Winter Colours of the Violet Bank
This week we took a bit of a break from our guided walks on the seabed in Jersey and headed out on our own private “Moonwalk” to explore the Violet bank and low tide zone around la Rocque and Seymour tower.
Already there are signs of spring though the sea temperature has not dropped as low as it usually does this winter.
Small green blobs – eggs of the Greenleaf Worm have appeared lying on the mud or attached to pieces of seaweed.
Turn over a rock and sponges are in evidence. The sponge Myxilla incrustans is visible. This animal sucks in water through tiny holes and once filtered the water is expelled via the larger holes.
The wonderful iridescent kingfisher blue seaweed is Cystoseira tamariscifolia. Lift it out of the water and it becomes a boring dull green.
Like lace on a frond of Dulse: the Frosted Sea-mat, a colony of minute moss animals, each only 1 mm is revealed. Look carefully and tiny stalks can be seen.
Each little cell has tiny hairs which beat rapidly to move and create vortexes of water. The hair like tentacles enable the creature to feed off minute particles of food. Sea mat likes to grow near the base of the frond. If the top of the weed is ripped off in a storm they are more likely to survive.
Purple Lithothamnia covers the rocks.
Could the Violet Bank have got its name because of the encrusting Lithothamnia and beds of Maërl which are also revealed at low tides off the east coast of Jersey?