Otolith output - Project to study alternative life history types of fall Chinook based on otoliths

Metadata Updated: February 8, 2018

The life-history complexity of Snake River fall Chinook salmon has hindered efforts to manage the ESU. In particular, the existence of an overwintering behavior in a portion of the population has complicated our ability to estimate survival through the hydropower system and to assess the benefit of transportation. Many of the yearling migrants move downstream after PIT-tag detection systems are disabled in the fall/winter, and consequently we have limited information on migratory patterns of these fish, which comprise a substantial proportion of returning adults. Further, because of this uncertainty in migratory behavior, major modeling efforts (such as COMPASS modeling and life-cycle modeling of the Interior Columbia Technical Recovery Team) were not able to model the population dynamics of Snake River fall Chinook, and there is a strong desire with the region to rectify this problem. Until we have a better understanding of these life-history patterns, particularly the habitat usage of overwintering juveniles, it will be difficult to efficiently manage the entire ESU. Effective management of reservoir-type fish will require an understanding of the details of their life-history, including the proportion of juveniles that exhibit the strategy, where they over-winter, when they initiate downstream migration in the spring, and estuarine residence time.

We propose to continue our ongoing research by conducting micro-chemical and micro-structural analyses of otoliths, sampled from both juveniles and adults. The geochemical analysis of fish otoliths (inner ear balance organs) allows for the reconstruction of important migrational behaviors because the tissue preserves a record of chemical experience of individual fish. By analyzing these chemical signatures, it is possible to identify the location and duration of juvenile Chinook residences during rearing in their natal site, downstream migration from their rearing areas, migration through the hydrosystem, migration through and residence in the estuary and plume, and into the ocean. In addition, the width of daily increments is related to fish growth, and growth trajectories can be back-calculated from daily growth increments. Combining these approaches, we can use the otoliths of returning adult Fall Chinook to quantify seasonal and spatially explicit patterns of habitat usage and growth. We already have made considerable progress in establishing the validity and limitations of this approach for Snake River fall Chinook salmon.

In this proposal, we propose to utilize these established methods to describe variability within the population. We also propose to refine current methodology and to devise new methods. As part of our preliminary work, we have access to archived otoliths sampled from juveniles in the 1990s; we collected otoliths from wild returning adults in 2006-2010; and we collected otoliths from PIT-tagged juveniles in 2007-2011. Thus, we are well situated to conduct the research proposed here in a timely manner. Images, increment measurements, and microchemistry trajectories.

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Metadata Date April 5, 2017
Metadata Created Date September 26, 2015
Metadata Updated Date February 8, 2018
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Resource Type Dataset
Metadata Date April 5, 2017
Metadata Created Date September 26, 2015
Metadata Updated Date February 8, 2018
Reference Date(s) (publication)
Responsible Party (); Northwest Fisheries Science Center (Point of Contact, Custodian)
Contact Email
Access Constraints Access Constraints: NA | Use Constraints: Disclaimer - While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
Bbox East Long -118.2183
Bbox North Lat 46.6063
Bbox South Lat 46.5963
Bbox West Long -118.2283
Coupled Resource
Frequency Of Update
Guid gov.noaa.nmfs.inport:18138
Harvest Object Id b6bba291-f5f8-4faa-a2c4-69d2726fcd18
Harvest Source Id 2aed8e29-fc5b-4cde-aa66-fb1118fd705e
Harvest Source Title NOAA CSW Harvest Source
Metadata Language eng
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 2010-10-01

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