to provide guidance for future conservation planning. My second goal was to evaluate the fine scale habitat characteristics of larval Pacific lamprey. To determine tribal values for the purpose of informing conservation planning of Pacific lamprey, I used: 1) oral history interviews of tribal elders, and 2) questionnaires distributed across entire adult (18 years and older) tribal populations. We conducted semi-structured interviews with tribal elders to gain insights into the biology, distribution, and cultural value of lamprey. I interviewed 32 tribal elders, 11 from the Grand Ronde, 10 from the Siletz, and 11 from the Umatilla. To understand modern fishing practices and current values of lamprey, I distributed a standardized questionnaire (n = 753) to a sample of each adult (18 years and older) tribal population, and received a total of 188 responses total: 38 from the Grand Ronde, 60 from the Siletz, and 90 from the Umatilla. From my interviews, I found that each tribe has noticed a decline in Pacific lamprey populations within their ceded areas, and has witnessed traditional harvest locations lost due to population declines and/or anthropogenic damage, leaving Willamette Falls as the sole harvest site for the three tribes. Questionnaire results showed that the strongest issues relating to the traditional usage of Pacific lamprey amongst each tribe are cultural awareness, harvest accessibility, and Pacific lamprey populations. I evaluated two fine scale habitat associations of larval Pacific lamprey in the Willamette River Basin to understand the association of stream sediment and larval abundance. Study objectives were to: 1) evaluate the substrate size most closely associated with larval abundance, and 2) to evaluate the influence of organic material upon larval abundance. We used a backpack electrofisher to enumerate larval lamprey in six wadeable Willamette River tributaries, using a nested two-pass sample design at a lower, middle, and upper reach (each reach composed of ten 1-m² quadrats). Stream sediment cores were collected for subsequent determination of particle size and organic composition content. I used particle size sieve analysis to estimate dominant substrate size class per sample, from the following size classes: silt (< 0.063 mm), very fine sand (0.063–0.125 mm), fine sand (0.125-0.25 mm), medium fine sand (0.25-0.50 mm), coarse sand (0.50-1.0 mm), very coarse sand (1.0-2.36 mm), and fine gravel (>2.36 mm). I analyzed organic content by loss of weight through combustion. Larvae were present in 17 of 18 reaches (94%) 18), but only detected in 37% of the quadrats. Larval Pacific lamprey abundance was highest in habitats with predominantly medium fine sand (0.25-0.50 mm) substrate. I fit negative binomial mixed models using parameters for sediment depth, percentage of medium fine sand (0.25-0.50 mm), organic material and a random effect for basin. My top model consisted of percentage of medium fine sand (0.25-0.50 mm), organic material and a random effect for basin. At the fine scale, substrate characteristics were associated with the abundance of larval Pacific lamprey. Appropriate conservation measures should be taken to address the restoration of Pacific lamprey, activities that promote natural river flow and distribution of sediment could be of benefit. Efforts that educate mainstream society should be implemented to reduce further species decline. With the continued decline of Pacific lamprey, there is potential for further degradation of tribal cultural values. Conservation work that promotes the restoration of Pacific lamprey is crucial to the tradition and culture of the Grand Ronde, Siletz, and Umatilla Tribes. |
| Genre | Thesis/Dissertation |
| Access Condition | http://creativecommons.org/licenses/by-nd/3.0/us/ |
| Topic | lamprey |
| Identifier | http://hdl.handle.net/1957/54846 |
