|The Edge of the Sea|
Navigating the site:
The sea's margins.
"The place of our dim beginnings..."
said Henry David Thoreau, one of America's great coastal naturalist.
Shark Bay, Australia.
West coast beside the Indian Ocean.
Along the western coast of the continent in an isolated area of salt lagoons, these formations exist, as enduring examples of the earliest life in the seas.
They are called stromatolites and are blue-green or photosynthetic bacteria that inhabited the Precambrian sea's ancient shore lines.
In what may be called the "Tales of Ancient Oceans" these colonial creatures, precursors of plants, were photosynthetic. They were able, that is to use sun light for energy and produce oxygen as a gas, or vapor by product of their making a living by the sea. They represent among the most significant changes to have ever occurred on earth, triggered by living beings.
[Wiley. Interscience series] See: www3.interscience.wiley.com:8100/ legacy/
are commonly found in an interval known as the Ediacaran, named for the location in Australia where fossils of this age were first found. Examples of Cnidaria ("jellyfish", "sea anemones", and "sea pens") are common, as well as other groups of uncertain affinities (possible annelid worms, lophophorates, etc.).
The Ediacaran fauna is found world-wide in rocks of late Precambrian age, and is entirely soft-bodied.
In the latest Precambrian and early Paleozoic,
supercontinent Rodinia, centered about the south pole, broke apart
as blocks drifted northward. Most notable of these blocks were the large
continents North America [Laurentia], Baltica, and Siberia.
The Edge of the Sea pp. xiii- 38.
Places inform us if we know how to pay attention to what they say, do, emit, & signal
Coastal zones are wide areas in which barrier islands indicate conditions.
Geology as a theme.
What does Carson describe about the margins of the sea?
II "Patterns of Seashore Life"
Rachel Carson is always describing the physical conditions to which living organisms, and living communities adapt.
" a strong sense of inter-changeability of land and sea..."
"over all these patterns there are others created by the seawater itself--bringing or withholding food, carrying substances of a powerful chemical nature that for good or ill, affect the lives of all they touch."
The vast current systems:
The northward migration of warm water species pole-ward of Cape Cod, green crab as an example
intertidal zones. important & signal indication of the inter-changeability of the sea and land, anomalous quality of creatures, and special case of property ownership,
For it is now clear that in the sea nothing lives to itself.... so [too] the present is linked with the past and future, and each living thing with all that surrounds it.
Weaving the intricate design of the fabric of life.
Sea grasses in a Pacific Ocean tide pool.
adaptive responses to shifting tides:
To what extent does life alter its surroundings?
Life alters the places in which it finds a niche within which to thrive.