Predicting Productivity Part 1

Every second breath you take was created by the Ocean

Animals cannot live without oxygen. 

Plants create almost all the oxygen on Earth through photosynthesis. While many people think trees are the planet’s primary source of oxygen, every second breath you take was created by millions of tiny plants floating out in the sea. 

These drifting organisms, called phytoplankton, are mostly too small to see; they use sunlight and carbon dioxide to make food and release oxygen, just like plants on land.  Much of the oxygen produced by phytoplankton remains in the sea.

Fish, snails, corals, horses, humans, and every living animal use oxygen to breathe.

Although breathing looks different beneath the waves. Fish pump water over their gills, jellyfish absorb oxygen through their membrane, and sea cucumbers have a special internal organ called the respiratory tree.

Oxygen is just as vital to ocean animals as it is to land dwellers.

Oxygen also enters the Ocean through atmospheric exchange — the water at the surface is constantly interacting with the atmosphere, exchanging various molecules at this interface.

While atmospheric oxygen remains relatively stable, oxygen levels in the Ocean vary widely from place to place. Some regions, called oxygen minimum zones, naturally have very little. These zones usually lie a few hundred meters below the surface or overlying continental shelves, where bacteria use up oxygen as they break down dead material sinking from above, and where the water is renewed only slowly.

While oxygen minimum zones have existed for millions of years, scientists have observed a global decline in the Ocean’s oxygen over the past few decades. Several factors drive this loss, including human pollution from agricultural and wastewater runoff and increased stratification from ocean warming.

As the climate changes, the surface waters are warming. Warm waters hold less dissolved oxygen than cooler waters, and most of the Ocean’s oxygen is absorbed or created at the surface. Warming surface temperatures also increase stratification between the top layer and the deep sea, preventing oxygen from moving into deeper waters. 

Many of the Ocean’s naturally occurring oxygen minimum zones also appear to be growing. But not everywhere is losing oxygen: in parts of the equatorial Atlantic, oxygen levels have been rising over the past decade. Scientists think this is due to a strengthening equatorial ocean current that carries oxygen-rich water into the region, but many questions remain. 

Drs. Fawcett and Flynn and their team will conduct a holistic survey to determine the controls on oxygen and biogeochemistry in the equatorial Atlantic. Their work will provide a better understanding of why this region has bucked the global trend of oxygen loss, how long that might last, and how the biogeochemistry of the equatorial Atlantic connects to the rest of the Ocean. 

An Interconnected Ocean

The equatorial Atlantic separates the North and South Atlantic and serves as the interface between the different hemispheres, each with distinct physical and chemical properties. For example, the South Atlantic is relatively rich in phosphorus and poor in nitrogen, whereas the North Atlantic is the reverse. 

During the summer and fall in the Northern Hemisphere, the eastern equatorial Atlantic experiences upwelling. Trade winds blow at their strongest, pushing surface waters away from the equator. The displaced surface water is replaced with cold, nutrient-rich water from the Ocean’s depths. These nutrients fuel phytoplankton blooms, providing a feast for zooplankton and small fish that, in turn, sustain larger fish, whales, dolphins, and other charismatic marine organisms. 

The Ocean is connected — what happens in the equatorial Atlantic influences other regions, including the West African Margin (WAM), the continental shelf and coastline along western Africa.

Oxygen along the WAM fluctuates, and some coastal regions experience periods with little to no oxygen. Low oxygen levels can negatively impact fisheries, as fish either die or move away from their typical habitat. Declining fish stocks devastate artisanal fishing communities.

Local fishers lose their livelihood and communities lose their access to reliable food supplies. 

This expedition — the first of two — is part of a larger project to thoroughly evaluate oxygen dynamics along the West African Margin. This science team will examine the controls on oxygen in the equatorial Atlantic and the relationship between its biogeochemistry and that of the West African coastline. Their work will determine how the two regions influence and are influenced by the global ocean system.

Deoxygenation is largely driven by climate change and pollution, yet computational models that project our planet’s future still struggle to capture it adequately, often underestimating the extent of oxygen loss in the Ocean. One reason is that scientists lack the detailed, real-world measurements needed to understand what controls oxygen in the Ocean.

The WAM project addresses this problem by collecting thorough data on the biogeochemistry of the waters off West Africa and what controls oxygen there, with the goal of improving models of how this region is responding to climate change and deoxygenation. The team hopes their research will, in time, inform fishers and help coastal African communities prepare for and respond to deoxygenation.  

The Ocean Biogeochemistry Virtual Institute 

The Ocean Biogeochemistry Virtual Institute (OBVI) is a Schmidt Sciences’ Climate Science program. Schmidt Sciences is a 501 (c) (3) non-profit organization founded by Eric and Wendy Schmidt and a sister organization of Schmidt Ocean Institute. 

Schmidt Sciences focuses across five centers: AI & Advanced Computing, Astrophysics & Space, Biosciences, Climate, and Science Systems. The organization envisions a world where science is bold, collaborative, and provides well-researched solutions for planetary challenges. To meet this goal, they provide grant funding, staff collaboration, and host grantee convenings across their programs. The primary programs are virtual institutes — long-term, global collaborations that bring together scientists from across disciplines to tackle societal challenges. 

OBVI focuses on advancing our understanding of ocean carbon cycling and other critical processes, such as oxygen cycling. The Ocean has captured nearly one-third of human-produced carbon dioxide emissions over the last century. Projects funded by OBVI seek to fill knowledge gaps on how the ocean’s biogeochemistry and animal life are responding to the excess carbon dioxide being absorbed by the system.

Artist-at-Sea, Lidia Lisboa
(From the artist’s website)

Lidia Lisbôa (1970, Vila Guarani – Terra Roxa, PR, Brazil) is an artist. She lives and works in São Paulo. Her artistic practice is fundamentally based on autobiography and everyday experiences, which are currently articulated mainly through drawing, sculpture, crochet, and performance. Among her main solo exhibitions, the following stand out: Fio: Mulher Esqueleto, Sesc Pompeia (2023), Acordelados , Galeria Millan, São Paulo (2022); She has participated in group exhibitions such as Hands: 35 Years of the Afro-Brazilian Hand – MAM – São Paulo-SP (2023), From Brazil – Black Art and Thought – Sesc Belenzinho- São Paulo -SP (2023),  An Ocean to Wash Hands , Sesc Quitandinha Petrópolis- RJ (2023), 37th Panorama of Brazilian Art – Under Ashes, Embers, MAM, São Paulo, SP- Brazil (2022), Flaw of Color , Rio Art Museum, Rio de Janeiro (2022), Carolina Maria de Jesus: A Brazil for Brazilians , Instituto Moreira Salles, São Paulo, SP- Brazil (2021); Hope , Museum of Sacred Art, São Paulo, SP, – Brazil (2021); Substance of the Earth: The Sertão , Slag Gallery, New York, USA; and National Museum of the Republic, Brasília, DF, Brazil (2021);