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The Coastal Biome

By: Denise Moraes

 Fernando de Noronha, an Unesco World Heritage Center (1)

Fernando de Noronha, an Unesco World Heritage Center (1)

The Brazilian coast is 5,200 miles long. Along it, there are many ecosystems. The coastal biome is the combination of ecosystems that exist along the coast, which include mangroves, “restingas”, dunes, beaches, islands, rocky shores, bays, swaps, coral reefs, among others.

Plants, animals and physical aspects change a lot from place to place and, therefore, we cannot talk about common characteristics of animals, plants, soil, terrain and climate. This is why, in this last piece on Brazilian biomes, we will do something different: we will see each of the ecosystems in the coastal biome separately.

Scarlet ibis (2)

Scarlet ibis (2)

Aerial roots (3)

Aerial roots (3)

Mangroves

Mangroves occur in transition areas between land and sea environments. They’re very prevalent in the mouths of rivers (that is, where rivers meet the sea), coves and salt-water lagoons. They take up around 30% of the Brazilian coast.

The soil in mangroves is swampy, black and constantly flooded. It has a layer rich in organic matter, which, under the action of microorganisms, might be reutilized as nutrients.
Mangroves have a dense and intricate vegetation. Trees usually have aerial roots, that is, roots that grow from the trunk of trees. Aerial roots in mangroves are respiratory; they have small holes (pneumatodes) that allow aeration.

In general, the word “mangrove” also refers to the vegetation in a mangrove (ecosystem), which includes Rhizophora mangle (or the “red mangrove”), Laguncularia racemosa (or the “white mangrove”), Conocarpus erectus (or the “buttonwood”), and Avicennia schaeriana (or the “black mangrove”). Algae, lichens, orchids, bromeliads and ferns can also be found at mangroves.

Since mangroves are flooded, they are also the home of many fish, mollusks and crustaceans. Sardines, groupers and mullets live there, besides many shellfish and oysters. It is a true nursery for fish. Some fish are born and remain there until they reach adulthood. When the tide is low, crabs hide in an underground system of tunnels. When the tide is high, they go up the trees.

Seabirds also participate in this ecosystem: if you visit a mangrove, it is likely that you will find herons, scarlet ibis and spoonbills; besides a couple of mammals that seek refuge there, such as the otter and the crab-eating raccoon.

Sea cliff at Torres, RS (4)

Sea cliff at Torres, RS (4)

Rocky shores

Rocky shores are environments which, like the name suggests, are rocks on shores. They are very prevalent along the Brazilian coast: from Maranhão to Rio Grande do Sul.

They are very common where mountains are close to the sea. Sea cliffs and boulders (spherical fragments of rock) are part of the ecossystem.

Most creatures found on rocky shores are related to the sea. They use the rocky shores for fixation or locomotion.

Sponges, sea anemones, crabs, shrimp and sea urchins are some of the animals that live in the ecosystem.

Numerous types of algae (blue, green, red and brown) can also be found in that environment.

Lençóis Maranhenses National Park (5)

Lençóis Maranhenses National Park (5)

Dunes

Dunes are elevations formed by the accumulation of sand transported by the wind. They appear in large sections of dry sand. As they grow, dunes become a larger obstacle for the wind and, thus, accumulate more sand.

There are not many plants and animals on dunes. Only a small number of animals have adapted to the conditions of this wind-ruled environment, but there are a few insects and the tuco-tuco, a sand-digging rodent, that live there.

As to plants, grasses and bushes, such as the “cipó-de-flores”, are common. Plants play an important role in settling dunes, since their roots keep dunes from being dragged by the wind.

Jurubatiba Sandbank National Park (6)

Jurubatiba Sandbank National Park (6)

Restingas

Restingas are combinations of dunes and sandy plains. The vegetation is similar to that of dunes: low and sparse. However, since the ecosystem is larger, restingas have more species than dunes. The Cattley guavas (or Peruvian guavas), cowhorn orchids, lilies, bromeliads, orchids and “sepetibas” are prevalent there.

Crabs, southern black widows, cockroaches, thrushes, owls and tree frogs are some of the animals that inhabit the restingas. But the environment is also filled by other animals: migratory birds, such as the sandpiper and the kelp gull - as well as a few mammals like the elephant seal and the monk seal - use the restingas to rest. Sea turtles also use it to reproduce and spawn.

Photo: Gidsicki/Flickr

Photo: Gidsicki/Flickr


Images:

(1) Photo: Bjorn Christian Torrissen/Wikipedia

(2) Photo: Dario Sanches/Flickr

(3) Photo: deltafrut/Flickr

(4) Photo: Valdiney Pimenta/Wikipedia

(5) Photo: Jonathas Rodrigues/Flickr

(6) Photo: Paulo Noronha/Flickr

Find out more about other Brazilian biomes:

The Amazon biome

The Pantanal biome

The Atlantic Rainforest biome

The Caatinga biome

Cerrado Biome

Southern Plains Biome

Consultancy:

Vânia Rocha, biologist at Fiocruz’s Museu da Vida (Life Museum).
 

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