Earthquakes trigger the loss of groundwater biodiversity

Abstract

Earthquakes are among the most destructive natural events. The 6 April 2009, 6.3-Mw earthquake in L'Aquila (Italy) markedly altered the karstic Gran Sasso Aquifer (GSA) hydrogeology and geochemistry. The GSA groundwater invertebrate community is mainly comprised of small-bodied, colourless, blind microcrustaceans. We compared abiotic and biotic data from two pre-earthquake and one post-earthquake complete but non-contiguous hydrological years to investigate the effects of the 2009 earthquake on the dominant copepod component of the obligate groundwater fauna. Our results suggest that the massive earthquake-induced aquifer strain biotriggered a flushing of groundwater fauna, with a dramatic decrease in subterranean species abundance. Population turnover rates appeared to have crashed, no longer replenishing the long-standing communities from aquifer fractures, and the aquifer became almost totally deprived of animal life. Groundwater communities are notorious for their low resilience. Therefore, any major disturbance that negatively impacts survival or reproduction may lead to local extinction of species, most of them being the only survivors of phylogenetic lineages extinct at the Earth surface. Given the ecological key role played by the subterranean fauna as decomposers of organic matter and “ecosystem engineers”, we urge more detailed, long-term studies on the effect of major disturbances to groundwater ecosystems.

Exploring copepod distribution patterns at three nested spatial scales in a spring system: habitat partitioning and potential for hydrological bioindication

“…Six stygobiotic species have a potential role as tracers of groundwater flowpaths: Parastenocaris sp.1 and Eucyclops intermedius were exclusively linked to the Capo Pescara groundwater, while Nitocrella pescei, Nitocrella morettii and Diacyclops goticus were linked to the Santa Liberata groundwater. Nitocrella pescei was by far the most abundant species in fractured sectors of the spring-bed in the River Tirino springs (Galassi and De Laurentiis, 1997a;Fiasca et al, 2014;Galassi et al, 2014), the largest karstic springs exclusively fed by the Gran Sasso aquifer which feeds the Santa Liberata spring unit.…”

“…Biological assemblages are even more intricate, as springs are unique aquatic habitats, hosting species either preferentially or exclusively inhabiting spring mouths, or colonizing the spring from the surface (epigean species) or from the aquifer which feeds the spring (hypogean species) by a constant wash out (Rouch, 1968(Rouch, , 1982Fiasca et al, 2014;Galassi et al, 2014). However, spring ecology has mainly focussed on the surface-water biota (Hahn, 2000;Bottazzi et al, 2011;Cantonati et al, 2011Cantonati et al, , 2012Spitale et al, 2012), even if increasing attention is being paid to the fauna constantly living below the spring bed (Danks and Williams, 1991;Gerecke et al, 1998;Rossetti et al, 2005;Fiasca et al, 2014).…”

“…Similarly, beyond their uniqueness in terms of degree of endemism, rarity and relictuality De Laurentiis, 1997a, 1997b;Botosaneanu, 1998;Barquín and Scarsbrook, 2008;Galassi et al, 1999Galassi et al, , 2011Cantonati et al, 2011), some groundwater species have been claimed as good candidates for identifying dual aquifer flowpaths (Petitta et al, 2015;Mori et al, 2015) or changes in groundwater pathways feeding spring systems (Stoch et al, 2009;Galassi et al, 2014). However, the reliability of spring meiofauna assemblages as hydrological biotracers has not been investigated to any great extent.…”

Effect of Temperature Rising on the Stygobitic Crustacean Species Diacyclops belgicus: Does Global Warming Affect Groundwater Populations?

“…Groundwater ecosystems are generally poorer in nutrients and oxygen than surface water ecosystems [12][13][14][15][36][37][38][39][40]. In order to reduce energetic costs, groundwater ectotherms have evolved metabolic rates that are lower than those of their close epigean relatives [20,[41][42][43][44].…”

Water-table and discharge changes associated with the 2016–2017 seismic sequence in central Italy: hydrogeological data and a conceptual model for fractured carbonate aquifers

“…Esposito et al (2001) describe the effects of four earthquakes in southern Apennines including the 1980 Irpinia earthquake, which generated important hydrogeological changes as far as 200 km from the epicenter, including a significant increase of Caposele spring flow. Amoruso et al (2011) describe the hydrogeological changes in a fractured aquifer after the L'Aquila 2009 earthquake, inferring that those changes were probably connected with the increase of bulk hydraulic conductivity at the aquifer scale, mainly due to fracture cleaning, raising hydraulic heads in the discharge zones, and correspondingly lowering them in the recharge areas (Adinolfi Falcone et al 2012;Galassi et al 2014).…”