J&A 6.302-1 - Section and Age Sea Otter and Walrus Teeth

Contract No. 701816M116TAS 14 1161 100 US Department of the InteriorSole Source Justification Scope of Work - Matson's Laboratory Title: Cementum Age Analysis for Sea Otter & Walrus Teeth Background/History: The U.S. Fish & Wildlife Service, Marine Mammals Management office collects walrus and sea otter teeth from subsistence harvested and beach cast animals. Age analysis from the harvested segment of the population can provide important demographic parameters necessary for the successful conservation and management of the Service's trust species. The Service has a long term tooth age data set dating back to the 1950's. Age determination (actually estimation) is interpretive - based upon expert interpretation of tissue structure. There is an inherent reader bias in the process; therefore reader consistency is critically important to minimize inter-observer differences. In order to reduce these biases, the same contractor must be used very year. In order to maintain scientific integrity of this data set, the contractor must have extensive experience with cementum age analysis of sea otter and walrus teeth. Scope:Using a microtome, section the root tip longitudinally, stain and mount to microscope slide. Age walrus and sea otter tooth sections based on standardized cementum age analysis techniques. For a description of standardized methods, see (Garlich-Miller et al. 1993, Fay et al. Matson 19811986, and Working Group 1 1993). Each tooth should be read in 3 replicates with the median age returned as the final estimate. Deliverables:1. Provide tooth sections mounted on slides.2. Return unused tooth material. 3. Provide an age estimate for each individual tooth by sample number.4. Provide a certainty code for each tooth indicating how closely the cementun characteristics match those of the standardized ageing model for the species and tooth type. 5. All data returned must be in a Microsoft Excell format. Schedule:Services should be covered for a period of 5 years, beginning March 1. 2010. Walrus teeth will be submitted once per year with approximately 150 - 300 teeth per batch. Sea otter teeth will be submitted twice per year with approximately 150 - 200 teeth per batch. Results should be returned within 12 months.