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• 1. [Article] On the Validity of the Radiographic Method for Determining Age of Ancient Salmon

  White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, ...

  Citation × Citation Citation Abstract Copy Title: On the Validity of the Radiographic Method for Determining Age of Ancient Salmon Author: Hofkamp, Anthony R., Butler, Virginia L. Year: 2017 White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, season of capture and season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Recent aDNA analysis has shown that the X-ray approach has flaws but the source of the error has been unknown. Given the value of reconstructing salmon population demographics and life history from ancient remains, establishing a valid and reliable method of ageing salmon vertebrae is extremely worthwhile. The main goal of our study was to evaluate if X-ray images of ring patterns on vertebrae provide a valid method of estimating fish age. Vertebrae from 66 adult Chinook salmon (O. tshawytscha) of known age were studied with X-rays, thin sections or low-powered (10–30 ×) magnification. We found that the white bands observed in X-rays are structural walls that do not grow annually. While X-rays are not a valid method for ageing salmonids, incremental growth seen on the surface of fish centra shows great promise for reconstructing ancient fish life history. Title: On the Validity of the Radiographic Method for Determining Age of Ancient Salmon Author: Hofkamp, Anthony R., Butler, Virginia L. Year: 2017 White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, season of capture and season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Recent aDNA analysis has shown that the X-ray approach has flaws but the source of the error has been unknown. Given the value of reconstructing salmon population demographics and life history from ancient remains, establishing a valid and reliable method of ageing salmon vertebrae is extremely worthwhile. The main goal of our study was to evaluate if X-ray images of ring patterns on vertebrae provide a valid method of estimating fish age. Vertebrae from 66 adult Chinook salmon (O. tshawytscha) of known age were studied with X-rays, thin sections or low-powered (10–30 ×) magnification. We found that the white bands observed in X-rays are structural walls that do not grow annually. While X-rays are not a valid method for ageing salmonids, incremental growth seen on the surface of fish centra shows great promise for reconstructing ancient fish life history. Close

• 2. [Article] Tracking Fish and Human Response to Earthquakes on the Northwest Coast of Washington State, USA: A Preliminary Study at Tse-whit-zen

  Evidence of large earthquakes occurring along the Pacific Northwest Coast is reflected in coastal stratigraphy from Oregon to British Columbia, where there also exists an extensive archaeological record ...

  Citation × Citation Citation Abstract Copy Title: Tracking Fish and Human Response to Earthquakes on the Northwest Coast of Washington State, USA: A Preliminary Study at Tse-whit-zen Author: Mohlenhoff, Kathryn A., Butler, Virginia L. Year: 2017 Evidence of large earthquakes occurring along the Pacific Northwest Coast is reflected in coastal stratigraphy from Oregon to British Columbia, where there also exists an extensive archaeological record of Native American occupation. Tse-whit-zen, a large Native American village dating between ∼2800 yrs BP and the historic era, located on the Olympic Peninsula of Washington State, was excavated with exceptionally fine stratigraphic control allowing for precise comparison of these natural and cultural records. Here we report on the ∼10,000 fish remains from one 2 × 2 m excavation block; this assemblage spans the timing of one seismic event, allowing study of changes in relative taxonomic abundance through time that may coincide with earthquakes or other environmental changes. Results indicate a wide variety of fish taxa were used throughout the dated occupation. Comparisons of fish use before and after one earthquake event shows a decline in salmon (Oncorhynchus sp.) and an increase in herring (Clupea pallasii), shifts consistent with earthquake-related habitat loss. This serves as a pilot study for a large-scale collaborative project that is drawing on the range in animal types (invertebrates, mammals, birds, and fishes) to assess human response to gradual and abrupt environmental change at Tse-whit-zen. Title: Tracking Fish and Human Response to Earthquakes on the Northwest Coast of Washington State, USA: A Preliminary Study at Tse-whit-zen Author: Mohlenhoff, Kathryn A., Butler, Virginia L. Year: 2017 Evidence of large earthquakes occurring along the Pacific Northwest Coast is reflected in coastal stratigraphy from Oregon to British Columbia, where there also exists an extensive archaeological record of Native American occupation. Tse-whit-zen, a large Native American village dating between ∼2800 yrs BP and the historic era, located on the Olympic Peninsula of Washington State, was excavated with exceptionally fine stratigraphic control allowing for precise comparison of these natural and cultural records. Here we report on the ∼10,000 fish remains from one 2 × 2 m excavation block; this assemblage spans the timing of one seismic event, allowing study of changes in relative taxonomic abundance through time that may coincide with earthquakes or other environmental changes. Results indicate a wide variety of fish taxa were used throughout the dated occupation. Comparisons of fish use before and after one earthquake event shows a decline in salmon (Oncorhynchus sp.) and an increase in herring (Clupea pallasii), shifts consistent with earthquake-related habitat loss. This serves as a pilot study for a large-scale collaborative project that is drawing on the range in animal types (invertebrates, mammals, birds, and fishes) to assess human response to gradual and abrupt environmental change at Tse-whit-zen. Close