About Sea Vegetables
What are Sea Vegetables?
Sea Vegetable is perhaps a better way to describe edible seaweeds as the term 'weed' does seaweeds a disservice with it's negative connotations! Sea vegetables, or seaweeds is an umbrella term for a group of macroalgae (multicellular organisms) that live in salt water, brackish water or freshwater. We refer to them as sea vegetables because they are simply vegetables from the sea!
Different Physical and Chemical Make Up to Land Vegetables
Unlike land plants, seaweeds don’t have roots, but instead a ‘holdfast’ where they attach to shells, other weeds and rocks, and some will just float. Supporting the leaves (also known as fronds or blades) is a stalk (or stipe), connected to the holdfast (in land plants this would be the equivalent of a root system).
The cell structure of seaweeds is different to that of land plants. Each has a different life cycle
All Sea Vegetables Photosynthesize
As land plants do, seaweeds absorb the sun’s energy, nutrients from their environment and practice photosynthesis, absorbing carbon dioxide and releasing oxygen into the atmosphere. Scientists quote the ocean contributes between 50% -85% of the earth’s oxygen. Additionally when they are grown they require neither additional water or fertiliser so this makes them a truly carbon negative food source.
Different Species Found at Different Latitudes and Depths
Seaweeds (macro algae) and algae are found around the world. There are thousands of species which differ vastly from each other, just as land plants do. Different seaweeds grow at different latitudes and also different depths in the ocean. There are three main colour groups – red, green, brown and blue. Macro-algae (seaweeds) are grouped as follows:
- ‘Green seaweeds’ are normally found in shallower salt and fresh waters and tend to favour nutrient rich waters. Sea Lettuce (also known as Ulva) is a delicious green seaweed which is bursting with nutrients and can be used in lots of ways in the kitchen.
- ‘Brown seaweeds’ are almost exclusively found in salt waters, and prefer colder temperatures. Kelp (some can grow up to 60m long) and Wakame are popular edible brown seaweeds.
- Typically ‘red seaweeds’ live at the deeper depths (up to 250m) and mostly prefer warmer waters. Examples of popular edible red seaweeds are karengo (used in sushi), Dulse, Irish Moss and Agar.