Martin Mohrmann - Voice of the ocean
Wednesday April 19th, 15.00-16.00
Interview by: Josefin Hanson and Erik Junkers
Location of interview: Voice of the Ocean office
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Background
Martin Mohrmann is a Baltic marine researcher at Voice of the Ocean (VOTO). He analyzes data collected from the Baltic Sea using sea explorers and sailbuoys equipped with multiple sensors. The sensors typically collect data on pressure, ocean depth, temperature, salinity, and oxygen. Mohrmann works with the different layers of the ocean and checks processes that can mix these layers. For instance, he focuses on ways to mix the bottom layer, which has very low oxygen levels, with oxygen-rich water to improve its condition.
Moreover, VOTO has recently equipped the sea explorers and sailboats with methane sensors to assess how the Nord Stream leak has affected the Baltic Sea. Mohrmann also recognizes the importance of pH data, which affects ocean acidification and can harm shellfish with calcareous shells. While he doesn't work directly with pH-value data, he sees clear uses for it.
In his work, Mohrmann faces challenges such as integrating sensors with software and calibrating them to ensure good data quality. He recommends ordering sensor parts well in advance and making the sensors completely waterproof to achieve accurate data collection. He draws inspiration from plumbers' techniques for making drains tight to improve sensor designs.
Overall, Mohrmann and his team at VOTO strive to better understand the health of the Baltic Sea and protect its diverse marine life amidst ongoing challenges such as eutrophication, climate warming, and microplastic pollution.
Data collection and sensors
VOTO is a data collection platform that leverages various sensors to gather valuable information primarily in Skagerak, Bornholm, and Gottland. Their main objective is to provide the collected data to scientists for further analysis, but they also offer infrastructure support. While they do not rent out their sensors, VOTO's sea explorers and sailboats are equipped with sophisticated technology, including satellite-connected sensors that function in real-time. However, their sensors are primarily used in the ocean and not along the coast.
The users of the data VOTO collects are diverse, ranging from divers interested in water quality to scientists studying oceanic ecosystems. One of the significant challenges faced by VOTO is integrating the collected data with the software. It is crucial to calibrate the sensors for accurate data quality, which can be a daunting task. Some sensors are self-sufficient and require minimal maintenance, while others are more complex and demand continuous attention. Additionally, the growth of algae on sensors can significantly impact the data quality, posing an additional challenge for VOTO to tackle.
Ocean Challenges
One of the most pressing issues facing the oceans today is eutrophication, which leads to reduced oxygen levels. Climate warming is another significant problem that causes a range of consequences, including increased stratification in the Baltic Sea, making it difficult for warm and cold water to mix at depth. This warming is largely caused by increased levels of CO2 and methane in the atmosphere, which also contribute to ocean acidification, negatively impacting biodiversity, particularly calcareous species. Microplastics are yet another critical problem that has detrimental effects on marine biodiversity.
Despite the implementation of various initiatives aimed at addressing these problems, many issues persist and are worsening over time. For instance, the removal of the previous government's place tax raises concerns about its potential impact on the ocean's health. Could it result in an increase in the amount of microplastics present? These are important questions that require further investigation to better understand the complex interactions between environmental policies, human behavior, and the health of our oceans.
Building your own sensor
Mohrmann suggests that ordering sensor parts well in advance is crucial. Ensuring that the sensor is completely waterproof is also essential to achieve accurate data collection. He highly recommends the website https://oceanographyforeveryone.com as a helpful resource for sensor construction.
During his master's thesis, Mohrmann built a temperature sensor using a raspberry pi to collect data. He advises aspiring sensor builders to learn from plumbers' techniques for making drains tight and to incorporate those strategies into their sensor designs.