The Edwards Aquifer: Earth's Most Diverse Groundwater Ecosystem?, 1981, Longley Glenn

Recent studies on the Edwards Aquifer, a karstic formed cavernous system in Texas, indicate an extremely diverse community of aquatic troglobites. Sampling of wells and springs is providing new insight into the dynamics of this fascinating system, which is possibly the most diverse subterranean aquatic ecosystem known in the world today.

Australian Aquatic Cavernicolous Amphipods, 1985, Knott, Brenton

The purpose of this paper is to acquaint speleologists with preliminary results of recent researches into the amphipodan fauna from aquatic ecosystems of Australian caves, with particular reference to Western Australia. Attention is focussed particularly on the systematic and zoogeographic significance of this fauna.

GROUNDWATER AGE: A VITAL INFORMATION IN PROTECTING THE GROUNDWATER DEPENDENT ECOSYSTEM, 2005, Serdar Bayari, N. Nur Ozyurt, Zubeyde Hatipoglu

Economic gains of use have led to a global explosion of groundwater development in the last several decades. Consequently, groundwater reserves have been depleted extensively. Continuing use of groundwater, which is initially supplied from the storage, causes increasing derivation of additional water from groundwater dependent ecosystems such as, streams, lakes and wetlands. A systematic groundwater age dating in the vicinity of a surface water body may help to quantify the spatio-temporal dynamics of interaction between these resources. Though, numerical flow and transport models may be used to infer the age distribution of groundwater feeding a surface water body, their efficient use requires extensive data that properly characterize the flow domain. In cases, such data is not available or requires to be supplemented by an independent approach, spatio-temporal age dating of groundwater by various tracers can be helpful in understanding the dynamics of flow in the aquifer. This paper provides brief information on how the groundwater age data can be used in surface water ecological problems. Examples from several field sites in Turkey are also presented.

Sensitivity of ancient Lake Ohrid to local anthropogenic impacts and global warming, 2006, Matzinger A. , Spirkovski Z. , Patceva S. , Wuest A. ,

Human impacts on the few ancient lakes of the world must be assessed, as any change can lead to an irreversible loss of endemic communities. In such an assessment, the sensitivity of Lake Ohrid (Macedonia/Albania; surface area A = 358 km(2), volume V = 55 km(3), > 200 endemic species) to three major human impacts-water abstraction, eutrophication, and global warming-is evaluated. It is shown that ongoing eutrophication presents the major threat to this unique lake system, even under the conservative assumption of an increase in phosphorus (P) concentration from the current 4.5 to a potential future 9 mg P m(-3). Eutrophication would lead to a significant reduction in light penetration, which is a prerequisite for endemic, deep living plankton communities. Moreover, a P increase to 9 mg P m(-3) would create deep water anoxia through elevated oxygen consumption and increase in the water column stability due to more mineralization of organic material. Such anoxic conditions would severely threaten the endemic bottom fauna. The trend toward anoxia is further amplified by the predicted global warming of 0.04 degrees C yr(-1), which significantly reduces the frequency of complete seasonal deep convective mixing compared to the current warming of 0.006 degrees C yr(-1). This reduction in deep water exchange is triggered by the warming process rather than by overall higher temperatures in the lake. In contrast, deep convective mixing would be even more frequent than today under a higher temperature equilibrium, as a result of the temperature dependence of the thermal expansivity of water. Although water abstraction may change local habitats, e.g., karst spring areas, its effects on overall lake properties was shown to be of minor importance