Dr. Schmidt explains the world: When the seaweed reacts acidly

A seaweed was found in the Baltic Sea that, according to a report, is 1,402 years old. How can you determine age so precisely?

Exciting question. There are different counting and perspectives when it comes to determining the age of plants. The seaweed is likely to be similar to the oldest known clonal plant, an aspen colony in North America. That brings it to around 80,000 years.

What is called clone plant?

The joke is that they are different plants that are all connected to each other via a network of roots. They are genetically almost identical. However, the individual “seagrass blades” show mutations compared to the original plant. These genetic changes can be used to determine age with some degree of certainty.

Exactly to the year?

I wouldn’t bet on a one or two year difference. But that’s how it will work over the centuries. By the way, there are even more ancient creatures, such as a giant sponge in Antarctica that is said to live to be 10,000 years old.

Can you imagine the mutations in the offshoots like genetic changes in humans from one generation to the next?

Yes, something like that, I think. By the way, if you compare the genome of people living today with that of a Neanderthal, you can also see how much time is necessary for certain evolutionary developments.

Why hasn’t the ancient seaweed been completely eaten away by some sea creatures long ago?

This will happen, but not completely, and it will sprout again from the roots. A pasture is also grazed and then something grows there again.

What role does such seaweed play in the marine ecosystem?

It is a source of food and, in a sense, a nursery. Some species of fish lay their spawn where they are somewhat protected from ocean currents and other nuisances. But asking about the meaning of nature is a pretty anthropogenic view.

Do aquatic plants have a similar function to land plants?

They also carry out photosynthesis, i.e. take CO₂ and produce oxygen. However, further down in the sea this production is not very large, especially since the Baltic Sea is not necessarily one of the clear, transparent seas.

Are such ancient creatures particularly adaptable?

These will be species that can survive in unfavorable environments. The giant sponge in Antarctica has adapted to the extremely poor conditions in very cold water with a moderate food supply. If it gets warm there, it would probably die.

Does this mean that observing such plants could provide insights into global warming and the climate crisis?

This could make sense because this seaweed is obviously quite well adapted to the optimum that human development has achieved over the past 2,000 years. So if the seaweed reacts acidly, we should assume that serious questions arise for us too. Just like it is with other animal and plant species.