Population Dynamics, Relative Abundance, and Habitat Suitability of Adult Red Drum (Sciaenops ocellatus) in Nearshore Waters of the North-Central Gulf of Mexico

In the Gulf of Mexico, the red drum (Sciaenops ocellatus) is an immensely popular sportfish, yet the Gulf of Mexico stock is currently managed as data-limited in federal waters. The results of the federal stock assessment conducted in 2016 for Gulf of Mexico red drum were not recommended for providing management advice. Consequently, we sought to address data gaps highlighted in the assessment by producing up-to- date overall and sex-specific growth models, standardized indices of relative abundance, and predictions of habitat suitability and by updating estimates of natural mortality. Using a time series for the period of 2006–2018, we assigned ages of 0–36 years to 1178 red drum. A negative binomial generalized linear model including variables for year, depth, surface temperature, dissolved oxygen, and bottom salinity was used to standardize an index of relative abundance. Examination of catch per unit of effort revealed that adult red drum were significantly more abundant in state waters than in federal waters. These findings were explained by habitat suitability models, which were used to identify surface current velocity, surface temperature, and depth as the strongest predictors of relative abundance. The results of our investigation reveal that the adult spawning stock of red drum in the Gulf of Mexico is not fully protected by the catch moratorium in federal waters

Documentation of Atlantic Tarpon (Megalops atlanticus) Space Use and Move Persistence in the Northern Gulf of Mexico Facilitated by Angler Advocates

Atlantic tarpon (Megalops atlanticus, hereafter tarpon) are facing a multitude of stressors and are considered Vulnerable by the IUCN; however, significant gaps remain in our understanding of tarpon space use and movement. From 2018 to 2019, citizen scientists facilitated tagging of 23 tarpon with SPOT tags to examine space use and movement across the northern Gulf of Mexico. Movement-based kernel densities were used to estimate simplified biased random bridge-based utilization distributions and a joint move persistence model was used to estimate a behavioral index for each fish. Tarpon showed consistent east–west movement from the Alabama/Florida border to Louisiana, and utilization distributions were highest in the Mississippi River Delta. Move persistence was highest in Alabama and Mississippi and lowest in Louisiana. Our examination of tarpon space use and movement indicates that Louisiana is a critical, yet understudied, part of their range

CCDC 1953060: Experimental Crystal Structure Determination

Related Article: Michael J. Celestine, Mark A.W. Lawrence, Olivier Schott, Vincent Picard, Garry S. Hanan, Emily M. Marquez, Chekeyl G. Harold, Cole T. Kuester, Blaise A. Frenzel, Christopher G. Hamaker, Sean E. Hightower, Colin D. McMillen, Alvin A. Holder|2021|Inorg.Chim.Acta|517|120195|doi:10.1016/j.ica.2020.12019

Photophysics and Luminescence Spectroelectrochemistry of [Tc(dmpe)₃]^+/2+ (dmpe = 1,2-<i>bis</i>(dimethylphosphino)ethane)

The ligand-to-metal charge transfer (LMCT) excited state luminescence of [Tc­(dmpe)₃]²⁺ (dmpe is 1,2-<i>bis</i>-(dimethylphosphino)­ethane) has been measured in solution at room temperature and is compared to its Re analogue. Surprisingly, both [M­(dmpe)₃]²⁺* (M = Re, Tc) species have extremely large excited-state potentials (ESPs) as oxidants, the highest for any simple coordination complex of a transition metal. Furthermore, this potential is available using a photon of visible light (calculated for M = Tc; <i>E</i>°′* = +2.48 V versus SCE; λ_max = 585 nm). Open shell time-dependent density functional theory (TDDFT) calculations support the assignment of the lowest energy transition in both the technetium and rhenium complexes to be a doublet–doublet process that involves predominantly LMCT (dmpe-to-metal) character and is in agreement with past assignments for the Re system. As expected for highly oxidizing excited state potentials, quenching is observed for the excited states of both the rhenium and technetium complexes. Stern–Volmer analysis resulted in quenching parameters for both the rhenium and technetium complexes under identical conditions and are compared using Rehm–Weller analysis. Of particular interest is the fact that both benzene and toluene are oxidized by both the Re and Tc systems