Practical Best Practices for Ocean Acidification Monitoring

Practical methodologies and operating procedures for ocean acidification researchers, especially users of the GOA-ON in a Box ocean acidification monitoring kit.

Acknowledgments

Coordination support for this work has been provided by The Ocean Foundation, the IAEA Ocean Acidification International Coordination Centre (OA-ICC), and the NOAA Ocean Acidification Program. In-person coordinating meetings in 2019 and 2024 have been funded by the IAEA OA-ICC. The Ocean Foundation’s coordination and editing time has been supported by the Government of Sweden and an anonymous grantor.

Introduction

Welcome to the Practical Best Practices guide for conducting ocean acidification research with the Global Ocean Acidification Observing Network (GOA-ON) in a Box kit. This kit is a set of sampling and analysis equipment that contains nearly all materials required to obtain “weather-quality” measurements at a fraction of the price of costly conventional monitoring and analysis systems. This guide is centered around using components of the kit, which is comprised of sensors to collect in situ measurements, Van Essen’s CTD-Diver and Sunburst Sensor’s iSAMI-pH, and lab equipment to measure total alkalinity and spectrophotometric pH from discrete water samples. A full list of kit components, suppliers, and U.S. pricing is maintained and periodically updated in this spreadsheet. Yet, many sections will be of general use, such as those on lab management, sample collection, and data management, and some of the practices described for parameter measurements may be applied to other instrument setups.

There exist many other references for ocean acidification and carbonate chemistry research, including the Guide to Best Practices for Ocean CO₂ Measurements. This guide references these resources throughout, and it is not intended as a replacement or update to those SOPs. The aim of this guide is to provide practical approaches to conduct ocean acidification monitoring that enables practitioners to study their coastal waters, address research questions of local importance, and contribute important data to global databases without necessarily having a high level of access to the resources, training, and/or equipment that may be assumed as necessary in other guides. As a result, these practical approaches may not result in the highest accuracy but suitable precision. Yet, the signals in most coastal regions are large enough that these measurements remain valuable and contribute to the important understanding of carbonate chemistry parameters around the ocean. Ultimately, achieving weather-quality measurements of pH and total alkalinity should be possible with the GOA-ON in a Box kit and using these methodologies. As defined by GOA-ON (Newton et al., 2015), the weather objective necessitates an uncertainty of approximately 0.02 in pH and of 10 µmol kg–1 in measurements of total alkalinity (TA).

General Practices

Guidelines for Laboratory Management: Recommendations for safety, efficiency, and quality

Selecting a Research Site: Considerations before finalizing a site

Packing for field sampling: Checklist for field trips

Cleaning Sample Bottles: Clean and store borosilicate bottles for discrete sampling

Field Sampling Sheet Template: Downloadable datasheet

Sensors

Operating the Van Essen CTD-Diver: Collecting salinity, temperature, and depth data

Operating the Sunburst Sensors iSAMI pH Sensor: Measuring pH in the field

iSAMI Frequently Asked Questions: Troubleshooting the pH sensor

Discrete Samples

Water sampling: Collect discrete bottle samples