A new study published in the journal Current Biology is shedding light on the activities of invertebrate animals that burrow at the bottom of the ocean, known as bioturbation. Researchers have long debated the role of these mud-churning species and how they impact ocean chemistry, carbon sequestration, and marine ecosystems globally. By utilizing global seafloor and seawater data, as well as machine learning techniques, scientists were able to map out the ocean environments where these animals live and determine the factors that shape environmental conditions. The study’s findings suggest that bioturbation is influenced by a combination of factors, including seawater depth, nutrient levels in the water, and sediment composition.
Lead author Shuang Zhang, now an assistant professor at Texas A&M University, highlights the importance of understanding how bioturbation is linked to other aspects of the environment in order to predict how these systems might change in response to climate change. The research revealed that the environmental factors driving deep sea bioturbation differ significantly from those influencing seafloor communities in coastal and shallow ocean waters. In deep ocean waters, factors such as seawater nutrient levels, surface ocean currents, and organic matter enrichment play key roles in shaping bioturbation. These findings have implications for ocean conservation efforts and the development of strategies to protect marine biodiversity.
Co-author Lidya Tarhan emphasizes that the complex relationships sustaining marine life, both today and in Earth’s past, are directly impacted by food supply and other environmental factors. The study’s results indicate that the present global network of marine protected areas may not be sufficient to protect important seafloor processes like bioturbation, and protection measures need to be better tailored to promote ecosystem health. Professor Martin Solan adds that while ocean sediments play a crucial role in maintaining the health of the ocean, only now do researchers have insights into the contribution of bioturbation communities.
The research team discovered that seemingly similar animal behaviors on a global scale can be shaped by entirely different sets of environmental factors, depending on the location and depth of the ocean. For instance, environmental factors influencing deep-sea bioturbation differ from those affecting seafloor communities in coastal and shallow waters. While seawater nutrient levels remain impactful in deep ocean waters, factors such as water depth, sediment type, surface ocean currents, and organic matter enrichment play key roles in shaping bioturbation. These insights provide a better understanding of how marine invertebrates interact with their surroundings and influence global marine ecosystems.
By identifying the variety of ways that animals excavate the seafloor and the different environmental factors that shape their behaviors, researchers can now better predict how these systems may respond to changing environmental conditions. The study’s findings have implications for predicting the impact of climate change on marine ecosystems and developing strategies to mitigate habitat deterioration and protect biodiversity. With funding support from the Natural Environment Research Council and Yale University, this research contributes valuable insights into the importance of bioturbation in maintaining the health and functioning of ocean ecosystems worldwide.
