Data for: Sea urchin control of macroalgal communities across a productivity gradient

Data sets relate to the surveys and grazer-exclusion experiments performed by Kriegisch, Reeves, Johnson, Ling in Port Phillip Bay Victoria, Australia. The manuscript that describes the data sets is entitled:

"Sea urchin control of macroalgal communities across a productivity gradient"
Kriegisch, N., Reeves, S., Johnson, C., Ling, S. D.*
Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania 7004, Australia
*Corresponding author: [e-mail]
Telephone: [phone]

Data sets are:
1. "0.25m_Quadrat_Pt_Intercept__Algal_Community_PPB.xlsx"
2. "0.25m_Quadrat_Algal_Community_covariates_PPB.xlsx"
3. "Pilot_octocoral_grazer-exclusion_experiment_PPB.xlsx"
4. "Ulva_production_estimates_by_zone_PPB.xlsx"
5. "Procedural_control_octocoral_graer-exclusion_experiment_PPB.xlsx"

Data set (1.) contains survey data - point intercept counts of macroalgae across 3 distinct environmental zones of Port Phillip Bay in Oct/ Nov 2013. Percentage cover of macroalgae was assessed visually by inspecting algae present at each of 50 intersecting points (defined by the intersection of perpendicularly strung wires) within five 0.5 m by 0.5 m metal quadrats placed at 10 m intervals along a single 50 m transect line laid at each of 6 sites within each of the environmentally distinct zones during Spring (October/ November). The intersecting points were then multiplied by two to obtain percentage cover estimates for each macroalgal taxa (resolved to species-level where possible, or genera-level). The total number of intersecting points counted could exceed 50 points (i.e. >100% cover) as algal taxa composing the overstory, understory and substratum were assessed.

Data set (2.) contains co-variates concurrently measured at each survey transect in data set (1.).

Data set (3.) contains data for the pilot octocoral grazer-exclusion experiment. Data is planar percentage cover of macroalgae in grazer-exclusion and background control plots in each of 3 distinct environmental zones of Port Phillip Bay.

Data set (4.) contains Ulva seaweed production estimates in the absence of grazers across the 3 distinct environmental zones of Port Phillip Bay.

Data set (5.) contains data for the procedurally-controlled octocoral grazer-exclusion experiment. Data is planar percentage cover of macroalgae in grazer-exclusion and background control plots in each of 3 distinct environmental zones of Port Phillip Bay.