Three boats carried scientific sampling equipment during The Ocean Race Europe and the race Prologue, in May - June 2021. In ocean science terminology the racing boats are known as 'Vessels of Opportunity', providing access to direct measurement of ocean conditions outside of routine research and shipping routes.

Over 31 days sailing Ambersail-2, AkzoNobel Ocean Racing and 11th Hour Racing Team measured Essential Ocean Variables including dissolved carbon dioxide levels, sea surface temperature, sea surface salinity and chlorophyll a, from the Baltic Sea, Atlantic Ocean and into the Mediterranean Sea. Two of the boats also collected samples for examination of microplastic pollution levels.

The key findings are summarised below. More detail and background information can be found on the pages Ocean Vitals, Microplastics and Collaborating for Ocean Science.

CArbon dioxide levels in the ocean are increasing

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Ocean carbon dioxide [pCO2] levels measured by the boats align with the long-term increase of carbon dioxide that is impacting the ocean environment.

The northwest area of the Mediterranean Sea where the race route crossed is particularly known to be subject to rapid and drastic responses to climate change.3 The graphic above illustrates how dissolved ocean carbon dioxide1 measured by moored buoys in an area of the northwest Mediterranean has increased since measurements began in 1996. The quality-checked data from the racing boats, noted as a green circle in this graph, support the evidence of this increase. The pattern of increasing atmospheric carbon dioxide is shown in orange [extracted from the Jena Carboscope model2].

In this area, the increase in dissolved ocean carbon dioxide during the first 18 years of this century represents 30% of the increase recorded since pre-industrial (pre 1800’s) levels.4

This has an impact on the chemistry of the ocean as higher levels of dissolved carbon dioxide result in lower pH, i.e. the ocean is becoming more acidic, and the trend in this part of the Mediterranean aligns with the global trend of ocean acidification4. Ocean acidification is the ongoing increase of the acidity (decrease in pH) of Earth's ocean due to the dissolution of anthropogenic carbon dioxide in seawater, which is a major threat to marine life.

1 Data drawn from the Surface Ocean Carbon Atlas [SOCAT]

2 Rödenbeck,C., Keeling R.F., Bakker D.C.E, Metzl N., Olsen A., Sabine C., and Heimann M.: Global surface-ocean pCO2 and sea-air CO2 flux variability from an observation-driven ocean mixed-layer scheme. Ocean Science . 9, 193-216 (2013), doi:10.5194/os-9-193-2013.

3 Giorgi, F. Climate change hot-spots. Geophysical Research. Letters. 33, 1–4 (2006)

4 Merlivat, L., Boutin, J., Antoine, D., Beaumont, L., Golbol, M., and Vellucci, V.: Increase of dissolved inorganic carbon and decrease in pH in near-surface waters in the Mediterranean Sea during the past two decades, Biogeosciences, 15, 5653–5662,, 2018

100% of samples contaminated with microplastic particles

Highest microplastic concentration in the Baltic Sea

36 microplastic samples were collected by the Ambersail-2 and AkzoNobel Ocean Racing boats. 100% of samples contained microplastic particles.

Samples from the Baltic Sea had, on average, the highest microplastic pollution concentrations. Average levels were over double the averages recorded from the Mediterranean Sea and the Atlantic Ocean.

Microplastic pollution is poorly understood and measurements from specific areas are prone to variability over time. The samples collected during the prologue and race courses represent important baseline data for the Baltic Sea, Atlantic Ocean and Mediterranean Sea.

microfibres accounted for over 80% of microplastics found

Microplastic fibres originate from clothes, fragmented fishing gear and car tyres 5 that lose very small thread-like plastic fibres into the environment through washing and abrasion.

The largest proportion of microplastic pollution entering the sea comes from washing of synthetic textiles and from the abrasion of tyres during driving.6

Plastic microfibre pollution is a relatively new area of study that is receiving increasing attention as it is thought to be a major marine pollutant throughout the world. It is estimated that up to 13 million tonnes of synthetic fabric waste are entering the ocean each year, mainly from rivers and coastal sources.7

This has an impact on marine ecosystems and wildlife because microplastic fibres are the most frequent microplastic type eaten by marine animals 8 and therefore of particular concern for ocean biodiversity and human health.

5 Evangeliou, N., Grythe, H., Klimont, Z., Heyes, C., Eckhardt, S., Lopez-Aparicio, S., & Stohl, A. (2020). Atmospheric transport is a major pathway of microplastics to remote regions. Nature Communications, 11.

6 Boucher, J. and Friot D. (2017). Primary Microplastics in the Oceans: A Global Evaluation of Sources. Gland, Switzerland: IUCN. 43

7 Mishra, S., Rath, C.C., & Das, A. (2019). Marine microfiber pollution: A review on present status and future challenges. Marine pollution bulletin, 140, 188-197 .

8Rebelein, A., Int-Veen, I., Kammann, U., & Scharsack, J.P. (2021). Microplastic fibers - Underestimated threat to aquatic organisms? The Science of the total environment, 777, 146045 .

why are measurements from racing boats important?

Imagine if The Ocean Race teams raced without any wind or weather instruments, with no GPS and with no access to wind or weather forecasts.

Compare this to the crisis our ocean is facing. Imagine if scientists had no measurements from the ocean and no idea how conditions were changing. How could they attempt to predict or monitor ocean health and climate trends ?

At a critical time for restoration of the ocean and earth system the data from the racing boats contribute to understanding the complex ocean system by recording high quality direct measurements. Unlike research vessels that sample specific areas over a period of time, the racing fleet's high speed provides an opportunity to capture a snapshot of variables over a short time span. This can support better evaluation of spatial variability at a point in time.

In a wonderfully complex four-dimensional environment like the ocean, a single dataset alone can’t generate all the knowledge we need to address pressing issues. The value of a dataset is realised when it is combined with multidisciplinary observations from all over the globe, from different sources and across different timescales to be integrated into models and assessments.

Such ‘integrated ocean observing’, provides insight into how our earth system is functioning, responding to human pressures such as increasing carbon dioxide and temperature, and changing over time.

From Science to Policy

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The data collected by the boats are processed and quality checked by our scientific partners and made available through open-source global databases.


Importantly, the data quality has been validated for submission to the Surface Ocean Carbon Atlas (SOCAT), which provides an annual update of surface ocean carbon dioxide levels and plays a central role in informing and feeding into the Global Carbon Budget. The Global Carbon Budget forms a basis for Intergovernmental Panel on Climate Change (IPCC) targets and projections and climate negotiations at the Conference of the Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC). Data from The Ocean Race have a unique role within SOCAT products because the fleet races through areas not covered by the traditional ocean observing network (e.g. moored buoys, research or shipping vessels), for which there are typically very few or no observations available.

SDG 14.3.1

The United Nation’s Sustainable Development Goal 14.3.1 Data Portal gathers data about average marine acidity (pH) with the aim of mitigating the impacts of ocean acidification e.g. biodiversity loss, negative impacts on fishing and aquaculture.

Copernicus Marine Service

Copernicus Marine Service is the marine monitoring service of the European Union. It is designed to serve EU policies and international legal commitments related to ocean governance. It caters for the needs of society at large for global ocean knowledge and support of the blue economy, by providing free-of-charge state-of-the-art ocean data and information.


The European Marine Observation and Data Network is a network of organisations supported by the EU’s integrated maritime policy. These organisations work together to observe the sea, process the data according to international standards and make that information freely available as interoperable data layers and data products.

NCEI MicroPlastic database

The NCEI Marine Microplastics product provides access to aggregated global data on microplastics in the ocean.


NOAA's National Centers for Environmental Information (NCEI) hosts and provides public access to one of the most significant archives for environmental data on Earth.