[CHILD PAGE 1 - main page]
Introduction to Coastal Zone Management
WHAT IS A COASTAL ZONE?
Source: visitmaui.com
For all the vast miles of open waves, for all the leagues of deep, dark water, for all the huge openness and mystery of the open ocean, some of the most important waters are those within several hundred miles of the coasts.
A coastal zone is often described as the coastal ocean and the land adjacent. It covers approximately 7% (26x106 km2) of the surface of the interface between land and ocean. Despite its relatively modest surface area, a coastal zone is one of the most geochemically and biologically active areas in the biosphere. For example, it accounts for at least 15% of oceanic primary production; 80% of organic matter burial; 90% of sedimentary mineralization; and 50% of the deposition of calcium carbonate. It also represents 90% of the world fish catch and its overall economic value has been recently estimated as at least 40 % of the value of the world's ecosystem services and natural capital. Additionally, coastal areas contain high proportion of the faunal and floristic biodiversity. However, this region is changing rapidly as a consequence of human influence; about 40% of the world's population lives within 100 km of the coastline. As a result, our goal is to create solutions that would mitigate the effects of these negative influences on coastal habitats and wild fish stocks. (Gattuso et al. 2007)
In this section, we will treat the coastal zone primarily as the freshwater bodies that drain to the sea, the land area influencing those water-bodies, and the water within the continental shelf of a landform, especially estuarine waters (waters where salt and freshwater mix).
WHAT IS THE PROBLEM?
Source: hickerphoto.com
The water on earth is a constantly changing, dynamic system; it flows, evaporates, condensates, is stored, is absorbed. Events in one waterway later affect downstream waters and the ocean. The impacts of coastal zones on marine ecosystems and fisheries is profound, not only because of the incredibly biodiversity and biomass in coastal waters, but also because of the various ecosystem functions that coastal areas provide. Coastal and estuarine areas are often critical spawning and recruitment grounds; damages to the ecosystem and to fisheries there can have wide-ranging effects on the population elsewhere. Furthermore, many fish migrate upstream into freshwaters to spawn (anadromous fish, like shad) or live in freshwater and spawn in the ocean (catadromous fish, like eels); changes in water quality or physical habitat can destroy these populations by decimating their reproductive capacity. The connections between freshwater, estuarine, and marine areas are many and are not yet fully understood. However, we do know that in order for creatures to survive, they require--on the most basic level--food, water, and a place to live. An organism's habitat encompasses these concepts. It is the foundation for a healthy ecology. Without an environment in which its basic needs can be fulfilled, an organism cannot survive. As such, our group proposes to maximize habitat and water quality in these areas so as to minimize fishery mortality from environmental factors.
Specifically, there are several classes of problems that affect habitat quality and fisheries. They include:
(1) Point source pollution [Link to Child page 2]
(2) Non-point source pollution [Link to child page 3]
(3) Obstruction to migration [Link to Child page 4]
(4) Habitat destruction or alteration [link to child page 5]
(5) Invasive species [link to child page 6]
WHAT ARE THE PROPOSED SOLUTIONS?
(1) Water Quality Assessment and Regulation [ link to child page 7]
(2) Establishment of Riparian Buffers [link to child page 8]
(3) Establishment and Protection of Wetlands and other Fragile Coastal Ecosystems [link to child page 9]
(4) Dam Planning and Regulation [link to child page 10]
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Point Source Pollution:
The most easily identifiable form of environmental contamination is point source pollution. Point source pollution occurs when contaminants are introduced to an ecosystem at a singular location and point in time. Common examples include:
- Chemical waste dumping
- Thermal discharge
- Oil spills
- Waste-water disposal !stormflow.jpg|width=651,height=434!Source: USGS
The effects of these various materials in aquatic ecosystems vary with respect to the chemical or contaminant involved and with respect to the amount of the discharge; the regulation of discharges into water is an important aspect of the preservation of overall water quality.
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Non-point Source Pollution:
Photo from NOAA
Non-point source pollution arises when contaminants are carried into waterways by natural processes, like run-off or air currents. A common example is when run-off carries fertilizers from farms into waterways. Harder to pin-point - because the source covers a large land area - and more difficult to regulate than point-source pollution, especially because of the lack of explicit fault by any one person, non-point source pollution is a serious but insidious threat to ecosystem health. Examples of major contaminants include:
Source: USGS and Barbara Hite
- Suspended sediment
Sediments occur naturally and are integral components of aquatic systems. Nearly all waters contain suspended sediments that may be of physical, chemical or biological origin, and the quantities of these sediments usually vary with season. This natural variation in suspended sediment concentrations occurs typically in response to natural events (i.e. rainfall and snow melting) which increase the flow and sediment levels of the waterways. As a result, in order to ensure the survival of their species, aquatic organisms have adapted their life cycle to accommodate these natural variations in their environment (Birtwell 1999). However, the input of suspended sediment from catastrophic events such as floods and volcanic eruptions, and anthropogenic activities such as dredging, mining, and spilling water from dams are recognized as a potential threat to the well being of marine biota.
Although sediment, and its associated effects on water clarity and turbidity, is an inherent component of aquatic systems, it is apparent from scientificresearch that there is an increased risk to the survival of aquatic organisms when levels exceed background values for a particular period of time. There are many ways which an excessive amount of sediment might be harmful to a fishery. These are by:
A) Acting directly on the fish swimming in the water in which solids are suspended, and either killing them or reducing their growth rate, resistance to disease etc. For example, increased turbidity and decrease light penetration alters fish feeding and schooling practices which can lead to reduced survival. The high concentrations of sediments also irritate the gills of fish, and can cause death. In addition, they destroy the protective mucous covering the eyes and scales of fish which makes them more susceptible to infections.
B) Preventing the successful development of fish eggs and larvae. For example, settleable solids in river waters have the potential to be deposited in the stream, especially under reduced flow conditions, where they may exert a detrimental influence on fish eggs in spawning beds.
C) Modifying natural ecosystems of the aquatic organisms. For example, high concentrations of sediments can dislodge plants, invertebrates, and insects in the delta bed. This directly affects the food source of fish, and can result in smaller and fewer fish.
D) Carrying toxic agricultural and industrial compounds. If these toxins remain in the areas they can cause abnormalities or death in the fish. (Environment Canada 2001) In order to facilitate the protection of aquatic organisms from elevated levels of sediment in their environment, guidelines and criteria have been formulated. Dating back to 1964, the European Inland Fisheries Advisory Commission (EIFAC) was one of the first to put forth such guidelines for the protection of fisheries resources, which are as follows:
<25 ppm* of suspended solids - no
evidence of harmful effects onfish and fisheries; 25 - 80 ppm - it should be possible to
maintain good to moderate fisheries,
however the yield would be somewhat
diminished relative to waters with <25
ppm suspended solids; 80 - 400 ppm - these waters are unlikely to
support good freshwater fisheries; and 400 ppm - suspended solids - at best, only
poor fisheries are likely to be found. * Parts per million approximate (mg- L--1 ) Numerous criteria and guidelines have been formulated since then, and more recent ones have been based on the analyses of Newcombe and MacDonald (1991), Anderson et al. (1996), and Newcombe and Jensen (1996) and Caux et al. (1997). These authors state that aquatic biota respond to both concentration of suspended sediments and the duration of exposure to them, and relate the two through an "index of pollution intensity" or "stress index" (Birtwell 1999). Newcombe and MacDonalsd' 1991 paper recommended the use of a "stress index" that is "calculated by taking the natural logarithm of the product of concentration and duration" would provide resource managers with a method to predict the effects of pollution episode on aquatic biota. The British Columbia Ministry of Environment, Lands, and Parks (BCMELP) (1998), and the Canadian Council of Ministers of the Environment (CCME) (1999) guidelines are the most recent documents on this topic, and they are based, in part, on the publication by Caux et al. (1997).
It is recognized that there is some level of risk to aquatic organisms depending on the sediment levels discharged and the sensitivity of the organisms in the receiving stream. However, scientists have concluded that these impacts would be best assessed using the concentration of suspended sediment above background levels. The levels of risk and the corresponding concentrations of sediment follow:
Source: Birtwell 1999
It is concluded that elevated levels of sediment (typically over background) may be harmful to fish (i.e. acutely lethal, or elicit sublethal responses that compromise their well-being and jeopardize survival), and in addition, negatively impact their habitat. Criteria, guidelines and recommendations, though having been formulated by different agencies, all tend to be mutually supportive. At the same time they have application limitations, especially relating to the protection of aquatic organisms from the effects of sediment concentrations £ tens of mg- L-1. Application of the criteria must be done while recognizing potential impacts on aquatic organisms at both the lethal and the sublethal level. Particle size and nature of the sediment must be considered as well (Birtwell 1999).
- Excess nutrients
Nutrients are required by aquatic ecosystems for primary production; plants, often algae, absorb these nutrients and use them to grow. These plants form the base of the food chain in aquatic ecosystems. However, excess nutrients, especially nitrogenous compounds, are carried by runoff from agricultural areas and cause a phenomenon called eutrophication. The nutrients over-fertilize the ecosystem and cause an explosion in algae population--an algal bloom. When this huge mass of algae dies, however, it consumes oxygen in its decomposition, lowering the dissolved oxygen content for the waterway in general. Eutrophication has been a major problem in estuarine areas, like the Chesapeake Bay in Maryland, USA and continues to be a problem in freshwater lakes and ponds as well.
- Metals
Trace metals are required for aquatic life but in higher concentrations heavy metals, such as iron, lead, mercury, aluminum, and magnesium are toxic to fish, especially at low pHs (PA FBC). One reason metal toxicity is such a problem is that no natural processes exist to neutralize or remove them (Chapman, 1996). Metals also tend to accumulate in bottom sediments (Chapman, 1996), which presents a problem if those sediments are later disturbed. Industrial wastewater discharges (point-source) and mining are common metal sources, although metals like lead (from automobiles) can also come from atmospheric deposition. Al, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn, As, and Se are the commonly monitored "metals" although Be, Tl, V, Sb, Mo are also important if it is believed they will occur in an area (Chapman,1996).
- Detergents, pesticides, industrial toxins, pharmaceuticals, etc.
There are a variety of other toxins that can harm fish, even in small quantities. Some toxins, such as PCBs and chlordane are not only toxic but also tend to bioaccumulate, meaning they build up in members higher in the food chain so that large fish have high levels of these contaminants in their fatty tissue. Not only is this detrimental for fish and ecosystem health, but it is also a danger to consumers, who can also take up the toxins. Health advisories are in place in many parts of the United States for high levels of mercury, PCBs, and chlordane in many fish and other aquatic species (see state fishing regulations, for example). However, other contaminants that may seem innocuous, like pesticides, can have severe effects of aquatic ecosystems, by poisoning the most sensitive organisms. There is also evidence that pharmaceutical products, especially hormones, in the water has been causing health problems in many species (Boxall et al, 2003). Contaminants like detergents, petroleum products, and industrial toxins also can be carried into waterways at the detriment of ecosystem health
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Obstruction to Migration:
DAMS
I. Significance: Humans need fifty liters of water per person per day on average (World Commission on Dams, 2000). Less than .007% of the water on earth is liquid freshwater that is regularly cycled and renewed (Human Appropriation).
The world population is increasing at an unprecedented rate and urbanization is occurring at a similarly impressive scale. These increases will result in a larger demand for limited water resources; due to uneven water distribution, it is expected that one-third of water stressed countries will experience severe water shortages in the next century (WCD, 2000). Currently, most water is used for agricultural purposes, especially in developing countries. Currently, dams are a major factor in obtaining the water we so desperately need.
In the 1970's, there was a major boom in dam construction, especially in China, the United States, Japan, Spain, and India (WCD, 2000). Currently, of the thousands of large dams (defined by the International Commission on Large Dams as dams with a head height of over fifteen meters) 2/3 are in developing countries (WCD, 2000). These dams fulfill a variety of functions including but not limited to water storage, hydroelectric power generation, and flood control. The figure at the right shows the distribution of dams by the their functions. One third of countries rely on hydropower for over half their energy needs (WCD, 2000). Overall, it is easy to see the incredible importance and economic impact of dams. However, there are many environmental and social problems associated with dams. Dams have a significant impact on the marine fisheries, either directly through destruction of spawning habitat or blocking migration or indirectly by increasing pressures on marine fisheries.
II. Issues: Of the several problems associated with large dams, they can be broken into several categories:
1) Changes to the chemical and physical properties of a river
2) Biotic changes to the ecosystem resulting from the aforementioned riverine changes
3) Human impact due to change in either the river or ecosystem According to the World Commission on Dams, 46% of the 106 primary watersheds on earth are affected by dams. These effects can included temperature changes (water held in a reservoir warms, while water which is released over the dam's head is cooled), dissolved oxygen level changes (again, the warmer water in a dam's reservoir will have lower DO levels resulting from higher water temperatures and slower water velocity, while water below the dam may become super-saturated with oxygen and poison fish). These changes often favor invasive species, which can then outcompete the native biota. Dams also change the natural flow regimes, which are important triggers for biological cycles. Flow levels can enhance or suppress reproductive success for many species, as well functioning in redistribution of substrates and bed-loads (Young, 1997). Furthermore, starvation of sediments because of retention by dams can alter the substrate composition downstream with huge effects on fish; studies on the Colorado river indicated that natural reproduction of fish species was suppressed because sand-bar formation had ceased due to a lack of sediments (Young, 1997). The WCD reports that in many cases wetlands may dry out and recharge of groundwater is diminished. Besides "trapping" water behind them, dams also act as particle traps, holding back nutrients and sediment. The downstream ecosystems that rely on these nutrients can suffer severely; the crash of Kokanee salmon was attributed to the drastic decrease in nutrient loading caused by the construction of two dams (Wuest). The changes in sediment transport can heavily influence the channel, floodplain, and delta morphology. In coastal areas, the erosion caused by waves is no longer counter-acted by deposition on sediment; the WCD reports that the coastline of Togo and Benin has decreased by 10-15 meters per year after the Akosombo Dam on the Volta River was completed. There are indications that this may also result in a lack of floodplain fertility.
One of the largest problems facing biota in face of dams is obstruction to migration; dams provide a large, physical barrier to aquatic passage. Diadromous fish (includes anadromous fish, which live in salt water and spawn in freshwater--such as shad, sturgeon, and salmon-and catadromous fish, which live in freshwater and spawn in salt water--notably eel) are in many cases entirely unable to reach their spawning grounds. Salmon and shad have died out in areas due to dam construction (WCD, 2000); in the United States, shad populations rebounded only after extensive stocking and fish passage efforts (Richardson); in the Caspian Sea, sturgeon must be stocked because dams entirely obstruct their reproduction (WCD, 2000). Dams can also obstruct the movements of aquatic insects and larval clams (glochidia); reductions in these populations, which serve as food for higher order predators can have chain reaction affects on fish populations. Dams have been reported as the largest cause for freshwater species extinction (WCD, 2000). Loss of freshwater species as a food source (6% of fish caught are from freshwater) may result in more pressure being placed on marine species, so it is important to regard the loss of those species as important to overall ability of the ocean to provide fish (WCD, 2000). Thus far, it is estimated that 20% of freshwater fish have become extinct, endangered, or threatened in recent years.
However, it is not just by obstructing fish passage that dams affect marine fisheries. Dams have been shown to decrease catches of fish in upstream portions of rivers (ex. Senegral and Niger Rivers, Nile Delta, and Zambezi River) which again may put more stress on marine fisheries (WCD, 2000). Downstream, changes in freshwater flows and nutrient levels can influence the estuarine habitats where many marine fish come to spawn. Lowered nutrient levels can result in lowered overall productivity from a diminished food source, as occurred with the Aswan High Dam in Egypt (WCD, 2000). Furthermore, increases in salinity from lessened freshwater flows can allow marine predators to invade can lower recruitment rates (WCD, 2000). The overall effects of these changes can be significant; in the Zambezi Delta, there is an estimated $10 million loss per year from the shrimp fishery (WCD, 2000).
Other problems associated with dams that are not related to fisheries at large but are large-scale impacts of dams, include displacement of native people (40-80 million) and a diminished ability of native people to collect the river's resources (WCD, 2000). Dam reservoirs also emit greenhouses gases, at times at levels larger than the area in a pre-dammed state, which can be a factor when dealing with climate change issues and legislation (WCD, 2000). It is also notable that in solving these issues, international politics may come heavily into play, as 261 watershed cross political boundaries and water security issues have been heated in the past (WCD, 2000).
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Habitat Destruction or Alteration:
Conversion of coastal ecosystems for agriculture or aquaculture has adverse effects on marine fisheries because it destroys the habitat of exploited fish stocks. For example, conversion of mangroves in a number of South and South-East Asian countries during the mid 1990s caused an increased risk of diseases in wild stock. It also significantly reduced the recruitment and survival rate of the stocks. Since some 90% of fish stocks depend on coastal habitat for at least parts of their life cycle, this habitat is critical. (Perrings 2000)
Areas of special concern include wetlands, coral reefs and mangrove swamps.
Wetlands:
According to the EPA, a wetland is an area where water covers the soil, or is present either at or near the surface of the soil for significant portions of the year, including during the growing season. Wetlands act as the transition between the land and the water. The hydrology of the site or the amount that the water is saturated plays an integral part in the composition of the soil and on the aquatic life that lives there. Wetlands are unique ecosystems as they support both terrestrial and aquatic life. The prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promote the development of characteristic wetland (hydric) soils. !aerial2LG.jpg!Source: USGS
Wetland soils are saturated long enough in the growing season to create an anaerobic (low oxygen) state in the soil horizon (the layers of soil found as you dig a hole) The wetlands soil becomes so saturated with water that it cannot hold much, if any, oxygen.
Wetlands are often called "nurseries of life", meaning they support thousands of species, both terrestrial and aquatic. But they do more than just provide a habitat for these animals. When rivers overflow, wetlands help absorb the flood waters, which can help alleviate property damage and loss.
Rain water runs-off and brings exposed soil sediment (or particles) towards larger bodies of water. In water, sediment may either settle to the bottom or remain suspended in the water column. Settled sediments may destroys the spawning grounds for fish and may suffocate fish eggs. Sediments may also smother macro-invertebrate benthos---an important source of food for fish. Suspended sediment also affects aquatic organism. Sediment makes water more opaque so the water temperature increases. It can also abrade fish gills and make feeding difficult for fish that rely heavily on site for finding food.
Wetlands, in general, slow water velocity which allows much of the suspended sediment to settle out (slow moving water can transport a smaller sediment load). Plants within the wetland also mechanically slow sediments. This helps prevent the sedimentation (or mud-clogging) of streams, lakes, or rivers.
Runoff entering wetlands contains much more than just sediments. Pesticides, excess nutrients from fertilizers, bacteria, salts from winter road maintenance, and other chemicals also wash from the land and enter our water ways. Studies have found that after this polluted water has flowed through a wetland it becomes much cleaner. Wetlands, with their dense plant life and unique anaerobic environment can protect downstream waters from these substances by using the extra nutrients for plant growth, and storing and breaking down the chemicals. This filtrating process improves the quality of the water for wildlife and humans. (Dietz)
In an economic perspective, about 75% of the nation's commercially important species of marine fish and shellfish, and 80-90% of recreationally important species are dependent for their survival (for spawning, nursery, migration and feeding areas) on shallow inshore waters that include bays, estuaries and rivers flowing to the sea (Vymazal, 2007). However, the importance of wetlands is perhaps best shown by example:
New OrleansThe coastal area of New Orleans discovered the importance of wetlands first-hand through Hurricane Katrina. Every 2.7 miles of marshland reduces a hurricane surge tide by a foot, dispersing the storm's power. Simply put, had Katrina struck in 1945 instead of 2005, the surge that reached New Orleans would have been as much as 5-10 feet less than it was. These marshes, as well as the barrier islands, were created by the sediment-rich flood waters of the Mississippi River deposited over thousands of years. But modern levees have prevented this natural flooding, and the existing wetlands, starved for new sediments and nutrients, have eroded and "subsided;" they just washed away. Every ten months, even without hurricanes, an area of Louisiana-land equal to Manhattan is covered by water---50 acres per day, a football field every 30 minutes (Tidwell, 2005).
Three Gorges Dam in ChinaIn China, The Yangtze River branches out into a broad estuary that stretches 655 kilometers into the East China Sea, and forms one of the largest continental shelves in the world. Over half of the Yangtze's annual sediment load is deposited in the estuary. The health of the estuary depends on the delivery of this sediment because a significant relationship exists between inter tidal wetland growth rate and riverine sediment supply. Yet, due to the Three Gorges project and other dams, the sediment accumulation rate in all reservoirs on the river has increased from close to zero in 1950 to more than 850 * 106 tons per year in 2003. This is causing erosion of the wetland habitat there, which provides nurseries for fish and resting areas for migratory birds and is considered one of the world's most important wetland ecosystems. There is also concern about the impact the project will have on biological diversity. The baiji dolphin, the ancient river sturgeon, and the finless porpoise depend on the Yangtze for their survival. The population of Siberian cranes in Poyang Lake will also be affected by the dam (Cleveland 2007).
Coral Reefs !GrecianRocks.1965.jpg|width=547,height=358!A star coral. Source: USGS
Coral reefs are unique and beautiful ecosystems. They have the most species per unit area of any marine environment and hold perhaps 1-8 million as of yet undiscovered species (Reaka-Kudla, 1997). These species hold great promise for new pharmaceuticals (NOAA) and also provide goods and services worth $375 billion per year, despite their only covering under 1% of the Earth's surface (Costanza et al, 1997). Developing countries rely on coral reefs for approximately ¼ of total fish catch (Jameson et al, 1995). Coral reefs offer benefits to people living in coastal areas by acting as buffers to wave action; they may also protect coastal wetlands (NOAA).
Currently, wetlands are threatened by many natural and anthropogenic forces, significantly, pollution from land (NOAA). Eutrophication--the overfertilization of aquatic ecosystems--affects coral reefs especially because the algal growth can smother the coral (Jones and Endean, 1976). Oil spills also can negatively affect coral spawning (Bryant, et al, 1998). Direct destruction from practices such as harvest for aquariums, blast fishing, careless diving, cyanide fishing, and trawling also destroy coral reefs (NOAA).
Mangrove Swamps !ellen1.jpg!Source: USGS
According to the U.S. Environmental Protection Agency, mangroves are coastal wetlands found in tropical and subtropical regions (2006). Mangroves are characterized by trees or shrubs that have the common trait of growing in shallow and muddy salt water or brackish waters, especially along quiet shorelines and in estuaries. These halophytic trees are able to thrive in salt water conditions because of specialized rooting structures (such as prop roots and pneumatophores), specialized reproduction (vivipary or live birth) and the ability to exclude or excrete salt (Lee County Government). In North America, mangroves are found from the southern tip of Florida along the Gulf Coast to Texas. The importance of mangroves has been well established. They support a wide diversity of animals and vegetation since these estuarine swamps are constantly replenished with nutrients transported by fresh water runoff from the land and flushed by the ebb and flow of the tides (U.S. EPA 2006). They also play a pivotal role in the life cycles of aquatic organisms. For example, they function as nurseries for a variety of marine biota, For example, seventy-five percent of the game fish and ninety percent of the commercial species in south Florida depend on mangrove ecosystems (Law et al.). In addition, these coastal wetlands are valued for their protection and stabilization of low-lying coastal lands from storm winds, waves, and floods. The amount of protection afforded by mangroves depends upon the width of the forest (Lee County Government). Although mangroves are increasingly threatened by anthropogenic activities (such as the damming and mangrove conversions), efforts are underway to enhance the protection of these threatened and valuable ecosystems (U.S. EPA 2006).
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(5) Invasive Species !1354035_lg.jpg|width=194,height=176!A seemingly innocuous invader, the zebra mussel, has devastated fisheries and industries in its host lands. Source: USGS !db_snakehead0031.jpg!The invasive snakehead. Source: USGS, Artist: Susan Trammell
Invasive species are non-native species that have been introduced to a water-way and that have been able to establish themselves in that ecosystem at the expense of other species. Increase in invasive species is correlated with a decrease in overall biodiversity and loss of ecosystem services and is a major concern in coastal ecosystems (Worm et al, 2006). Invasive species often upset the entire ecosystem balance, driving less competitive species into extinction and fundamentally altering the food web. High profile examples include the proliferation of zebra mussels in the Great Lakes--which have caused the decline in many native species and caused many industrial problems--and the Nile perch, which caused the extinction of hundreds of aquatic species in Lake Victoria. Invasive species are listed as the second greatest source of species extinctions (Wilcove et al, 1998).The figures at the right illustrate the interrelations between biodiversity, ecosystem services, and risks; species invasions is shown at the far right under "risks."
Invasive species are often transported via ballast water, or water taken on-board ships to keep it level in water. The water is taken from the starting point and then released at the end point--along with any organisms living inside. High risk ballast in regards to transport of invasives is water taken onboard in a freshwater or estuarine port as those organisms have a high chance of surviving in their new environment (Portland University, 2006). Invasives are also released intentially-as with unwanted pet release or through aquarium dumping--such as the release of the red-eared slider in the United States.
An important aspect of the invasive species problem is the difficulty in redressing the issue once a species is established. Once an invasive is present in an ecosystem, it is nigh impossible to remove it from the ecosystem; thus, the issue is one of preventing species from arriving, since the damage is essentially irreversible.
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Water Quality Assessment and Regulation
In order to determine the management techniques for a specific waterway in respect to water quality, it is necessary to know the current and desired water quality levels for the waterway. Since the surroundings, hydrology, biota, etc. for each waterway differs, it is not feasible to generalize management techniques for each waterway, especially as water quality variables often interact (such as pH and dissolved metals concentration) (Chapman, 1996). As such, it is necessary for each country to establish a system of water quality monitoring and a set of regulations regarding water quality levels. !RPE_AL_Dist5_lg.jpg!Source: USGS
The water quality regulations should set:
(1) minimum standards for levels of various contaminants
(2) biological standards for water quality
(3) an anti-degradation policy (i.e. a waterway's state cannot decrease in quality)
The water quality should be measured both by concentrations or levels of contaminants as well as by biological measures, as these measures are more robust to temporal change (a chemical dump into a waterway, for example, can kill a large amount of biota in a waterway but can flush rather quickly, so chemical water quality analyses may not detect the contaminant unless the measure happened to occur soon after the incident; however, a lack of biota in the area will indicate that a contaminant was present) [adapted from US EPA policy].
Furthermore, a permitting process for activities that are likely to cause environmental harm (such as earth moving operation or construction and discharges into waterways) should be instituted so that environmental harm may be assessed and so that plans for development are sensitive to environmental needs. The permitting process allows the government to have a say in how the activity is carried out and to set regulations specifically for that project.
As indicated by the WHO (World Health Organization) in their report on Water Quality Assessments, the choice of water quality parameters to be selected can depend on the use of the waterway or on the expected pollution source. We recommend that for major waterways that drain directly to the ocean and for estuaries that water quality tests be conducted regularly; standards should be sufficient to support aquatic life in all cases. Initial attention should be given to the largest waterways or those that are expected to be highly affected by pollutants (i.e. those travelling through an industrial sector or city), so that problem areas and areas of great importance are addressed first. Furthermore, by testing a larger body, the effects of tributary streams are taken into account, as those contaminants will still be present in the larger waterway. These tests should include the following parameters recommended by the WHO for aquatic ecosystems (see chart below). From the data collected with respect to these parameters, the state of the waterway can be assessed and various solutions can be implemented.
Temperature |
Suspended solids |
Turbidity/transparency |
Conductivity |
|
Total dissolved solids |
pH |
dissolved oxygen |
hardness |
|
chlorophyll a |
ammonia |
nitrate/nitrite |
chemical oxygen demand |
|
biochemical oxygen demand |
cyanide |
heavy metals |
arsenic and selenium |
|
oil and hydrocarbons |
organic solvents |
phenols |
pesticides |
|
surfactants |
|
|
SOURCE: Chapman, 1996 |
|
For parameters that are found to be below the standards, the source of the contamination should be identified. For point-source pollutants that were discharged before the implementation of the law, the perpetrator shall be notified of their infraction and mandated to stop the discharge and also be given a time frame (suggested time is a year) in which the pollutant's effects must be mediated in order for business to continue. For point-source pollutants that were discharged after the implementation of the law, the perpetrator must pay a fine in to cover the expense with regard to the environmental damage.
For non-point source pollutants, there are several ways to reduce the effects. Non-point source pollutants are carried into the water by run-off. Water travelling over the land picks up soil and other contaminants and carries them into the waterway. To reduce the concentrations of these contaminants, maintenance and re-establishment of riparian buffers is an effective solution, as is maintaining and re-establishing wetlands.
Biological indexes and standards are independent of the pollutant source; they merely categorize the species composition of an area by abundance of species sensitive to pollutants or environmental disturbance, of species somewhat sensitive, and of species tolerant of such disturbance. The complexity of the indexes can vary, but the underlying principle is that a healthy waterway has a variety of species of all three categories, and impaired waterways have a smaller variety and the variety that is possessed falls into the bottom two (or bottom) category. If biological monitoring is considered too expensive, it is possible to choose a method of sampling that is less expensive by sampling fish and large macroinvertebrates, since effects will eventually manifest in these levels; studies by the EPA have shown these studies to be more cost effective (EPA, 1988). However, it is important to note that small amounts of contaminants will affect the young and most sensitive organisms first, which may not necessarily be the fish. Monitoring of the habitat may also be taken into account.
The EPA's guide to establishing a biological index shows an example of how such a system may be implemented (http://www.epa.gov/waterscience/biocriteria/States/estuaries/estuaries.pdf).
With regards to discharge into waterways, the set water quality standards must be met; that is, discharges cannot change the quality of water to levels below those specified by the standards. Furthermore, the non-degradation policy necessitates that the quality level of the waterway cannot be lessened were it to exceed the mandated standards. To effect this, before a discharge is to be implemented, water quality measures should be taken to determine the baseline water quality of the waterway; note that water quality sampling parameters should be expanded or modified to accommodate pollutants that are likely to result from the industry in question. Both chemical and biological indexes will be used. Subsequent water quality measurements should be taken multiple times per year both above and below the discharge site; emphasis will be given to the biological indexes as it is more robust to temporal change, as aforementioned. If the discharge is found to be in the "pollutant" range, the company will be fined an amount sufficient to cover the environmental damage and proportional to the damage caused; the fine will be used to remediate the damage caused by the pollutant. Non-discharge offenses (i.e. dumping by a citizen or other unplanned discharges) will be dealt with in the same manner.
However, extraction of materials from ecosystems is also an issue in coastal zone management. Extraction of sediments or other mining operations causes severe changes in substrate composition and the overall habitat, not to mention the possible pollutant re-suspension involved in these operations (i.e. of sediments). Extraction of water itself also changes the aquatic ecosystem in many ways---both from a physical and chemical standpoint. Dams also fall into the category of large-scale changes to water flow, however, this issue is addressed in its own section (LINK TO DAMS PAGE?) because of the scope and specificity of the issue.
To address these aspects of regulation, research needs to be conducted to elucidate the relationships between the habitat parameters in question and the functionality of the ecosystem as a whole. For example, with dredging or sediment extraction, the functional role of the substrate formations should be investigated to discover if the extraction would negatively impact critical spawning or other ecosystem services and if such damages that are predicted could be redressed. Findings of such studies should then be applied to minimize disturbance to the environment if the activity still needs to occur; the principle of "avoid, minimize, compensate" as advocated by the US policy towards wetlands applies here---disturbances should be avoided, especially in fragile areas; effects should be minimized if the disturbance must occur by changes in planning; and if neither of the former two options are sufficient to address environmental impacts, compensation for the damage should take place in the form of habitat restoration or re-establishment. The permitting process is here instituted to provide a manner in which this process should occur and to provide a legal framework for this scientific process.
For water withdrawals (or large water discharges, specifically of coolant water) we propose the use of IFIM (Incremental Flow Incremental Methodology) to evaluate the effects of the withdrawal before it takes place, so that planning and permitting can take place before withdrawals begin. The IFIM model can be used to predict how changes in flow will affect various other water quality parameters like temperature and how these changes will affect fish populations (Young, 1997). (These results can be used in the permitting process to make initial suggestions and limitations; however, regulation should be elastic enough so that withdrawal limitations can be changed if harm is observed. Special attention should be given to processes which may fundamentally alter sediment and nutrient transport, as alterations can negatively impact estuarine and lower waters to an incredible extent, as is discussed in the section on dams.
Shipping RegulationShipping is a major source of contamination in coastal areas; ballast water, for example, is a large transport mechanism for invasive species, while oil tankers are a hazard for oil spills. Shipping regulations should be passed to minimize the risks associated with these threats and other issues that the government feels pertinent to its waters and shipping industry.
Invasive Species Transport !01178_lr.jpg|width=477,height=403!Sediment in a ballast tank; this sediment can host aquatic invasives. Source: NOAA
For international ships, the current wisdom is that the country should require that in order to come into port, the ballast water must be exchanged at sea, past the continental shelf. The idea behind this is that the a species can only establish itself if its biological needs are met and changes in salinity and water temperature as found between fresh or estuarine waters and open ocean are great enough to kill most potential invasives.(Portland State University, 2006)
While this may be an effective control in the present, future research should look to alternative forms of ballast that involve water contained in tanks that can be temporarily jettisoned and then reclaimed or other mechanisms to purify water within the ship. In this way, the transport of invasive species would be greatly diminished. Interested countries should support research into alternative forms of ballast.
However, many invasive species travel via other means---including intentional release (ex. Hydrilla in United States) (PA's 10 Least Wanted). To prevent this, strict trade regulations should be placed that prohibit the transport of non-native species into the country or from one waterway within the country to another (as species may be invasive in watershed in close proximity, as the sea lamprey was in the Erie watershed, despite its being native to the nearby Susquehanna watershed in Pennsylvania) (PA's 10 Least Wanted).
Tanker Spill Prevention
Regulations should be effected to mandate which types of boats may carry hazardous materials such as oil into a State's waterways. The regulations should include provisions for hull strength and prevention measures for a spill if the ship runs aground or afoul of rocks (i.e. a double hull). Ships should also be required to maintain current technology with respect to their containers, communications equipment (with shore), and navigation equipment (for avoidance of obstacles). Shipping lanes for oil tankers that are safer or easier to navigate may also be deemed beneficial. Ships should also be required to have an emergency response plan for the event of an oil spill that needs to be approved by the State whose waters are traversed. The State should also have an emergency plan on their end, so that quick action can be taken to contain the extent of the damage. Legislation should also be put in place that places the culpability of the spill on the possessor of the oil at the time. (adapted from the EPA's Oil Pollution Prevention and Response Final Rule, 2002)
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[child page 8]
Establishment of Riparian Buffers:
Riparian BuffersImportance:
Riparian buffers provide various important stream functions.
(1) Leaves that fall into the water provide energy for headwaters (i.e. a food source).
(2) Branches and roots provide shelter for in-stream organisms.
(3) Overhead leaf cover shades water and keeps it cool, by as much as 10° in summertime (Great Fishing).
(4) Roots hold stream banks in place and prevent erosion.
(5) Vegetation slows water velocity, thus reducing run-off induced erosion and also allows particulates (including many water contaminants) to settle out.
(6) Soils and root systems filter nutrients and pollutants (especially from agriculture and residential areas) before they reach surface areas from groundwater (Haberstock, 2000). !DCP00013.JPG!The vegetation on the sides of this waterway are an example of a riparian buffer. Source: USGS
These functions are not only important to the biota that lives in these regions year round, but also to anadromous species that come to spawn. For example, salmon require clean gravel for spawning; if silt settles over the gravel, it not only destroys suitable spawning substrate, but it can also smother eggs and the invertebrates that juveniles feed upon (Haberstock, 2000). Haberstock also reports that branches and other woody structures provide places for invertebrate prey to live, as well as structural habitat and varied flow patterns that are important for salmon. The improved water quality provided by riparian buffers and the cooling effect they provide are also critical (Haberstock, 2000).
Another important function of riparian buffers is their filtering capacity via the deceleration of water. As non-point source pollutants are difficult to regulate and control, it is critical to provide rivers with a defense against run-off contaminants.
Riparian buffers should be established along rivers; the width should be determined based on various criteria as detailed below.
The width of the buffer depends on many factors, especially the slope of the land (steeper slopes require wider buffers, since steeper slopes allow water to flow faster and water's ability to carry sediments increases exponentially with volume (Chapman, 1996), the permeability of the soil (less permeable soils require wider buffers because water takes longer to infiltrate), and the presence of overland water sources--like intermittent streams or gullies-which can render small buffers ineffective (Haberstock, 2000). The type of vegetation-such as wooded or ground level vegetation--as well as factors such as duff height can influence buffer efficacy (Haberstock, 2000). Buffer width is measured from the end of alluvial soils (floodplain edge) (Haberstock, 2000). Haberstock also notes that wetlands in these areas should be preserved, because they function more effectively in nitrogen-fixation and retention of contaminants and sediments; the issue of wetlands preservation is detailed in a later section (LINK TO WETLANDS PAGE?). Ideally, a consult should be taken to determine the ideal width for an area.
However, if it is not economically feasible to establish a buffer of the recommended width, it is still beneficial to establish a riparian buffer of a smaller width. Studies have found that buffers of 20 feet of native grasses can remove up to 90% of nutrients and 80% of sediments (Lutz). Furthermore, a riparian buffer does not mean that no human activity or industry can take place in these zones; for example, selective logging can take place if best-management practices are followed (for example, see http://mdc4.mdc.mo.gov/documents/441.pdfpages 5-21) and some agriculture such as growing nut trees can easily serve as a buffer and a source of income.
Riparian buffers also are significant because they offer a potential mediation against the effects of increased precipitation and run-off predicted by some models of climate change (IPCC). Overhead leaf canopy mechanically slows water velocity as it falls thereby reducing the eroding capacity of the water and the ability of it to carry other particulates.
In terms of scale of implementation, regulation should be enacted for the preservation of existing riparian corridors. However, additional efforts and funding should be provided to establish new buffers in problematic areas or in re-establishing destroyed buffers. Tax incentives to maintain or establish riparian zones, funding for establishment, and regulations for the maintenance of these zones can be used to effect this.
[end of child page 8]
[child page 9]
Establishment and Protection of Wetlands and Other Fragile Ecosystems:
Legislation should be enacted to provide for the protection of wetlands against disturbance or destruction. Again, the principle of "avoid, minimize, compensate" should be realized with the application of a permitting process, which identifies wetland areas and has provisions for their maintenance. In this way, harm of a wetland is the last resort and must be mediated by the construction of another wetland or by a fine paid to the government for the construction of such a wetland or for enhancement of another wetland, as the government sees fit. (See [LINK TO RIPARIAN BUFFER PAGE] for this concept's application to riparian areas).
In areas where wetlands have been historically depleted, wetland re-establishment should be considered and economic incentives such as tax breaks could be offered to encourage the implementation of wetland re-establishment. These projects should be researched prior to planning and should involve consultation with experts. It should also be noted that re-established or created wetlands may not perform ecological functions to the extent that the previous wetland or that other wetlands do.
With respect to the time-scale implementation of legislation or prioritizing wetland preservation, special attention should be given to wetlands that possess species of concern (i.e. Endangered Species), wetlands that are unique, and wetlands that are functionally critical. An example of this type of prioritization can be seen in the Ramsar Convention's Wetland's of International Importance list (http://www.ramsar.org/about/info2007-05-e.pdffor criteria).
Our goal in creating a more stable and healthier fish population as it pertains to wetlands translates to lessening the rate of depletion of wetlands and restoring needed wetlands on a basis of regional necessity. While the lack of them is common across the globe, the need for specific ones and often the destruction of them due to natural disasters or human interference varies with location. Thus an important compilation of both local task forces, primarily lead by wetlands international (a compilation of regional offices and groups) assisted by and encouraged by laws and regulations is the best solution. Organizations like Wetlands International play a particularly important role in this setup because they both organize the needed local tasks forces and catalyze the political action process. Wetlands International's mission statement serves to clarify its duality in its proposal that it "works in local areas to help create restoration programs combined with stricter enforcement," (Finlayson, 2006).
A similar tactic should be employed for coral reef protection, especially with regards to regulation of destructive practices. Coral reefs should be given top priority in terms of aquatic resource protection. Educational efforts should also be expended to encourage public support for coral reef protection; education in this sector should be effective considering the immense beauty and intrinsic value in these areas. Other unique and critical habitats should be afforded specific legislative protection as well.
Tourism
Tourism to these unique ecosystems may be a source of income and also may make protection of these ecosystem easier as it will increase public knowledge and support for their existence. For coral reefs in the Florida Keys, the economic benefit derived from tourism is valued at $7.6 billion (Johns et al, 2001). The subsidy of ecologically friendly tourism ventures in these areas should be considered as a way to increase
interest in this area. Regulations should be in place, however, to ensure that ecological harm does not occur to these areas due to increased human and boat traffic.
[end of child page 9]
[child page 10]
(4) Dam Planning and Regulation:
States should impose a permitting process for dams so as to have a direct role in the planning and implementation of regulations. For dams that have not yet been built there are many steps that can be taken to minimize the impacts. First, efforts should be extended to maximize energy and water efficiency as much as possible; in the past, increases in technological efficiency, recycling, enforcement of environmental legislation, and industrial minimization of intensive water use resulted in a water consumption rate increase much lower than the population demand pressure (WCD). This can be seen as a cost effective method, considering that large-scale dam projects require an incredible amount of capital and are usually both over budget and are completed later than scheduled (WCD). However, if a dam is definitively needed, research should be thoroughly conducted to determine the environmental impacts. The World Commission on Dams reports that many of the negative impacts from dam construction resulted from complications that were unforeseen; it predicts that use of environmental impact assessments could significantly lower these effects (WCD). A State should consider requiring the implementation of these assessments for any project proposed within the permitting process. Furthermore, proper placement of dams (such as on tributaries rather than on a main branch) and the use of minimal numbers of dams on a given river (because multiple dams can have cumulative effects, such as the dams leading to the Aral sea, which decreased water flow to such an extent that an increase in salinity and pollutants caused the entire fishery to collapse at a cost of approximately $1.25-2.5 billion per year) should be legislated by governments as these restrictions can minimize the large-scale negative impacts of large dams (WCD). Once these data are collected, the dam planning may begin; in this way, the dam design can take into account such features as gates that allow managed flood releases on a scale that can mitigate effects to the ecosystem; the permit for dam construction can require these provisions. The use of such managed floods in Kenya has been economically favorable by maintaining sectors of the economy that relied upon flows that would have been blocked entirely by damming (WCD). These floods help to release nutrients and sediments and help lessen the impact of the dam overall (WCD). These managed floods should be tailored to a specific river, as flood cycles are highly unique. It is important, however, that all such planning occurs before dam construction, as post-construction mitigation techniques have not been shown to be effective; the WCD reports rates of 20% effectiveness. It is possible that the IFIM (Instream Flow Incremental Methodology), as described earlier in (LINK TO WATER QUALITY ASSESSMENT AND LEGISLATION) could be used to help predict the effects of a dam and the effects of controlled flooding. !damphoto.gif!Source: USGS
In terms of fish passage, fish passes have a very low success rate currently. In Norway, fish passes report a 26% rate of "good efficiency" and 32% of no success at all (WCD). In many parts of the world, fish passes are not used at all. Also, even with fish passes, fish often suffer from a lack of environmental cues (like currents) that help them find their spawning site (WCD). However, properly designed fish passes (specific to each dam and species of intended use) do hold promise; in Pennsylvania, fish passes were ineffective until tailored to the American shad, at which point they became very helpful in shad restoration (Richardson). Fish hatcheries and stocking may also be required to augment populations until the spawning routine is re-established with the dam in place; successful restoration of American shad and striped bass required such measures (Richardson), and these methods are likewise advocated by the WCD. The creation of artificial wetlands around shallow dam can also help mitigate dam impact by providing new habitat (WCD). Our recommendation is for governments to require dams to create a fish pass specifically designed for that river and its species or to pay a yearly fee to the government which can be used for species restoration and research; the law can stipulate these provisions if the company wishes to operate.
For developed countries with large budgets and effective environmental legislation (such as France and the United States) decommissioning dams is a solution for aiding fish in special habitats (historically for salmon) (WCD, 2000). While short-term effects of dam removal include large-scale sediment flushing, over relatively short time scales fish will return and spawn in those areas. However, dam removal is costly and must be studied beforehand; in many cases, toxins and chemicals can build up behind dams and the effects of these toxins washing downstream can be severe (Francisco).
For existing dams that are negatively impacting fisheries, studies should be conducted on a site specific basis to find solutions for the particular issue; as was aforementioned, potential solutions include controlled flooding and wetland installation and can also extend to direct mitigation of consequences, such as introduction of nutrients downstream of the dam (Wuest). Limitations to these solutions may range from budgetary concerns to design limitations of the dam itself.
To implement these suggestions, countries should establish a permitting process that fully encompasses the scope of a large dam process in regards to the wide range of benefits and costs. By legally requiring this process to occur, the best way to create a dam can be found and later consequences can be taken into initial design.
[end child page 10]
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