The eco-geographic distribution of Seagrasses in the entire coast of the Korean peninsula including Jeju Island appears as 14 peak points in the east coast, 11 peak points in the west coast, and 25 peak points in the south coasts and is often composed of single or two classes that create a seagrass field. The type of breeding site varies depending on the appeared classes and coastal zones. Seagrasses in the Korean coastal areas appear in a range of breeding grounds including brackish water, ports in subtidal areas that are shielded from air with little influence from tides, area around ports, or wide bays in the coastal area. They are distributed from low water lines to shallow sandy water in 15 m depth and spread by underground stems to create a large colony like a field. Seagrass groups tend to be clustered around inner bays where tides are smooth so that the movement of seawater is relatively smaller than surrounding water zones. In addition, as seagrasses grow, they change the chemical characteristics of the area.

In general, Zoster marinas, maritime phanerogamous plants create perennial fields through the growth in underground stems and the ramification of branches. Some of Zoster marinas in North America and Europe are annual plants. They might pass inappropriate seasons for breeding in forms of seeds then complete their life cycles within several months, then the entire individual plants including underground stems withered away.
As shown below, seagrasses’ growth was rapidly accelerated from February then started blooming at Wonpo-ri in Yeosu-si on March. In April, they had grown more than 50% in all sea areas. In May, they started to make seeds from fertilized individuals then they grew more than 95%, dropped seeds to the lower levels, and fertilizing stems fall from the rhizomes in June. In July they discarded most of the fertilizing stems and aged leaf blades while one-year-old leaf blades remained growing
After August, the overall growth slowed, then they discarded leaf blades that has impeded photosynthesis activities due to attached mud.

- Provide abundant organic sediments and dissolved oxygen
- Use essential nutrient salts such as nitrogen and phosphorous to use as nutrient source for growth
- Absorb a wide range of heavy metals from the sea water then accumulate them in their leaf tissues
- Improve and ameliorate water quality by controlling the flow of seawater and suspended solids’ diffusion through
   attaching to the individual plants
- Provide creatures places to attach to
- Offer habitats for fishes and invertebrates
- Underground stems in the ground prevent sediments from moving and stabilize them then provide oxygen in anaerobic
   level
- Organic substances created by seagrasses serve as foods for many animals

Dissolved phosphorous and nitrogen are elements that have influence over the growth of seagrasses and are absorbed at the epithelial level of underground stems and leaves. As the amount of absorbed nitrogen is similar to that from soils with root tissues, seagrasses quickly absorb and eliminate excessive inorganic salts pouring from estuarine. They can also prevent an abnormal propagation of phytoplankton or harmful algae and reduce environmental disasters such as eutrophication and red tide.
In addition, seagrasses absorb a variety of heavy metals from seawater and accumulate in leaf tissues and improve water quality by controlling the flow of seawater and suspended solids’ diffusion by attaching to the individual plants

A seagrass field has a wide variety of animals and plants with high productivity and is one of the most prolific ecosystems, producing more than 10ℓ oxygen per unit area (m2), in the world. A seagrass field is used as the source of foods for fish and shellfish, as spawning and breeding grounds. About 3% of seagrasses are consumed by herbivores such as sea urchins and gastropodas and the rest of them create abundant organic sediments and dissolved organic matters after withering and decomposing. The dissolved organic matters are consumed by filter feeders attached to thallus of seagrasses while dissolved sediments serve to be a food source for various invertebrates. There is a huge variety of living creatures in seagrass habitats and they can be largely divided into 8 different species including attaching algae, attaching animals, benthos, invertebrate, fishes and soil microbes and reptiles such as sea turtles and mammalians such as dugongs or manatees.

There are five Zostera marina classes and two Phyllospadix iwatensis in the Korean coast. It is conjectured that all seagrass classes live in Namhae coastal area. Zostera marina is one of the most widespread seagrasses in the world and is distributed throughout all coastal area of Korea. In Namhae coastal zone, it is widely distributed in all areas and creates broad fields compared with other classes.
This experiment uses Zostera marina habitats around Hwayang-myeon, Yeosu si, a pilot district.

Floating-type seagrass cultivating device is a device that links seagrass cultivating beds to keep the same depth of water level with floats and crate artificial habitats for seagrass with a view to restore the surrounding ecosystem and provide habitats for economically valuable fish resources while reducing environmental disasters such as red tide. In addition, by installing artificial reefs on the lower part of the seagrass cultivating beds they offer spawning and dwelling places for fish and shellfish and restore ecosystems around coasts.

After installation we monitored four times over 21 weeks, mostly during low tide using the high water and neap tide when there is a large difference between tides

Monitoring 4 weeks after planting seagrasses into floating seagrass cultivating device (Nov. 11, 2004), it seemed that there was no seagrass loss but they failed to take roots in planting mats. Also there was no withered or dead seagrass. 

On January 27, 2005, 11 weeks after planting seagrasses, we found that cotton wrapped seagrasses mats have larger macrophyte attached than the coir net mats. It seems that as seagrass inhabits sandy mud, it was easier for it to settle down in coir nets which have net structure but in more dense cotton it failed to take root and attracted more macrophyte

At the 3rd monitoring, we found seagrasses planted with coir nets took roots in planting mats. As for cotton-wrapped floating seagrass cultivating device, there are more macrophyte than seagrasses, appearing that there was not enough room for seagrass to live. Also it was observed that seagrasses within 10 weeks still survived but failed to take roots in planting mats 

Seagrasses start growing in March and its growth accelerates in April. The 4th monitoring result showed that as seagrasses growing around floating seagrass cultivating devices started to grow fast, artificially-planted seagrasses gradually withered away. It seemed that as seagrass absorbs growth-affecting elements from soil and seawater through underground stems and epithelial cells on leaves, the artificially-planted seagrasses could not absorb nutrients from soil thereby withering away. Also with the rapid growth of surrounding seagrasses, inorganic salts such as phosphorus and nitrogen were promptly absorbed, the artificially-growing seagrasses could not secure enough nutrients to propagate.