Wrack 'n Hoppers
Beachhoppers
on wrack
It's "a trace of something destroyed"... It's "seaweed or other vegetation cast on the shore".
These definitions are from the Randon House Webster's College Dictionary and pretty well describe shoreline wrack.
Any of us who walk beaches know it well - have perhaps slipped on it, as it can be slippery when damp or wet. So we know to side-skirt it - slip on around it - for a third definition is a "wreck"... "a person of ruined health; someone in bad shape physically", and such wreckage we definitely like to avoid!
But beach walks do reveal dislodged seaweeds or wrack, and on incoming tides we can often see it being moved about in the nearshore water - being brought up on the beach slope by the rising water and on the leading edge of waves. Hopefully not, but sometimes, it's accompanied by pieces of light-weight styrofoam, empty cigarette and food packaging, plastic beverage bottles and such.
On one day the predominant algae making up the wrack will be the brilliant green sea lettuce - Ulva sp. - perhaps great quantities of it - thin transparent pieces or sheets which were ripped from their rocks or supporting structures. Sometimes there are big masses of it which are not green - globs which have bleached white in the sunlight.
Another day the reigning wrack is Laminaria saccharina or Sugar Kelp - the big brown kelp with two lines of blisters along its meter long blades.
Mixed in could be any number of other algal species from the red algaes, Turkish Towel and Porphyra sp, to Rockweed and the familiar Bull Kelp.
Further back on a sandy or rocky beach slope can be more weathered wrack left behind by previous tides - wrack that's dried a bit - perhaps developed a crispy crust on top. Consider breaking apart and more closely scrutinizing some of this. Lots of small creatures we call Sand Fleas or Beach Hoppers may begin scurrying about, jumping, behaving in a rather unpredictable manner. I recently learned they have been know to jump 40 times their mature 3/4 of an inch length. Having six pairs of legs, the hind three are the ones used for these seemingly hap-hazard hurtles.
These beach hoppers are quite abundant on our protected beaches - are critters that may be small but have been given big, more formal, Linnean genus and species names, Traskorchestia traskiana.
Also dubbed amphipod crustaceans, they are dark gray in color, have short antennae and flattened bodies. And they keep themselves marvelously cool and moist by burrowing into the damp decaying seaweed wrack - a place too where they scavenge for food and seek protection from larger crustaceans, birds, and other creatures which may gourmandize them (that is if the predators can catch them as they cavort about!)
Walks at, and visits to the beach. Always revealing - always engaging.
Pat Nash
Beach Watcher
Class of '94
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