Coastal Ecosystems of Martinique

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Coastal Ecosystems of Martinique
Exchange New-York/Marin 2004 Translation by
Daniel Nethery
Micheline Elisabeth-Mesnager, Josiane
Mahieu-Pain, Claude Séraline Base nautique de
South Discover plongée Sainte-Luce, FWI
téléphone 0596 62 46 74
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Part 1

• Martinique

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Martinique, a Caribbean Island
http//www.lib.utexas.edu
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Physical Aspects

• Tropical Climate Temperatures ranging between
  20C and 31C (68F and 88F)
• Two Seasons
• Dry Season (February to May)
• Wet Season (August to November) characterised by
  hurricanes.
• The island belongs to the Caribbean Volcanic Arc.

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Three PrincipalMarine Ecosystems
Photos J. Mahieu-Pain
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Where are they found?

• Along the coast, in particular
• along the Atlantic coast, and
• to the south of the island

Document Ifrecor http//www.environnement.gouv.f
r/ifrecor/domtom/matdmf.htm
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Part 2

• The Three PrincipalMarine Ecosystems

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The Mangrove Swamp
Photos J. Mahieu-Pain
Rhizophora mangle
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The Mangrove Swamp

• A littoral forest covering 1800 hectares (4450
  acres).
• Develops in calm zones.
• Very rich in sediments.
• A special physiology to tolerate a salty
  enviroment in oxygen starved and unstable
  conditions.

Photos J. Mahieu-Pain
Rhizophora mangle
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The Mangrove Swamp
In Marine Life of the Caribbean A.Jones N.
Sefton

• A particular structure

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Living in a Salty and Oxygen-Starved Environment

• The prop-roots of the Rhizophora mangle.
• The pneumatophores (small, woody roots) of the
  Avicennia germinans and Laguncularia racemosa.
• The presence of salt glands to excrete salt.
• The germination of the seeds of the Rhizophora
  mangle on the mother-plant viviparity.

Photos J. Mahieu-Pain
Avicennia germinans
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Roles of the Mangrove Swamp

• Nurseries for numerous species.
• Stablisation of sediments and filtration by
  roots.
• Protection of the coasts against erosion.

In Marine Life of the Caribbean A.Jones N.
Sefton
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A Haven for Numerous Species
Photos J. Mahieu-Pain
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Sea Grass Beds
Photos J. Mahieu-Pain
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Sea Grass Beds

• Submarine prairies of flowering plants covering
  an area of 3900 ha (9600 acres).
• Two dominant species Thalassia testudinum and
  Syringodium filiforme.

Thalassia testudinum
Photos J. Mahieu-Pain
Syringodium filiforme
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The Sea Grasses
Photos J. Mahieu-Pain

• Photosynthetic organisms that live to a depth of
  10m (30ft).
• Accompanied in general by green algae.
• Provide a haven for numerous species,
  particularly during early stages of development.

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Sea Grass Functions
Photos Claude Séraline
Strombus giga

• Retain sediments and so contribute to the
  prevention of erosion.
• Provide a habitat for species with an important
  economic value white sea urchins (Tripneuses
  ventricosus) and conches (Strombus giga).

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The Coral Reef
Photos J. Mahieu-Pain
Montastraea annularis
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The Coral Reef

• 75 km (47 miles) of fringing reef, giving rise to
  a total surface of 150 km2 (60 square miles).

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The Coral Reef

• Rocky formation, constructed by living creatures.
• Requires warm sea temperatures from 20C to 30C
  (68F to 88F) and clear, aerated waters to a
  maximum depth of 60 m (180 ft).
• Associated with the mangrove swamp and sea
  grasses.
• How is the reef constructed?

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The Constituants of the Reef

• Foundation structure coral colonies.
• These are building elements associated with other
  organisms fixed to the colony algae and sponges.

Photos J. Mahieu-Pain
Diploria labyrinthiformis
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What is a Colony?
Photos J. Mahieu-Pain
Diploria labyrinthiformis

• An organised structure of several thousand
  identical animals called polyps.
• The exterior is the only living part of the
  colony.

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The PolypThe Fundamental Element

• Each colony comprises a multitude of identical
  organisms the polyps.
• The polyp is a very simple organism that can be
  compared to a sack with a single opening that
  functions as a mouth-anus surrounded by tentacles
  (a multiple of six).

Photos J. Mahieu-Pain
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Structure of the Polyp

• A simple organism.
• Epidermis with stinging cells cnidoblasts to
  capture prey.

Classification phylogénique du vivant Guillaume
Lecointre et Hervé Le Guyader Ed Belin
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How Does The Polyp Feed?

• The stinging cells paralyse small prey which are
  then ingested
• But this is extremely insufficient!
• The cells of the polyp shelter minuscule algae
  (Zooxanthellae) which undergo photosynthesis.
• 95 of nutrients are provided by these algae.
• In exchange, the polyp provides CO2 and mineral
  substances the term symbiosis is used.

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Birth of a Colony

• Sexual reproduction permits the colonisation of
  new territory.
• The polyps lay eggs.
• A larva forms which is mobile in the water.
• The larva undergoes metamorphosis into a polyp
  which fixes itself to the sea floor.

Photo NOOA http//www.nos.noaa.gov/education/cor
als/coral06_reproduction.html
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From Polyp to Colony

• The polyp, having landed on the sea floor,
  constructs a calcium carbonate skeleton.
• It multiplies through budding or division, an
  asexual mode of reproduction.
• The result a colony of identical individuals
  originating from an initial polyp.

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Functions of the Coral Reef

• Biological large biodiversity.
• Physical protection of the coasts against the
  ferocity of the ocean swell.
• Economic
• Fishing
• Tourism

Photos J. Mahieu-Pain
Diploria labyrinthiformis
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Part 3The Inhabitants
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Biological Diversity
Doc Ifrecor
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Algae

• Red, brown and green algae, always
  photosynthetic.
• Macro algae and micro algae.
• Live fixed, mobile (phytoplankton) or symbiotic
  (corals).
• Proliferation according to availability of
  mineral material.
• Primary Producer at the base of the trophic
  food pyramid.

Photos Claude Séraline
Caulerpa verticilata
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Porifera
Photos J. Mahieu-Pain

• Primitive animals, always non mobile.
• Animals which filter
• The external surface comprises miniscule pores
  which allow water to enter.
• Oxygen and nutrients are retained by the cells.
• Filtered water is released through osculum pores.

Desmosponge
Classification phylogénique du vivant Guillaume
Lecointre et Hervé Le Guyader Ed Belin
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Cnidarians

• Coral which builds the reef, anemones, soft
  coral, jellyfish.
• All species have stinging cells in common,
• cells specialising in the defence of the animal
  and in the capture of prey that they paralyse.

Photo Claude Séraline
Condylactis gigantea
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Segmented Worms

• Soft ringed body.
• Some worms live in a tube or burrowed into the
  sand.
• Have elaborate fanlike or elongated tentacles for
  respiration and nutrition,
• tentacles which retract when the animal is
  threatened.
• Others wander (errants).
• Feed on polyps and other animals.
• Harmful to touch.

Hermodice carunculata
Photo Paul Humann reef creature, ed Ned Deloach
Photos J. Mahieu-Pain
Sabellastarte magnifica
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Molluscs

• A soft body, often protected by a shell.
• The shell is secreted by the mantle.
• They feed themselves
• By filtration (filaments) (oysters) the
  lamellibranchia.
• By digesting vegetable (algae or sea grass) or
  animal (polyps of the gorgonia) material with a
  rough tongue.
• By hunting prey (octopus) which are captured with
  tentical arms.

Cyphona gibbosum
Photos J. Mahieu-Pain
Lima scabra
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Crustaceans

• Have a body covered by a shell.
• In order to grow, the shell must be periodically
  cast aside. The rigid shell is eliminated and
  replaced by another which remains soft for a few
  days.
• After mating, millions of eggs are laid from
  which hatch the larvae which eventually
  metamorphose into adults.
• Body divided into two main parts the tail and
  the cephalothorax (head and thorax).

Photos J. Mahieu-Pain
Periclimenes pedersoni
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Echinoderms

• Echinoderms the sea lily, sea star, serpent
  star, sea cucumber and sea urchins.
• Black Sea Urchins live particularly on the reef,
  the White among the sea grasses.
• Posses a pentagonal symetry
• 5 arms
• 5 teeth in the buccal system
• Eat algae on the coral, therefore aiding its
  development.

Davidaster rubiginosa (haut) Diadema antillarum
(en bas)
Photos J. Mahieu-Pain
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Fish

• Vertebrates with spindle-shaped or even wavy
  bodies.
• Fins propulsion and stabilisation.
• Respiration by gills.
• Herbivores micro- or macroscopic algae.
• Carnivores, predators or not. Important predators
  at the head of the food chain (extremely
  concentrated toxins).

Photos J. Mahieu-Pain
Diodon holocanthus
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Part 4 Environments Worth Protecting
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Fragile Environments

• Highly endemic
• Climatic, natural and human threats

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The Mangrove SwampA Threatened Environment

• Destroyed
• for coastal developments.
• by the overexploitation of resources.
• by the disposal of toxic substances or the
  dumping of waste.

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Coral is Fragile!

• Temperature Rise the zooxanthellae die.
• Reduction of light (turbidity) the algae produce
  less.
• Human traffic, shocks serious disruptions to the
  living surface.
• Chemical products (hydrocarbons, pesticides etc)
  polyps become more fragile.
• Different natural diseases.

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Part 5 New species
Homo delphinus
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And that is all!!Thank you for listening.