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Endangered Marine Plants

By Izzy McPhee ; Updated September 21, 2017

The ocean offers a wealth of plant and animal species; each one plays its own special role in the life cycle of the sea. Beneath so much water and waves, it is easy to think that loss of habitat and pollution cannot find marine plants. The thought is wrong. More and more species are becoming endangered or extinct as time passes. From overharvesting to loss of habitat, many marine plant species have become endangered.

Johnson's Seagrass (Halophila Johnsonii)

Johnson’s seagrass grows up to 1 inch in height, as it spreads by runners across the bed of its habitat. The critical habitat of Johnson’s seagrass is scattered from Ft. Pierce Inlet, Florida, all the way down to Miami-Dade, Florida. This seagrass is an important nursery ground for juvenile finfish and shellfish. They also play a part in water clarity, as their roots capture sediment and other debris. Various marine invertebrates take up residence on the grass blades. Johnson’s seagrass also provides an important foraging ground for endangered sea turtles, birds and manatees.

Tumu Berau (Bruguiera Sexangula)

This mangrove plant is listed as critically endangered throughout Singapore. The T. berau grows to 30 meters and boasts knotty, brown-gray bark. It produces yellow to reddish blossoms that are held singly while they wait for birds for pollination. Pollen is released in an explosion to cover the heads of visiting birds. T. berau is used medicinally, as well as for food and timber. This plant is considered the rarest of all Bruguiera.

Marine Brown Algae (Nereia Lophocladia)

Marine brown algae is one of four algae species in the genus Nereia. As of today, this algae has only been found in two places in the Australian coast: Port Phillip Heads and the north and south sides of Muttonbird Island. It is found growing on rocks on the seabed at depths of 5 to 7 meters. It has not been determined why this algae is declining in populations. According to New South Wales Department of Primary Industries, speculation is that an increase of sea urchin grazing and poaching for aquarium use has played a part in its decline in the north. The cause of the algae decline at Coffs Harbor has been determined to be the construction of the breakwall and marina of Muttonbird Island that joins the mainland.