Dataset: Recruitment and Succession
Deployment: Paytan_2010-11

The purpose of this study was to determine how ocean acidification impacts recruitment and development of a benthic reef community using a field site that experiences naturally low drops in saturation state. To mimic the natural karst substrate of the Yucatan, the investigators deployed 40 limestone tiles (15 x 15 cm), acquired from a quarry near Puerto Morelos. Twenty tiles were deployed at each of two sites (Ojo Gorgos and Ojo Laja); 10 in a low saturation zone (Ωarag ~ 1.5) in the direct vicinity of the spring discharge (Center), and 10 in an ambient zone (Ωarag ~ 3.8) about 5 m from the springs (Control). The tiles were bolted to concrete masonry blocks. The investigators deployed the tiles on 28 August 2010, and removed subsets of three randomly selected tiles from each treatment after 3 months (25 November 2010) and 6 months (14 March 2011), and removed the four remaining tiles after 14 months (19 October 2011). Upon removal, the tiles were photographed, fixed in a 4% formalin solution for 48 hours, and then stored in 70% ethanol until analyzed.

The main focus of this study was to determine how acidification may impact community level changes, and specifically, to determine functional differences between the communities inside and outside of the springs. Organisms on the tiles were assigned to eleven functional groups. The tiles were divided into 1.5 x 3 cm subplots on the edges and 3 x 3 cm subplots on the face of the tiles for visual estimates of percent cover. Subplot estimates were then summed for total percent cover. Encrusting foraminifera, molluscs, and polychaetes were counted and measured using a Celestron digital microscope (0.1 mm accuracy).

Sampling and analytical methodology are modeled after:
Kroeker KJ, Micheli F, Gambi MC. 2012. Ocean acidification causes ecosystem shifts via altered competitive interactions. Nature. doi: 10.1038/NCLIMATE1680