> **Session No. 15**

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**Course Title: Coastal Hazards Management**

**Session Title: Biological and Anthropogenic Coastal Hazards**

**Author: Stephen Meinhold, University of North Carolina at Wilmington**

> **Time: 50 Minutes**

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**Objectives:**

Objective 15.1 Define the term "anthropogenic," and describe the primary
anthropogenic hazards facing coastal communities.

Objective 15.2 Discuss anthropogenic impacts on estuarine ecosystems.

Objective 15.3 Discuss anthropogenic impacts on coastal wetlands.

Objective 15.4 Discuss anthropogenic impacts on coral reefs.

Objective 15.5 Discuss the impacts of invasive species on coastal
ecosystems.

Objective 15.6 Discuss the impacts of human interference with coastal
processes.

Objective 15.7 Discuss mitigation approaches for anthropogenic hazards.

Objective 15. 8 Describe the occurrence and effects of Harmful Algal
Blooms (HABs) in coastal regions of the United States and possible
management options to minimize the impacts of HABs

**Scope:**

Session 15 continues the discussion begun in Session 14 of manmade
hazards in the coastal zone, focusing on the impacts these hazards may
cause. The session begins with a definition of the term "anthropogenic,"
and the most common sources of anthropogenic hazards, namely development
and pollution. Session 15 then goes on to describe some common
anthropogenic impacts on specific coastal environments, including human
impacts on estuaries, human-caused destruction of wetlands, damage to
coral reefs, the introduction of invasive species, and human
interference with coastal processes. The session concludes with a brief
discussion of harmful algal blooms in the coastal zone

**Readings (for sessions 14 and 15):**

*Instructor and Student Readings:*

Beatley, Timothy, David J. Brower, and Anna K. Schwab. 2002. *An
Introduction to Coastal Zone Management, 2^nd^ Edition.* Washington, DC:
Island Press, Chapter 1 "Introduction," and Chapter 3 "Coastal Pressures
and Critical Management Issues."

Bush, David M., Orrin H. Pilkey, Jr., and William J. Neal. 1996. *Living
by the Rules of the Sea*. Durham, NC: Duke University Press, chapter 5
"Evolving Approaches to Property Damage Mitigation: Focusing on the
Island Front through Engineering and Regulation," and pp. 115-117.

Coch, Nicholas K. 1995. *Geohazards: Natural and Human*. Englewood
Cliffs, NJ: Prentice Hall, Chapter 12 "Waste Disposal," Chapter 13
"Estuarine and Wetland Problems," Chapter 14 "Problems of Mangrove
Wetlands and Coral Reefs," Chapter 15 "Coastal Problems."

Freudenburg, William R. 1997. "Contamination, Corrosion and the Social
Order: An Overview." *Current Sociology* 45(3):19-40.

 

Gramling, Robert and Naomi Krogman. 1997. "Communities, Policy and
Chronic Technological Disasters." *Current Sociology* 45(3):41-58.

> [Note]{.underline}: The publication *Current Sociology* may be
> difficult to access for students at smaller schools. However, the
> publication is typically available through inter-library loan programs
> of most higher education institutions.

*For information on Harmful Algal Blooms:*

The harmful algae page <http://www.whoi.edu/redtide/>

<http://www.ocean.us/documents/docs/BAKDOC6_Mitigating_Natural_Hazzards.doc>

A variety of government and scientific information about HABs can be
found at: <http://www.whoi.edu/redtide/relatedsites/relatedsites.html>

*For information on Non-Point Source Pollution:*

U.S. Environmental Protection Agency <http://www.epa.gov/owow/nps/>

*Additional Readings:*

Baum, Andrew, Raymond Fleming, and Laura M. Davidson.1983. "Natural
disaster and technological catastrophe." *Environment and Behavior*
15:333-354.

Crouch, Stephen Robert and J. Stephen Kroll-Smith. 1991. *Communities at
Risk: Collective Responses to Technological Hazards*. New York: Peter
Lang.

Cutter, Susan. 1993. *Living With Risk*. London: Edward Arnold.

LaPlante, Josephine M. and J. Steohen Kroll-Smith. 1989. "Coordinated
emergency management: The challenge of the chronic technological
disaster." *International Journal of Mass Emergencies and Disasters*
7:116-132.

Levinson, Jay and Hayim Granot. 2002. *Transportation Disaster Response
Handbook*. New York: Academic Press.

National Academy of Engineering. 1986. *Hazards: Technology and
Fairness*. Washington, D.C.: National Academy Press.

Quarantelli, E.L. 1994. "Technological and Natural Disasters and
Ecological Problems: Similarities and Differences in Planning for and
Managing Them." Conference paper:
<http://www.udel.edu/DRC/preliminary/192.pdf>

Shaluf, Ibrahim M.; Fakharul-razi Ahmadun, and Sa\'ari Mustapha. 2003.
"Technological disaster\'s criteria and models." *Disaster Prevention
and Management* 12:305-311.

Waugh, William L. 2000. *Living With Hazards, Dealing With Disasters: An
Introduction to Emergency Management.* New York: ME Sharpe.

**General Requirements**:

The session should be presented as lecture supported by PowerPoint
slides. Class discussion is to be encouraged.

The instructor may begin the session by asking each student to write
down a list of the biological and anthropogenic hazards about which they
aware. Also ask the students to make a list of biology and chemistry
classes they have taken. The instructor may also make an assignment
before class requiring the students to obtain recent job descriptions
and requirements for coastal management positions. Use these lists and
job descriptions to spark class discussion about the scientific
background required of coastal managers. This could lead to a broader
discussion about the role of "science" in coastal hazards management.

Other topics for class discussion include:

-   Discuss the biological and anthropogenic hazards facing your coastal
    community

-   Identify your state level administrative unit responsible for
    addressing nonpoint source pollution

Obtain a copy of your local coastal area management plan and examine and
discuss efforts to manage the human interaction with the coast.

###### PowerPoint Slides

**PowerPoint 15.1** Development Threatens Coastal Environments

**PowerPoint 15.2** High Density Coastal Development

**PowerPoint 15.3** Human Disturbances to Estuaries: Construction

####### PowerPoint 15.4 Dredging in Estuaries

###### PowerPoint 15.5 Channelization of Estuaries

**PowerPoint 15.6** Toxic Substances in Estuaries

**PowerPoint 15.7** Pathogens Entering Estuaries

**PowerPoint 15.8** Nutrient Pollution in Estuaries: Eutrophication

**PowerPoint 15.9** Thermal Pollution in Estuaries

**PowerPoint 15.10** Wetland Clearing

**PowerPoint 15.11** Wetland Conversion to Agriculture

**PowerPoint 15.12** Clearing Wetlands for Development

**PowerPoint 15.13** Draining Wetlands for Irrigation

**PowerPoint 15.14** Wetland Channelization

**PowerPoint 15.15** Siting Industrial Operations in a Wetland

**PowerPoint 15.16** Agricultural Runoff into Wetlands

**PowerPoint 15.17** Agricultural Runoff Causes Waterfowl Embryo
Deformities

**PowerPoint 15.18 C**oral Reefs Indicate Coastal Watershed Health

**PowerPoint 15.19** Coral Reef Degradation

###### PowerPoint 15.20 Dead Coral

**PowerPoint 15.21** Bleaching Hard Coral

**PowerPoint 15.22** Visitors Damage Coral Reefs

####### PowerPoint 15.23 **Lamprey**

**PowerPoint 15.24** Rusty Crayfish

**PowerPoint 15.25** Sea Squirt

**PowerPoint 15.26** Purple Loosestrife

**PowerPoint 15.27** Water Hyacinth

**PowerPoint 15.28** Ballast Water Brings Invasives

**PowerPoint 15.29** Zebra Mussels

**PowerPoint 15.30** Brown Tree Snake

**PowerPoint 15.31** Guam Rail

**PowerPoint 15.32** Adult Nutria

**PowerPoint 15.33** Water Alligator Weed

**PowerPoint 15. 34** Dune Destruction

**PowerPoint 15.35** Beach Renourishment

**PowerPoint 15.36** Beach Scraping: Earthmovers Loading Sand

**PowerPoint 15.37** Equipment with Scraper Blades

**PowerPoint 15.38** Beach Scraping: Regrading and Dressing Slopes

###### PowerPoint 15.39 **Scraped Sand in Place against Seawall**

**PowerPoint 15.40** Groins at Folly Beach, SC

**PowerPoint 15.41** Groins at Work

**PowerPoint 15.42** Inlet and Jetties

**PowerPoint 15.43** Seawall in Front of Private Home

**PowerPoint 15.44** Seawall at Work

**PowerPoint 15.45** Seawall at Folly Beach, SC

**PowerPoint 15.46** Gabion Revetment

####### PowerPoint 15.47 Damaged Gabion

**PowerPoint 15.48** Harmful Algal Bloom

**PowerPoint 15.49** Red Tide

**PowerPoint 15.50** Major HAB-Related Events in the U.S.

**PowerPoint 15.51** Occurrence of Harmful Algal Blooms

**PowerPoint 15.52** Satellite Imagery of Harmful Algal Bloom

Objective 15.1 Define the term "anthropogenic," and describe the primary
anthropogenic hazards facing coastal communities.

**Requirements:**

This Objective is to be presented as lecture, supported by PowerPoint
slides. Class discussion should be encouraged.

The following PowerPoint slides will be used during this Objective:

**PowerPoint 15.1** Development Threatens Coastal Environments

**PowerPoint 15.2** High Density Coastal Development

**Remarks:**

####### Definition of Anthropogenic

-   The term anthropogenic hazard is often used in the sense that
    "people's activities can interact with natural systems and result in
    a hazard." (Coch).

    -   ***Anthro*** for "human"

    -   ***genic*** for "generated by" (Coch)

-   In a human-induced hazard, the harm results from anthropogenic
    activities that **accelerate or alter a normally benign process** to
    cause a problem. (Coch)

    -   A good example of an anthropogenic hazard used in this sense is
        **pollution,** which is caused by human activities that increase
        the concentration of undesirable substances in air and water,
        creating a hazard.

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-   The pressures that are placed on the coastal zone by **increased
    populations and development** are another prime example of an
    anthropogenic hazard.

####### Population and Pollution

-   The dramatic increase in human population is degrading the
    environment ...and increasing injuries, property damage and loss of
    life. (Coch)

> **\[PowerPoint 15.1 Development Threatens Coastal Environments\]**
>
> **\[PowerPoint 15.2 High Density Coastal Development\]**

-   While the direct causes of coastal **environmental quality
    problems** are often difficult to document, evidence is mounting
    that many are **the result of general development patterns.**

    -   **Natural processes of coastal ecosystems are being disrupted**,
        and the ecological and economic values of coastal areas are
        being threatened. Fundamental changes are occurring in the way
        natural systems work and look.

    -   As coastal population grows, many of the qualities that
        initially attracted people to those areas are diminishing.
        Consequently, coastal development and the maintenance of a
        quality environment represent enormous management challenges to
        both public and private interests as we move into the next
        century. (NOAA NOS)

-   As populations become more concentrated, **pollution increases
    dramatically** and waste disposal becomes a major problem. The urban
    concentration of waste cannot be dispersed effectively or diluted by
    winds, rivers or oceans. (Coch)

####### Disturbing Dynamic Equilibrium

-   The phrase "**the balance of nature**" means that natural systems
    maintain a balanced state over long periods, called the dynamic
    equilibrium. A change in one part of the system tends to become
    balanced by change in another part to preserve overall system
    equilibrium.

    -   Even **catastrophic events are "absorbed**" and adjusted for by
        dynamic equilibrium, over the long term.

        -   For example, a severe hurricane may seem to "destroy" a
            coral reef. However, reefs have evolved to be tough,
            wave-resistant structures s long as they have time to
            regenerate and if the surviving corals have favorable living
            conditions. If these conditions are met, the damaged reef
            will regenerate by growing a new layer of live coral over
            the storm-torn rubble.

        -   Other factors can disrupt the dynamic equilibrium however.
            Natural regrowth may be slowed or prevented if pollution
            inhibits new coral growth.

    -   This is one of many ways in which people interfere with natural
        systems that have been in dynamic equilibrium for millions of
        years.

-   Many pure **inland activities can lead to the ecological changes in
    the marine environment**.

    -   Examples include

        -   dam construction,

        -   removal of river water for irrigation,

        -   cutting of forests,

        -   use of chemicals in agriculture,

        -   atmospheric emissions from factories and automobiles,

        -   sewage discharges into lakes and rivers,

        -   and many other impacts that take place hundreds and
            thousands of kilometers away from the seashore.

    -   Sooner or later, these **activities affect the ecology of
        estuaries, bays, coastal waters, and sometimes of entire seas**.

    -   From a broader perspective, we may state that effective
        protection of the water environment is impossible without
        protection of the inland ecosystems and vice versa.

####### Marine Pollution

-   Often the hazard is the result of **marine pollution** from one or
    more of the following **categories:**

    -   **discharge of effluents** and **solid wastes** into the seas
        and oceans (industrial discharge, municipal waste discharge,
        coastal sewage, and others);

    -   **land runoff** into the coastal zone, mainly with rivers
        (including agricultural runoff)---commonly thought of as
        **nonpoint source pollution**;

    -   **atmospheric fallout** of pollutants transferred by the air
        mass onto the seas\' surface. (Source:
        <http://www.offshore-environment.com/anthropogenicimpact.html>)

####### Nonpoint Source Pollution

-   Nonpoint source pollution (NPS) is one of the **most serious
    hazards** facing coastal managers.

-   NPS, unlike pollution from industrial and sewage treatment plants,
    comes from **many diffuse sources**.

    -   NPS pollution is caused by **rainfall or snowmelt** moving over
        and through the ground. **As the runoff moves**, **it picks up
        and carries away** natural and human-made **pollutants**,
        finally depositing them into lakes, rivers, wetlands, coastal
        waters, and even our underground sources of drinking water.

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-   **Pollutants include:**

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-   Excess fertilizers, herbicides, and insecticides from agricultural
    lands and residential areas;

-   Oil, grease, and toxic chemicals from urban runoff and energy
    production;

-   Sediment from improperly managed construction sites, crop and forest
    lands, and eroding streambanks;

-   Salt from irrigation practices and acid drainage from abandoned
    mines;

-   Bacteria and nutrients from livestock, pet wastes, and faulty

> septic systems;

-   Atmospheric deposition and hydromodification are also sources of
    nonpoint pollution.

> (Source: U.S. Environmental Protection Agency)

-   Considerable **government effort** has been placed on **studying the
    consequences** of nonpoint source pollution and all coastal managers
    are now engaged in addressing this hazard with their land use
    planning process.

-   The **Environmental Protection Agency (EPA)** is the federal
    government agency responsible for addressing nonpoint source
    pollution and every state has a corresponding unit addressing this
    hazard.

-   Coastal managers should be closely monitoring the possible location
    of sources of pollution

Objective 15.2 Discuss anthropogenic impacts on estuarine ecosystems.

Requirements:

This Objective is to be presented as lecture, supported by PowerPoint
slides. Class discussion should be encouraged.

The following PowerPoint slides will be shown during this Objective:

**PowerPoint 15.3** Human Disturbances to Estuaries: Construction

####### PowerPoint 15.4 Dredging in Estuaries

###### PowerPoint 15.5 Channelization of Estuaries

**PowerPoint 15.6** Toxic Substances in Estuaries

**PowerPoint 15.7** Pathogens Entering Estuaries

**PowerPoint 15.8** Nutrient Pollution in Estuaries: Eutrophication

**PowerPoint 15.9** Thermal Pollution in Estuaries

###### Remarks:

-   As we learned in an earlier session, the area where a river merges
    with the sea -- an **estuary** --is **very productive
    biologically**.

-   Because they are transitional areas between the land and the sea,
    and between freshwater and saltwater environments, estuaries **can
    be seriously impacted** by any number of **anthropogenic
    activities**.

    -   The greatest threat to estuaries is, by far, their large-scale
        **conversion from natural areas to human uses**. Estuaries are
        drained, filled, dammed and dredged on a regular basis.

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-   These activities result both in the **immediate destruction** and
    loss of estuarine habitats, and **long-term impairment** of
    estuarine water quality and function.

> **\[PowerPoint 15.3 Human Disturbances to Estuaries: Construction\]**

-   Many estuary ecosystems in the United States have been drained and
    converted into **agricultural areas**; others have been dredged to
    improve **navigation**. Many estuaries have been filled as urban
    areas have expanded, bringing **residential** and **commercial
    development**, as well as **industrial** and **power-generating**
    facilities.

-   In some coastal areas, the estuarine habitat **loss is as high as
    60%**. (NOAA National Ocean Service)

######## Dredging and Navigation in Estuaries

####### \[PowerPoint 15.4 Dredging in Estuaries\]

-   **Transportation is a very important function** of estuaries.
    Estuaries provide sheltered harbors for river craft from the
    continental interior and for seagoing vessels.

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-   Deep **navigation channels** within estuaries naturally **fill with
    sediment** that is delivered by rivers and carried inland by tides.
    This requires continual **dredging of the estuary bottom** to
    maintain adequate depth for ships.

    -   Unfortunately, **dredging releases pollutants** at the bottom,
        increases **turbidity**, and creates the problem of moving the
        dredged material to some new location.(Coch)

###### \[PowerPoint 15.5 Channelization of Estuaries\]

######## Artificial Canals

.

-   **Navigation canals** that exist at the seaward edge of estuaries
    detrimentally affect natural estuarine flow, allowing **salt water
    to encroach inland**, converting freshwater and low-salinity marshes
    into high-salinity marshes.

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-   **Salt-intolerant species are extirpated**, leading to **erosion**
    before other species can become established.

-   In addition, the channels are responsible for circulating
    **contaminants** released from oil wells, refineries, and vessels.
    (NOAA National Ocean Service)

**[Pollution\
]{.underline}**

-   Of the remaining estuaries around the world, many are **seriously
    degraded by pollution.**

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-   People have historically viewed estuaries and waterways as places to
    discard the unwanted by-products of civilization. Pollution is
    probably the most important threat to water quality in estuaries.

    -   **Poor water quality** affects most estuarine organisms,
        including commercially important fish and shellfish.

> **\[PowerPoint 15.6 Toxic Substances in Estuaries\]**

-   The pollutants that have the greatest impact on the health of
    estuaries include toxic substances like **chemicals** and **heavy
    metals**, **nutrient pollution** (eutrophication), and **pathogens**
    such as bacteria or viruses.

> **\[PowerPoint 15.7 Pathogens Entering Estuaries\]**

-   **Pathogens** can enter estuaries from many different sources.
    **Storm-water runoff** and improper or inadequate **sewage**
    treatment may all allow disease-causing organisms to enter
    estuaries, affecting the plants and animals that live there, as well
    as the people who may consume them. (NOAA National Ocean Service)

> **\[PowerPoint 15.8 Nutrient Pollution in Estuaries:
> Eutrophication\]**

-   One of the most serious estuarine problems is the increased **input
    of organic waste**, which is rich in nitrogen and phosphorous. The
    sources are **sewage and industry**.

    -   Nutrient pollution often causes **explosive algal growth**,
        which depletes the water of oxygen when the algae die. Toxic and
        foul-smelling compounds may also be produced through this
        process.

    -   Wherever raw sewage, treated sewage, or other organic waste is
        discharged into estuaries or tributary streams, the potential
        exists for **serious reduction of aquatic animals**.

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-   Another, less widely discussed human-caused disturbance in estuaries
    is the introduction of nonnative **or invasive species** into
    estuarine environments, as discussed in a later Objective.

> **\[PowerPoint 15.9 Thermal Pollution in Estuaries\]**

-   One use of water in estuaries is for industrial cooling. After use,
    the water, now much warmer, is returned to the estuary. However,
    when water is heated, the risk of **thermal pollution** exists.

    -   Thermal pollution **reduces the amount of oxygen** that water
        can hold and can kill aquatic organisms.

    -   Thermal pollution can be **minimized with cooling canals**,
        which are open, lined ditches through which water circulates to
        cool.. The cooled water then is released into the estuary.
        (Coch)

Objective 15.3 Discuss anthropogenic impacts on coastal wetlands.

**Requirements:**

This Objective is to be presented as lecture, supported by PowerPoint
slides. Class discussion should be encouraged.

The following PowerPoint slides will be used during this Objective:

**PowerPoint 15.10** Wetland Clearing

**PowerPoint 15.11** Wetland Conversion to Agriculture

**PowerPoint 15.12** Clearing Wetlands for Development

**PowerPoint 15.13** Draining Wetlands for Irrigation

**PowerPoint 15.14** Wetland Channelization

**PowerPoint 15.15** Siting Industrial Operations in a Wetland

**PowerPoint 15.16** Agricultural Runoff into Wetlands

**PowerPoint 15.17** Agricultural Runoff Causes Waterfowl Embryo
Deformities

**Remarks:**

###### [The Value of Wetlands]{.underline}

-   Wetlands are some of the most **dynamic, valuable, and diverse
    ecosystems** on earth.

    -   They provide habitat for numerous **plant and animal species**,
        play an important role in **filtering pollutants** out of the
        hydrosphere, and help **mitigate** the impacts of **flooding.**

-   Over the past century, coastal watersheds of the United States have
    experienced **major environmental changes**, including conversion of
    more than 80 percent of forested wetlands in some locations to
    agriculture and urbanization, channelization, dam construction, and
    river levees.

> **\[PowerPoint 15.10 Wetland Clearing\]**

-   The construction of massive **flood control structures** designed to
    keep rivers from switching channels in their natural meandering
    patterns has resulted in a restriction of sediment flow and
    freshwater supplies to many flood plains and deltas.

###### [Major Causes of Wetland Losses]{.underline}

-   Among the **human actions** that physically alter, degrade or
    destroy coastal wetlands are the effects of:

> **\[PowerPoint 15.11 Wetland Conversion to Agriculture\]**

-   Conversion to agriculture

> **\[PowerPoint 15.12 Clearing Wetlands for Development\]**

-   Clearing for development

> **\[PowerPoint 15.13 Draining Wetlands for Irrigation\]**

-   Draining for irrigation

-   Dredging for navigation

> **\[PowerPoint 15.14 Wetland Channelization\]**

-   Stream channelization

-   Deposition of fill material

-   Diking and damming

-   Levees

-   Logging

-   Mining

> **\[PowerPoint 15.15 Siting Industrial Operations in a Wetland\]**

-   Industry

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-   Wetlands have also been destroyed in **ways that are not as
    obvious** as direct physical destruction or degradation, including:

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-   Runoff

-   Air and water pollution

-   Chemical contaminants

-   Changes in temperature and salinity

-   Sedimentation

-   Changing nutrient levels

-   Release of toxic chemicals

-   Introduction of non-native species

-   Grazing by domestic animals

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-   Wetlands are also damaged by **natural forces**:

    -   Erosion

    -   Subsidence

    -   Sea level rise

    -   Drought

    -   Hurricanes and other storms

    -   Below or above average precipitation

-   **Global climate change** could affect wetlands through increased
    air temperature; shifts in precipitation; increased frequency of
    storms, droughts, and floods; increased atmospheric carbon dioxide
    concentration; and sea level rise.

    -   All of these impacts could affect species composition and
        wetland functions.

###### [Untreated Runoff Impacts to Wetlands]{.underline}

-   Since wetlands are typically the **lowest area on the landscape**,
    they often receive runoff from surrounding land.

    -   Runoff (or "stormwater\" or \"nonpoint source pollution\") is
        caused by rainfall or snowmelt moving over and through the
        ground. Runoff carries natural and manmade pollutants into low
        areas such as wetlands, lakes, streams, and eventually into
        ground water. (US EPA)

> **\[PowerPoint 15.16 Agricultural Runoff into Wetlands\]**

-   **Impacts to wetlands** have resulted in consequences such as
    changed species composition, increased pollutant loadings (e.g.,
    heavy metals), and replacement of complex wetland systems with less
    desired open water.

> **\[PowerPoint 15.17** **Agricultural Runoff Causes Waterfowl Embryo
> Deformities\]**

-   Some impacts have resulted in mortality and deformities of wildlife
    populations, particularly fish and migratory birds. (US EPA)

###### [To Use or Not To Use Wetlands for Treatment?]{.underline} 

-   Because wetlands have a natural water quality improvement function,
    there has been a tremendous amount of **interest in using wetlands
    to treat runoff** from urban areas, agricultural lands, and other
    pollutant sources.

    -   However, the critical question is, \"**What can wetlands safely
        handle before they are contaminated or their functions
        degraded?\"**

    -   While wetlands do provide valuable water quality protection for
        downstream rivers, lakes, and estuaries, the quality of the
        wetlands, as waters of the United States, should also be
        protected. (US EPA)

###### [Future Changes to Wetlands]{.underline}

-   One of the most critical **climate change issues** for coastal
    ecosystems is how the already highly altered and rapidly degrading
    **wetlands will be impacted**.

    -   It is likely that the combined effects of **increased sea-level
        rise and human alterations to sediment** supply will continue or
        even increase the current wetland loss rates in many areas for
        years to come.

-   This loss of wetlands **threatens** **navigation** and the
    **industrial, agricultural, and fisheries sectors** of regional
    economies.

-   Although **hurricanes can play a positive role** in natural wetland
    development by remobilizing sediments and assisting in building
    marsh substrate, **channelized coastal landscapes** such as
    Louisiana\'s **allow storm surges to move farther inland**,
    increasing saltwater penetration into freshwater marshes.

    -   **Sea-level rise will exacerbate** **this** whether or not
        hurricanes and storms become more frequent or intense.

Objective 15.4 Discuss anthropogenic impacts on coral reefs.

Requirements:

This Objective is to be presented as lecture, supported by PowerPoint
slides. Class discussion should be encouraged.

The following PowerPoint slides will be shown during this Objective:

**PowerPoint 15.18 C**oral Reefs Indicate Coastal Watershed Health

**PowerPoint 15.19** Coral Reef Degradation

###### PowerPoint 15.20 Dead Coral

**PowerPoint 15.21** Bleaching Hard Coral

**PowerPoint 15.22** Visitors Damage Coral Reefs

**Remarks:**

####### Coral Reef Ecosystems

-   As we learned in earlier sessions, coral reef ecosystems are
    **unique, biologically diverse systems** recognized as valuable
    economic and environmental resources.

    -   In addition to providing recreational and possible medicinal
        value, coral reefs form a safe haven for many different marine
        species, contributing to the **biodiversity** of the ocean
        ecosystem.

    -   Furthermore, coral reefs serve as protective barriers against
        **hurricane and coastal storm impacts**, by absorbing the energy
        of waves and storm surge.

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-   However, coral reefs are extremely **sensitive environments** that
    have special temperature, salinity, light, oxygen, and nutrient
    requirements.

    -   When environmental conditions fall outside the acceptable range
        of these requirements, the health and dynamics of a coral reef
        community can be severely disrupted.

> **\[PowerPoint 15.18 Coral Reefs Indicate Coastal Watershed Health\]**

-   In this way, coral reefs provide a **good indicator of environmental
    conditions** -- particularly water quality and clarity -- for the
    surrounding watershed.

####### Threats to Coral Health

-   Coral reef habitats are extremely sensitive to disturbances, such as
    various forms of pollution and physical contact.

    -   **Pollution** of coastal watersheds poses a threat to the
        existence of coral reefs. Impacts can result from activities
        occurring near the reef itself or from areas within the coastal
        watershed that drain to the reef.

> **\[PowerPoint 15.19 Coral Reef Degradation\]**

-   **Natural occurrences**, such as hurricanes, can adversely impact
    coral reefs through high-energy storm surges and the resulting
    resuspension of sediment. However, reefs are usually able to recover
    from natural disturbances if they are healthy to begin with.

####### Coral Bleaching

###### \[PowerPoint 15.20 Dead Coral\]

-   One manifestation of **coral ill health** is coral reef bleaching,
    caused by various anthropogenic and natural variations in the reef
    environment.

    -   Coral bleaching is the **whitening of coral colonies** due to
        the loss of the symbiotic zooxanthellae. This loss exposes the
        white carbonate skeletons of the coral colony as the algae that
        give corals their color die.

**\[PowerPoint 15.21 Bleaching Hard Coral\]**

-   The **exact mechanism** by which corals bleach or the trigger that
    includes bleaching is **unknown**, but documentation has shown that
    coral bleaching events have been increasing in both frequency and
    extent worldwide in the past 20 years.

-   **Global climate change** may play a role in the increase in coral
    bleaching events, and could cause the destruction of major reef
    tracts and the extinction of many coral species.

###### [Coral reef impacts]{.underline}

-   ***People*** using the reef can have an adverse impact on reef
    resources. Portions of a coral reef can be broken by the impact of
    **boat anchors** and boat groundings.

> **\[PowerPoint 15.22 Visitors Damage Coral Reefs\]**

-   **Divers and snorkelers** can harm the reef by simply touching it or
    by removing the corals.

-   **Suntan oil** from swimmers and snorkelers can harm or even kill
    sensitive corals.

-   Dragging **hooks, fishing line, and nets** across the coral reef, as
    well as placing and recovering lobster traps on reefs, can be
    damaging.

-   **Overfishing** also harms coral reefs by removing important species
    that eat the algae growing on corals. When these fish species are
    removed, the algae overgrow the corals, smothering them.

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-   ***Marine debris*,** trash floating on the ocean or resting on the
    ocean floor, comes from many sources, including boaters, divers,
    improper disposal of trash on land, storm water runoff to rivers and
    streams, ships and other vessels, and offshore oil platforms.

    -   Marine **debris can harm fish species** and other aquatic
        organisms that use the reef. Trash that lands on the reef can
        **kill corals** by continually rubbing against it or smothering
        it.

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-   An excessive amount of ***nutrients*** from improperly treated
    sewage, atmospheric deposition, agricultural and urban runoff, and
    cleaning products high in phosphates can **harm coral reef
    habitats**.

    -   In excess levels, **nutrients overstimulate the growth of
        aquatic plants and algae.** When nutrient levels increase, the
        delicate balance that exists between corals and algae is
        destroyed and the algae can overgrow the corals.

    -   When this situation is prolonged, the **corals are smothered and
        die** beneath the algal carpet. This, in turn, affects the fish
        and other aquatic organisms using the area, leading to a
        decrease in animal and plant diversity and affecting use of the
        water for fishing and swimming.

-   Some of the leading causes of nearshore coral decline can be related
    to ***land development*** and nearshore construction that are not
    environmentally sensitive.

    -   **Sediment, silt,** and other **suspended solids** wash off

        -   plowed fields

        -   construction and logging sites

        -   urban areas

        -   strip-mined land

        -   eroded stream banks when it rains.

    -   Increases in **coastal sediment** are also caused by

        -   construction of seawalls,

        -   docks, and marinas;

        -   land-clearing;

        -   boats running through shallow waters, disturbing and
            suspending silts with their propellers;

        -   snorkelers and divers kicking up sediment.

    -   **Sediment can block sunlight** that is essential for the
        survival of some corals, which live in a very close relationship
        with microscopic plants that require sunlight to survive. In
        addition, heavy sedimentation can **bury corals**, inhibiting
        their growth or killing them.

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-   ***Pathogens*** are disease-causing microorganisms such as viruses,
    bacteria, and parasites.

    -   Pathogens are harmful to corals, causing **disease and
        scarring** in many species.

    -   These **microorganisms** enter water bodies from **sources**
        such as:

        -   inadequately treated sewage

        -   storm water drains

        -   septic systems

        -   runoff from livestock pens

        -   boats that discharge sewage.

-   Coral reefs are vulnerable to the introduction of a wide variety of
    ***toxic substances*,** including

    -   metals (such as mercury and lead)

    -   toxic organic chemicals (such as PCBs and dioxin)

    -   pesticides

    -   herbicides

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    ```
    -   These toxic substances derive from numerous sources, including:

        -   industrial discharges

        -   urban and agricultural runoff

        -   mining activities

        -   runoff from landfills.

    -   These toxic substances can cause **scarring, death, or
        reproductive failure** in fish, shellfish, and other marine
        organisms.

    -   In addition, they can **accumulate in fish tissue**, leading to
        fish consumption advisories. The sensitivity of corals makes
        them especially vulnerable to the introduction of toxic
        substances.

Objective 15.5 Discuss the impacts of invasive species on coastal
ecosystems.

**Requirements:**

This Objective is to be presented as lecture supported by PowerPoint
slides. Class discussion should be encouraged.

The following PowerPoint slides will be used during this Objective:

####### PowerPoint 15.23 **Lamprey**

**PowerPoint 15.24** Rusty Crayfish

**PowerPoint 15.25** Sea Squirt

**PowerPoint 15.26** Purple Loosestrife

**PowerPoint 15.27** Water Hyacinth

**PowerPoint 15.28** Ballast Water Brings Invasives

**PowerPoint 15.29** Zebra Mussels

**PowerPoint 15.30** Brown Tree Snake

**PowerPoint 15.31** Guam Rail

**PowerPoint 15.32** Adult Nutria

**PowerPoint 15.33** Water Alligator Weed

**Remarks:**

###### [What Are Invasive Species]{.underline}

-   Invasive species, or invasives, are **nonindigenous plants** **and
    animals** that have found their way into areas **outside their
    normal geographic range**.

    -   Most non\--indigenous introductions are a **direct result of
        human impacts**; bays and estuaries are particularly vulnerable
        due to the abundance and variety of human activities.

-   Invasive species have been called a type of **biological
    pollution**. Unlike pesticides or sewage, however, invasive species
    do not dissipate over time. With no natural enemies in their new
    habitat, invasive species often grow, reproduce and spread quickly.

-   **On their home turf**, plant and animal **populations are kept in
    check** by natural controls, like predators and food supply.

    -   However, when a species is introduced, accidentally or
        intentionally, into a new landscape---one not adapted to its
        presence---the consequences can be devastating.

-   Not all of these "non-native" species misbehave. But some non-native
    species spread unchecked, **disrupting natural cycles**, **crowding
    out native species** and **costing billions** in property damage and
    lost economic productivity.

###### [Increasing Rates of Invasive Species]{.underline}

-   Invasive species are appearing around the world at an unprecedented
    rate and scale.

    -   There already are more than **500 non-native species in the
        coastal waters** of the United States, with more arriving every
        day.

        -   The **San Francisco Bay** estuary is probably the most
            invaded estuary in the world. Over 230 non-native species
            now live there; so many, in fact, that they now dominate the
            ecosystem.

        -   Over 160 invasive species are now found in the **Chesapeake
            Bay**, and their numbers are growing.

> **\[PowerPoint 15.23 Lamprey\]**
>
> **\[PowerPoint 15.24 Rusty Crayfish\]**

-   The **Great Lakes** have seen a dramatic increase in invasive
    species as well, in some cases causing devastating consequences to
    native plant and animal species.

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-   Invasive species often go undetected for years, until their impact
    is so great that it becomes damaging to the marine environment.

> **\[PowerPoint 15.25 Sea Squirt\]**

-   NOAA research vessels have recently found what is believed to be an
    invasive species of sea squirt on the northern edge of Georges Bank,
    colonizing a 6.5 square mile area about 160 miles off outer Cape
    Cod, at a depth of just over 150 feet.

###### [How Are Invasive Species Introduced?]{.underline}

> **\[PowerPoint 15.26 Purple Loosestrife\]**

-   Some invasive species are **introduced intentionally**:

    -   **Purple loosestrife**, for example, was introduced to the
        United States from Europe as an **ornamental plant** in the
        early 1800s. Today it has invaded estuaries in 48 states,
        crowding out 44 species of native plants. Controlling purple
        loosestrife costs about \$45 million a year.

> **\[PowerPoint 15.27 Water Hyacinth\]**

-   Large and costly infestations of **scotch broom** and **water
    hyacinth** resulted from **gardeners planting these species** for
    their bright showy flowers. The plants continue to be sold by
    aquarium suppliers, further encouraging their spread. These plants
    have been especially damaging to the estuarine ecosystems of
    Louisiana.

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-   Other invasive species are introduced accidentally or
    unintentionally

> **\[PowerPoint 15.28 Ballast Water Brings Invasives\]**

-   Non-native species are often introduced to estuaries and other
    coastal waters in the **ballast water of ships**.

-   When ships are empty, they take in water to help keep them balanced.
    When cargo is loaded onto the ships, they release the ballast water.
    In addition to water, aquatic organisms are sucked into the ships\'
    ballast tanks.

-   When ships take on water in one part of the world and release it in
    another, aquatic plants and animals are transported along with the
    water and introduced into foreign estuaries.

> **\[PowerPoint 15.29 Zebra Mussels\]**

-   A Caspian Sea tanker dumped its ballast water---and the **Asian
    zebra mussel**---into the **Great Lakes** during the 1990s. Now the
    tiny mussels threaten to smother 140 native mussel species, and
    waterfront industries, like dams and power plants, must pay billions
    in on-going repairs to clogged pipes while passing the cost to
    consumers.

**[Impacts of Invasive Species]{.underline}**

-   The sudden introduction to a new landscape of a foreign species, one
    free from natural competitors and predators, can cause **ecological
    chaos**.

-   **Competing** with native species for food, or **preying** upon
    native species, invasive species have drastically **reduced the
    populations of native species** and have, in some cases, caused
    their extinction.

> **\[PowerPoint 15.30 Brown Tree Snake\]**

-   For instance, the first **brown tree snakes** were seen on **Guam**
    in the mid-1950s, likely arriving from their native New Guinea as
    **cargo stowaways** on U.S. military ships during World War II.

> **\[PowerPoint 15.31 Guam Rail\]**

-   Guam\'s **birds made easy prey** for the eight-foot serpent, which
    extirpated 12 bird species on the island, some found nowhere else in
    the world.

-   The snake has also decimated native populations of **bats** and
    **lizards**, and even causes frequent **power outages**.

-   Brown tree snakes now threaten to invade Hawaii and other Pacific
    Islands.

> **\[PowerPoint 15.32 Adult Nutria\]**

-   Introduced animal species, such as nutria, **graze marsh plants** to
    decimation, causing **erosion** and **displacing native animals**.

> **\[PowerPoint 15.33 Water Alligator Weed\]**

-   **Invasive plants** can be just as damaging as animals, outgrowing
    native plants, **hoarding** much-needed **light, water and
    nutrients**, and sometimes even altering **soil chemistry**, pushing
    native species to the brink of extinction.

    -   The non-native plants can also **contaminate grazing pastures**,
        threaten **drinking water** supplies, and render valuable land
        **unfit for crops**.

    -   When weed mats get very thick, they can impede stream flow,
        promoting **sedimentation and flooding problems** as well as
        providing a habitat for **mosquitoes.**

Objective 15.6 Discuss the impacts of human interference with coastal
processes.

**Requirements:**

This Objective is to be presented as lecture supported by PowerPoint
slides. Class discussion should be encouraged.

The following PowerPoint slides will be shown during this Objective:

**PowerPoint 15.34** Dune Destruction

**PowerPoint 15.35** Beach Renourishment

**PowerPoint 15.36** Beach Scraping: Earthmovers Loading Sand

**PowerPoint 15.37** Equipment with Scraper Blades

**PowerPoint 15.38** Beach Scraping: Regrading and Dressing Slopes

###### PowerPoint 15.39 **Scraped Sand in Place Against Seawall**

**PowerPoint 15.40** Groins at Folly Beach, SC

**PowerPoint 15.41** Groins at Work

**PowerPoint 15.42** Inlet and Jetties

**PowerPoint 15.43** Seawall in Front of Private Home

**PowerPoint 15.44** Seawall at Work

**PowerPoint 15.45** Seawall at Folly Beach, SC

**PowerPoint 15.46** Gabion Revetment

####### PowerPoint 15.47 Damaged Gabion

**Remarks:**

###### [Anthropogenic Changes to Coastal Processes]{.underline}

-   Throughout history, humans have attempted to slow or alter the
    dynamic coastal zone.

-   The **anthropogenic (human-influenced) changes** to coastal
    environments may take many forms:

    -   creation or stabilization of inlets

    -   beach nourishment and sediment bypassing

    -   creation of dunes for property protection

    -   destruction of dunes for development

    -   dredging of waterways for shipping and commerce

    -   introduction of hard structures such as jetties, groins, and
        seawalls.

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    -   **These modifications change coastal features** and have
        far-reaching **effects on coastal processes and ecosystems.** An
        understanding of how human changes alter shoreline environments
        is vital for the management of coastal areas. (National Park
        Service)

> **\[PowerPoint 15.34 Dune Destruction\]**

**[Sea Level Rise]{.underline}**

-   Variations in sea levels are **natural responses** to climate
    change, geodetic variations, movements of the sea floor, and other
    Earth processes. (National Park Service)

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-   **Human actions,** including drainage of wetlands, withdrawal of
    groundwater (which eventually flows to the sea), and deforestation
    (which reduces terrestrial water-storage capacity), may also
    **contribute to global rise in sea level**. (National Park Service)

-   Additionally, **human-induced climate change**, primarily through
    the burning of fossil fuels, is also of importance.

-   **Local changes** may be caused by **large engineering works**
    nearby, such as river channeling or dam construction that influence
    sediment delivery and deposition in deltaic areas. (National Park
    Service)

 

 

###### [Beach Nourishment]{.underline}

> **\[PowerPoint 15.35 Beach Renourishment\]**

-   Beach nourishment is the process of **placing additional sediment on
    a beach**. This material is obtained from another source that either
    lies inland or is dredged offshore.

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-   Nourishment entails the removal of sediment from **"borrow sites**,"
    and the subsequent transport of the sediment to beach areas. Borrow
    sites may **alter** **hydrodynamic patterns**, **marine
    ecosystems**, and **sediment transport**, such as creating
    **erosional "hot spots**" on adjacent shorelines. (National Park
    Service)

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-   **Subaqueous nourishment** is an alternative form of replenishment.

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-   The creation of **offshore berms** (mounds) may be utilized for the
    subsequent landward migration of sediments, often leading to
    sediment accretion on adjacent beaches.

-   Although still a fairly new replenishment method, and not documented
    as fully effective, subaqueous nourishment may be substituted on
    account of cost limitations or biotic complications (e.g., migration
    and preserving endangered species) resulting from direct beach
    nourishment. (National Park Service)

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-   Often, beach nourishment is needed to **counteract the effects of
    the hard-structure** stabilization of coastlines.

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-   These structures (e.g., jetties, groins, and seawalls) typically
    **increase downdrift erosion rates**, promoting a need for continued
    coastal modifications through nourishment.

    -   The need for beach nourishment after human alteration is quite
        evident at **Assateague Island National Seashore** (Maryland).

    -   In the mid-1930s, the U.S. Army Corps of Engineers established a
        jetty system to stabilize the Ocean City inlet. While sediment
        transported by north-to-south long-shore currents increased
        sediment accretion up-drift of the jetties at Ocean City,
        excessive erosion and barrier island migration have occurred on
        the island to the south of the jetties. That is, Assateague
        Island has migrated westward more than 1,148 feet (350 m) since
        1933!

    -   The deterrence of long-shore sediment transport to Assateague
        Island National Park has had numerous detrimental impacts on
        biological, geologic, and cultural resources. Both short-term
        and long-term beach nourishment plans are in place to mitigate
        the destructive effects of jetty placement.

 

###### [Beach Scraping]{.underline}

> **\[PowerPoint 15.36 Beach Scraping: Earthmovers Loading Sand\]**
>
> **\[PowerPoint 15.37 Equipment with Scraper Blades\]**
>
> **\[PowerPoint 15.38 Beach Scraping: Re-grading and Dressing
> Slopes\]**

###### \[PowerPoint 15.39 Scraped Sand in Place Against Seawall\]

**\]**

-   Beach scraping (i.e., grading and bulldozing) is the **process of
    reshaping beach and dune landforms** with heavy machinery.

    -   Usually a layer of sand from the lower beach is moved to the
        upper beach.

-   **Beach scraping creates dunes**, which are used to give property
    owners some security from beach erosion, severe storms, and winter
    washover events.

    -   During the **summers,** the created sandbanks may be **bulldozed
        flat**, providing water views to property owners. (National Park
        Service)

-   However, **the effects of beach scraping on coastal environments are
    little known**, and this procedure may be harmful to coastal biota
    and habitats.

    -   Proponents claim that beach scraping is a time and
        cost-effective method to ensure shoreline protection,

    -   while opponents state that this method may be the most
        ecologically destructive form of coastal manipulation to date.
        (National Park Service)

 

**[Hard Structures]{.underline}**

-   **Hard structures** are often placed in marine environments **to
    counteract erosion** in sediment-deficient areas, or **to deter
    accretion** in sediment-rich areas such as inlets.

    -   Unfortunately, these anthropogenic modifications **may
        accelerate erosion** in adjacent downdrift areas, increasing the
        need for additional hard structures. (National Park Service)

        -   The creation of new hard structures is currently banned in
            many states, or strongly discouraged as coastal management
            practice.

> **\[PowerPoint 15.40 Groins at Folly Beach, SC\]**

-   **Groins** are shore-perpendicular structures, used to maintain
    up-drift beaches or to restrict long-shore sediment transport.

**\[PowerPoint 15.41 Groins at Work\]**

-   **Permeable groins** are becoming popular, and may negate some of
    the negative effects of impermeable groins. (National Park Service)

> **\[PowerPoint 15.42 Inlet and Jetties\]**

-   Another type of shore-perpendicular hard structure is **jetties**,
    which are normally placed adjacent to tidal inlets to control inlet
    migration and to minimize sediment deposition within the inlet.
    (National Park Service)

-   Shore parallel structures include **seawalls, bulkheads, and
    revetments**. These structures are designed to protect coastal
    property.

> **\[PowerPoint 15.43 Seawall in Front of Private Home\]**

-   Development permits are relatively easy to obtain in many states
    because seawalls may be built above the high-water mark on private
    property, and they are relatively inexpensive, compared to beach
    nourishment. (National Park Service)

> **\[PowerPoint 15.44 Seawall at Work\]**
>
> **\[PowerPoint 15.45 Seawall at Folly Beach, SC\]**

-   Ironically, **seawalls usually accelerate erosion** on beaches they
    are intended to protect. Wave energy is reflected off seawalls,
    increasing erosion in front of them. The placement of a seawall will
    decrease the sediment supply near seawalls, increasing erosion on
    adjacent beaches. In many areas, beaches have completely eroded and
    disappeared on account of seawalls. (National Park Service)

> **\[PowerPoint 15.46 Gabion Revetment\]**

-   **Gabions** are used to construct seawalls or revetments. Wire cages
    are filled with rocks to form a wall, permitting sand accumulation
    and dune grass growth.

####### \[PowerPoint 15.47 Damaged Gabion\]

-   However, the wire cages may rust and disintegrate, forming a public
    safety hazard and defeating the original purpose of the structure.

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-   Other anthropogenic structures that are used to stop or alter
    natural coastal changes include **breakwaters, headlands, sills, and
    reefs**.

    -   These structures are composed of either natural or artificial
        materials, and are designed **to alter the effects of waves**
        and **slow coastline erosion** and change.

    -   Submerged reefs and sills dampen wave energy and may create new
        habitat, which is significant for local fisheries.

    -   However, the **long-term effects** of these structures, on both
        physical and biological processes, **are not understood** and
        require thorough examination.

Objective 15.7 Discuss mitigation approaches for anthropogenic hazards.

**Requirements:**

The content should be presented as lecture. Class discussion is to be
encouraged.

**Remarks:**

####### Mitigation of Anthropogenic Hazards

-   The mitigation strategies for dealing with anthropogenic hazards
    follow more closely the mitigation of natural hazards than most
    other human induced hazards such as terrorism and accidents.

-   The mitigation of anthropogenic hazards generally involves
    restrictions on human behavior through such means as land use
    planning and regulation.

-   Extensive regulation, particularly of nonpoint source pollution and
    effluent discharges, put limitations on the quantity and quality of
    pollutants that communities are allowed to produce. Many of these
    state and federal regulatory programs operate through the issuance
    of permits.

Refer to later session that will address regulatory and planning
programs in more detail.

Objective 15. 8 Describe the occurrence and effects of Harmful Algal
Blooms (HABs) in coastal regions of the United States and possible
management options to minimize the impacts of HABs

**Requirements:**

The content should be presented as lecture, supported by PowerPoint
slides. Class discussion is to be encouraged.

The following slides will be used during this Objective:

**PowerPoint 15.48** Harmful Algal Bloom

**PowerPoint 15.49** Red Tide

**PowerPoint 15.50** Major HAB-Related Events in the U.S.

**PowerPoint 15.51** Occurrence of Harmful Algal Blooms

**PowerPoint 15.52** Satellite Imagery of Harmful Algal Bloom

**Remarks:**

-   The **most serious of biological hazards** to coastal areas is
    generally believed to be the appearance of **harmful algal blooms**
    (HABs). These HABs are sometimes referred to as "red tides," though
    many scientists disagree about the appropriateness of this label.

<http://www.whoi.edu/redtide/whathabs/whathabs.html>

**[Definition:]{.underline}**

-   Algae are **microscopic, single-celled plants** that live in the
    sea. Most species of algae or phytoplankton are not harmful and
    serve as the energy producers at the base of the food web, without
    which higher life on this planet would not exist.

-   Occasionally, the **algae grow very fast or "bloom**" and accumulate
    into dense, visible patches near the surface of the water. When
    toxic varieties of algae multiply rapidly, it is called a "Harmful
    Algal Bloom"

> **\[PowerPoint 15.48 Harmful Algal Bloom\]**

-   These organisms thrive and multiply principally **during the spring
    and summer**, in response to increased light intensity and favorable
    levels of salinity and nutrients in ocean water. During the growth
    period, or bloom, each single algae cell may **replicate itself one
    million times** in two to three weeks.

-   During the reproductive riot of the bloom, warm, shallow
    **seawater** tends to become **discolored** by the sheer
    concentration of algae seeking the sunlight.

> **\[PowerPoint 15.49 Red Tide\]**

-   This discoloration is a result of the **various pigments the plants
    use** **to trap sunlight**;

-   depending on the species of algae present, the water may reflect
    pink, violet, orange, yellow, blue, green, brown, or red.

-   Since red is the most common pigment, the phenomenon has come to be
    called **Red Tide**.

-   The **term \"red tide\" is thus a misnomer** because

    -   they are not associated with tides;

    -   they are usually not harmful; and

    -   those species that are harmful may never reach the densities
        required to discolor the water.

**[Causes and Occurrence]{.underline}**

> **\[PowerPoint 15.50 Major HAB-Related Events in the U.S.\]**

-   Harmful Algal Blooms occur in the waters of nearly **every coastal
    and Great Lakes state**, as well as around the world.

-   The blooms may be **caused by nutrient and hydrographic
    conditions**, although the environmental conditions which result in
    red tides are not completely understood.

    -   Some scientists think **coastal pollution helps produce red
        tides**.

> **\[PowerPoint 15.51 Occurrence of Harmful Algal Blooms\]**

-   There is evidence that HABs are **increasing in frequency and
    severity** worldwide. Effective monitoring of HABs has improved and
    contemporary records show that the expansion of HABs during the last
    thirty years has been substantial.

-   **Natural events, as well as human activities**, appear to
    contribute to this increase.

    -   For example, **storm runoff** and the flow of **coastal
        currents** have helped HABs to spread along the New England
        coast and the coast of Florida.

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    -   **Weather** may also influence the frequency, severity, and
        duration of HABs due to the **increase in nutrient runoff** from
        land.

###### [Effects of Harmful Algal Blooms]{.underline}

-   Most species contributing to algal blooms are harmless, but some
    species are **poisonous** to the animals that feed upon them
    directly or indirectly.

    -   Often, the algae themselves are unaffected, as are the filter
        feeders, especially shellfish, for whom micro-algae are the
        principal diet.

    -   However, to **carnivores further up the food chain**, these
        toxins are **potentially fatal**. The toxins produced by these
        species cause finfish and shellfish poisoning, and mortality of
        marine animals, including mammals and birds. Humans can be
        poisoned, sometimes fatally, by eating contaminated shellfish
        and finfish.

    -   The **various types of poisoning** that can occur in humans who
        eat contaminated shellfish or finfish include:

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-   [Amnesiac Shellfish Poisoning (ASP]{.underline}): A life-threatening
    syndrome involving both gastrointestinal and neurological disorders.
    Symptoms include nausea, vomiting, abdominal cramps, diarrhea,
    dizziness, headache, seizures, disorientation, memory-loss,
    respiratory difficulty, coma.

-   [Ciguatera Fish Poisoning (CFP]{.underline}): Produces
    gastrointestinal, neurological and cardiovascular symptoms of
    numbness, tingling, paralysis and may result in death.

-   [Diarrheic Shellfish Poisoning (DSP]{.underline}): Produces
    gastrointestinal symptoms; usually not fatal.

-   [Neurotoxic Shellfish Poisoning (NSP]{.underline}): produces an
    intoxication syndrome similar to CFP, although generally less
    severe. In addition, toxic aerosols can be formed by wave actions,
    producing respiratory asthma-like symptoms.

-   P[aralytic Shellfish Poisoning (PSP):]{.underline} a rapid-onset
    life-threatening syndrome producing neurological symptoms including
    tingling, drowsiness, fever, rash, staggering, giddiness.

###### 

###### [Economic Impact of Harmful Algal Blooms]{.underline}

-   HABs have been responsible for an **estimated \$1 billion in
    economic losses** over the past few decades.

-   These blooms have **decimated many seafood industries**, including
    the scallop fishery in Long Island's estuaries.

-   HABs have also led to **seasonal closures of various
    shellfisheries**, from North Carolina to Louisiana, and throughout
    the Pacific Northwest.

-   They may also have contributed to **deaths** of hundreds of
    **manatees** in Florida, **sea lions** in California, and other
    marine mammals, including **dolphins** in the Northern Gulf of
    Mexico.
    <http://www.cop.noaa.gov/stressors/extremeevents/hab/overview.html>

###### [Management Options]{.underline}

-   **Management options** for harmful algal blooms are **limited**. For
    now, the focus remains on minimizing the impacts of HAB ev**ents**.

-   HAB impacts can be **minimized through monitoring** programs that
    regularly sample shellfish to detect HAB toxins---human illness and
    death from shellfish poisoning has been reduced through such
    efforts.

-   In addition, monitoring coastal waters for the presence of HAB cells
    may provide coastal regions with an **early warning of HAB events**.

####### \[PowerPoint 15.52 Satellite Imagery of Harmful Algal Bloom\]

-   Recent **technological advances** have **increased detection** of
    algal blooms, from satellite remote sensing that can be used to
    track blooms offshore, to molecular probes that can detect
    individual HAB cells in seawater or minute amounts of HAB toxins in
    blood samples.

-   It may be possible to **prevent or control some HABs**.

    -   The type of HABs that are stimulated by nutrient enrichment of
        coastal waters may be reduced by **controlling nutrient
        inputs**.

    -   However, other HABs appear to **occur naturally and cannot be
        prevented**.

    -   Scientists believe that a potential approach to **controlling
        HABs by physical means**, such as applying clay to the HAB, may
        cause the toxic cells and HAB specific viruses to sink. However,
        **more research is needed** to determine the effectiveness and
        environmental impacts of these methods.

-   The **role of coastal managers** in mitigating a disaster associated
    with HABs includes:

    -   Increasing awareness

    -   Contributing to research efforts, and

    -   Engaging in or assisting scientists with regular monitoring of
        coastal waters.

**Course Developer References**

(See also *Readings* above)

U.S. Environmental Protection Agency <http://www.epa.gov/owow/nps/>

United Nations Atlas of the Oceans <http://www.oceansatlas.org/>

UN Sustainable Development
<http://www.un.org/esa/sustdev/sdissues/ocean/ocean.htm>

US EPA Coastal Waters Factsheets
<http://www.epa.gov/owow/oceans/factsheets/fact5.html>

Patin, Stanislav, trans. Elena Cascio. 1999. *Environmental Impact of
the Offshore Oil and Gas Industry*. East Northport, NY: EcoMonitor
Publishing.

National Park Service: [www.nps.gov](http://www.nps.gov/)

National Oceanic and Atmospheric Administration
[http://spo.nos.noaa.gov](http://spo.nos.noaa.gov/)