Marine Marine GrassesGrasses

By: Megan Schmelzle, Mitch Woods, and Kelly CohenBy: Megan Schmelzle, Mitch Woods, and Kelly Cohen

Marine GrassesMarine Grasses

• It is in the plant kingdom.• Marine grasses typically grow along the shores

of protected bays and inlets along the coasts of the Atlantic Ocean, the Pacific Ocean, and the Gulf of Mexico.

• There are two predominant types of marine grasses;

» Marsh Grasses» Sea Grasses

Marsh GrassesMarsh Grasses• Marsh grasses grow in calm bays and along sandy beaches.• Marsh creeks, sounds, and inlets are all part of estuaries,

where seawater meets and mixes with fresh water from the coastal rivers and runoff from the surrounding uplands.

• There are two common types: reed grass and cordgrass.

Reed grass Cord grass

• Short life cycle much of the salt marsh contains dead and decaying marsh grasses.

The products formed from the decay enrich the water with important nutrients.

Plankton feed on these nutrients.

• These plankton are a major food source for other organisms and therefore marshes are the most biologically productive ecosystems in the world.

Environmental ImpactEnvironmental Impact

Reed GrassReed Grass• One abundant type of reed grass is

called Phragmites australis, (the common reed).

• It is a large perennial found in wetlands throughout temperate and tropical regions of the world.

– (perennials are plant that grows through all seasons rather than dying in the winter and regenerating.)

• They are easily identified by their fluffy brown tassels.

• They grow in extensive stands (known as reed beds) and usually in damp ground at the upper edges of estuaries and in other wetlands.

CordgrassCordgrass• Cordgrass is a type of marine grass found along the water’s edge in the intertidal zone.• Grows in the lower intertidal zone which means that it is covered by water during periods of high tides and it can tolerate changes in salinity and temperature.• Species of cordgrass have adaptations that enable them to survive in water that is salty• Special glands are able to excrete salt through the leaves. Salt crystals can be seen and tasted on the surface of cordgrass leaves.

Spartina AlternifloraSpartina Alterniflora Also known as Smooth Cordgrass or Salt marsh Cordgrass.It is native to the Atlantic coast of the Americas from Newfoundland, Canada south to northern Argentina, where it forms a dominant part of brackish coastal salt marshes. Fiddler crabs and mussels live on and around its roots. It can transport oxygen from its leaves through the stems to the roots through a system of air spaces called aerenchyma. Besides providing a supply of oxygen to the roots, it also oxygenates the soil immediately surrounding the plant. The oxygen allows bacteria to live in the soil near the plant's roots, and the bacteria supply nutrients (nitrates, phosphates, sulfates, potassium…) to the cordgrass.

•[This is called a symbiotic relationship]

Environmental ImpactEnvironmental Impact

• InvasivenessInvasiveness– Spartina alternifloraSpartina alterniflora can become an invasive plant, can become an invasive plant,

either by itself or by hybridizing with native species either by itself or by hybridizing with native species and preventing continuation of the pure native strain.and preventing continuation of the pure native strain.

– However, Common reed can also become invasive However, Common reed can also become invasive and is harmful to the and is harmful to the Spartina alternifloraSpartina alterniflora. This is . This is detrimental to the environment because it is not as detrimental to the environment because it is not as productive or beneficial to a salt marsh as cordgrass.productive or beneficial to a salt marsh as cordgrass.

• It also has the ability to break down industrial It also has the ability to break down industrial pollutants that flow into the marshes, releasing pollutants that flow into the marshes, releasing the chemicals as a harmless gas.the chemicals as a harmless gas.

Spartina PatensSpartina Patens

• It is a shorter, more slender species of cordgrass

• It is found in the upper intertidal zone– It gets flooded only during

periods of very high tides.

• It produces flowers and seeds. The flowers are a deep purple from June to October and turn brown in the winter months.

• It is also less tolerant of saltwater than some other marsh grasses.

GlasswortGlasswort• It is another type of marsh grass that is salt-tolerant and

grows in the upper intertidal zone of beaches from Massachusetts to the Gulf Coast.

• The short, thick waxy stems store the fresh water that the plant needs to survive.

• They have a high salt content in their cytoplasm, which dispels the need to eliminate salt

• A common variety of the glasswort is Salicornia.

Dune GrassesDune Grasses• Dune grasses are

planted to retain or increase sand volume.

• These plants stabilize the sand that already exists by reducing the ability of wind to move it elsewhere

• In addition, the plants will – over time - cause more sand to be deposited.

Sea GrassesSea Grasses

• They grow in the shallow subtidal zones along shore.• Sea grass beds are highly diverse and productive

ecosystems. They can harbor hundreds of animals.• There are four commonly recognized species:

» Eel grass» Turtle grass» Shoalgrass» Widgeongrass

Sea Grass EcologySea Grass Ecology• The sheltering canopy of sea grass creates a calm, stable and protected habitat The sheltering canopy of sea grass creates a calm, stable and protected habitat

for a wide assortment of marine life. Grass beds are especially important as for a wide assortment of marine life. Grass beds are especially important as nursery areas for young life stages of marine fish, shrimp and crabs.nursery areas for young life stages of marine fish, shrimp and crabs.

• Healthy green sea grasses provides numerous grazers, such as manatees, sea Healthy green sea grasses provides numerous grazers, such as manatees, sea urchins, and green sea turtles with their main source of food. Most of the sea urchins, and green sea turtles with their main source of food. Most of the sea grass, however, becomes part of the food chain as decaying matter. Microbes, grass, however, becomes part of the food chain as decaying matter. Microbes, shrimp, many fish and invertebrates feast upon the decaying sea grass. Predators shrimp, many fish and invertebrates feast upon the decaying sea grass. Predators visit grass flats in their search for food. visit grass flats in their search for food.

• Sea grasses help other organisms by recycling nutrients, improving water clarity Sea grasses help other organisms by recycling nutrients, improving water clarity and cleaning marine waters of pollutants, aiding the growth of other marine life, & and cleaning marine waters of pollutants, aiding the growth of other marine life, & stabilizing sedimentsstabilizing sediments

• They have leaves, stems and flowers, as well as roots. In healthy sea grass beds, They have leaves, stems and flowers, as well as roots. In healthy sea grass beds, when leaves are lost to storms, grazing, or other natural disturbances, they grow when leaves are lost to storms, grazing, or other natural disturbances, they grow back quickly, But when sea grass roots are damaged, often by motorboat back quickly, But when sea grass roots are damaged, often by motorboat propellers, they may not grow back for years, if ever...propellers, they may not grow back for years, if ever...

Sea Grass Ecology 2Sea Grass Ecology 2

• They are called this because their leaves are long and narrow and are very often green. They often grow in large "meadows” which look like grassland.

• They are photosynthetic, thus limited to growing in the photic zone. They mostly occur in shallow and secluded coastal waters anchored in sand or mud bottoms. They pollinate and complete their entire life cycle underwater.

• Sea grass is crucial to the food-chain: dugongs, manatees, fish, geese, swans, sea urchins and crabs feed on it.

Sea grass distribution shown in redSea grass distribution shown in red

Sea Grass ReproductionSea Grass Reproduction• Sea grasses produce flowers (small structures located at

the base of the plant.)• Pollen from the flowers is dispersed in long threads in

the water.• When the egg cells are fertilized by pollen, seeds are

produced and shed into the water• If they settle on a suitable

substrate, the seeds will germinate.

Eel GrassEel Grass• Grows in protected bays and inlets of the subtidal zone.• The individual plants grow close together forming beds that

provide shelter for mollusks, arthropods, and fish.• Eelgrass is widely distributed in temperate and subtropical

regions. Found along Atlantic coast from Maine to Florida and Pacific coast from Washington to California.

Zostera MarinaZostera Marina

• A.k.a common eelgrass• Grows mainly on sand or fine

gravel in the subtidal zone. They are found in sheltered shallow inlets, bays, estuaries and lagoons.

• Grass like flowering plant with dark green, long, narrow, ribbon shaped leaves 20-50 cm in length with rounded tips

ZosteraZostera Continued Continued

• Zostera beds are important for:– sediment deposition– substrate stabilization– as substrate for epiphytic algae and micro-invertebrates– as nursery grounds for many species of economically important

fish and shellfish.

• Zostera often beds in bay mud in an estuarine setting.

• It is an important food source for several species of birds as well as marine animals.

Turtle GrassTurtle Grass

• Large beds grow in the bays and inlets of warmer waters, along the coasts of Florida and the Gulf of Mexico

• Has underground stems

Called rhizomes– They form an interlocking

mat that helps to stabilize the

sandy seafloor. • They are also home to a variety of sea animals• It is an important source of food for sea turtles

• Turtle grass is often washed ashore in such quantities following storms at sea that it is collected and used as a fertilizer.

ShoalgrassShoalgrassHalodule wrightii

•Shoalgrass ranges from North Carolina, south along the Atlantic and Gulf of Mexico coasts, to the Caribbean. It is also found off of portions of South America, northwestern Africa, Indian Ocean, and the west coast of Mexico.

•It is a colonizer of disturbed area where turtle grass and manatee grass cannot grow. It is often found in waters too shallow or too deep for other sea grasses to grow. Of all the sea grasses shoal grass can withstand the widest range of temperatures and salinities.

•Ecologically the important thing about Shoal Grass is that its roots penetrate an average of four inches into the substrate, thus stabilize offshore sand.

WidgeongrassWidgeongrassRuppia maritima

• Widgeon grass is a completely submerged perennial plant with single or multi-branched stems up to 3 feet long. Leaves are alternate, simple, and thread-like up to 4 inches long with sheaths. Flowers and fruits in clusters at the end of individual stalks. Widgeon grass can live in fresh or brackish water.

• Widgeon grass is a very important wildlife plant with the stems and leaves being heavily utilized by many duck species, especially after its death and decomposition. In addition, many animals call this grass home: amphibians, reptiles, etc.

In Conclusion…In Conclusion…

These amazing and unusual marine plants are clearly crucial to the environment of

the true “Final Frontier.” Without any type of marine grass, it is evident that not only

would the oceans cease to function, but so would life outside the water. It is important

to keep our oceans healthy, as we continue to not only learn, but grow as a

world.

SourcesSources

• http://www.kingston.ac.uk/international/guidance-and-advice/your-home-country/overseas-representatives/

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