A cookbook for using model diagnostics in integrated stock assessments

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Variable water input controls evolution of the Lesser Antilles volcanic arc

Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging1. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform2. Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc3, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentine—that is, hydrated mantle rather than crust or sediments—is a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history of dehydration is consistent with the locations of higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards

Performance review of simple management procedures

Using a management strategy evaluation approach, we compare a range of new and established management procedures (MPs) for setting catch-limits in fisheries. Performance is evaluated with respect to fish life history type, level of stock depletion, data quality, and autocorrelation in recruitment strength. We quantify the robustness of each MP with respect to the various observation processes. Methods using observations of absolute biomass or stock depletion offer the best overall performance and this is consistent across life history types, data qualities, and stock depletion levels. Simple MPs can outperform conventional data-limited methods and data-rich assessments that use time-series of catch and effort data. MP performance is most sensitive to biases in catch data. Our results indicate that often tuning MPs for specific stocks is important, though this may not be viable in data-poor assessment scenarios because of insufficient data and analysis resources

Data for "Variation in Upper Plate Crustal and Lithospheric Mantle Structure in the Greater and Lesser Antilles from Ambient Noise Tomography"

This is the phase velocity information and the shear wave model for the g-cubed paper: &quot;Variation in Upper Plate Crustal and Lithospheric Mantle Structure in the Greater and Lesser Antilles from Ambient Noise Tomography&quot;</span