February 16 th, 2011 Brittanica.com

Mangrove Swamps Also known as tidal forests Have received inadequate attention until recent years

Mangroves Worldwide distribution Between 25 0 North and 25 0 South latitude 75% of coastline in this area has mangroves 25% of all Caribbean coastline has mangroves Mangrove Distribution

Mangrove and Reef Distribution Mangrove DistributionCoral Reef Distribution

Environmental Conditions Mangroves are rooted in anoxic sediment Belowground tissue is subjected to long periods of anaerobic conditions Slows nutrient uptake Allows for accumulation of toxins Mangrove tissue is also exposed to decomposing bacteria

Environmental Conditions Few plant species grow in highly saline environments Those that can are called halophytes Less than 2% of all plant species are halophytes Only 110 sp. of mangroves in the world Mangroves transpire less than other plants, must find a way to conserve water Vadose layer of soil

Adaptations to environment Anoxic sediment Broad roots, shallow depth Root extensions that project into the air Root strategies Root props Knee roots Finer roots

Adaptations to the environment Salt excluders Ultrafiltration systems Store Na+ in vacuoles Salt excreters Salt glands

Zonation Vertical zonation in mangrove species distribution Red- Extend into water Black- Inundated at high tide White- Above high tide line

Red Mangroves Rhizophora mangle Most swamps are dominated by it Extend into water Able to grow roots completely submerged in seawater Extensive prop root system Salt excluder - membrane at root surface Leaves with waxy coating Promotes siltation by slowing wave action Promotes island building

Red Mangroves

Black Mangroves Avicennia germinans In areas not underwater all of the time, only during high tides Soil is very saline and low in oxygen Have vertical pneumatophores in root system Extend above ground Allows them to get oxygen from air Secrete excess salt from leaf glands as crystals Waxy coating

Black Mangroves

White Mangrove Laguncularia racemosa Found only above high tides Soil is very muddy and water-logged or can be sandy Can not stand high moisture levels (like the first two species) Tolerant of high levels of salt Salinity usually increases towards shore Salt excretion via leaf glands

White mangroves

Zonation in Mangrove Swamps in Jamaica (Warner 1968) Five Zones: 1. Fringe Zone 5% of total swamp In water Pure stands of red mangrove 2. Red Mangrove Zone 20-25% of swamp Closed growth, tangled mesh of prop roots Pure stands of red mangrove 3. Transitional Red and Black Zone 5-10% of swamp Dominated by red mangrove, but with black mangrove present

Zonation cont. 4. Mixed Red, Black and White Mangrove Zone 40% of swamp Less than half are red mangrove The rest are black and white mangroves 5. Back Zone 15% of swamp Dominated by black and white mangroves

Functions Important ecological bridge between land and sea Provide protection of land during storms

Functions Important ecological bridge between land and sea Provide protection of land during storms Trap nutrients to help productivity of surrounding sea Trap sediments that would kill coral populations

Functions Important ecological bridge between land and sea Provide protection of land during storms Trap nutrients to help productivity of surrounding sea Trap sediments that would kill coral populations Provides nursery areas for many juvenile reef fishes

Animals of the Mangrove Community Prop roots of red mangroves provide substrate for benthic organisms (algae, sponges, hydroids, tunicates) Mangrove swamps provide critical protected nursery areas for fishes, crustaceans, and shellfish.

Impacts of Mangroves as Nurseries Very few reef species dependent on mangroves Some are dependent: Goliath grouper, Rainbow parrotfish Presence of nearby mangroves does not impact total reef species diversity Total fish biomass significantly impacted by presences of nearby mangroves (up to a 25X increase) Haemulidae Lutjanidae

Impacts of Mangroves as Nurseries Rainbow parrotfish- Scaridae Largest herbivore in Atlantic Ocean (over 1.2 m) Juveniles dependent on mangroves Heavily influence physical structure of coral formations Coral structure = coral community structure

Threats to Mangroves More than half of world’s mangroves have been eliminated Deforestation for shrimp farms Loss of invertebrate food for fishes salinization of freshwater Leads to decline in coastal fisheries Documented in Thailand Antibiotics into oceans *Current rate of mangrove destruction exceeds that of rain forests (~900 sq. mi. per year)

Threats to Mangroves

Global climate change Storms cause seawater to enter freshwater systems Flooding Hypoxia Salt-stress Loss of plant biodiversity Less protection from hurricanes

Salt Marshes Also known as tidal marshes, temperate equivalent of mangrove forests Associated with estuaries Common along Atlantic and Gulf coasts

Salt Marshes Muddy bottom held together by roots of marsh plants Includes creeks and mudflats Experience extreme salinity, temperature changes, and tides

Salt Marshes- Zonation Similar to mangroves Varies due to height relative to tide, geographical location, type of substrate Most common plants: Cordgrasses Stabilizes soil

FIG The aerenchymal tissue allows Spartina to exchange gases, even when surrounded by an anoxic soil. The tissue in this photograph is visible as a series of circular passageways around the periphery. (Photograph courtesy of Mark Bertness.)

Salt Marshes- Conservation Salt marshes are overfished for benthic inverts Trophic cascades Human dredging for development

Deep Water Habitat 84% ocean lies deeper than 2000 m Deep-sea bottoms are mainly sand and mud, but populations exhibit high level of patchiness Bottom currents Larval settlement Animal modification of sediment

Deep Water Habitat Organic matter supplied from primary producers in surface waters Only 2-7% of surface production reaches bottom of North Atlantic gyre Carnivores become less abundant

Adaptations to the Deep Sea Low food supply Sluggish fish, low muscle mass Low metabolic rates Predators with large mouths and stomachs Long guts Low/no light Large eyes Eye placement Gulper eel Barreleyes

Deep sea biodiversity Stable environment Sheer area Larger number of species relative to continental shelf bottoms Difficult to sample

Deep water coral mounds From 30 to m deep Hard coral (without zooxanthellae), sea fans, sea whips Over 2000 spp. Demersal fisheries

Leiopathes sp. Black coral Oldest living organisms in sea? Over 2000 years old

Deep sea vents Hot vents are located near areas of submarine volcanic activity Spew out sulfide-rich water

Deep sea vent biodiversity Large tubeworm Riftia pachyptila Bathymodiolus thermphilus Whoi.edu

Deep sea vent biodiversity Photosynthetic anaerobic bacteria Oxidizes S to obtain CO2 Has photosynthetic pigment that absorbs energy from geothermal radiation Taq polymerase