Marine Ecosystem

MARINE ECOSYSTEM

JOEMAR J. CABRADILLAInstructor I

Ilocos Sur Polytechnic State College

Most of the Earth is Covered with Water

We live on the water planet, with precious film of water, most of it saltwater covering about 71% of the Earth’s surface. Thus, a more accurate name for Earth would be OCEAN.

The aquatic equivalents of biomes are called aquatic life zones. The major types of organisms found in aquatic environments are determined by the water’s salinity- the amounts of various salts such as NaCl dissolved in a given volume of water.

Oceans Provide Ecological &

Economic Resources Climate moderation

CO2 absorption

Nutrient cycling

Waste treatment and dilution

Reduced storm impact (mangrove, barrier islands, coastal wetlands)

Habitats and nursery areas for marine and terrestrial species

Genetic resources and biodiversity

Scientific information

Food

Animal and pet feed (fish meal)

Pharmaceuticals

Harbors and transportation routes

Coastal habitatsfor humans

Recreation

Employment

Offshore oil and natural gas

Minerals

Building materials

EcologicalServices

EconomicServices

Marine Ecosystems

Natural Capital

The world’s ocean occupy most of the Earth’s surface and provide many important ecological and economic services.

As land dwellers, we have a distorted and limited view of the blue aquatic wilderness that covers most of the Earth’s surface. We know more about the surface of the moon than about the oceans.

Which two ecological services and which two economic services do you think are the most important? Why?

1. Coastal ecosystems – includes:estuaries, salt marshes, mangrove swamps, rocky and sandy shores

2. Coral reefs

3. Oceans

Categories of Marine Ecosystem

An area in which fresh water from a river mixes with salt water from the ocean; a transition area from the land to the ocean.Other names: bay, sound, lagoon, harbor, bayou

Estuaries

The Ocean

Area where fresh and salt water mix

River bringing freshwater to the sea

Water is brackish: a mixture of freshwater and saltwater

There is a gradient (gradual change) in the salinity

near the input from the river: 0-5 pptin the middle of the estuary: 5-25pptat the ocean: >25 ppt

(ppt = parts per thousand, a unit for salinity)

Characteristics of Estuaries

Natural Capital

Mobile Bay

Tensaw River

Mobile River

Mobile Bay

Dauphin Island

Gulf of Mexico

What is the approximate salinity in ppt for these locations?

Characteristics of Estuaries

Very nutrient rich ecosystems leads to high productivity and high biodiversity

Fast-moving rivers and waves carry nutrient-rich particles

Sediment settles out in the estuary when the water slows down

It accumulates on the bottom (benthic zone)

Great place for plants to grow!

Functions of Estuaries

1. habitat2. nursery3. fisheries4. recreation

Functions of Estuaries

5. Water purification

6. Flood control (from upstream)

7. Buffer land from hurricanes, absorb storm surge

Loss of coastal wetlands in Louisiana made Hurricane Katrina’s effect worse than it would have been

Plants must be adapted to salty habitat

Estuary Plants and Animals

Cord grass

Eel grass

glasswort – a succulent

Huge variety of animals

Estuary Plants and Animals

Horse shoe crab Mosquito oyster lobster

bass egret Manatee Tern

Marshes are located in a low area that is subject to regular, but gentle tides which commonly dominated by grasses.

(Remember, marshes do not have trees or shrubs

Salt Marshes

Mangrove Swamps

Coastal wetlands located in tropical and subtropical zones; characterized by salt-tolerant trees and shrubs, such as mangrove trees

Mangrove

These are plants of different species (e.g Red Mangrove) with tangled roots that reach above the water line, which form an important habitat for many aquatic animals.

Each Mangrove species has its own environmental niche defined by its tolerance range for two abiotic factors:a. Soil salinityb. Soil oxygen levels

Mangrove Adaptations

Red Mangroves have special roots growing from the tree trunks that hold the plants up off the ground. This allows (prop roots) oxygen to enter the plant through the above ground roots and then move into the below ground roots.

Black Mangroves, in contrast, send out horizontal roots in the soil close to the surface and then grow vertical hollow roots up out of the ground to provide oxygen for the plant. White Mangrove, with no specialized root system are the

most successful of the mangrove species in more oxygenated, fresher water conditions.

Rocky Shores

Also called rocky intertidal zone – there are many places to live in this type of habitat, which means high biodiversity

Organisms must be adapted to wave action, changing tide levels

Rocky Shores

At low tides, there are often tide pools left behind where you can see starfish, anemones, crabs, octopus

Rocky Shores

Monterey flatwormSea lettuce

KelpBarnacles

Mussel

Hermit Crab

Shore CrabSea Star

Anemone

Skulpin

Sea Urchin

Nudibranch

Periwinkle

Low Tide zone

High Tide zone

Rocky Shores

There are a large number of factors that favour the survival of life on rocky shores. Temperate coastal waters are mixed by waves and convection, maintaining adequate availability of nutrients. Also, the sea brings plankton and broken organic matter in with each tide. The high availability of light (due to low depths) and nutrient levels means that primary productivity of seaweeds and algae can be very high. Human actions can also benefit rocky shores due to nutrient runoff.

Rocky Shores

There are also a number of challenges to marine organisms associated with the rocky shore ecosystem. Generally, the distribution of benthic species is limited by salinity, wave exposure, temperature, desiccation and general stress. The constant threat of desiccation during exposure at low tide can result in dehydration. Hence, many species have developed adaptations to prevent this drying out, such as the production of mucous layers and shells. Many species use shells and holdfasts to provide stability against strong wave actions. There are also a variety of other challenges such as temperature fluctuations due to tidal flow (resulting in exposure), changes in salinity and various ranges of illumination. Other threats include predation from birds and other marine organisms, as well as the effects of pollution.

Sandy Shores

Not as much biodiversity as rocky shores – Why?1. not much habitat diversity 2. sand dries out at low tide

Some small things can live in the sand, food for shorebirds

Barrier Islands

Barrier Islands, a coastal landform and a type of dune system, are exceptionally flat or lumpy areas of sand that are parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen.

Barrier Islands

Silverside

Blue Crab

White Sand Macoma

Sand Dollar

Moon Snail

Sand piperMole Shrimp

Ghost Shrimp

Tiger Beetle

Beach Flee

Peanut Worm

Dwarf Olive Clam

Hide Tide Zone

Low Tide Zone

Barrier Islands

Ocean Beach

Intensive recreation,no building

Primary Dune

No direct passageor building

Trough

Limitedrecreation

and walkways

Secondary Dune

No direct passage

or building

Back Dune

Most suitablefor development

Bay orLagoon

Intensiverecreation

Grasses or shrubs Taller shrubs Taller shrubs and trees

Primary and Secondary dunes on gently sloping barrier beaches helps protect land from erosion by the sea. Ideally, construction is allowed only behind the second strip of dunes, and walkways to the ocean beach are built so as not to damage the dunes. This help preserve barrier beaches, and protect building from damage by wind, high tides, beach erosion and flooding from storm surges.

Rising sea levels from global warming may put barrier islands under water for the coming century.

Barrier Islands

Notice the beach erosion. Barrier islands are constantly changing.

Coral Reefs

Coral reefs form in clear, warm coastal waters of the tropics and subtropics . These stunningly beautiful natural wonders are among the world’s oldest , most diverse, and most productive ecosystems. In terms of biodiversity, they are the marine equivalents of tropical rain forest.

Require two things: warm temperatures and sunlight Found between 30°N and 30°S of the equator

Coral Reefs

Corals are animals that belong to the phylum Cnidaria, the stinging-celled animals such as jellyfish and hydra.

Coral polyps resemble small sea anemones with tentacles that can sting and paralyze prey

Coral Reefs

Coral polyps slowly build reefs by secreting a protective crust of limestone (CaCO3) around their soft bodies. When the polyps die , their empty crust remain behind as a platform for more reef growth. The resulting elaborate network of crevices, ledges and holes serves as CaCO3

condominiums for a variety of marine animals.

Polyps in limestone skeleton

Elkhorn Coral

Coral Reefs

ZooxanthellaeCorals live in a

symbiotic relationship with algae called zooxanthellae; the algae are photosynthetic and give the coral food and oxygen; the algae get carbon dioxide and nutrients from the nitrogenous wastes of the coral

Coral ReefsAlthough coral reefs only occupy about 0.1% of the world’s ocean area, they provide numerous ecological and economic services:

1. They help moderate the Earth’s temperature by removing carbon dioxide from the atmosphere.

2. 2. Act as natural barriers that help protect 15% of the world’s coastline.

3. They provide habitat for as many as 1 million species

4. Molecules derived have been used to develop antibiotics and drugs for certain cancers and HIV.

Coral Reefs Destruction

Coral reefs are vulnerable to damage because they grow slowly and disrupted easily.

1. Coral bleaching – when temperatures go above normal, the zooxanthellae (algae) in the coral can be rejected, the coral turns a whitish color and dies .Temperature should only range to 18-30 degrees Celsius.

2. Water Acidity – increasing levels of Carbon dioxide in the atmosphere and ocean which makes polyps harder to create CaCO3

Coral Reefs Destruction

3. Dynamite Fishing4. Moro Ami5. Land Development/ Reclamation Activities6. Loss of Mangrove Forest7. Fish and Coral Trade8. Exposure to UV radiation due to Ozone Depletion.9. Deep Sea Bottom Trawling

Coral Reefs Destruction

Before trawling

After trawlingDeep sea bottom trawling poses the greatest threat to the coral

habitatsIt does not just take away

targeted fish speciesThere is a considerable amount

of by catch and corals are a major part of it

Coral Reefs Destruction

In 2005, 240 experts from 96 countries estimated that 1/5 of the world’s coral reefs are so damaged that they are unlikely to recover. They also projected that by 2050, half of the remaining coral reefs are likely be lost due to climate change, habitat loss, pollution and overfishing. Only about 300 of the world’s 6000 coral reefs are protected (at least on paper) as reserves or parks.

From the book of G. Tyler Miller and Scott Spoolman

Ocean: Deep and Wide

Defining characteristics: light and depth of waterVarying surface of ocean floor: continental shelf, slope, trenches (deepest is Mariana Trench at about 35,000 feet below sea level), plains, geologic features (hydrothermal vents, volcanoes, fault lines that produce earthquakes and tsunamis)

Ocean: Deep and Wide

Characteristics: dark, cold, high pressureHow can anything live there?What is the base of the food chain?Two ways:

1. marine snow – organic particles that settle down from above

2. hydrothermal vents - cracks in the earth that allow hot gases to escape, certain bacteria can make food in these conditions (chemosynthesis)

Ocean: Deep and Wide

Phot

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thes

isTw

iligh

tD

arkn

ess

Euphotic Zone

Bathyal Zone

Abyssal Zone

Depth inmeters

200

2,000

10,000

Open SeaSea level

Coastal Zone

Continentalshelf

Euphotic zone – full sunlight, phytoplankton (the producers), zooplankton, nektonBathyal zone – the twilight zoneAbyssal zone – cold, dark, pressure high, specialized “weird” organisms live hereBenthic zone – all along the ocean bottom, benthos are organisms that live on the bottom of the ocean, filter feeders, scavengers, decomposers

References:American Geological Institute. Environmental Science, Philippine ed. Cengage

Learning Asia Pte Ltd. Philippine Branch. 2014G. Tyler Miller and Scott Spoolman. Introduction to Environmental Science.

Philippine ed. Cengage Learning Asia Pte Ltd. Brookes Cole. 2009Deauna, Melecio C. Et.al.Environmental Science for Philippines Schools. PhilippinesPhoenix Publishing House Inc., 1996Mosteiro, Arnaldo P. Environmental Science: Text-Workbook, 1st ed. Educational Publishing House.Ermita, Manila. 2012.Odum, Eugene P. Fundamentals of Ecology. London W.B. Sauders

Company.1971

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Agyaman ti inkayo panagdengeg..!JOEMAR J. CABRADILLA

Instructor IIlocos Sur Polytechnic State College