Steller sea lion biological opinion released

The Steller Sea Lion Bering Sea and Aleutian Islands and Gulf of Alaska Groundfish Fisheries Section 7 Consultation was posted in August 2010 by the Alaska Regional Office. Eli's work on Steller sea lion fecundity figures prominently in that (papers and a reanalysis of rookery mark-resight data). http://alaskafisheries.noaa.gov/protectedresources/stellers/esa/biop/draft/0810.htm

New blog on Stable Isotope Analysis

Eric and Brice have a new blog on stable isotope analysis: Stable Isotope Models for Biologists and Environmental Scientists. The blog has links to their course material for the 2010 IsoEcol7 meeting in Fairbanks AK.

Paper on identifying groups using hierarchical Bayesian modeling

Ward, E.J., Semmens, B.X., Holmes, E.E., and K.C. Balcomb. 2010. Identifying links between population groupings and demography in at-risk species with multiple levels of social structure. In press,Conservation Biology

New paper on analysis of stable isotope data

Ward, E.J., Semmens, B.X., and D.E. Schindler. 2010. Including source uncertainty and prior information in the analysis of stable isotope mixing models. In press, Environmental Science & Technology. doi:10.1021/es100053v

MARSS package uploaded to CRAN

The official release of 1.0 has been uploaded to CRAN (Here's the link to the CRAN page). This is an R package to fit unconstrained and constrained multivariate autoregressive state-space models via maximum-likelihood (EM algorithm). It was developed by Eli Holmes, Eric Ward and Kellie Wills. It is fully documented with a user guide/manual: Analysis of multivariate time-series using the MARSS package, by E.E. Holmes and E.J. Ward. MARSS has bootstrap AICb and CIs and simulation features. MARSS 1.0 doesn't allow you to estimate the B matrix. MARSS 2.0 will allow that, and MARSS 3.0 will provide Bayesian fitting. If you are looking for the derivation of update equations for the Kalman-EM algorithm, take a look at Derivation of the EM algorithm for constrained and unconstrained multivariate autoregressive state-space (MARSS) models.

R short course

Taught by various statisticians at NWFSC and organized by Eric Ward. Lectures and exercises are online:
NWFSC R Short Course

Two new papers: stable isotopes meet hierarchical Bayesian models

Semmens, B.X., E.J. Ward, J.W. Moore, and CT. Darimont. 2009. Quantifying inter- and intra-population niche variability using hierarchical Bayesian stable isotope mixing models. PLoS One. Open Access Paper

Semmens, B. X., J. W. Moore, and E. J. Ward. 2009. Improving Bayesian isotope mixing models: a response to Jackson et al. (2009). Ecology Letters 12:E6-E8.