Consecutive earthquakes temporarily restructured the zooplankton community in an Alpine Lake

Abstract

-Two consecutive earthquakes temporary changed a zooplankton community in a high-mountain Lake Krn (altitude 1383 m a.s.l.). It was dominated by the eurytherm copepod, Cyclops vicinus, until 1998, when the first earthquake hit the lake (EMS = 5.6). After the earthquake, the population of C. vicinus collapsed and the thermophilic cladoceran, Ceriodaphnia quadrangula, took over. After the second earthquake in 2004 (EMS = 4.0), C. vicinus became untraceable. In 2008, few copepods reappeared and by 2010 they became the sole dominant again. Only Secchi-disc depth showed a statistically significant increase over time, while N tot , P tot and temperature showed an increasing trend, yet the relationship was insignificant. To compare multi-parameter properties of the water column, the studied period was divided into Period 1 (before the first earthquake), Period 2 (between earthquakes) and Period 3 (after the second earthquake). A Hotteling T 2 test confirmed a statistically significant difference between Periods 1 and 2 & 3 (P < 0.01), but not between Periods 2 and 3 (P > 0.1). During simple laboratory experiment, specimens of C. vicinus were covered with a thin layer of sediment, to mimic the earthquake's effect on their survival. A hypothesis was that the timing of both earthquakes had been crucial for decimation of C. vicinus population as they re-suspended sediment with hibernating copepodites. As these became subsequently buried they were deprived of a re-activation signal and exposed prolonged anoxic conditions there. C. quadrangula temporary filled the void left by the copepod, which needed 6 years to regain its dominance.

Earthquake-Related Changes in Species Spatial Niche Overlaps in Spring Communities

“…This suggests that the increase in spatial overlap within s,s and s,n pairs is related to an increase in interspecific interactions in turn determined by changes in species distribution in the spring subsurface microhabitats. Shifts from segregation to aggregation/randomness have also been observed in ant communities suddenly altered by the introduction of non-native species 30 , 31 and severe, albeit transient, changes were noticed in lacustrine planktonic communities after an earthquake 32 , suggesting that this pattern can be a recurrent consequence of a strong disturbance.…”

Changes in animal activity prior to a major (M= 7) earthquake in the Peruvian Andes

“…Taxonomic composition has been shown to change in connection with earthquakes [Brancelj et al 2012]. Two orders of ground dwelling birds (galliformes and tiniamiformes) and six orders of terrestrial mammals (carnivora, cetartiodactyla, cingulata, perissodactyla, primates and rodentia)…”

Earthquake impacts on microcrustacean communities inhabiting groundwater-fed springs alter species-abundance distribution patterns

“…In general, the study of ecosystem responses to major disturbance events may produce important ecological and resource management insights 13 and there is increasing literature on the effects of fires 14 , 15 , floods 16 , 17 , hurricanes 18 – 20 , tornadoes 21 , 22 , volcanic eruptions 23 – 25 , and tsunamis 26 , 27 on biodiversity. However, information on how animal communities respond to the disturbance of seismic events is still very limited 12 , 28 . In particular, the consequences of earthquakes on invertebrate biodiversity have been rarely addressed and remain therefore largely unknown 29 – 32 .…”