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Other
differences between coastal locales, is that coastal structures can be broken
by many long and narrow bays, so called fjords or of many small islands
known as skerries that form archipelagoes. Furthermore, certain rocky beaches
are situated by the open sea, others are more secluded, while certains places
are dominated by low-lying skerries, others are dominated by mountainous
skerries with steep precipices. Further differences can also be from which
direction the wind predominately blows, towards or away from land. Variations
can also be seen amongst the local fauna depending on if they live on the
sunny
side of an island compared to a
shady side.
Organisms life cycle
Marine organisms can reproduce in a variety of
ways, sexually or asexually.
Reproduction can also, in suitable circumstances, result in a vigorous spreading
and colonization. That organisms have different life cycles and that different
processes effect the different stages of their development, these are vital
factors effecting the richness of the fauna within a given area.
Bladder
wrack for example has a relatively simple life cycle. Many other
algae have a more complicated life cycle where two or three generations
occurr without the repetition of a development stage. The different generations
can have varying appearances and the switching from one generation to the
other is accomplished with spores and in other cases with eggs and sperms.
Although those specie that have heavy and sticky spores and eggs have a
tendency to spread badly, they can still give rise to widespread populations
when specie, whole or part of, drift into new areas.
Animals can also have fairly
complicated life cycles and certain
larvae can survive several weeks in the water, while certain other animals
do not have a pelagic larvae stage.
Organisms ability to spread is not just of importance for
where they can exist, but also for how
they adapt to different environmental conditions. Good distribution
ability can counteract the occurrance of special adaptions to environmental
conditions, while a limited distribution allows a local
population to gain special and perhaps unik characteristics that function
well in the immediate environment.
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