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The Coastal Ocean

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Title: Chapter 11: The coastal ocean Author: Darlene S. Richardson Last modified by: Jamey Created Date: 3/17/2004 3:19:37 PM Document presentation format – PowerPoint PPT presentation

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Title: The Coastal Ocean


1
The Coastal Ocean
2
  • Coastal waters support about 95 of total biomass
    in ocean
  • Most commercial fish caught within 320 km (200 m)
    from shore
  • Important also for shipping, oil and gas
    production, and recreation
  • Many pollutants found here thats a problem!

http//www.safmc.net/Portals/0/shrimp20trawler2.j
pg
3
Characteristics of coastal waters
  • Adjacent to land (to edge of continental shelf)
  • Influenced by river runoff, wind, tides
  • Salinity variable
  • Freshwater runoff
  • Winds
  • Mixing by tides

4
Characteristics of coastal waters
  • Temperature variable
  • Low-latitudes restricted circulation, very warm
  • High-latitudes sea ice
  • Mid-latitudes
  • Seasonal changes
  • Prevailing winds

5
Types of coastal waters
  • Estuary
  • Partially enclosed coastal area with ocean water
    and freshwater (runoff) mixing mouths of rivers,
    bays, etc.
  • Lagoon
  • Shallow coastal water separated from ocean by
    barrier island
  • Marginal sea
  • Relatively large semi-isolated body of water

6
Estuaries - Origin of estuaries
  • Rising sea level drowns what was once land
  • Coastal plain estuary
  • Former river valley now flooded with seawater
  • Fjord
  • Former glaciated valley now flooded with seawater
  • Bar-built estuary
  • Lagoon separated from ocean by sand bar or
    barrier island
  • Tectonic estuary
  • Faulted or folded down-dropped area now flooded
    with ocean

7
Estuaries - Classification of estuaries
  • 4 types - Based on mixing of freshwater and
    saltwater
  • Vertically mixed
  • Shallow, low volume
  • Salinity uniform
  • Slightly stratified
  • Deeper than previous
  • Upper layer less salty lower layer more salty
  • Estuarine circulation
  • Highly stratified
  • Deep, relatively strong halocline
  • Salt wedge
  • Deep, high volume
  • Strong halocline
  • Typical at mouths of deep, high volume rivers

8
Lagoons
  • Water isolated by barrier islands
  • 3 main zones
  • Freshwater zone
  • Transition zone of brackish water
  • Saltwater zone
  • Hypersaline in arid regions

9
Indian River Lagoon
  • Well-mixed due to winds and shallow depths
  • Seasonal changes in salinity, temperature,
    dissolved oxygen
  • Most biologically diverse estuary in north
    americaover 4,000 species of plants and animals
  • Threats habitat destruction, stormwater runoff,
    and invasive exotic species

10
Marginal seas
  • Mostly from tectonic events
  • Ocean crust between continents, e.g.,
    Mediterranean Sea
  • Behind volcanic island arcs, e.g., Caribbean Sea
  • Shallower than ocean
  • Connected to ocean

http//www.shinesforall.com/images/Caribbeanmap.gi
f
11
Caribbean Sea
  • On Caribbean plate defined by Greater and Lesser
    Antilles volcanic island arc
  • Relatively shallow marginal sea deepest is
    Cancun Trough at 7,686 m (25,220 ft)
  • Underlain by oceanic crust

http//woodshole.er.usgs.gov/project-pages/caribbe
an/images/PBATHY1.GIF
12
Coastal Wetlands - Types of coastal wetlands
  • Ecosystems that are saturated with water
  • Swamps, tidal flats, coastal marshes, bayous
  • Salt marsh
  • Any latitude
  • Mangroves
  • Low latitude

13
Characteristics of coastal wetlands
  • Efficiently cleanse polluted water
  • Absorb water from coastal flooding during storms
  • Protect shores from wave erosion

http//soundwaves.usgs.gov/2008/03/WetlandLG.jpg
14
Coastal Wetlands - Loss of coastal wetlands
  • Half of U.S. coastal wetlands lost to development
    (housing, industry, agriculture)
  • U.S. Office of Wetland Protection, 1986
  • Minimize loss of wetlands
  • Protect or restore wetlands

http//www.on.ec.gc.ca/wildlife/factsheets/images/
glfs-coast-stress.jpg
15
Marine pollution
  • Any harmful substance or energy put into the
    oceans by humans
  • Harmful to living organisms
  • Standard laboratory bioassay concentration of
    pollutant that causes 50 mortality among test
    organisms
  • Hindrance to marine activities (e.g., fishing)
  • Reduction in quality of sea water

16
Waste disposal in ocean
  • Diluting pollutants with huge volume of ocean
    water
  • Long-term effects not known
  • Debate about dumping wastes in ocean
  • None at all ??
  • Some, as long as properly disposed and monitored
    ??

17
Main types of marine pollution
  • Petroleum
  • Nutrient excess
  • Sewage sludge
  • Fertilizer runoff
  • DDTs and PCBs
  • Mercury
  • Non-point-source pollution and trash
  • Drainage from roads, canals, etc.

18
DDT and PCBs
  • Pesticide DDT and industrial chemicals PCBs
    (polychlorinated biphenyls)
  • DDT pesticide that was widely used
  • PCBs used in transformers and other areas of
    industry
  • Widespread in oceans
  • Persistent organic pollutants
  • Toxic
  • Long life dissolved in seawater
  • Accumulated in food chain
  • Bioaccumulation its happening in us, also!

19
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20
Bioaccumulation and biomagnification
  • Bioaccumulation organisms concentrate pollutant
    from seawater
  • Biomagnification organisms gain more pollutant
    by eating other organisms

21
DDT
  • Decline in bird populations and thin eggshells
  • Long Island osprey
  • California brown pelican
  • DDT banned in U.S. in 1972
  • Some marine bird populations rebounded

22
Mercury and Minamata disease
  • Methyl mercury toxic to most living organisms
  • Chemical plants, Minamata Bay, Japan, released
    mercury in 1938
  • By 1950 first reported ecological changes
  • By 1953 humans poisoned
  • Neurological disorder numbness, muscle
    weakness, paralysis, coma, congenital defects

23
Non-point-source pollution and trash
  • Not from underwater pipelines
  • Hard to regulate
  • For example, from storm drains
  • Pesticides and fertilizers
  • Road oil
  • Trash

24
Trash from dumping
  • Some trash can be legally dumped far from shore
  • Biodegradable (e.g., food) or
  • Sinkable (e.g., glass, metal)
  • Some trash cannot be dumped
  • Plastic
  • Lightweight (floats)
  • Not easily biodegradable
  • Plastic can incorporate pollutants, such as DDT
    and PCBs

http//www.sciencepunk.com/v5/gallery/greenpeace_t
able.JPG
25
It is up to us!
  • Dont throw trash out your car window
  • Dont leave trash on the beach
  • Dont throw trash off the side of your boat
  • Dont use fertilizers irresponsibly
  • Dont just dump things down the drain without
    reading about proper disposal
  • Get onto people you know that do this!
  • Think of your kids and grandkids!

26
Problems with Contaminants in Oceans
  • Research into immunosuppression and reproductive
    problems in many species
  • Chemicals that are banned in US and other
    countries are still used in others it is 1
    ocean, doesnt matter where it is dumped
  • It will effect us all!

All drains lead to the ocean!
27
Fig. 11.32a,b
28
Misconceptions What have we learned that make
the following statements false?
  • Science and technology can solve all of our
    problems.
  • The Earth can absorb and neutralize any amount of
    waste and pollution over time.
  • Dilution is the solution to the problem.
  • Microorganisms are not important to human
    survival.
  • Local people cannot improve their environments
    it is out of their hands.
  • If we run out of oil and gas we will just find
    more.
  • Earth is both an endless supply of resources and
    a limitless sink for the waste products of our
    society.

29
Ocean Literacy Principles
  • 1.d - Sea level is the average height of the
    ocean relative to the land, taking into account
    the differences caused by tides. Sea level
    changes as plate tectonics cause the volume of
    ocean basins and the height of the land to
    change. It changes as ice caps on land melt or
    grow. It also changes as sea water expands and
    contracts when ocean water warms and cools.
  • 1.h - Although the ocean is large, it is finite
    and resources are limited.
  • 5.f - Ocean habitats are defined by environmental
    factors. Due to interactions of abiotic factors
    such as salinity, temperature, oxygen, pH, light,
    nutrients, pressure, substrate and circulation,
    ocean life is not evenly distributed temporally
    or spatially, i.e., it is patchy. Some regions
    of the ocean support more diverse and abundant
    life than anywhere on Earth, while much of the
    ocean is considered a desert.
  • 5.i - Estuaries provide important and productive
    nursery areas for many marine and aquatic species.

30
Sunshine State Standards
  • SC.6.E.6.1 - Describe and give examples of ways
    in which Earth's surface is built up and torn
    down by physical and chemical weathering,
    erosion, and deposition.
  • SC.6.E.6.2 - Recognize that there are a variety
    of different landforms on Earth's surface such as
    coastlines, dunes, rivers, mountains, glaciers,
    deltas, and lakes and relate these landforms as
    they apply to Florida.
  • SC.912.E.6.6 - Analyze past, present, and
    potential future consequences to the environment
    resulting from various energy production
    technologies.
  • SC.912.L.17.2 - Explain the general distribution
    of life in aquatic systems as a function of
    chemistry, geography, light, depth, salinity, and
    temperature.
  • SC.912.L.17.3 - Discuss how various oceanic and
    freshwater processes, such as currents, tides,
    and waves, affect the abundance of aquatic
    organisms.
  • SC.912.L.17.8 - Recognize the consequences of
    the losses of biodiversity due to catastrophic
    events, climate changes, human activity, and the
    introduction of invasive, nonnative species.
  • SC.912.L.17.11 - Evaluate the costs and benefits
    of renewable and nonrenewable resources, such as
    water, energy, fossil fuels, wildlife, and
    forests.
  • SC.912.L.17.13 - Discuss the need for adequate
    monitoring of environmental parameters when
    making policy decisions.
  • SC.912.L.17.16 - Discuss the large-scale
    environmental impacts resulting from human
    activity, including waste spills, oil spills,
    runoff, greenhouse gases, ozone depletion, and
    surface and groundwater pollution.
  • SC.912.L.17.20 - Predict the impact of
    individuals on environmental systems and examine
    how human lifestyles affect sustainability.
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