Aquatic Biodiversity

Chapter 8

Why do we live on the planet Earth?Should it be called the planet ocean?

Core Case Study: Why Should We Care about Coral Reefs?

Read the core case study, “Why should we care

about the Coral Reefs. P. 126

List five (5) economic and environmental

services coral reefs provide. (10 total)

Core Case Study: Why Should We Care about Coral Reefs? (2)

Degradation and decline• Coastal development• Pollution• Overfishing• Warmer ocean temperatures leading to coral

bleaching occurs when the algae the coral feeds on dies out---

• Increasing ocean acidity

Most of the Earth Is Covered with Water (2)

Aquatic life zones (71 % of the Earth’s surface)• Saltwater: marine • Oceans and estuaries• Coastlands and shorelines• Coral reefs• Mangrove forests

Distribution of the World’s Major Saltwater and Freshwater Sources

So, what causes the tides

90% of all marine species are found in the coastal zone

• Page 130 in book

Fig. 8-5, p. 166

Low tideCoastal Zone

Open Sea

Depth in meters

High tideSun

Sea level

50Estuarine Zone

Euphotic Zone

100

Ph

oto

syn

thes

is

Continental shelf

200

Bathyal Zone 500

1,000

Twil

igh

t

1,500

Water temperature drops rapidly between the euphotic zone and the abyssal zone in an area called the thermocline .

Abyssal Zone

2,000

3,000

4,000

Dar

knes

s

5,000

10,000

0 5 10 15 20 25 30

0

Water temperature (°C)

Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (2)

Key factors in the distribution of organisms• Temperature• Dissolved oxygen content• Availability of food• Availability of light and nutrients needed for

photosynthesis in the euphotic, or aphotic

Major Ecological and Economic Services Provided by Marine Systems

Fig. 8-4, p. 165

Marine Ecosystems

Economic Services

Climate moderation Food

CO2 absorption Animal and pet feed

Nutrient cycling Pharmaceuticals

Harbors and transportation routes

Waste treatment

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

Coastal habitats for humans

RecreationHabitats and nursery areas Employment

Genetic resources and biodiversity

Oil and natural gas

Minerals

Scientific information Building materials

Ecological Services

NATURAL CAPITAL

Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water (1)

Plankton• Phytoplankton• Zooplankton• Ultraplankton

Nekton

Benthos

Decomposers

Estuaries and Coastal Wetlands Are Highly Productive (1)

Estuaries and coastal wetlands include• River mouths• Inlets• Bays• Sounds• Salt marshes• Mangrove forests• These areas are rich in nutrients and thus are

very biologically productive.

View of an Estuary from Space

Estuaries and Coastal Wetlands Are Highly Productive (2)

Important ecological and economic services• Coastal aquatic systems maintain water quality

by filtering• Toxic pollutants• Excess plant nutrients• Sediments

• Absorb other pollutants • Provide food, timber, fuelwood, and habitats• Reduce storm damage and coast erosion

Some Components and Interactions in a Salt Marsh Ecosystem in a Temperate Area

Fig. 8-7a, p. 167

Herring gulls Peregrine falcon

Snowy egret Cordgrass

Short-billed dowitcher

Marsh periwinkle

PhytoplanktonSmelt

Zooplankton and small crustaceans

Soft-shelled clam

ClamwormBacteria

Producer to primary consumer

Primary to secondary consumer

Secondary to higher-level consumer

All consumers and producers to decomposers

So, what do food webs and light bulbs have in common?

Fig. 8-7b, p. 167

Mangrove Forest in Daintree National Park in Queensland, Australia

Rocky and Sandy Shores Host Different Types of Organisms

Intertidal zone• Rocky shores• Sandy shores: barrier beaches

We find 90% of all species here.

Organism adaptations necessary to deal with daily salinity and moisture changes

Importance of sand dunes p. 133

Adaptations for intertidal zone

Cling, hold on Dig in! A clam digs in with its foot.

Fig. 8-9, p. 169

Rocky Shore Beach

Sea star Hermit crab Shore crab

High tide

Periwinkle

Sea urchin AnemoneMussel

Low tideSculpin

Barnacles

Kelp Sea lettuce

Monterey flatwormBeach fleaNudibranch

Peanut worm Tiger beetle

Barrier Beach

Blue crab ClamDwarf olive

High tide

SandpiperGhost shrimpSilversides Low tide Mole

shrimp

White sand macoma

Sand dollar

Moon snail

Beach flea

Peanut worm Tiger beetle

Barrier Beach Blue crab ClamDwarf olive

High tide

SandpiperGhost shrimpSilversides Low tide Mole

shrimp

White sand macoma

Sand dollar

Moon snail

Fig. 8-9, p. 169

Rocky Shore BeachSea star Hermit

crab Shore crab

High tide

Periwinkle

Sea urchin AnemoneMussel

Low tideSculpin

Barnacles

KelpSea lettuce

Monterey flatworm

Nudibranch

Stepped Art

Coral Reefs Are Amazing Centers of Biodiversity

Marine equivalent of tropical rain forests. Coral need fairly shallow water that is warm.

Habitats for one-fourth of all marine species

Natural Capital: Some Components and Interactions in a Coral Reef Ecosystem

Fig. 8-11, p. 171

Gray reef shark

Sea nettle

Green sea turtle

Blue tang

Fairy bassletParrot fish

Sergeant major

Hard corals Algae Brittle star

Banded coral shrimpPhytoplankton

Symbiotic algae

Coney

Coney

ZooplanktonBlackcap basslet

Sponges

Moray eel

Bacteria

Producer to primary consumer

Primary to secondary consumer

Secondary to higher-level consumer

All consumers and producers to decomposers

The Open Sea and Ocean Floor Host a Variety of Species

Vertical zones of the open sea• Euphotic zone What would be expect about

DO in this area of the ocean? What about the water TEMPERATURE?

• Bathyal zone• Abyssal zone: receives marine snow rich in

nutrients Read page 135 on ocean topography• Deposit feeders• Filter feeders

• Upwellings (retro concept) Primary productivity and NPP

Fig. 8-10, p. 170

Ocean Beach Primary Dune

Trough Secondary Dune

Back Dune Bay or Lagoon

Recreation, no building

Walkways, no building

Limited recreation and

walkways

Walkways, no building

Most suitable for development

Recreation

Grasses or shrubs

Bay shore

Taller shrubsTaller shrubs and trees

Case Study: Dams, Deltas, Wetlands, Hurricanes, and New Orleans

Coastal deltas, mangrove forests, and coastal wetlands: natural protection against storms read page 140 on Dams, Deltas and Wetlands.

Dams and levees reduce sediments in deltas: significance?

New Orleans, Louisiana, and Hurricane Katrina: August 29, 2005

Global warming, sea rise, and New Orleans

New Orleans, Louisiana, (U.S.) and Hurricane Katrina

Projection of New Orleans if the Sea Level Rises 0.9 Meter

Chesapeake Bay

Human Activities Are Disrupting and Degrading Marine Systems

Major threats to marine systems • Coastal development• Overfishing• Runoff of nonpoint source pollution• Point source pollution• Habitat destruction• Introduction of invasive species• Climate change from human activities• Pollution of coastal wetlands and estuaries

Threats to marine ecosystems.

Point source or non point source pollution?

Water Stands in Some Freshwater Systems and Flows in Others (1)

Standing (lentic) bodies of freshwater• Lakes• Ponds• Inland wetlands

Flowing (lotic) systems of freshwater• Streams• Rivers

Water Stands in Some Freshwater Systems and Flows in Others (2)

Formation of lakes

Four zones based on depth and distance from shore• Littoral zone most productive zone due,

shallow enough for sunlight to penetrate.• Limnetic zone• Profundal zone• Benthic zone

Fig. 8-14, p. 174

NATURAL CAPITAL

Freshwater Systems

Ecological Services

Economic Services

Climate moderation Food

Nutrient cyclingDrinking water

Waste treatmentIrrigation water

Flood control

HydroelectricityGroundwater recharge

Habitats for many species

Transportation corridors

Genetic resources and biodiversity

Recreation

Scientific information Employment

Distinct Zones of Life in a Fairly Deep Temperate Zone Lake

Phosphates and nitrates are plant nutrients.

Eutrophic lake Rich in nutrients, or has

excess plant nutrients associated with older established lakes. If too rich in phosphates and nitrates the lake might have excess plant and algae growth. Algal blooms

Oligotrophic lake a lake with a low supply

of plant nutrients. Might be associated with a newly formed lake

Freshwater Streams and Rivers Carry Water from the Mountains to the Oceans

Surface water water that does not infilltrate or percolate into the ground

It will

Runoff-freshwater from precipitation and melting snow flows on the Earth’s surface into nearby streams lakes and wetlands.

Watershed-land area that delivers water, sediment and dissolved substances via small streams into larger rivers.

Broad river watershed

Waterfall

LakeGlacierRain and

snowRapids

Source Zone

Fig. 8-17, p. 176

Transition Zone

Tributary

Flood plainOxbow lake

Salt marsh

Delta Deposited sediment

Ocean

WaterSediment

Floodplain Zone

Stepped Art

Freshwater Inland Wetlands Are Vital Sponges (2)

Provide free ecological and economic services• Filter and degrade toxic wastes• Reduce flooding and erosion• Help to replenish streams and recharge

groundwater aquifers• Biodiversity• Food and timber• Recreation areas