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1. Age and growth of Atlantic chub mackerel ( Scomber colias ) in the Northwest Atlantic

   https://doi.org/doi:10.2960/J.v50.m717  

   Daley, Taylor T; Leaf, Robert T (January 2019, Journal of Northwest Atlantic fishery science)

   The Atlantic chub mackerel (Scomber colias) stock is commercially exploited throughout the Atlantic and Mediterranean and has been recently targeted by a small, but emerging, fishery off the Northeast coast of the United States. Recent efforts by the Mid-Atlantic Fishery Management Council to manage the Northwest Atlantic stock have necessitated the description of its life-history characteristics. The objectives of this study were to evaluate the utility of ageing methods, describe the length-at-age and weight-at-length relationships, and compare estimated growth parameter values to those reported from other regions. We found that whole otoliths provided the most precise method for age determination of Atlantic chub mackerel. Age estimates were derived for adult (n = 422) and larval fish (n = 60). Parameter estimates of individual growth models were determined using a Bayesian framework. The length-at-age relationship was described using four non-linear candidate growth models, which were fit to total length (TL, cm) and age estimates (y). We found that the three-parameter VBGF (L∞ = 33.56 cm TL, k = 1.75 y-1, t0 = 0.07 y) was the best candidate model to describe the length-at- age relationship. A power function was used to describe the weight-at-length relationship from 1 136 individuals (a = 0.0258, b = 2.72). We found that individuals exhibit a greater rate of growth and reach smaller average maximum length when compared to published estimates in other regions. The rate of increase of weight relative to length was found to be significantly lower than that reported in other regions. These results can be used to inform assessment of the Atlantic chub mackerel stock in the Northwest Atlantic. 

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2. Uppermost Mantle Velocity beneath the Mid-Atlantic Ridge and Transform Faults in the Equatorial Atlantic Ocean

   https://doi.org/10.1785/0120200248  

   de Melo, Guilherme W.; Parnell-Turner, Ross; Dziak, Robert P.; Smith, Deborah K.; Maia, Marcia; do Nascimento, Aderson F.; Royer, Jean-Yves (December 2020, Bulletin of the Seismological Society of America)

   null (Ed.)

   ABSTRACT Seismic rays traveling just below the Moho provide insights into the thermal and compositional properties of the upper mantle and can be detected as Pn phases from regional earthquakes. Such phases are routinely identified in the continents, but in the oceans, detection of Pn phases is limited by a lack of long-term instrument deployments. We present estimates of upper-mantle velocity in the equatorial Atlantic Ocean from Pn arrivals beneath, and flanking, the Mid-Atlantic Ridge and across several transform faults. We analyzed waveforms from 50 earthquakes with magnitude Mw>3.5, recorded over 12 months in 2012–2013 by five autonomous hydrophones and a broadband seismograph located on the St. Peter and St. Paul archipelago. The resulting catalog of 152 ray paths allows us to resolve spatial variations in upper-mantle velocities, which are consistent with estimates from nearby wide-angle seismic experiments. We find relatively high velocities near the St. Paul transform system (∼8.4  km s−1), compared with lower ridge-parallel velocities (∼7.7  km s−1). Hence, this method is able to resolve ridge-transform scale velocity variations. Ray paths in the lithosphere younger than 10 Ma have mean velocities of 7.9±0.5  km s−1, which is slightly lower than those sampled in the lithosphere older than 20 Ma (8.1  km±0.3  s−1). There is no apparent systematic relationship between velocity and ray azimuth, which could be due to a thickened lithosphere or complex mantle upwelling, although uncertainties in our velocity estimates may obscure such patterns. We also do not find any correlation between Pn velocity and shear-wave speeds from the global SL2013sv model at depths <150  km. Our results demonstrate that data from long-term deployments of autonomous hydrophones can be used to obtain rare and insightful estimates of uppermost mantle velocities over hundreds of kilometers in otherwise inaccessible parts of the deep oceans. 

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3. Weakening of the Atlantic Meridional Overturning Circulation abyssal limb in the North Atlantic

   https://doi.org/10.1038/s41561-024-01422-4  

   Biló, Tiago Carrilho; Perez, Renellys C; Dong, Shenfu; Johns, William; Kanzow, Torsten (May 2024, Nature Geoscience)
4. Age and growth of Atlantic chub mackerel ( Scomber colias ) in the Northwest Atlantic.

   https://doi.org/10.2960/J.v50.m717  

   Daley, T T; Leaf, R T (January 2019, Journal of Northwest Atlantic Fishery Science)
5. North Atlantic Oscillation contributes to the subpolar North Atlantic cooling in the past century

   https://doi.org/10.1007/s00382-023-06847-y  

   Fan, Yifei; Liu, Wei; Zhang, Pengfei; Chen, Ru; Li, Laifang (December 2023, Climate Dynamics)