Sediment characteristics influence benthic macroinvertebrate vertical migrations and survival under experimental water loss conditions

Body size affects the vertical movement of benthic amphipods through subsurface sediments in response to drying

“…Our results demonstrate that larger amphipod individuals have a reduced ability to access and move through subsurface sediments. In agreement with previous studies (Gayraud & Philippe, 2001;Loskotová et al, 2019;Mathers et al, 2019b), these results indicate that body size is a key factor influencing an individual's ability to access subsurface sediment. Furthermore, we found clear evidence that larger individuals of both amphipod species were more susceptible to stranding during water level reduction, whereas smaller individuals readily accessed deeper subsurface sediments.…”

“…Fig. 3 Mean distance travelled (mm) during each 20 min observation period associated with an amphipod's head size through the sediment, whereas individuals of a similar size or larger than the sediment pore size are more likely to become stranded during water level reduction (Vadher et al, 2017;Loskotová et al, 2019); although direct measurement of pore size openings would be required to verify this.…”

“…The ability of fauna to access the subsurface habitat reflects both sedimentary characteristics (Gayraud & Philippe, 2003;Vadher et al, 2018b) and faunal traits (Wickson et al, 2012;Loskotová et al, 2019). Sediment characteristics such as pore size, ratio of gravel framework to fine sediment matrix, and particle size and heterogeneity have been highlighted as key abiotic factors affecting the ability of invertebrate fauna to access subsurface sediments (Mathers et al, 2014;2019b;Vadher et al, 2017;Loskotová et al, 2019). A reduction in sediment pore space due to excessive deposition of fine sediments and clogging may limit the ability of macroinvertebrates to move vertically through interstitial pathways and access subsurface habitats (Navel et al, 2010;Vadher et al, 2015;2017).…”

“…A reduction in sediment pore space due to excessive deposition of fine sediments and clogging may limit the ability of macroinvertebrates to move vertically through interstitial pathways and access subsurface habitats (Navel et al, 2010;Vadher et al, 2015;2017). These abiotic factors operate in conjunction with faunal traits that may facilitate resistance to drying and dewatering including behavioural adaptations (Lytle et al, 2008), vermiform body morphology (Vadher et al, 2017;Loskotová et al, 2019) and physiological traits (Wickson et al, 2012;Stubbington et al, 2016). Recent research has also demonstrated how the vertical movement of macroinvertebrates may be influenced by their relative body size within sediments of varying heterogeneity (Mathers et al, 2019b).…”

Beneath the surface: Application of transparent super absorbent polymer substrates to track faunal activity within the sediment layer

“…It has been hypothesised that the hyporheic zone may act as a nursery and refugium for benthic invertebrates during adverse surface conditions such as supra seasonal drought conditions (Boulton, 2003; Wood et al., 2010), ephemeral and intermittent streams (Datry, 2012; Loskotová, Straka, & Pail, 2019), and high flows (Dole‐Olivier, Marmonier, & Beffy, 1997); however, evidence is still equivocal. Recently the hyporheic zone has also been demonstrated to act as a thermal refuge from warming surface waters (Folegot et al., 2018) associated with the cooler temperatures often located in the deeper substrates.…”