Christina A. Kellogg

African and Asian Dust: From Desert Soils to Coral Reefs

Abstract Many hypotheses have been proposed to explain the decline of coral reefs throughout the world, but none adequately accounts for the lack of recovery of reefs or the wide geographical distribution of coral diseases. The processes driving the decline remain elusive. Hundreds of millions of tons of dust transported annually from Africa and Asia to the Americas may be adversely affecting coral reefs and other downwind ecosystems. Viable microorganisms, macro- and micronutrients, trace metals, and an array of organic contaminants carried in the dust air masses and deposited in the oceans and on land may play important roles in the complex changes occurring on coral reefs worldwide.

The global transport of dust

dirt is carried aloft. Drifting with the sus pended dust particles are soil pollutants such as herbicides and pesticides and a significant number of microorganisms? bacteria, viruses and fungi. We can gain some appreciation of how much micro bial life is actually floating in our atmos phere by perfonning a quick calculation. There are typically about one million bacteria per gram of soil, but lef s be con servative and suppose there are only 10,000 bacteria per gram of airborne sed iment. Assuming a modest one billion metric tons of sediment in the atmos phere, these numbers translate into a quintillion (1018) sediment-borne bacte ria moving around the planet each year?enough to form a microbial bridge between Earth and Jupiter.

Dust in the Wind: Long Range Transport of Dust in the Atmosphere and Its Implications for Global Public and Ecosystem Health

Movement of soil particles in atmospheres is a normal planetary process. Images of Martian dust devils (wind-spouts) and dust storms captured by NASAs Pathfinder have demonstrated the significant role that storm activity plays in creating the red atmospheric haze of Mars. On Earth, desert soils moving in the atmosphere are responsible for the orange hues in brilliant sunrises and sunsets. In severe dust storm events, millions of tons of soil may be moved across great expanses of land and ocean. An emerging scientific interest in the process of soil transport in the Earths atmosphere is in the field of public and ecosystem health. This article will address the benefits and the potential hazards associated with exposure to particle fallout as clouds of desert dust traverse the globe.

Dust Storms and Their Impact on Ocean and Human Health: Dust in Earth’s Atmosphere

Satellite imagery has greatly influenced our understanding of dust activity on a global scale. A number of different satellites such as NASA’s Earth-Probe Total Ozone Mapping Spectrometer (TOMS) and Sea-viewing Field-of-view Sensor (SeaWiFS) acquire daily global-scale data used to produce imagery for monitoring dust storm formation and movement. This global-scale imagery has documented the frequent transmission of dust storm-derived soils through Earth’s atmosphere and the magnitude of many of these events. While various research projects have been undertaken to understand this normal planetary process, little has been done to address its impact on ocean and human health. This review will address the ability of dust storms to influence marine microbial population densities and transport of soil-associated toxins and pathogenic microorganisms to marine environments. The implications of dust on ocean and human health in this emerging scientific field will be discussed.

Evidence for groundwater and surface marine water contamination by waste disposal wells in the Florida keys

Abstract One of the methods for domestic wastewater disposal in the Florida Keys is injection of partially treated wastewater into the highly porous limestone bedrock using waste disposal or injection wells. In an effort to understand the transport and fate of wastewater, we utilized bacteriophages as tracers in a 12.2-m deep, simulated injection well in Key Largo and an active (27.4 m deep) class V disposal well in the Middle Keys. The latter is the currently permitted type of injection well used for multi-unit domestic waste disposal in the Keys. Surface waters and groundwater at several sites were monitored for 5 days after seeding of the injection wells. In both environments, viral tracers appeared after short periods of time in groundwater (8 h after injection) and surface marine waters (10 h and 53 h for Key Largo and the Middle Keys, respectively). Estimated rates of tracer movement were greatest in Key Largo (2.5–35 m/h), where tidal pumping was implicated in tracer movement. In the Middle Keys, the pattern of movement showed little evidence of tidal pumping, and migration rates were slower (0.12–2 m/h). Collectively these results indicate that wastewater injected into the subsurface can make its way rapidly to surface marine waters, where it may contribute to water quality deterioration.

Cross-kingdom amplification using Bacteria-specific primers: Complications for studies of coral microbial ecology

ABSTRACT PCR amplification of pure bacterial DNA is vital to the study of bacterial interactions with corals. Commonly used Bacteria-specific primers 8F and 27F paired with the universal primer 1492R amplify both eukaryotic and prokaryotic rRNA genes. An alternative primer set, 63F/1542R, is suggested to resolve this problem.

Culture-Independent Characterization of Bacterial Communities Associated with the Cold-Water Coral Lophelia pertusa in the Northeastern Gulf of Mexico

ABSTRACT Bacteria are recognized as an important part of the total biology of shallow-water corals. Studies of shallow-water corals suggest that associated bacteria may benefit the corals by cycling carbon, fixing nitrogen, chelating iron, and producing antibiotics that protect the coral from other microbes. Cold-water or deep-sea corals have a fundamentally different ecology due to their adaptation to cold, dark, high-pressure environments and as such have novel microbiota. The goal of this study was to characterize the microbial associates of Lophelia pertusa in the northeastern Gulf of Mexico. This is the first study to collect the coral samples in individual insulated containers and to preserve coral samples at depth in an effort to minimize thermal shock and evaluate the effects of environmental gradients on the microbial diversity of samples. Molecular analysis of bacterial diversity showed a marked difference between the two study sites, Viosca Knoll 906/862 (VK906/862) and Viosca Knoll 826 (VK826). The bacterial communities from VK826 were dominated by a variety of unknown mycoplasmal members of the Tenericutes and Bacteroidetes, whereas the libraries from VK906/862 were dominated by members of the Proteobacteria. In addition to novel sequences, the 16S rRNA gene clone libraries revealed many bacterial sequences in common between Gulf of Mexico Lophelia corals and Norwegian fjord Lophelia corals, as well as shallow-water corals. Two Lophelia-specific bacterial groups were identified: a cluster of gammaproteobacteria related to sulfide-oxidizing gill symbionts of seep clams and a group of Mycoplasma spp. The presence of these groups in both Gulf and Norwegian Lophelia corals indicates that in spite of the geographic heterogeneity observed in Lophelia-associated bacterial communities, there are Lophelia-specific microbes.

A rapid and efficient assay for extracting DNA from fungi

Aims: A method for the rapid extraction of fungal DNA from small quantities of tissue in a batch‐processing format was investigated.

Microbial ecology of corals, sponges, and algae in mesophotic coral environments

Mesophotic coral ecosystems that occur at depths from 30 to 200 m have historically been understudied and yet appear to support a diverse biological community. The microbiology of these systems is particularly poorly understood, especially with regard to the communities associated with corals, sponges, and algae. This lack of information is partly due to the problems associated with gaining access to these environments and poor reproducibility across sampling methods. To summarize what is known about the microbiology of these ecosystems and to highlight areas where research is urgently needed, an overview of the current state of knowledge is presented. Emphasis is placed on the characterization of microbial populations, both prokaryotic and eukaryotic, associated with corals, sponges, and algae and the factors that influence microbial community structure. In topic areas where virtually nothing is known from mesophotic environments, the knowledge pertaining to shallow-water ecosystems is summarized to provide a starting point for a discussion on what might be expected in the mesophotic zone.

Microbial consortia of gorgonian corals from the Aleutian islands

Gorgonians make up the majority of corals in the Aleutian archipelago and provide critical fish habitat in areas of economically important fisheries. The microbial ecology of the deep-sea gorgonian corals Paragorgea arborea, Plumarella superba, and Cryogorgia koolsae was examined with culture-based and 16S rRNA gene-based techniques. Six coral colonies (two per species) were collected. Samples from all corals were cultured, and clone libraries were constructed from P. superba and C. koolsae. Cultured bacteria were dominated by the Gammaproteobacteria, especially Vibrionaceae, with other phyla comprising <6% of the isolates. The clone libraries showed dramatically different bacterial communities between corals of the same species collected at different sites, with no clear pattern of conserved bacterial consortia. Two of the clone libraries (one from each coral species) were dominated by Tenericutes, with Alphaproteobacteria dominating the remaining sequences. The other libraries were more diverse and had a more even distribution of bacterial phyla, showing more similarity between genera than within coral species. Here we report the first microbiological characterization of P. arborea, P. superba, and C. koolsae.