It’s the height of summer – time to hit the beach, whether for an afternoon or a week or two. People love the ocean and have always been drawn to it, but as much as it affects us, we affect it, too.
The ocean's health is crucial to the planet’s health – and ours. That’s why the devastating impacts from climate change are so concerning: as the temperatures warm, glaciers melt, and seawater becomes more acidic, as fish and mammals are overfished, the oceans are dying.
Fortunately, many scientists – including those at the Weizmann Institute of Science – are working hard to sound the alarm and find ways to understand what is happening, prevent further damage, and, if possible, heal the harm already done.
Here are just some of the ways Weizmann scientists are helping save our seas:
Prof. Assaf Vardi is often literally at sea, studying phytoplankton and their impacts on the ocean and the climate. While these plantlike, single-celled organisms might seem too tiny to make a big impact, Prof. Vardi says that “even though they make up just 0.5% of Earth’s biomass, phytoplankton rival the planets’ rainforests when it comes to absorbing CO2 and releasing oxygen – they carry out about half the photosynthesis on the planet.”
However, algae sometimes over-reproduce and erupt in mysterious blooms that can cover thousands of miles, suffocating waterways and causing “red tides” that produce deadly neurotoxins.
Interestingly, algal blooms can suddenly collapse and disappear – but why? It turns out that viruses are the culprit, killing off blooms the same way they sweep through cities during an epidemic. Prof. Vardi and Weizmann colleague Prof. Ilan Koren made the first-ever effort to analyze the effect of viruses on algal blooms in the ocean, using satellite data to observe and track changes. As the two explain in an article they wrote for Science 2.0, these “observations from space” allowed them to show that viruses can “eat” a huge algal bloom in just two weeks.
In follow-up research, the duo found that after viruses do their work, some of the blooms’ left-behind bits and pieces get into the atmosphere, where they can affect cloud formation and reduce the sun’s glare – thus impacting our atmosphere and climate.
Profs. Vardi and Koren’s research on algae bloom demise and marine viruses is so important that they were invited to join a voyage on the prestigious Tara research schooner.
In other research, Prof. Aldo Shemesh and a team of Israeli researchers conducted a 5,000-km- (about 3,000-mi-) long ocean survey – from Eilat to the Seychelles, the Gulf of Aden to the Western Indian Ocean – to study acidification.
Because of human-made emissions, CO2 is dramatically increasing not only in the atmosphere, but in the oceans, where it is making the water more acidic. This means that shelled organisms like coral lose the tiny animals that build their skeleton – and provide the vibrant colors and Seussian shapes we so admire – thus resulting in coral bleaching. Bleaching is so worrying because it means the coral is dead. However, in order to measure the scope of the damage going forward, we need a baseline measurement of conditions today.
Prof. Shemesh’s study provided this baseline, meaning that scientists can now track the impact of damage from human activities. As Phys.org reports, Prof. Shemesh provides “a new way to measure how the acidification of water is affecting marine ecosystems over an entire oceanic basin.”
Prof. Vardi is also conducting research in this area: “In order to understand what happens during bleaching, we need to understand what happens to these organisms at the cellular and molecular levels under various conditions.”
To that end, he and Weizmann colleagues, collaborating with MIT, created “coral on a chip.” This system allowed the scientists to examine living coral polyps in the lab – a world’s first. Coral are finicky and notoriously hard to grow, so having a way to study the living animals closely is a boon to understanding how they grow and thrive. (Bonus: In coverage of the research, Wired published a stunning photo of water moving around a coral as it breathes, feeds, and cleans itself.)
“Many corals are running out of time; it is crucial to know how our actions are affecting their survival, and how they affect ours,” Prof. Vardi says. “Our method can help researchers investigate everything from the coral genes that affect survival, to the strategies coral use to build reefs, to their effects on the marine carbon cycle.”
