Sandhoppers On The Move
Interestingly, one evening down at Sth New Brighton sand dunes accompanied by a torch, I noticed what looked like a serious migration of many sand hoppers moving up into the sand dunes and shortly afterwards, either the next day or the one after that, a heavy southerly swell arrived and removed masses of sand from the dunes. Were they able to detect this advancing swell in advance and so take evasive action?
It may be that these amphipods detect vibrations from far off, (with sound travelling faster through water) the damp sand where they form their temporary homes assisting in the detection of vibrations.
Busy in the dunes
Sandhopper print & jump marks