Why is the sea not getting saltier?

Every year rivers carry millions of tonnes of salt and minerals into the ocean. So why isn't the ocean getting saltier and saltier? Scientists have various explanations involving sediments and vents on the sea floor. I would like to put forward another explanation which I believe has been overlooked.

Seaweed.

Just as our kidneys filter our blood and keep the salt in our bodies at the right level, I believe that the great seaweed and kelp forests of the world act as the kidneys of the sea, constantly filtering the water and keeping the salt in balance.

"The sea is a living body. Like any living body it has organs. The seaweed is the organ that manages salt." — from my notebook, 1996

Evidence

1. Seaweed tastes salty. This shows it is absorbing salt from the water.
2. Seaweed washed up on the beach (called "wrack") leaves a white salt crust as it dries. This is the salt the seaweed has removed from the sea.
3. Beaches with a lot of seaweed feel "softer" to swim at. Beaches with no seaweed feel "harsher". I have recorded this at over 30 beaches.
4. Seaweed has existed for over a billion years. The sea has stayed salty but not too salty for that whole time. This is not a coincidence.

Beach Wrack - Leave It Alone!

Some councils rake the seaweed off beaches to make them look tidy for tourists. This is a mistake. The wrack is the seaweed doing its job, carrying salt up onto the beach where it can be held in the sand and dunes. When you remove the wrack you are interrupting the salt cycle.

Anything that gets between the seaweed and the beach will upset the balance. This includes groynes, seawalls, rock walls and breakwaters.

What You Can Do

Do not remove seaweed from beaches
Learn the names of your local seaweeds
Keep a notebook of how the water feels when you swim
Tell your friends about the kidneys of the sea!

I am not a marine biologist and I do not have a university degree. But I have been watching the sea for 40 years and I trust my own eyes.

Links

» The Living Salt Page - very interesting work on salt and memory
» Fungal Salt Barriers - mycelium experiments
» Masaru Emoto - water crystals
» Kelp forests (Wikipedia)