Marine Science: Ecosystems

What Is An Estuary?

Where salt and fresh water meet

What Does Brackish Mean?

A body of water has less salt in it than salt water, but it also isn’t fresh water

What Are Estuaries Influenced By?

• Tides

• Coriolis effect

• Currents

• Storm surges

• Wind

• Global warming

• Rain

• Melted water

• Dams

• What Are Human Uses Of Estuaries?

• Transportation corridors

• Nurseries for wildlife

• Feeding grounds

• Decomposers reside here → sewage dispersal

• Tourism and recreation

• Landfills → waterfront properties

• Harbours and marinas

• Drinking water

• Seafood traps/ fisheries operations

What Are The Physical Aspects Of Estuaries?

• Salinity

• Substrate

• Other

Physical Aspects Of Estuaries: Salinity

• Fluctuates dramatically from place to place and time to time

• Seawater averages around 35ppt salinity while fresh water is 0ppt

• Decreases when moving upstream

• Varies in depth

• Salt wedges form

• Semidiurnal tides and salinity change 4 times a day

• Influences: bottom of the estuary, wind, evaporation, changes in tide, currents, Coriolis effect

Physical Aspects Of Estuaries: Substrate

• Type of bottom

• Soft mud rich in organic material

• Interstitial water is the water between sediment particles

• Anoxic means devoid of oxygen

Physical Aspects Of Estuaries: Other

• Water temperature varies because of shallow water and large SA

• Large amounts of suspended sediments which reduce water visibility and allows little light to penetrate the water

• Particulate material can also clog feeding apparatus of some filter feeders and kill some organisms

What Are The Types Of Estuaries?

• Drowned river valleys or coastal plain

• Bar-built

• Tectonic

• Fjords

Types Of Estuaries: Drowned River

• Most common type

• Eg: Chesapeake Bay, mouths of Delaware and St. Lawrence rivers

Types Of Estuaries: Bar-Built

• Sediments along the coast accumulate and build sand bars an barrier islands

• Theses act as walls between the ocean and fresh water from rivers

• Found along the Texan coast of the Gulf of Mexico, North Caroline coast, North Sea coast

Types Of Estuaries: Tectonic

• Created because of the land sinking or subsiding as a result of movements of the crust

• Found at San Francisco Bay in California

Types Of Estuaries: Fjord

• Created when retreating glaciers cut deep valleys along the coast

• Valleys were partially submerged when the sea level rose, now rivers flow into them

• Common in southeastern Alaska, British Columbia, Norway, southwestern Chile, south island of New Zealand

What Is The Productivity And Function Of Estuaries?

The mixing of lighter fresh water and heavier salt water traps and circulates nutrients to be recycled by benthic (bottom dwelling) organisms which creates a self-enriching system

What Are Some Habitats That Can Make Up An Estuary?

• Fresh/ brackish marsh and water

• Dunes and vegetated beach ridges

• Sand flats

• Salt marsh and salt pond

• Mudflats

• Oyster and mussel bars

• Rockweed

• Beaches

• Sea bottom

• Shallows

• Seaweed beds

• Eelgrass beds

What Are The Factors Of Estuaries Suffering From Degradation?

• Sedimentation from soil erosion caused by deforestation

• Overgrazing and other poor farming practices

• Overfishing

• Drainage and filling of wetlands

• Eutrophication

• Pollutants including heavy metals, PCBs, radionuclides, hydrocarbons from sewage

• Diking or damming for flood control or water diversion

Estuarine Communities: What Are Mudflats?

• Formed by exposed bottom of an estuary at low tide

• Particle size can vary

• Not much plant life

• Organisms live with regular variations of salinity

• Diatoms and bacteria account for most of the primary production

• Burrowing helps to oxygenate the sediments

• Lots of bivalve here

• Infauna are dominant animals

Estuarine Communities: What Are Salt Marshes?

• Have muddy bottoms

• Held together by roots of marsh plants

• Can develop along sheltered open coasts

• In temperate and subarctic regions and bordered with vast grassy areas

• Dominated by salt-tolerant land plants

• Pacific coast is usually dominated by pickle weeds

Estuarine Communities: What Is Open Water

• Rich variety of fish live in estuaries

• Are commercially important worldwide

• Few fish spend their entire lives in them

• Commercially valuable species use them as nurseries

• Murky water restricts light and has the ability to limit primary production of plankton

Estuarine Communities: What Are Mangrove Forests

• Tropical equivalent of salt marshes

• Survive high salinity levels

• Can reach as far inland as 320km

• Plants are designed to live in water

• 60% to 75% of all tropical shores are fringed with mangroves

What Are The Other Names For The Intertidal Zone

• Foreshore

• Seashore

• Littoral Zone

What Are The Major Problems With Living In The Intertidal Zones?

• Heat stress

• Oxygen exchange

• Wave Shock

• Reduced feeding time

What Is Heat Stress?

Organisms have to deal with extreme environmental conditions

What Is Oxygen Exchange?

Animals don’t have access to much oxygen so they have to hold it in

What Is Wave Shock?

Animals have to hold onto things to not be swept away by the waves

What Is Reduced Feeding Time?

Can’t eat as long/ as much

What Zones Can The Intertidal Zone Be Split Into?

• High tide zone

• Middle tide zone

• Low tide zone

What Does Low Tide Exposure Include?

• Water loss

• Temperature and salinity

• Feeding restrictions

Low Tide Exposure: Water Loss

• Marine organisms dry out when out of water

• Cope by running, hiding, or clamming up

• Tide pools are depressions in rocks that hold sea water

• Seaweed and sessile animals cannot run but many can hide

Low Tide Exposure: Temperature And Salinity

• Temperature is mild and constant because of the high heat capacity of water

• Organisms can tolerate wide temperature ranges

• Evaporation causes salinity to increase

• Salinity fluctuates

• When the tide decreases organisms suffer from the sun’s heat or the freezing cold of winter

Low Tide Exposure: Feeding Restrictions

• Most sessile animals are filter feeders

• Cannot feed when the tide is out

• Mobile animals are grazers

• Grazers scrape algae, bacteria, etc from rocks

• Clamming up prevents them from moving and getting food

• Higher dwellers cannot be under water long

How Do Organisms Cope With Wave Shock?

• Some cannot tolerate wave shock, but can tolerate sediment so they are found in sheltered locations

• Exposed animals tend to have thicker shells

• Byssal: mass of strong silky filaments

• Mussels can move by putting out new byssal threads and detaching old ones

What Are The Parts Of Vertical Zonation?

• Upper intertidal

• Middle intertidal

• Lower intertidal

What Is The Upper Intertidal Zone?

• Seldom submerged

• Must withstand exposure to air

• Above the hightide mark

• Called the “splash zone”

• Dark green mats of cyanobacteria about abundant

• Organisms here may breath air, live out of water form months

What Is The Middle Intertidal Zone?

• Submerged and uncovered by tides

• Diurnal tide: exposed once a day

• Semidiurnal tide: mostly exposed twice a day

• Different heights support different plants and animals

• Mixed tide: tidal pattern where two successive high tides are of different heights

• Disturbances can increase diversity of species in an area

What Is The Lower Intertidal Zone?

• Submerged most of the time

• Feeding for predators is easy here

• Mussels and barnacles are rare

• Dominated by seaweeds

• Grazing is a must

• Kelp mark lower limits

• Subtidal zone: part of the continental shelf never exposed by low tide

What Is Pneumatocyst?

Large float containing gas

How Was Sand Made?

Mechanical forces such as wind, rain, hail, and ice would break the rock into smaller parts with identical chemical properties

What Is Weathering?

• Process that breaks down rocks to produce minerals, nutrients, silica, and oxides of iron and aluminum; these combine into clay.

• The other components are silt and sand (quartz)

What Does Biogenic Mean?

• Living things

• Synthesis of macro molecules

• Life begets life

What Does Abiogenic Mean?

• Non-living things

• Idea that living organisms can be created from non-living matter

• Disproven “false”

What Does Sandy Beach Mean?

A moving river of sand

Where Does A Beach Actually End?

20 meters off shore under the water

What Are Some Types Of Beaches?

• Long stretch

• Large river delta

• Crescent-shaped bay

• Rocky headland

• Lagoons and closed bays

What Are Some Different Kinds Of Waves?

• Ocean surface waves

• Radio waves, mircowaves, infrared waves, x-rays, etc

• Sound waves

• Waves of traffic

• Seismic waves in earthquakes

• Gravitational waves

• Inertial waves

• Matter waves

What Is A Longshore Current?

The movement of sand down the beach

What Is A Rip Current?

Pulls items, sand, and people away from the shore

Why Is It Hard To Stop Beach Erosion?

The beach is no longer flat and we have no way of slowing the waves as they come to the seawall

Why Are Manmade Constructions Considered Temporary?

Towns are throwing their beaches more out of equilibrium and the construction will fall into the ocean eventually

Define The Term Groyne

Traps sand and stops littoral transport

Define The Term Jetty

Wall constructed on each side of an inlet

Define The Term Seawall

Protect land behind the wall not the beaches

What Is Bikini Atoll? (Summary)

An atoll that was a really nice place; however, the USA started to use it as a nuclear testing ground and the island is now uninhabitable as there is so much toxins in the air and ground that no animal or plant can properly live there.

What Are Coral Reef Fish? (Summary)

Coral reefs contain many different sizes and colors of fish. They work together and against each other as predators and pray. Toxicity also plays a factor on how they interact with each other.

What Are The Requirements Of Coral Growth?

• Light

• Warm temperatures

• Sediments

• Steady salinity

• Low pollution

What Are The Three Types Of Coral?

• Fringing reefs

• Barrier reefs

• Atolls

Define The Term Planula

Ciliated larva of cnidarians

What Are Pilot Fish Relationship Benefits?

Nutrients and a place to live

What Are Shrimpfish Relationship Benefits?

Protection from predators

What Are Clown Fish Relationship Benefits?

Brood eggs; drive away predators

What Are Pearl Fish Relationship Benefits?

Live inside other reef dwelling animals

What Are The Three General Categories Of Coloration In Fish?

• Striped

• Spotted

• Motted

What Cell Type Controls Color/ Pigmentation?

Chromatophores

What Cell Type Controls Light?

Bioluminesence

What Is The Role Of Zooxanthellae?

Causes coral to deposit CaCO3 faster, without it they can’t build there skeleton

What Do Reef Fish Feed On?

Organic matter that zooxanthellae make along with zooplankton

What Are Sources Of Calcium Carbonate?

• Coralline red algae

• Coralline algae

• Encrusting algae

• Coral fragments

• Shells

• Skeletons

Define The Term Buttresses

Fore-reef areas exposed to strong winds

Define The Term Algal Ridge

On the outer edge of many reefs, mostly in the Pacific Ocean

What Are The Needs Of Coral?

• Light

• Shallow water

• Nutrients

What Is Coral?

Algae that grows on top of one another

Exoskeleton + Cnidarians =?

Coral

What Is An Exoskeleton?

CaCo2 and limestone

What Are Cnidarians?

Polyp and zooxanthellae

What Are Some Coral Reef Problems?

• Anchoring on reefs

• Pollution

• Landfills

• Storm water run off

• Global warming

• Disease

• Commercial fishing

• Sewage

• Human involvement

• Fertilaizers

How Can We Conserve Coral Reefs?

• Care/ carefulness

• Marine sanctuaries

• Fishing limits

• Worldwide bans

• Communication

• Controlled land development

• Boater education programs

• Studies of remains

• Updating current technologies and information

• Bill to expand marine sanctuaries

What Is A Shelf Break?

A boundary that separates the shelf from the continental slope

What Is A Continental Shelf?

A sloping and mostly flat extension of a continent in the ocean

Where Is The Deepest Continental Shelf Located?

Antarctica

What Does It Mean To Be Tectonically Active?

The tectonic plates shift and causing places to have earthquakes

What Are Some Valuable Resources Found In The Continental Shelf?

• Oil

• Gas

• Minerals

What Are Turbidity Currents?

Dense, sediment currents that flow downslope

What Is Mass Wasting?

Showers and smaller action of material moving down hill

What Is The Pelagic Zone?

• Any water not near the bottom or shore

• Also know as the open-ocean zone

What Are Fish In The Pelagic Zone Called?

Pelagic fish

What Is The Benthic Zone?

The ecological region at the bottom of the sea

What Are The Five Layers Of The Ocean In Order?

1. Epipelagic

2. Mesopelagic

3. Bathypelagic

4. Abyssopelagic

5. Hadopelagic

At What Depth Does The Ocean Become Depleted Of Oxygen?

500m

At What Depth Does The Ocean Become Pitch Black?

4,000m

List 5 Creatures That can Survive In Freezing Water And High Pressure

• Squid

• Basket star

• Swimming cucumber

• Sea pig

• Sea spider

What Is Another Name For The Hadopelagic Layer Of The Ocean?

Abysmal Layer

What Are 4 Main Challenges All Living Organisms?

• Where to live

• What to eat, how to get it

• How to avoid predators

• Where, how, when to reproduce

What Are Two Factors That Every Organism Faces?

• Temperature

• Density

How Do We Classify Pelagic Organisms?

Based on size and locomotion

What Are Microoplankton And When Were They Discovered?

Smallest microscopic forms that were discovered in the last 20 years or so

List The 4 Buoyancy Strategies

1. Size independence

2. Gas containers

3. Floaters

4. Swimmers

List The 5 Types Of Floaters

1. Siphonophores

2. Scyphazoans

3. Tunicates

4. Ctenophores

5. Nekton

What Are The 5 Types Of Caudal Fin?

1. Rounded (AR 1)

2. Truncate (AR 3)

3. Forked (AR 5)

4. Linate (AR 7-10)

5. Heterosexual (Assymetric Sharks)

AR= Aspect Ratio

How Do Marine Animals Adapt To Flucuations In Temperature? What Else Do They Have To Adapt To?

By developing counter current circulation of their blood. They have to also adapt to pressure and oxygen consumption

List 3 Examples Of Behavioural Adaptions By Marine Organisms

1. Schooling

2. Migration

3. Reproduction