Braving the Intertidal Zone

A floating forest? (Photo by Philippe Reichert)

Mangroves

• they don’t just float
• these trees have extremely complex root systems that keeps both them and their beloved sandy soil from washing out to sea
• mangrove trees thrive in the intertidal zone
• not an easy environment to thrive in at all
• high tides bring in sea water to surround their roots with salt
• then low tides expose the sandy substrate to the sun, causing the water to evaporate but allowing the salt to stay
• high salinity levels like this would quickly kill most plants
• but not the mangroves
• about 110 plant species are considered “mangroves”
• meaning they’re capable of living in these salty swamps
• only a few of these trees are actual members of the mangrove genus, Rhizophora
• this said, even if you went to a mangrove forest and took a species count of the different types of trees in one area
• you would probably only find 3, maybe 4 different species
• this is because mangrove trees are very picky about their environments
• if the salinity is too high chokes off the plant’s vascular system
• or if there is too much predation on seeds
• many species will not survive
• while a select few will do just fine and populate the area

Oysters taking up residence on mangrove roots (Photo by TRY Oyster Women)

• but once mangroves are established in an area
• they provide some important ecological benefits
• for one, they are a great place for oysters to live, as illustrated by the image above
• they also prevent erosion
• and act as sinks for heavy metal water pollutants
• which is why when mangroves are extirpated, it can disturb the toxic sediments
• poisoning the soil and the other organisms in the area

Mangroves are much more than just beautiful natural landscapes. They are the protectors of intertidal zones and home to an array of marine organisms. Perhaps we could take a note from their high salt tolerance.

Here’s to taking life lessons from the natural world.