Sampled Fish Snake River Chinook

Fish species.

Date when fish was collected.

Location where fish was collected.

Unique identifier for each fish that includes collection year.

Male or female.

Length of the fish from tip of snout to fork of tail. Units for values are millimeters.

Otolith radius was measured on the dorsal side of the otolith in the region perpendicular to the longest axis. Otolith radius at Snake River egress was measured at the point on the edge-to-core scan where 87Sr/86Sr ratio was between 0.70960 (upper and lower Snake River have a 87Sr/86Sr ratio of 0.709651 and 0.709746, respectively) and 0.70922 (the upper bound used to identify ocean entry). Units for values are microns.

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Otolith radius was measured on the dorsal side of the otolith in the region perpendicular to the longest axis. Otolith radius at ocean entry was measured at the point on the edge-to-core scan where the 87Sr/86Sr ratio converged with the range of 0.70914-0.70922, which is centered on the global marine signature of 0.70918. Units for values are microns.

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Otolith radius was measured on the dorsal side of the otolith in the region perpendicular to the longest axis. Otolith radius was measured to the 1st annulus, which denotes the completion of an individuals first winter of growth. Units for values are microns.

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An individual was classified as exhibiting the sub-yearling strategy if the otolith radius to the first annual mark was greater than the otolith radius at ocean entry. In other words, a fish was categorized as exhibiting a sub-yearling strategy if it was in the ocean before its first annulus formed. Alternatively, if the otolith radius to the first annual mark was less than or equal to the otolith radius at ocean entry then the fish was designated as exhibiting a yearling strategy. A sub-yearling migration strategy is when individuals migrate to the ocean a few months after their spring emergence (i.e., first feeding), while a yearling migration strategy is one in which juveniles remain in freshwater for an extended period (referred to as overwintering) prior to ocean entry the following spring.

Fork length (mm) estimated from a relationship between fork length and otolith radius (FL=(0.1914 * otolith radius at Snake River exit) - 7.8467). Units for values are millimeters.

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Fork length (mm) estimated from a relationship between fork length and otolith radius (FL=(0.1914 * otolith radius at ocean entry) - 7.8467). Units for values are millimeters.

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The differences between fork length at Snake River exit and fork length at ocean entry. Units for values are millimeters.

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Age based on scale analysis and provided by Lyons Ferry Hatchery. Units for values are year.

Hatch year determined by the subtraction of Age from Collection year.

The natal 87Sr/86Sr ratio was quantified as the first stable signature located between an otolith radius of 110m and 250m from the otolith core.

The rearing 87Sr/86Sr ratio was determined as the first stable signature located between an otolith radius of 250m and 500m from the otolith core.

Over-wintering Sr87/Sr86 ratio was quantified as the first stable signature between an otolith radius between 500m and the radius from the core corresponding to when a fish exited the Snake River.

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