SBC LTER: Reef: Benthic Composition Experiment: hourly photon irradiance at the seafloor

Photosynthetically Active Radiation (PAR) sensors measure
photosynthetic light levels in both water and air in micromoles of
photons per meter squared per minute (μmol
m-2 min-1).
PAR light sensors are deployed on the seafloor at the center of
each BCE plot across 5 sampling sites (Arroyo Quemado, Naples,
Isla Vista, Mohawk, Carpentaria) along the Santa Barbara Coast and
2 sites at Santa Cruz Island (San Pedro Point, and Cavern Point).
Sampling began December 2021 and is conducted seasonally every 3
months. An additional sensor is placed in air on the roof at the
Marine Science Biotech building near Campus Point which acts as a
calibration control when analyzing underwater light measurements.
Data collected from these PAR sensors are used to model primary
production by both giant kelp and understory algae in terms of
light availability and to compare the differences between control
and experimental plots cleared of giant kelp. Plot 1 represents
the control plot with no giant kelp removal and plot 2 represents
the kelp clearing plot where all giant kelp are removed.
Additionally, understory algae are removed seasonally from half of
the rock slates for both plots (Plot 1 rock plates #1-6 and Plot 2
rock plates #13-18). Continuous light data are contained in one
table depicting seasonally collected light measurements across all
sites and sampling periods.