Environnmental Influences on Caribbean Octocoral-Symbiodiniaceae Symbioses

A Caribbean octocoral colony is an assemblage of the octocoral host, dinoflagellate algae (family Symbiodiniaceae), bacteria and other microbes, together functioning as meta-organism (holobiont). Even though octocorals dominate many Caribbean reefs, compared to scleractinian corals, little is known about their biology under ambient or potentially stressful conditions. Of the nine species of octocorals (gorgonian corals, Order: Alcyonacea) studied, each had significantly different polyp behaviors, biochemical compositions, Symbiodiniaceae parameters, isotopic signatures, in addition to hosting distinct microbial assemblages. We identified multiple Symbiodiniaceae species (Breviolum minutum, Breviolum B41, Breviolum B1a and Breviolum B1i), inhabiting the gorgonians. These symbioses were temporally and spatially stable, remaining unchanged even when the holobionts were exposed to stressful environmental conditions. Furthermore, the gorgonian species maintained mixotrophic diets, with various reliance on autotrophy and heterotrophy. Particulate and suspended organic matter constituted the bulk of their heterotrophic quotient, with zooplankton contributing far less, explaining why the majority of gorgonians expanded their polyps and tentacles throughout the day but retracted them at night. Gorgonian species reacted to stressors in a species specific manner, with two species employing different techniques to cope with short term temperature and ultraviolet stress. Further, there were seasonal differences to these responses. Elevated temperature impacted multiple holobiont parameters, whereas ultraviolet radiation affected only a few, yet their combination led to additive, synergistic, and antagonistic interactions. Gorgonian colonies within the lagoon were nitrogen enriched, likely due to sewage released from nearby hotels. Experimental short term ammonium and phosphate enrichments did not affect the gorgonian host, but Symbiodiniaceae exhibited concentration dependent benefits. The bacterial phyla Proteobacteria and Tenericutes dominated the gorgonian bacterial microbiome, although each gorgonian species hosted a unique microbial assemblage. This assemblage varied temporally and spatially with changes in abundance of bacterial groups driving the majority of the differences. Under stressful conditions, shifts in bacterial composition may help maintain holobiont functional stability. Overall, I observed modifications to the host, algal and microbial parameters, enabling the octocoral holobiont to cope with changing environmental conditions. Such versatility in responding to environmental perturbations may help explain why gorgonian corals thrive in the Caribbean and may continue to do so

Paper Session III-A - Ergonomic Considerations in Launch Vehicle Design and Processing for Operational Efficiency

Ergonomics is the science of fitting the environment and activities to the capabilities, dimensions, and needs of people. Ergonomic knowledge and principles are applied to adapt working conditions to the physical, psychological, and social nature of the person. There have been numerous launch operations studies performed concerning processing operations at the Kennedy Space Center (KSC). These studies have not, to a significant extent, considered ergonomic principles in launch vehicle design and processing as a means for achieving the goals of operational efficiency. Many launch vehicle design and processing goals or objectives have been proposed to increase the operational efficiency of current systems, or to improve the operational efficiency of future systems over that experienced by current systems. Future proposed design or processing objectives may not take ergonomic principles and guidelines into consideration. A few of the launch vehicle design or processing objectives currently under consideration and their associated concerns, from an ergonomic aspect, are: • Paperless work documentation system and health related concerns with visual display terminal (VDT) and personal computer (PC) use. • Automated vehicle health management and built-in test equipment (BITE) causing troubles with human reliability and cognition associated with human-machine systems. • Hazardous operations scheduled for third-shift and problems associated with night-worker health. This examinational paper is intended to inform the reader on some of the ergonomic principles that should be considered in the design and processing of launch vehicles for operational efficiency

Microbiomes of Caribbean Octocorals Vary Over Time but Are Resistant to Environmental Change

The bacterial microbiome is an essential component of many corals, although knowledge of the microbiomes in scleractinian corals far exceeds that for octocorals. This study characterized the bacterial communities present in shallow water Caribbean gorgonian octocorals over time and space, in addition to determining the bacterial assemblages in gorgonians exposed to environmental perturbations. We found that seven shallow water Caribbean gorgonian species maintained distinct microbiomes and predominantly harbored two bacterial genera, Mycoplasma and Endozoicomonas. Representatives of these taxa accounted for over 70% of the sequences recovered, made up the three most common operational taxonomic units (OTUs), and were present in most of the gorgonian species. Gorgonian species sampled in different seasons and/or in different years, exhibited significant shifts in the abundances of these bacterial OTUs, though there were few changes to overall bacterial diversity, or to the specific OTUs present. These shifts had minimal impact on the relative abundance of inferred functional proteins within the gorgonian corals. Sequences identified as Escherichia were ubiquitous in gorgonian colonies sampled from a lagoon but not in colonies sampled from a back reef. Exposure to increased temperature and/or ultraviolet radiation (UVR) or nutrient enrichment led to few significant changes in the gorgonian coral microbiomes. While there were some shifts in the abundance of the prevalent bacteria, more commonly observed was “microbial switching” between different OTUs identified within the same bacterial genus. The relative stability of gorgonian coral bacterial microbiome may potentially explain some of the resistance and resilience of Caribbean gorgonian corals against changing environmental conditions

A Study of the Feasibility of a Transfer of Development Rights Program in Lewiston, Maine

This project was conducted in collaboration with David Hedinger in Lewiston’s City Planning Office in order to assess the feasibility of a Transfer of Development Rights (TDR) Program in Lewiston. The overall aim of this project was to apply scholarly literature, findings from case studies, and input from experienced professionals to determine what successful TDR programs look like, the factors they possess, and the conditions present. The primary problem that TDR programs seek to address is urban sprawl, or the slow spread of development outside of the urban centers into the rural fringes. Urban sprawl has two chief components: 1) it leads to the loss of valuable environmental assets, open space, and potential agricultural land to development; and 2) it pulls money and investment outside of urban centers and leaves them economically depressed and sometimes even blighted (Bruegmann 2005, 160). In terms of Lewiston, while on a smaller scale than many other cities across the country, the problems of urban sprawl are still being felt. A TDR program, which allows a landowner to voluntarily relinquish their right to develop on their rural land and sell that right to a developer looking to increase density in the urban or suburban growth zones, has been a proven to be a reasonable and cost effective way to mitigate the problems of sprawl. A successful TDR program, however, requires certain conditions and factors to be present. Many TDR programs across the country and even in Maine have failed because they were either improperly designed or under-stimulated by market conditions. The leading cause of failure in a TDR program is a lack of demand for high density development (Pruetz & Standridge 2009, 80). Without this necessary demand there is no driving force that will spur a TDR program into motion. Additionally, we found that the most effective TDR programs at preserving land are those administered at the county, regional, or state level (King County 2014; Montgomery County 2008; Pinelands 2009). Our primary findings show that there are many factors that lead to successful TDR programs. And while Lewiston may possess the physical makeup of a successful TDR program: designated urban growth zones and large tracts of rural and agricultural land, it still lacks many factors that may be difficult to stimulate in the short term. We conclude with these remarks and offer a few alternatives to traditional TDR programs that could also be used to preserve land and promote smart growth

Gut microbiomes of freshwater mussels (Unionidae) are taxonomically and phylogenetically variable across years but remain functionally stable

Freshwater mussels perform essential ecosystem functions, yet we have no information on how their microbiomes fluctuate over time. In this study, we examined temporal variation in the microbiome of six mussel species (Lampsilis ornata, Obovaria unicolor, Elliptio arca, Fusconaia cerina, Cyclonaias asperata, and Tritogonia verrucosa) sampled from the same river in 2016 and 2019. We examined the taxonomic, phylogenetic, and inferred functional (from 16S rRNA sequences) facets of their microbiome diversity. Significant differences between the two years were identified in five of the six species sampled. However, not all species that exhibited a temporally variable microbiome were functionally distinct across years, indicating functional redundancy within the mussel gut mi-crobiome. Inferred biosynthesis pathways showed temporal variation in pathways involved in deg-radation, while pathways involved in cellular metabolism were stable. There was no evidence for phylosymbiosis across any facet of microbiome biodiversity. These results indicate that temporal variation is an important factor in the assembly of the gut microbiomes of freshwater mussels and provides further support that the mussel gut microbiome is involved in host development and ac-tivity