Transcript General introduction

PORT OF ARMINTZA
This is a small old port lying in the cove of the
same name. Access to it is both difficult and
dangerous, due to the many stones and lowlying rocks along the entrance channel at the
end of the pier and over to the west.
Armintza is one more example of a former fishing port which has
become a harbour for recreational watercraft.
Location: l: 43-26 N L: 02-54 W
Tidal range: 4.5 m
Entrance mouth:
Width: 10 m
Depth in L.W.O.S.T.: 1m. 10 metres wide dangerous
entrance channel.
Orientation: W
GEOLOGICAL HISTORY OF
ARMINTZA
The especial shape of the bay of Armintza has been
created due to its uncommon geological structure; the
type of rock and the relative position of rocks to the sea
has determined the rate of erosion of the area.
As it can be seen in the picture above, the volcanic rocks have
protected the land from the erosion and thus has created a small
peninsula, which structure should have been eroded if the
volcanic rocks would not have been there.
THE COASTAL ZONE
The coastal zone is one of the richest areas in the world due to the high
availability of nutrients from several sources. We can distinguish three main
zones:
Types of habitat on the coastal zone:
-The water column (pelagic environment)
-The bottom (benthic environment):
*Hard (rocky) *Soft (sandy, muddy)
Armintza has a
northwest coast rocky
intertidal zonation:
Plants and animals are distributed in horizontal zones along rocky shores
according to their particular adaptations to exposure and wave shock.
There are some species that have distributions that are wide and some
species that have narrow distributions. Some species have sharp boundary
zones whereas some species gradually fade out. Some species share
precisely the same upper and lower limits of distribution, while some
species overlap only part of another species zone and some species never
come in contact with one another
The Intertidal Zone is an ECOTONE, that is located
between the continent and the sea.
Its distribution is limited by the high and low tides. In
the intertidal zone there are enough nutrients, but there
is no stability. All the phyla are represented here.
The intertidal zone can be divided in four areas:
1-.Spray (supra-littoral):
-The uppermost zone that extends from the highest reach
of spray and stom waves to about the mean of all high
tides.
-This zone is infrequently wetted.
-Organisms living in this zone are very hardy and
semiterrestrial.
-The communities of lichens are dominant.
-Littorina neritoides is a characteristic species of this area.
2-.High (mid-littoral):
-This zone extend from the mean high water to about
the mean flood of the higher of the two daily lows
which is slightly low below mean sea level.
-This zone is just above the mussel beds. It is also
called the Balanoid zone.
-Species that can suffer long uncovered periods
appear forming a brown narrow belt, such as Fucus
spiralis and Pelvetia canaliculata.
3-.Mid (lower mid-littoral):
-This zone extends from the mean higher-low water to
the mean lower low water wich is the zero of the tide
tables.
-This zone is tipically covered and uncovered twice each
day.
-It is also called the lower Balanoid zone.
-Among seaweeds, the most important are Cystoseira
spp., Gelidium sesquipedale and Gigartina elongata.
4-.Low (infra-littoral fringe):
-This zone typically is uncovered only by minus tides.
-It can only be examined for a few hours each month.
-The biodibersity of this area is very high.
-Organisms of this zone can tolerate only minimum
exposure.
-It is also called the Laminaria zone.