Hydrodynamics pertains to the physics of fluid movement and can be a major factor in creating variation within different regions of the rocky intertidal zone.
The rocky intertidal zone can have different coastal morphological features, shaped by waves, erosion, sediment deposit, and tides.
Campus Point, UCSB, is made up of a shore platform, meaning that the rocky shore is sightly sloping or horizontal, and steep, rocky ledges. A shore platform can also be describes as a dissipative surf zone (DSW), and the steep, rocky ledge can be described as a reflective surf zone (RSW). The distinct formations of the rocky intertidal at Campus Point interact with waves and tides in differing ways.
In a 2016 study done on surfzone hydrodynamics in rocky intertidal communities, researchers found that zooplankton had more abundance inside of a DSW area and outside of a RSW area, and early stage barnacle larvae where more abundant outside the surf zone but cyprid barnacles were more abundant inside of the surfzone.
If zooplankton and crypids have a larger presence in a DSW area, so should other small organisms and particles that are transported by the ocean, such as planktonic larvae and nutrients.
Therefore, using the results from the study, at Campus Point biodiversity should be higher in the shore platform region relative to the steep rocky ledges, contributing to spatial zonation. A higher biodiversity helps the shore platform have a greater resilience to ecosystem disturbances and also makes for great tidepooling!
This hypothesis should be easy to test: next time you head out to Campus Point, be sure to take note of how many species you see and where you see them during a low tide. Is there greater species richness and abundance in the shore platform region or in the steep rocky ledge region? Are there any patterns or distinctions between the two regions?
Leave your observations in the comments!
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