Phylogeography of Hypomasticus copelandii Reveals Distinct Genetic Lineages along Atlantic Coastal Drainages of Eastern Brazil (Teleostei, Anostomidae)

Hypomasticus copelandii is a Neotropical freshwater fish widely distributed across coastal drainages of southeastern Brazil, a highly impacted region of South America. The interspecific phylogenetic relationships within the genus and the taxonomic status of the species remain uncertain. Using two mitochondrial and one nuclear locus, we performed a phylogenetic, species delimitation, and time-calibrated analyses to test the hypothesis that H. copelandii is a species complex currently delimited by different Atlantic coastal systems. Results indicate that H. copelandii presents two well-delimited genetic lineages: one in the northern drainages of the Jucuruçu, Mucuri and Doce rivers, and the other in the southern region represented by the Paraíba do Sul River Basin. The time-calibrated phylogeny indicated a split between the two genetic lineages at around 2.8 million years ago (Ma), which might be related to headwater capture events during the Plio-Pleistocene. The discovery of a distinct genetic lineage for H. copelandii suggests distinct management plans for the northern and southern drainages. Such hidden diversity within the H. copelandii provides useful information for taxonomy and conservation across a severely impacted region of Brazil.

Lobsters, Whales, and Traps: The Politics of Endangerment in the Gulf of Maine

In 2019, a debate arose among Maine lobster fishers and environmental groups over the role of lobster traps in killing North Atlantic right whales, the world's most endangered whale species. Maine fishers denied that their gear was killing whales. To do so, they leveraged longstanding representations by regional natural and social scientists of lobster fishing as part of a unique and ecologically sustainable “heritage” economy—one that was itself “endangered” by over-regulation. Setting this debate in the context of a global climate crisis that is irrevocably changing Atlantic coastal environments, this article shows how ecological fragility and white working-class fragility become yoked together. Efforts to understand what lobster traps do, and how they might do it differently, perpetuated a key feature of settler colonialism, namely, the tendency to seek harmony between resource extraction and conservation.

The Yorktown Formation: Improved Stratigraphy, Chronology, and Paleoclimate Interpretations from the U.S. Mid-Atlantic Coastal Plain

The Yorktown Formation records paleoclimate conditions along the mid-Atlantic Coastal Plain during the mid-Piacenzian Warm Period (3.264 to 3.025 Ma), a climate interval of the Pliocene in some ways analogous to near future climate projections. To gain insight into potential near future changes, we investigated Yorktown Formation outcrops and cores in southeastern Virginia, refining the stratigraphic framework. We analyzed 485 samples for alkenone-based sea surface temperature (SST) and productivity estimates from the Holland and Dory cores, an outcrop at Morgarts Beach, Virginia, and the lectostratotype of the Yorktown Formation at Rushmere, Virginia, and analyzed planktonic foraminferal assemblage data from the type section. Using the structure of the SST record, we improved the chronology of the Yorktown Formation by establishing the maximum age ranges of the Rushmere (3.3–3.2 Ma) and Morgarts Beach (3.2–3.15 Ma) Members. SST values for these members average ~26 °C, corroborating existing sclerochronological data. Increasing planktonic foraminifer abundance, productivity, and species diversity parallel increasing SST over the MIS M2/M1 transition. These records constitute the greatest temporal concentration of paleoecological estimates within the Yorktown Formation, aiding our understanding of western North Atlantic temperature patterns, seasonality and ocean circulation during this interval. We provide a chronologic framework for future studies analyzing ecological responses to profound climate change.

Aping Blackness: Reading and Evaluating Racialized Images in Cartagena, Colombia

Why are residents of a city racialized as Black overwhelmingly in favor of representations of Blackness that caricature Afro-descendants as subservient, hypersexual and licentious, jovial, uninhibited and libertine, primitive (folklorized), and violent? This article bridges the literatures on the sociology of culture and cognition, racial signification, and frame theory to explore the various sociomental lenses and schemata that people use to perceive racial symbols and evaluate their legitimacy. It uses semi-structured and open-ended photo-elicitation interviews, primarily with residents of a largely-Afro-descendant community in Cartagena, Colombia, to systematically generate a collection of readings and evaluations of racialized imagery, resulting in an empirical example of the socio-optical construction of race within the Colombian cultural context. These readings and evaluations of external cultural primers such as photographs of racialized performance and ritual reveal (1) how a Colombian Atlantic Coastal “optical community” connects the signifiers and signifieds of Blackness; (2) that racial frames evoke three primary schemas (personal, spatiotemporal, and explicitly ideological), which interpreters use to decode and evaluate images; (3) that interpreters read the racial frames transmitted by cultural producers (e.g., performance artists and festival goers) via the visual language of racialized imagery as collectively credible and/or personally salient, and that this visual resonance is how the racialized imagery gain legitimacy and; (4) that personal experience, cultural knowledge, and social location account for variations in whether people consider racialized imagery credible and salient and, as such, legitimate forms of recognition.

Biogeographic, stratigraphic, and environmental distribution of Basilosaurus (Mammalia, Cetacea) in North America with a review of the late Eocene shoreline in the southeastern coastal plain

A new specimen of Basilosaurus cetoides was discovered on the banks of the Flint River in Albany, Georgia, USA, in 2010. This fossil, which was the most complete specimen of the species from Georgia to date, consisted of five nearly complete and two partial post-thoracic vertebrae, tentatively identified as S4 through Ca6. During excavation, however, the site was looted and most of the specimen was lost to science. Nonetheless, we use this discovery as an opportunity to update the current state of knowledge on the stratigraphic, biogeographic, and environmental distribution of Basilosaurus in North America, as well as the position of the late Eocene shoreline in the southeastern United States. The results show that Basilosaurus was most abundant across the southeastern coastal plain during the early to middle Priabonian, coincident with the late Eocene maximum marine transgression. The decline in Basilosaurus localities is associated with the retreating shoreline of the terminal Eocene. The majority of Basilosaurus localities fall well south of the position of the late Eocene shoreline hypothesized in this study, suggesting the genus favored middle to outer neritic zones of the epicontinental sea. The comparatively low number of Priabonian specimens in the Atlantic Coastal Plain versus the Gulf Coastal Plain, then, suggests the presence of shallow zones in the Atlantic Coastal Plain that may have limited the distribution of Basilosaurus across the region. The hypothesized shoreline of this study ultimately differs from earlier reconstructions by extending the Mississippi embayment at the Bartonian/Priabonian boundary farther north than previously noted.

Influence of wastewater discharges on benthic macroinvertebrate communities in a cantabrian-atlantic coastal river

This paper studies the effect of wastewater discharges on benthic macroinvertebrates in the Furnia River (Pontevedra, NW Spain). Semiquantitative surveys were carried out in spring 2008 and 2017 in three different locations, upstream and downstream of a sewage treatment plant built in 2013. Different indexes were calculated based on benthic macroinvertebrate assemblages: abundance, richness, Shannon-Wiener, EPT, IASPT, IBMWP and several physicochemical variables were measured concurrently. Although the indexes values decreased slightly along the water course, the results indicate an optimal water quality of the Furnia River, supporting a very diverse community of aquatic macroinvertebrates.