Sam Truesdell

Education Background Research Publications Curriculum Vitae

TRUESDELL_photo Post-Doctoral Research Associate
Office Location: 101C UPLA Building
Phone: 517-432-5099 or 517-355-0126
E-mail: truesd16@msu.edu
Area of Expertise/Interest: Fish population dynamics, fleet dynamics, stock assessment and fisheries management

Education

Ph.D. - Marine Biology, University of Maine, 2014
B.S. - Honors Marine Biology, Dalhousie University, 2007

Background

During my undergraduate Marine Biology degree at Dalhousie University I became interested in the assessment and management of living marine resources, especially fish populations. In 2007 I worked as a fisheries observer for the National Marine Fisheries Service. The year spent I working as an observer on commercial vessels dramatically changed my understanding of commercial fisheries, and this background has proved invaluable during my research career. In 2009 I began my PhD at the University of Maine in Orono with the goal of learning and applying quantitative methods for population assessment. My work was centered on sea scallops and the primary components of my research were to develop biomass estimates for scallops in the Northern Gulf of Maine management area, determine regional differences in scallop growth in the Gulf of Maine, and evaluate the impact of sea scallop fleet spatial dynamics on stock assessment. I graduated from University of Maine in December 2014.

Research

The use of stock assessment models to inform policy decisions assumes that the model and data used are sufficiently representative of the resource and its population dynamics. However, the interaction between the assessment model, the distribution and ecology of the resource and the quality and quantity of the data sources may lead to inaccurate conclusions from an assessment model. One aspect of my PhD research was to evaluate the assumption that all fish in a population have equal capture probability by the fishery and I quantified bias in a stock assessment model when this assumption was not met. My initial research at the QFC will involve (1) a review of historical stock assessments for lake trout and lake whitefish in order to document changes in model design; and (2) using operating models for fish populations with the capacity for varying levels of uncertainty and observation error together with stock assessment models of varying complexity, I will evaluate how bias, accuracy, and other measures of assessment model performance depend on data quantity, quality and the underlying characteristics of the fish population and fishery.

Publications

Truesdell, S.B., D.R. Hart and Y. Chen. (In Press). Effects of unequal capture probability on stock assessment abundance and mortality estimates: an example using the US Atlantic sea scallop fishery. Can. J. Fish. Aquat. Sci.
Truesdell, S.B., J.R. Bence, J.M. Syslo and M.P. Ebener. (In Press). Estimating multinomial effective sample size in catch-at-age and catch-at-size models. Fish. Res.
Cao, J. W. Guan, S.B. Truesdell, Y. Chen and S. Tian. (In Press). An individual-based probabilistic model for simulating fisheries population dynamics. Aquaculture and Fisheries.
Liu, B., J. Cao, S.B. Truesdell, Y. Chen, X. Chen and S. Tian. 2016. Reconstructing cephalopod migration with statolith elemental signatures: a case study using Dosidicus gigas. Fisheries Sci. doi: 10.1007/s12562-016-0978-8.

Truesdell, S.B. and J.R. Bence. 2016. A Review of Stock Assessment Methods for Lake Trout and Lake Whitefish in 1836 Treaty Waters of Lake Huron, Lake Michigan and Lake Superior. QFC Technical Report T2016-01. doi: 10.6084/m9.figshare.3123949

Truesdell, S.B., D.R. Hart and Y. Chen. 2015. Effects of spatial heterogeneity in growth and fishing effort on yield-per-recruit models. ICES J. Mar. Sci. doi: 10.1093/icesjms/fsv238.

Cao, J, SB Truesdell, and Y Chen. 2014. Impacts of seasonal stock mixing on the assessment of Atlantic cod in the Gulf of Maine. ICES J. Mar. Sci. 71(6): 1443-1457.

Wang, X, Y Chen, SB Truesdell, L Xu, J Cao and W Guan. 2014. The Large-scale deployment of fish aggregation devices alters environmentally-based migratory behavior of skipjack tuna in the western Pacific Ocean. PLoS ONE 9(5): e98226. doi: 10.1371/journal.pone.0098226.

Truesdell, SB, KH Kelly and Y Chen. 2014. Assessment of the sea scallop resource in the Northern Gulf of Maine management area. Appendix B7 to the 59th Northeast Regional Stock Assessment Workshop (59th SAW) Assessment Report. US Department of Commerce, Northeast Fish Science Center Ref Doc. 14-09. 16 p.

Truesdell, SB. 2013. Modeling Juvenile Atlantic cod and yellowtail flounder abundance on Georges Bank and in the Gulf of Maine using 2-stage generalized additive models. Final report to the Closed Area Technical Team of the New England Fisheries Management Council. 64 p.

Truesdell, SB, KH Kelly, CE O’Keefe and Y Chen. 2010. An assessment of the sea scallop resource in the Northern Gulf of Maine management area. Appendix B6 to the 50th Northeast Regional Stock Assessment Workshop (50th SAW) Assessment Report. US Department of Commerce, Northeast Fish Science Center Ref Doc. 10-09. 57 p.