DOI: 10.5061/dryad.rxwdbrvnn
title: Data from: Accounting for movement in spatial surplus production models: A case study of redfish on the Eastern Grand Banks of Newfoundland

description: Spatial surplus production models (SSPMs) are a key alternative to spatial
 population dynamics models when reliable spatial aging data is
 unavailable. However, fish movements present computational challenges for
 SSPMs and can be confounded with process errors, hindering the
 identification of SSPM parameters. We propose leveraging a Gaussian Markov
 Random Field (GMRF) with a Matérn covariance structure to account for
 spatiotemporal variation in dynamics and population production, thereby
 circumventing the computational and confounding issues. Through simulation
 studies, wherein data is generated explicitly considering movements, our
 novel random field model outperforms the alternative methods in estimating
 fish spatial abundance, as evaluated using statistical metrics including
 Akaike information criterion, Bayesian information criteria, and
 correlation between simulated and estimated populations. We also applied
 our method to reveal the spatial distribution of redfish in NAFO 3LN
 divisions based on survey and commercial catch data. Model validation
 confirms a good fit. Our model's ability to fit relatively short time
 series data (i.e., eight years) demonstrates the benefits of using the
 random field approach in data-poor fisheries stock assessments.
description: # Accounting for Movement in Spatial Surplus Production Models: A Case
 Study on 3LN Redfish Dataset DOI:
 [10.5061/dryad.rxwdbrvnn](10.5061/dryad.rxwdbrvnn) ## Description of the
 data and file structure The final_submitted_codes.zip file contains two
 folders: simulations and redfish. 1\. simulations This folder includes the
 TMB codes, R codes and data (i.e., redfish_results.RData) used for the
 simulation studies presented in the paper: Accounting for Movement in
 Spatial Surplus Production Models: A Case Study of Redfish on the Eastern
 Grand Banks of Newfoundland by Hoang Nguyen, Jin Gao, Noel G. Cadigan,
 Yanjun Wang, Fan Zhang, Nan Zheng. The CSV files are containers to store
 simulation results. 2\. redfish This folder contains the TMB code, R code
 and data used for the case studies in the paper. The data files include
 the .RData files and a landings.txt file. In both folders, the survey data
 are simulated due to restrictions from the Fisheries and Oceans Canada
 (DFO) on sharing actual survey data. Nonetheless, the simulated data
 effectively replicate key characteristics of the real data and are
 sufficient to demonstrate the performance of the proposed methodology in
 the paper. ### Files and variables #### File: final_submitted_codes.zip
 **Description:** This zip file contains two folders: simulations and
 redfish. 1\. simulations This folder includes the TMB codes, R codes and
 data (i.e., redfish_results.RData) used for the simulation studies
 presented in the paper: Accounting for Movement in Spatial Surplus
 Production Models: A Case Study of Redfish on the Eastern Grand Banks of
 Newfoundland by Hoang Nguyen, Jin Gao, Noel G. Cadigan, Yanjun Wang, Fan
 Zhang, Nan Zheng. The CSV files are containers to store simulation
 results. 2\. redfish This folder contains the TMB code, R code and data
 used for the case studies in the paper. The data files include the .RData
 files and a landings.txt file. In both folders, the survey data are
 simulated due to restrictions from the Fisheries and Oceans Canada (DFO)
 on sharing actual survey data. Nonetheless, the simulated data effectively
 replicate key characteristics of the real data and are sufficient to
 demonstrate the performance of the proposed methodology in the paper. ##
 Code/software R, any recent versions. TMB package in R.