marine algae(Seaweeds) are photosynthetic plants that live in seawater.
There are microalgae and macroalgae. The latter has been used as foods, feeds, medicines, industrial materials etc. for a long time and they are also used as an egg-laying and growing environments for many marine resources.
Classification of Seaweeds
- Algae refer to all kinds of photosynthetic organisms. The term “algae” does not limit to a specific type of algae but rather, it is a generic term that covers a very broad range of organisms.
- Algae are divided into two groups, marine algae and fresh water algae, depending on their habitat. Biologically speaking, they are divided into two groups, micro-algae and macro-algae.
- There are 40,000 different types of known algae around the world but according to a different source, it is possible that there are 4-8 times more algae than the known algae. (Norton et al. 1996)
- Algae are mostly micro-algae that are single celled and are called plant plankton. They are an important part of the marine ecosystem as they are fundamental sources of the food chain. Macro-algae are divided into three groups, greem algae, red algae, and brown algae, depending on their color and these are what we call “seaweeds.” Micro-algae have similar characteristics as land plants such as photosynthesis but as they live under the sea where there are water, Co2 and other nutrients, they are more effective when turning the solar energy into a biomass.
- There are about 500 different types of seaweeds that the human races uses and those that are industrially used are Kelp, Sea Mustard, Porphyra, Gelidium, Gracilaria, Petrocladia, etc.
Microalgae and Macroalgae Differences
|Size||Macroalgae||Visible in human eyes|
|Taxonomy||Everything except brown algae||Green algae, brown algae and red algae|
|Habitat||Seawater and freshwater||Mostly seawater|
|Examples||Freshwater - Chiorella, Scenedesmu etc.
Seawater – Tetraselmis, Nannochloropsis etc.
|Kelp, Sea Mustard, Porphyra, Gelidium, Gracilaria, Petrocladia, etc.|
|Production method||Indoor, by using a chemostat||Standard method of cultivation|
Their global distribution map is like the above. Seaweeds that are used for cultivation are limited to 5 types, more specifically; red algae such as Porphyra, Eucheuma, and Gracilaria and also brown algae such as Laminaria and Undaria.