Cavefish Population Status and Environmental Quality in Cave Springs Cave, Arkansas - Final Report submitted to Arkansas Natural Heritage Commission

This report summarizes the continuing effort to monitor environmental quality in the Cave Springs Cave Natural Area and to implement the Ozark Cavefish Recovery Plan. Last year’s report (Brown et al., 1998) identified certain environmental stressors, including a trend over 15 years of increasing nutrient pollution, a low cavefish population count of only 106, and the presence of heavy metals in the cave water and one semi-volatile organic compound (the phthalate DEHP at 500 ppb) in resident crayfish tissue. This year’s monitoring effort demonstrates that fecal coliforms continue to exceed Arkansas State Water Quality Standards (Regulation 2), sometimes by a factor of 1000. The presence of heavy metals is confirmed, in not only the cave water and sediments, but in crayfish tissue, which implies that it may be bioaccumulating in the cave foodweb. Furthermore, beryllium, copper, lead, selenium, and zinc are present in concentrations in the cave water that exceeded the Regulation 2 standards for chronic, and sometimes acute, toxicity to aquatic life. Significant amounts of nitrate are also present (with a yearly average of over 5 mg NO3-N/ L), and phosphate concentrations occasionally exceed Regulation 2 standards. Concentrations of nitrate, ortho-phosphate, total phosphate, total coliforms, and several dissolved metals (Al, Ba, Cu, Fe, and Pb) were all highly correlated with discharge, and concentrations were highest during stormflow events. No pesticides were detected in cave water, crayfish tissue or bat guano. Phthalates were again detected in crayfish tissue (DEP and DEHP at 1 ppb each), as well as the cave water (DEHP at 0.7 ppb). While the effects of these phthalates upon aquatic organisms are unknown, the U. S. Environmental Protection Agency considers phthalates to be human carcinogens and hormone disrupters. Ironically, while the cavefish habitat appears to be quite polluted, this year’s population survey counted 166 Ozark cavefish, the most ever counted for this (or any other) habitat. In order to integrate these pollution concerns and other data about this cave complex, a geographic information system was created for the Cave Springs Cave recharge zone. Preliminary analyses have detected several sensitive areas and pollution sources. The cave complex was determined to extend outside of the Natural Area boundary, and several sinkholes were identified. Photo-lineaments and fracture traces were identified, and other studies in Benton County demonstrate that these features, commonly expressed as intermittent streams on the surface, allow surface pollutants to rapidly enter the groundwater. Protection of these adjacent lands, sinkholes, and streams is recommended. The reduction or cessation of the land application of sewage sludge and agricultural waste in the recharge zone is also recommended

Protection of Cave Spring Cave Biota and Groundwater Basin

This is the fourth in a series of reports on the status of endangered biota and of environmental quality in Cave Springs Cave (CSC), Benton County, Arkansas (Brown et al., 1998; Graening and Brown, 1999, 2000), funded by the Arkansas Natural Heritage Commission (ANHC). As a result of these studies, Cave Springs Cave is now one of the most thoroughly studied cave ecosystems in Arkansas. This series of studies has spawned a renewed interest in cave ecosystems and their vulnerable condition. There are now many projects focusing upon the documentation of subterranean biodiversity and its protection. Partners include the Arkansas Game and Fish Commission, US National Park Service, US Forest Service, US Fish and Wildlife Service, Arkansas Department of Environmental Quality, The Nature Conservancy, and the Departments of Biological Sciences and Geosciences at the University of Arkansas, Fayetteville. Two studies are particularly germane to this Natural Area: Graening et al. (2001) compared the fauna, water and sediment quality at CSC to 63 other caves in the State; and Graening and Brown (in progress) are comparing the ecosystem dynamics and pollution effects elucidated in these studies of CSC to three other priority caves in Benton County. Thus, ANHC’s investment of resources in the study and protection of this Natural Area have been quite effective, and this investment is being leveraged to benefit other endangered species’ habitats. Very few long-term data sets exist for North American caves, and this seriously limits knowledgeable management of them. Cave Springs Cave should continue to be monitored to help fill this void and to enable successful management of its unusual biota and their habitat. But monitoring is only the first step - successful management sometimes requires taking bold actions to protect these natural resources. Our management recommendations at the end of this report outline the actions we feel need to be initiated now. Bacteria and some nutrient and metal concentrations chronically exceed Regulation 2 maximum contaminant levels and regional background levels. It is imperative to reduce the pollution input from septic leachates and landapplied manures in the CSC groundwater basin, especially if sensitive species, such as cave amphipods (Stygobromus ozarkensis, State Species of Concern) are to persist in this Natural Area. Despite the degraded water quality, the Ozark Cavefish population appears to be stable or increasing

Recent collections and additional records of Collembola from Arkansas caves

Recent collections and additional records of Collembola from caves in Arkansas are reported. Based on these collections and review of the literature, 35 collembolan species are known from Arkansas caves. Included in this group are 10 troglobiotic, or cave-limited, species: Lethemurus missus, Pygmarrhopalites buffaloensis, Pygmarrhopalites clarus, Pygmarrhopalites dubius, Pygmarrhopalites youngsteadtii, Pseudosinella dubia, Pseudosinella testa, Sinella barri, Sinella cavernarum, and Typhlogastrura fousheensis. Three of these species, Py. buffaloensis, Py. youngsteadtii, T. fousheensis, are endemic to Arkansas, while Ps. dubia is known only from the Ozark Plateaus Ecoregion. The remaining species are more widespread. Lethemurus missus, Ps. georgia, Ps. testa, and S. cavernarum are reported for the first time in Arkansas. On the basis of this information, revisions to the current rarity rankings for collembolan species classified as troglobionts are recommended

Monitoring Cavefish Populations and Environmental Quality in Cave Springs Cave, Arkansas

Cave Springs Cave, Benton County, Arkansas, was monitored from October 1997 to June 1998 to determine the chemical and physical environmental quality and the status of the population of threatened Ozark cavefish, Amblyopsis rosae. The majority of the chemical parameters measured were indicative of adequate environmental quality in the Cave Springs Cave ecosystem. However, several significant problems were revealed. A trend analysis of known water quality studies of this cave complex suggests that many organic and inorganic chemicals have increased in concentration in the last 14 years. This ecologically sensitive water body did not meet Arkansas water quality regulations for fecal coliform densities, and copper, selenium, and lead concentrations exceeded limits for exposure to aquatic life. The geometric mean total coliform count for base flows was 500 MPN/100ml, and during the March storm event, coliform densities exceeded 20,000 MPN/100ml. When compared to the national primary drinking water regulations, this spring water exceeds the maximum contaminant levels (MCL) for turbidity, nitrite, total coliforms, and Escherichia coli, and approaches the MCL’s for copper and zinc. During the March storm event, Escherichia coli densities exceeded 5,000 MPN/100ml. During the June storm event, nitrite levels reached 2 mg/L, twice the MCL for national drinking water standards. Nitrite toxicity is known to cause severe anemia in fishes and damage their tissues. One semi-volatile organic, Di (2-ethylhexyl) phthalate (DEHP), was found in significant concentration (500 ug/kg) in resident crayfish tissue. DEHP is known to bioaccumulate in fish tissue, and cause reproductive damage and reduced fertility in fish. A visual survey was performed on January 25, 1998, and 106 cavefish were sighted. This survey indicated a 30% decline in the Cave Springs Cave population. A comparison of base-flow sampling results at two different locations -- upstream and downstream of bat rookeries -- indicates that the majority of coliform bacteria are not attributed to bat guano. These findings suggest that bacteria are being imported into the cave stream from the recharge zone. The high nitrite, total coliform, and E. coli counts suggest that septic system leakage or the land application of animal waste is involved. Continued water quality monitoring and surveys of the Ozark cavefish population are recommended. Future monitoring should focus on storm events and parameters that measure pollutants originating from the recharge zone and their effect on the cave ecosystem. As well, investigation into the nature of the pollutants from the recharge zone is suggested

Annotated Checklist of the Amphipoda of Arkansas with Emphasis upon Groundwater Habitats

Based on recent collections and review of the literature, 20 species of freshwater amphipod crustaceans are listed from the state of Arkansas. Included are species from the families Allocrangonyctidae, Crangonyctidae, Gammaridae and Hyalellidae and the genera Allocrangonyx, Bactrurus, Crangonyx, Stygobromus, Gammarus, and Hyalella. Ten of the species are restricted to subterranean groundwaters, 2 are closely associated with groundwater but also occur in surface waters, and 8 are known primarily from surface waters. Two of the species are in the process of being described in the literature, whereas 2 remain only provisionally recognized to date. On the basis of this new list, some revisions to the current rarity rankings are recommended

Subterranean Biodiversity of Arkansas, Part 1: Bioinventory and Bioassessment of Caves in the Sylamore Ranger District, Ozark National Forest, Arkansas

Inventory and assessment of subterranean ecosystems of the Sylamore Ranger District (within Baxter, Marion, Searcy, and Stone counties) Ozark National Forest, was performed 2000 to 2002. The Sylamore District, completely underlaid in karst topography (occurring in Mississippian to Ordovician carbonates), contains approximately 10% of the known caves in Arkansas. Thirty-five sites were inventoried, six of which were sampled for environmental quality. These were combined and analyzed with previous studies, creating a database of 1,238 total species occurrences, 230 species, and 61 total sites. Most common were cave crickets, pipistrelle bats, woodrats, mosquitoes, and spiders. Fourteen species obligate to coves or groundwater were found, including four new to science, although a collector’s curve showed that sampling effort to date has not reached maximum species richness. Richness was significantly great in caves developed in Ordovician carbonates, in caves with organic inputs (especially bat guano), and as cave passage length increased. Richness was not significant between watersheds (Buffalo versus White Rivers), nor by water resource, nor by degree of recreational use. Caves were ranked by passage length, total and obligate richness, and overall biological significance. Blanchard Springs Caverns ranked highest and is the most biologically rich cave in Arkansas with 96 total and nice obligate species. Recommendations include continuation of physical and biological inventories, increased protection of high-ranked sites, and increased public education/outreach. The US Forest Service has invest 0.6 million dollars in cave research, monitoring, and protection on the Sylamore District to date

Updated checklist of the ice-crawlers (Insecta: Grylloblattodea: Grylloblattidae) of North America, with notes on their natural history, biogeography and conservation

Schoville, Sean D., Graening, G. O. (2013): Updated checklist of the ice-crawlers (Insecta: Grylloblattodea: Grylloblattidae) of North America, with notes on their natural history, biogeography and conservation. Zootaxa 3737 (4): 351-378, DOI: 10.11646/zootaxa.3737.4.