Tuesday, August 28, 2012

Newport, Oregon: Rocky Intertidal

Hi, Amy and Leo here,

Since we had some due dates and timelines to meet, we had to work the few days we had on land and stay in the vicinity of Newport, but we still had some time to visit the beautiful and rich intertidal of the Oregon coast.

The Oregon coast is part of the California-Oregon Upwelling System, driven by the California Current, which makes it one of the most productive areas in the world. This high productivity supports a large and diverse amount of fauna.  Currents bring deep water up to the surface with a lot of nutrients and this lets phytoplankton (the food of the sea) grow. With a lot of food around you get a lot of animal life too! The downside of upwelling, particularly in the northern part of this system, is that sometimes the deep water is low in oxygen and high in carbon dioxide. This region is thus another system that seems to be particularly vulnerable to climate change, but that question is for another day and another expedition. For the meanwhile we were just enjoying the beauty of the system.
Yaquina Head cliffs and rocky shore.
The high cliffs, on top of the rocky intertidal zones, are the habitat of the California Ground Squirrel

California Ground Squirrel warming up on the asphalt on the path to Quarry Cove, Yaquina Head. Photo: A. Maas

From the top of the cliffs it is easy to spot Harbor Seals resting on the rocks, and large colonies of cormorants.

Photos: A. Maas

Diversity in rocky intertidal zones is particularly high due to the small patches of different habitats we can find just within a few feet from the water’s edge. From regions exposed to the waves fronts, dominated by gooseneck barnacles, several species of acorn barnacles, and California mussels, you move on to the more protected internal pools full of calcareous tubeworms, anemones, limpets, chitons, seastars, sea-urchins and many others.

Exposed to the wave action, the frontal areas are dominated by strongly adhered sessile fauna, like barnacles, mussels and gooseneck barnacles. Photo: A. Maas

Depending on the amount of time that a particular pool is exposed to the air between tides, there is variability in the range of temperature and salinity levels (saltiness) that the animals experience. This creates a range in the distribution of both fauna and algae depending on their tolerance to drastic changes in their environmental conditions. This ranges from big changes in the higher pools, that suffer more contrasting levels of temperature and salinity, to the lower ones, were the conditions are more constant and are only exposed to slight changes during strong tidal events.

Intertidal rocky shore under Cape Perpetua. Upper pools are more protected from the mechanical stress of the waves, but they are exposed longer to the air temperature and evaporation, making them a highly variable environment. Lower pools are subject to less stress due to more constant temperature and salinity conditions. Photo: A. Maas

 Scorpion fish in a tidal pool in Quarry Cove, Yaquina Head. Photo: A. Maas
Purple sea urchins in a protected pool in the surroundings of Cape Perpetua. Photo: A. Maas
Green sea anemones near Cape Perpetua. These anemones have unicellular green algae living on their tissues in a symbiotic relationship. Photo: A. Maas
Chiton on Yaquina Head. These mollusks have eight plates protecting their back. Photo: A. Maas
This rich area also has large colonies of sea lions. More comfortable with close interaction with humans than seals, sea lions have no problems occupying human-made structures like harbor jetties and piers or, like in this case, resting under a human-crowded tourist pier on the Newport Waterfront. Photo: A. Maas
All of this diverse natural life supports a strong fishing community which, as a result, ended in some wonderful meals for us. In combination, the lovely views and good food make it a fantastic place to spend a few days. (Note: there are also some really nice espresso drive-throughs).
Amy and Leo at Cape Perpetua enjoying the windy clifside. Photo: L. Blanco-Bercial

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