The Netherlands has only artificial rocky shores
"Between de concrete rocks one can find beautiful rockpools.
These concrete blocks are placed on a asphalt layer, and weighting
up to 40 tons.
These heavy blocks sink slowly through the asphalt layer
and are damaged by wave action and erosion:
The seawater digged out a trench, the stat of a rockpool.
The rocky shore has zones
Pier of Ijmuiden.
bladder wrack kits itself on the rocks.
a marvelous mid littoral rockpool, with
brown an green seaweed open, unsave rockpools and deep sheltered rockpools
high tide near the lighttower,
with thanks to Geoffrey Baker
Once there was a light raiway on the Pier of Ijmuiden.
The Pier of Ijmuiden was build 1n 1876 to protect
the Northsea channel for the waves of the Northsea.
The sea locks are amongst the world's biggest
and are the main entry to the famous Port of Amsterdam
Splash zone
This is the highest and the most extreme zone, and
conditions resemble that of the desert
Most water that reaches this zone is fresh rainwater, but sometimes
the waves bring salty water, so a rapid change in salanity can occur.
By evaporation the water can get more salty then the sea (hypersaline).
In summertime al the water evaporates here and the temperature goes
higher then 40 degrees Celsius. The acidity raises sharply after a
period of high temperatures. Only very few animals can live in these
conditions. Lichen and algae survive on the basalt rocks. The Idotea baltica
is one of the few animals that feed on algae.
the (Eu)littoral
In these rockpools the water is changed regulary.
there are three zones: the high, mid and lowtide zones:
high tide zone
Sea water enters only at high tide and stormy weather.Most of the
animals kit themselves on the rocks, for example :mussels.
This phenome is called aggregation: animals and plants live in groops
as a way to protect themselves against the environment, like wave action
and great temperature fluctuations. Some animals that live in those
rockpools can't survive the fast change in salanity when the water
changes from salt into brakkish water after rainfall.
They end there lives as food for crab and heremite crab.
Other typically inhabitants are the shrimps
and young fishes that are locked in by accident.
Here the basaltrocks are covered with green weeds like bladder wrack.
Mussels, barnacels,and bladderwrack dominates these pools.
Crab and seastar are the bigger animals here.Most rockpools are protected
for sun ,wind and waves by the rocks. These rocks protect also for
hunting seabirds. Between the rocks and asphalt floor the pool inhabitants
find a hiding place. If an crab got stick with its legs under a rock it can
get rid of that leg: this is called autonomy.
lowtide zone
The rock pools between the basalt rocks are teeming with a myriad of marine life
including sea grasses, molluscs and crustaceans.
local situation
There are two kinds of rockpools that can be find in the lowtide zone:
the sheltered and unsheltered rockpools.
The unsheltered rockpools can be found near the beach. Most of these
rockpools are flat and the underground is black (asphalt).
The conditions in these rockpools are almost the same as
in the beachpools: temperatures can change vastly , there is wind
and wave action, rain can change the water from salt into brakkish
The rocks are covered with a layer of bladder wrack or mussels and are
slippery.
The sheltered rockpools The slits between the concrete blocks give shelter to a
beautiful miracle world. Conditions in these rockpools are much easier.
King of the rockpool is a crab , that eats the fishes that are brought
by the tide. The shadows created by the rocks give shelter for seabirds.
Under the rocks are small holes ,with hiding places for shrimps and crabs
and sandgobys.
The concrete block gives shelter against the seawaves, the shadow
protects against birds and the holes harbor crabs and sandgobys.
With thanks for the photo: Coos Ernens
Here there are both open and sheltered rockpools.
With thanks for the photo: Anton Aardenburg
