Assessing the impacts of the Deepwater Horizon oil spill (DWHOS) on deep-sea fish assemblages of the Gulf of Mexico (GOM) has been hindered by an absence of baseline (pre-spill) data concerning the population genetic dynamics of these fishes. The lanternfishes (Myctophidae) are a speciose, yet understudied, taxonomic group, that comprise a significant portion of the global deep-sea biomass, making them integral members of meso- and bathy-pelagic food webs. A DEEPEND Consortium team, led by NSU Research Scientist, Dr. Andrea Bernard, used a high-resolution genomic marker (SNP) approach to conduct the first investigation of the population genetic dynamics, including genetic diversity and temporal population structure, of three species of lanternfishes within the northern GOM. Surprisingly, even though all three species are presumed to have very large population census sizes, all were found to have low levels of genetic diversity and high inbreeding coefficients. For two of the three species (C. warmingii and L. guentheri), there was no evidence of temporal population genetic structure within northern GOM waters; conversely, significant intra-GOM genetic population structure was found for D. dumerilii. These results highlight the complex genetic dynamics of this group of fishes. There is a strong need for more surveys to characterize the baseline genetic makeup of lanternfishes to not only improve fundamental knowledge of this key group of fishes but also aid understanding how their populations may respond to future environmental perturbations.

 Read the paper here: Population Genomic Dynamics of Mesopelagic Lanternfishes