NEWLY DISCOVERED ARTHROPODS AT GAS VENTS AND FISSURES: CENTRALIA MINE FIRE, EASTERN PENNSYLVANIA
Vegetation and soil samples (15-50 °C) collected up to 6 meters from active coal-fire gas vents and fissures contained arthropods previously undocumented from such locations. Using Berlese funnels, the arthropods were flushed from the samples into a 70% ethanol-aqueous solution that preserved them. The most abundant and diverse of the mesofauna identified were Collembola, including endogeic and epigeic groups. Thrips, oribatid mites, insect larvae (tentatively Chrysomelidae), and adult beetles (Sphindidae) were also found. The diversity and abundance of these arthropods varies inversely with temperature. Collembola tolerate heat better than other organisms, and at higher temperatures than previously recorded in the literature. Although insufficient material was recovered to extract nematodes and estimate microbial activity, the diverse fauna indicates that despite continuous combustion, the soil food web is highly active. Coal-fire gas exhaled at the surface contains a minimum of 45 compounds including greenhouse gases and gases destructive to the ozone layer. Some of these gas compounds are toxic to humans, including methane, toluene, benzene, and carbon monoxide. The connection between the newly discovered arthropods and the coal-fire gas at Centralia is uncertain, but it is possible that these animals are “opportunists,” habituating the vents and fissures because of decreased competition from other organisms that are more sensitive to gas composition and temperature.
Further investigation of these animals is needed, but recent governmental intervention in the area may restrict future sample collecting. This study and previous science, engineering, and socio-economic research about the Centralia mine fire demonstrate that such fires are natural laboratories for interdisciplinary research.