Article
Biodiversity Conservation
Maurice C. Goodman, Gemma Carroll, Stephanie Brodie, Arnaud Gruss, James T. Thorson, Stan Kotwicki, Kirstin Holsman, Rebecca L. Selden, Elliott L. Hazen, Giulio A. De Leo
Summary: This study used spatiotemporal models to investigate the relationship between habitat changes, predation behavior changes, and increased predation pressure in the poorly observed eastern Bering Sea. The findings highlight the complexity of predicting predation dynamics in marine systems and emphasize the need for better methods to understand the potential ecological impacts of species redistributions. Furthermore, the study suggests that simple metrics of spatial overlap can be used to integrate predictions from species distribution models into ecosystem-based fisheries management, particularly for specialized predators.
Article
Fisheries
Christopher M. Legault, John Wiedenmann, Jonathan J. Deroba, Gavin Fay, Timothy J. Miller, Elizabeth N. Brooks, Richard J. Bell, Joseph A. Langan, Jamie M. Cournane, Andrew W. Jones, Brandon Muffley
Summary: This study evaluated the effectiveness of age-based stock assessments and data-limited methods in preventing overfishing and rebuilding overfished stocks. The results showed that using specific data-limited methods and a statistical model with retrospective adjustment can achieve better performance than other methods in achieving these goals.
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
(2023)
Article
Fisheries
Matthew R. Siskey, Andre E. Punt, Peter-John F. Hulson, Meaghan D. Bryan, James N. Ianelli, James T. Thorson
Summary: This study developed a framework for evaluating the impact of survey sampling designs on stock assessments and found that decreasing the number of tows sampled led to an increase in the uncertainty of the overfishing limit (OFL). The study also found that reducing the number of otoliths per tow had a smaller impact on OFL uncertainty. Applying this framework to all monitored stocks is important to identify which stocks benefit the most from increased sampling or have the least impact on OFL uncertainty with reduced sampling.
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
(2023)
Article
Fisheries
Adam Spear, Alexander G. G. Andrews III, Janet Duffy-Anderson, Tayler Jarvis, David Kimmel, Denise McKelvey
Summary: The study analyzed data from different temperature years and found that the vertical distribution of age-0 pollock is related to ocean temperature changes. In colder years, age-0 pollock was found in deeper water columns, while in warmer years, they were surface-oriented. This may affect spatial matching between pollock and prey, and impact the feeding environment and bioenergetic condition of age-0 pollock.
FISHERIES OCEANOGRAPHY
(2023)
Article
Fisheries
Julia Indivero, Timothy E. Essington, James N. Ianelli, James T. Thorson
Summary: Environmental conditions can lead to variability in growth and distribution processes, but current stock assessment methods often neglect these patterns. This study used data on walleye pollock in the Bering Sea to demonstrate a feasible approach for incorporating spatially unbalanced size-at-age samples into stock assessments. The analysis revealed extensive variation in size-at-age at fine spatial scales, with year-to-year differences in spatial patterning. Integrating spatiotemporally explicit size-at-age processes improved stock assessment consistency and provided insights into demographic processes. This approach could enhance stock-assessment forecasts under climate change.
ICES JOURNAL OF MARINE SCIENCE
(2023)
Article
Ecology
Merja Elo, Mira H. Kajanus, Jere Tolvanen, Vincent Devictor, Jukka T. Forsman, Aleksi Lehikoinen, Mikko Monkkonen, James T. Thorson, Maximilian G. R. Vollstadt, Sami M. Kivela
Summary: This study investigates the impacts of environmental filtering and biotic interactions on spatial and temporal associations among bird species using a novel hypothesis-testing framework based on joint dynamic species distribution models and functional trait similarity. The findings suggest that the aggregation of species is mainly driven by environmental filtering and heterospecific attraction, with no evidence of competition.
JOURNAL OF BIOGEOGRAPHY
(2023)
Article
Fisheries
Arnaud Gruss, James T. Thorson, Owen F. Anderson, Richard L. O'Driscoll, Madison Heller-Shipley, Scott Goodman
Summary: This study developed a spatio-temporal modelling framework that integrates research survey data and other data sources. It demonstrated the effectiveness of this framework through two case studies.
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
(2023)
Article
Biodiversity Conservation
James T. Thorson, Cheryl L. Barnes, Sarah T. Friedman, Janelle L. Morano, Margaret C. Siple
Summary: Species distribution models (SDMs) are commonly used to analyze the relationship between species occurrence/density and environmental conditions, often including a spatially correlated variable. Spatially varying coefficients (SVCs) in SDMs have received less attention but have the potential to improve interpretability and descriptive power. This article reviews the benefits of using SVCs in ecological contexts such as ecological teleconnections, density-dependent habitat selection, spatially varying detectability, and interactions with unmeasured covariates. Detailed examples using the vector autoregressive spatio-temporal (VAST) model illustrate the advantages of SVCs in analyzing decadal trends, community assembly, and population dynamics. SVCs extend the capabilities of SDMs and enhance our understanding of ecological processes.
Article
Ecology
James T. T. Thorson, Aurore A. A. Maureaud, Romain Frelat, Bastien Merigot, Jennifer S. S. Bigman, Sarah T. T. Friedman, Maria Lourdes D. Palomares, Malin L. L. Pinsky, Samantha A. A. Price, Peter Wainwright
Summary: This study extends previous methods by using structural equation models and associations among categorical traits to achieve mixed-trait imputation. Results show that a one-degree increase in habitat temperature is associated with an average 3.5% increase in natural mortality and a 3.0% decrease in fecundity.
METHODS IN ECOLOGY AND EVOLUTION
(2023)
Article
Ecology
Dana L. Wright, David G. Kimmel, Nancy Roberson, David Strausz
Summary: The eastern North Pacific right whale (NPRW), the most endangered population of whale, has been observed north of its core feeding ground with low sea ice extent. Sea ice and water temperature are important drivers for zooplankton dynamics. The study suggests that the whales and their prey C. glacialis may move northward due to the continued loss of sea ice and warming.
ECOLOGICAL APPLICATIONS
(2023)
Article
Fisheries
A. Gruess, A. R. Charsley, J. T. Thorson, O. F. Anderson, R. L. O'Driscoll, B. Wood, O. N. Breivik, C. A. O'Leary
Summary: Species distribution models often require multiple data sources to achieve their objectives. In this study, we developed a spatio-temporal modelling framework that integrated research survey data and observer data from fishing vessels, while accounting for physical barriers. Applying this framework to deepwater fisheries in New Zealand, we found that using both observer-only data and integrated data is essential for mapping fish biomass at a large scale and interpolating local biomass indices in years without survey data. We also demonstrated the importance of considering the reliability of interannual variability when choosing between models relying on integrated data or survey-only data for a given geographic area. Moreover, our simulation experiment revealed that the predictions of our spatio-temporal models were not significantly affected by the presence of physical barriers.
ICES JOURNAL OF MARINE SCIENCE
(2023)
Article
Fisheries
J. J. Badger, S. Large, J. T. Thorson
Summary: Many economic sectors rely on marine ecosystem services, and integrated ecosystem assessments (IEAs) are necessary for holistic management and sustainable use. This study demonstrates the utility of spatially and temporally explicit ecological indicators in assessing ecosystem performance and identifying localized processes. The examples highlight the benefits of spatio-temporal methods for integrated ecosystem analysis in the northeast US Shelf Ecosystem.
ICES JOURNAL OF MARINE SCIENCE
(2023)
Article
Fisheries
Daniel Ovando, Darcy Bradley, Echelle Burns, Lennon Thomas, James Thorson
Summary: Designing effective spatial management strategies for marine ecosystems is challenging due to their complexity and uncertainties. This paper presents a modelling framework called marlin, which can simulate the bio-economic dynamics of marine systems efficiently. The framework can be used for both management and research purposes. The study demonstrates the capabilities of marlin through two case studies on marine protected areas (MPAs) and their impacts on conservation and food production. It shows how the framework can assess the distributional outcomes and climate resilience of different MPA design strategies and fishing fleets. The paper highlights the importance of intermediate complexity simulation in predicting and managing trade-offs among conservation, fisheries yields, and distributional outcomes of management policies affected by spatial bio-economic dynamics.
FISH AND FISHERIES
(2023)
Article
Fisheries
James T. Thorson
Summary: Phylogenetic comparative methods (PCM) and phylogenetic structural equation models (PSEM) can replace linear models and improve performance in fisheries meta-analyses, but they are rarely applied in fisheries science.
FISH AND FISHERIES
(2023)