Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

This dataset represents measured marine intertidal habitat temperatures from June to October of 2012 and 2013 on horizontal surfaces in experimentally formed rock clearings and inside two different biogenic habitats dominated by the foundation species Mytilus californianus Conrad 1837, the California mussel, and the turf-forming ‘black pine’ alga, Neorhodomela larix (Turner) Masuda, 1982.

Study sites were embedded within three regions: a high-heat ‘hot spot’ for adult invertebrates living directly on rock surfaces (48° N, Washington, USA), a cooler mid-region (38° N, northern California), and a warm, lower latitude region (34° N, southern California). To account for potentially appreciable variation at the site level, we replicated measurements at two sites within each region that differed in wave exposure, directional orientation, and bedrock type. At each site, we measured habitat temperatures every 30 minutes for roughly 20 weeks in 2012 (June 3–October 15; 135 days) and 2013 (May 27–October 20; 147 days) with small temperature loggers placed in M. californianus beds (4–6 centimeters (cm) deep), N. larix turfs (2–6 cm deep) and in bare rock clearings scraped of biota (N = 4 loggers per habitat per site).

To compare how latitude, shore elevation, and habitat influence the occurrence of stressful high temperatures on rocky shores, we used ecologically relevant assays of physiological stress in intertidal invertebrates that occupy biogenic habitats. We used published studies and experiments to select two temperature thresholds beyond which lethal and sub-lethal stresses were highly likely for multiple rocky shore taxa. We then determined lethal thresholds experimentally for sample populations of a subset of invertebrates commonly found in the relevant habitats: juvenile mussels, Mytilus californianus; the predatory whelks Acanthinucella spirata Blainville, 1832 and Nucella ostrina Gould, 1852; and the herbivorous chink snail, Lacuna vincta Montagu, 1803.

We analyzed patterns in the duration of exposure to habitat temperatures over 35 °C and 26 °C thresholds by latitude, shore elevation, and habitat type. We calculated this response metric as the cumulative hours that habitat temperatures exceeded each threshold over the duration of temperature measurements. For analysis, we used the total hours per 30 days of measurement that habitat temperatures exceeded each threshold.

Data are summarized from files extracted from individual temperature loggers (Maxim thermochron iButtons) deployed in each associated location, as described in Materials and Methods.

Reading counts are different due to differences in hours and days deployed by year (due to shifts in the timing of low tides between years, which affected the dates we affixed and retrieved instruments in the study locations)

For further details see: Jurgens & Gaylord (2018).

BCO-DMO Processing:
- Adjusted field/parameter names to comply with BCO-DMO naming conventions
- Added a conventional header with dataset name, PI names, version date

NSF Award Abstract:
The absorption of human-produced carbon dioxide into the world's oceans is altering the chemistry of seawater, including decreasing its pH. Such changes, collectively called "ocean acidification", are expected to influence numerous types of sea creatures. This project examines how shifts in ocean pH affect animal behavior and thus interactions among species. It uses a case study system that involves sea star predators, snail grazers that they eat, and seaweeds consumed by the latter. The rocky-shore habitats where these organisms live have a long history of attention, and new findings from this work will further extend an already-large body of marine ecological knowledge. The project provides support for graduate and undergraduate students, including underrepresented students from a nearby community college. The project underpins the development of a new educational module for local K-12 schools. Findings will moreover be communicated to the public through the use of short film documentaries, as well as through established relationships with policy, management, and industry groups, and contacts with the media.

Ocean acidification is a global-scale perturbation. Most research on the topic, however, has examined effects on single species operating in isolation, leaving interactions among species underexplored. This project confronts this knowledge gap by considering how ocean acidification may shift predator-prey relationships through altered behavior. It targets as a model system sea stars, their gastropod grazer prey, and macoalgae consumed by the latter, via four lines of inquiry. 1) The project examines the functional response of the focal taxa to altered seawater chemistry, using experiments that target up to 16 discrete levels of pH. This experimental design is essential for identifying nonlinearities and tipping points. 2) The project addresses both consumptive and non-consumptive components of direct and indirect species interactions. The capacity of ocean acidification to influence such links is poorly known, and better understanding of this issue is a recognized priority. 3) The project combines controlled laboratory experiments with field trials that exploit tide pools and their unique pH signatures as natural mesocosms. Field tests of ocean acidification effects are relatively rare and are sorely needed. 4) A final research phase expands upon the above three components to address effects of ocean acidification on multiple additional taxa that interact in rocky intertidal systems, to provide a broad database that may have utility for future experiments or modeling.