Estuaries 1
Estuaries
are features of the coastal landscape where the mainland, barrier islands, or
vegetation semienclose a water body made brackish by the mixing of salt and
fresh water. Estuaries typically
contain marine plants and animals having anatomical, physiological, or
behavioral adaptations to the changing conditions found in estuaries. Estuaries produce numerous kinds and vast
amounts of sport and commercial fishes and provide numerous other ecological
services of direct and indirect value to humans (Douglas and Stroud 1971;
Wharton et al. 1977).
Florida
estuaries vary greatly in size, productivity, and health. Freshwater supplies to estuaries in the
state range in quantity over six orders of magnitude, from the periods of no
flow into the Myakka River estuary to peak flows of the Apalachicola River
(approximately 100,000 cubic feet per second).
The area of these estuaries can be measured in acres, as in the case of
tidal creeks and springfed streams entering the Gulf of Mexico, to the thousand
square miles of mangrove forest and brackish water in the Florida
Everglades. Florida estuaries differ
widely in shape and depth as well; estuaries such as the Indian River on the
Atlantic coast are long and narrow, whereas estuaries located on the Gulf coast
are more expansive. Tampa Bay, for
example, is 35 miles long, 10 miles wide, and connected to the Gulf of Mexico
by Egmont Channel, the deepest natural feature on the Florida coastline.
Fresh Water in Florida Estuaries
Not
all coastal embayments or waters sheltered by barrier bars are estuaries. The salinity (or effective concentration of
inorganic solids and salts or equivalents of salt) and quality of water varies
in estuaries, and salinity is lower than that of adjoining marine waters. Fresh water flows into Florida estuaries via
surface runoff or is discharged from underground water sources. The contribution of ground water to most
estuaries is poorly known, although records exist of early sailors and settlers
obtaining potable water at the surface of Biscayne Bay and other coastal areas
(Kohout and Kolipinski 1967). By 1980
numerous inshore and deep submarine springs had been discovered around the
Florida coast. However, because ground
waters of peninsular Florida originate from surface waters, the fresh water
supplied to an estuary can be said to originate from its respective watershed
and recharge area.
The
amount of fresh water entering the estuary by any route depends upon rainfall,
infiltration, evapotranspiration, watershed size, and human alterations of the
landscape. Changes in the quantity,
timing, and quality of fresh water reaching the estuary are critical to its
health and productivity. The amount of
discharge determines the geographic pattern of salinity gradients, and timing
affects the persistence and predictability of the gradients and numerous
ecological responses, including harvests of sport and commercial fishes. Discharges of fresh water to the St. Lucie
estuary, for example, significantly affect catch rates of nine important fish
species (Van Os, Carroll, and Dunn 1981).
Snedaker
and DeSylva (1977) identified several roles of fresh water in estuaries. The discharges of rivers import substances
to estuaries. In Apalachicola Bay,
river stages are correlated highly with levels of detritus (particulate organic
matter) reaching the estuary. The
detritus drains from inland forests and is flushed from tributaries,
accompanied by dissolved organic substances, color, lower pH and turbidity, and
elemental nutrients such as phosphorus and nitrogen (Livingston, Sheridan,
McLane, Lewis, and Kobylinski 1977).
Contaminants such as organochlorine residues may also be present
(Livingston, Thompson, and Meeter 1978).
Estuarine animals have been seen to avoid stormwater runoff in the bay;
juvenile and adult blue crabs avoid acidified runoff from recently cleared
fields, for example (Livingston, Cripe, Laughlin, and Lewis 1976).
Physical
forces exerted by fresh water in an estuary can affect estuarine organisms
significantly. In Charlotte Harbor,
sediment transported down the Peace River accumulates in mangrove and tidal
marshes above Punta Gorda. The
bathymetry and shape of the upper harbor are controlled by the channels and
discharges of the Peace and Myakka rivers.
During the rainy season, surface salinity may fall to zero over a large
part of the upper harbor and depress salinities at Boca Grande. Vertical stratification becomes pronounced
as fresh water overflows salt water.
Substances in solution may precipitate and solids will flocculate at the
interface of fresh and salt waters.
Levels of dissolved oxygen beneath the blanket of fresh water decline to
levels injurious to bottom-dwelling fishes and invertebrates (Fraser 1981).
Fresh
water creates a unique physiological, behaviour, and ecological environment in
estuaries. In the co, Everglades, fresh
water delivers nutrients to mangr and reduces their salt stress, resulting in
peaks of litte (a measure of productivity) during and after the ' wet
season. Fresh water promotes the export
of litter and' dissolved organic matter by stimulating their formation and
contributing to the physical forces driving the foodstuff from the forest. Seasonal differences in rainfall and runoff
to the mangrove forests result in cycles of food abundance and decreased
salinity. These cycles and spatial
salinity differences throughout the forest are correlated with feeding,
reproduction, migration, and population growth of benthic infauna (polychaetes,
mollusks, and small crustaceans) and epifauna (larger crustaceans, like the
shrimp and blue crab), numerous sport and commercial fishes, and a variety of
sea and shore birds. The timing of
salinity changes acts to cue numerous species that migrate to sea or into
rivers to complete their life cycle.
Salinity gradients in the Everglades also create refuge for larval and
juvenile animals and diversify the biota.
For example, species of algae, invertebrates, and fishes in the
Everglades near the Gulf differ in their identity and abundance from species
closer to the mainland.
The
intimate relationship of fresh water to estuaries may also have less desirable
consequences. Two of the five rivers
discharging to Tampa Bay, for example, are impounded by dams and a third dam is
planned (Dooris and Dooris 1984).
Another river was completely channelized, rerouted, and checked by locks
to prevent flooding in developed lowlands.
These physical alterations affect the quantity and timing of freshwater
discharge to Tampa Bay estuary. Fresh
waters deliver substances which by their quantity or biological toxicity are
inimical to estuarine life. Discharges
of the Alafia River deliver phosphate, flourides, and radionuclides in amounts
greater than naturally occur in the Hillsborough Bay estuary (Estevez and
Upchurch 1984). Acid runoff and
effluent from shoreside chemical plants have destroyed areas of once productive
bay bottom. The effluent from numerous
sewage treatment plants enrich the bay with nutrients and oxygen-demanding
substances (Moon 1984) and stormwaters deliver metals, pesticides, and other
contaminants from developed uplands (Giovanelli and Murdoch 1984). The economic and environmental costs of such
abuses to Florida's estuaries are undoubtedly high but at present are not well
documented.
Value of Estuaries
Emerging
from the shorelines and buried beneath estuaries along the Florida coast are
symmetrical ea works formed by the state's earliest human inhabitants. These refuse piles, living areas, and
ceremonial mounds are impressive testimony to the importance of estuaries as
sources of food, clothing and building material, tools, and other valuables
(Goggin and Sturtevant 1964). Estuaries
were then and are today rich concentrations of shellfish, and fish and other
vertebrates ;
The
productivity of the state s estuaries is made possible by the photosynthesis of
estuarine plants which are attuned to the Florida climate, particularly
sunlight, temperature, and supplies of fresh water and nutrients. Macroalgae and microalgae (phytoplankton)
occur in all Florida estuaries.
Macroalgae grow as large, drifting forms and as forms attached to sand
or mud, rocks, or other plants. Several
species of grasslike monocots grow in and near estuaries. In addition to their high productivity,
seagrasses trap sediment and stabilize the substratum and provide habitat and
refuge for marine life. Salt marshes
and mangrove forests grow as approximate analogs on tidal shores. In , many Florida estuaries, marsh and
mangrove communities grow together in a complex and productive mosaic
maintained by freezes, water stress, or tropical storms (Estevez and Mosura
1984).'Mangroves and salt marshes are replaced by freshwater vegetation above
the tidal reach of estuaries in rivers.
Freshwater and terrestrial plants contribute litter and detritus to
estuaries during the wet season.
Algae
and vascular plants are consumed directly by herbivores. Zooplankton, including fish larvae, microalgae, and mollusks and crustaceans
graze macroalgae and seagrasses. Vast
quantities of decomposing marsh and mangrove litter are consumed by filter
feeding and deposit feeding invertebrates and fishes. Food particules are enriched by microscopic bacteria, fungi,
algae, and animals during the decaying process. Very fine organic matter eventually dissolves and can be absorbed
by animals in every major estuarine group.
The enormous supply of food in estuaries results in high secondary
production, including the propagation of edible shellfish and fishes. Other animals grow in size and number to
sustain birdlife, dolphins, and other top carnivores.
Another
set of estuarine functions unrelated to direct consumption but of human concern
is the concept of estuaries as zones of transition. On the one hand, estuaries buffer coastal environments from
developed uplands and watersheds by sequestering heavy metals, biocides, and
other contaminants in runoff. Nutrients
and organic matter are retained and recycled by chemical and biological
processes. (In the same manner, toxic materials can be passed front prey to
predator with serious consequences to top carnivores.) On the other hand, the
estuary and its wetland fringe dampen the assault of storm surges, red tides,
and other offshore events.
Recreation
and aesthetic enjoyment of Florida estuaries play a significant role in the
state's tourist trade. Birdwatching and
nature study are popular activities dependent largely upon the maintenance of
healthy estuaries. Environmental education
in Florida has made effective use of field stations and other facilities located
on or near estuaries. The value of
waterfront and waterview real estate has literally skyrocketed, particularly
where new developments are integrated with natural landscape features. Overall, these tangible and intangible
benefits and value of Florida9s estuaries comprise the treasured 4 4 quality of
life" enjoyed in the state's coastal zone. According to the 1980 U.S. census, the coastal counties of
southwest Florida-an area of largely pristine estuaries-is among the nation's
fastest growing metropolitan areas.
Problems Facing Estuaries
Symptoms
of ecological problems in Florida's estuaries are easier to recognize than
their causes or solutions. gns of malaise in estuaries may be the consequence
of accumulated direct, indirect, and interacting impacts (Estevez 1982). A widely discussed issue concerns the status
of the state's sport and commercial saltwater fisheries. Elements of the controversy include
uncertain estimates of stock and inadequate information on life histories and
migration. The impacts of commercial
fishing upon recreational yields, and vice versa, are contested in public and
scientific forums. The impacts of
habitat destruction and alteration of nursery areas are poorly known and data
are few which describe levels of food fishery contamination (Saltwater
Fisheries Study and Advisory Committee 1982).
The
increasing number of "species at risk," e.g., those named on lists as
endangered or threatened over the last decade, is another indicator of problems
facing estuaries of the state. Birds
and mammals are well studied.
Endangered birds living in or near estuaries include wood storks,
wintering Peregrine falcons, and dusky (and cape sable) seaside sparrows. Threatened birds with estuarine affinities
have included the eastern brown pelican, Rothschild's magnificent frigate-bird,
southern bald eagle, osprey, American oystercatcher, least tern, and eastern
brown pelican (Kale 1978). The brown
pelican is considered "an excellent indicator species for the quality of
the marine-estuarine environment" as its number and reproductive success
have been related to pesticide contamination and food abundance (Schreiber
1978). These and other lines of
evidence link pelicans to the quality of fresh water entering estuaries.
The precise contribution to estuarine problems of
changes in the amount, timing, or quality of fresh water in Florida is not
presently known, although some insights from studies in Apalachicola Bay and
the coastal Everglades are instructive (Heald 1970; Livingston et al. 1977). Enough is known from studies throughout the
world to justify predictions of what will happen in Florida estuaries if
freshwater supplies are significantly changed (Snedaker and DeSylva 1977). When fresh water is deprived to estuaries,
nearshore
waters become more saline and mixing due to salinity differences is diminished;
salt
wedges may develop farther inland and saltwater intrusion in coastal water
supplies can result;
exchanges
of material between the water an substratum are affected and sediment chemistry
is adversely impacted;
patterns
of sediment erosion, deposition, and littoral drift are altered;
the
estuary is starved of nutrients of terrestrial origin;
salt
marshes, mangrove forests, and seagrass beds deteriorate under constantly
elevated salinity;
certain
fisheries decline or disappear for a variety of reasons related to fresh water;
other
species and communities develop in response to new conditions; and populations
of nuisance species increase.
Opportunities in Estuarine Management
The
problems of Florida estuaries are complex and farreaching where fresh ' water
from distant sources is involved.
Strategies of environmental management have evolved as perceptions of
these problems have improved. Numerous
areas have been designated as protected habitats. As examples, Rookery and Apalachicola bays are national estuarine
sanctuaries and much of the coastal Everglades is within a national park. The state legislature created thirty aquatic
preserves and other coastal areas are protected as Outstanding Florida Waters
by administrative action. Wetland
tracts are being acquired in environIs= mentally endangered lands
programs. Coordinated regional efforts
to protect estuaries have been attempted in
Charlotte Harbor and the Suwannee River by resource planning and management
task forces. Management plans are being
developed or implemented in Biscayne and Tampa bays. Scientists and resource managers are reviewing what is known and
needed as pragmatic research in these and other estuaries. Local governments have incorporated
estuarine resources in their comprehensive planning and have created municipal
preserve areas.
Three
programs offer some promise for solving the problem of freshwater quantity,
timing of discharge, and quality in relation to estuaries. First, the Department of Natural Resources
has authority to consider cumulative impacts in permitting activities in state
aquatic preserves: such authority will prove critical in the prevention of
piecemeal deterioration of preserves.
Numerous activities within preserves are exempt from regulation,
however, and the Department of Natural Resources lacks any authority over
activities outside of preserves, where fresh water originates. Second, the Department of Environmental
Regulation (DER), by authority of the 1984 wetlands legislation, may consider
cumulative impacts in issuing dredge and fill permits in wetlands. DER is also responsible for the maintenance
of water quality standards in all state waters. Third, regional water management districts may consider
preservation of natural resources, fish, and wildlife when permits for
consumptive use of water are issued.
Efforts by the water management districts to anticipate demands for
water and provide for the requirements of natural systems could become the
principal planning, research, and management tool for protecting freshwater
inflow to estuaries. The Southwest
Florida Water Management District already has sponsored a symposium on the
freshwater needs of estuaries (Seaman and McLean 1977) and has required
compliance monitoring in estuaries
by some users of tributary waters.
Adoption of these methods by other districts will help protect Florida's
invaluable estuarine resources.
What are Estuaries? 2
They
occur in areas where freshwater meets and mixes with salty ocean waters. The term estuaries, according to general
usage, refers to protected, nearshore waters such as bays and lagoons.
Survival of plants
and animals in estuaries requires special adaptations. Estuaries are dynamic systems where waters
are alternately salty and fresh. The ebb and
flow of tides may leave some plants and
animals, such as seagrasses and oysters, temporarily high
and dry. Shallow estuarine water can range from freezing to more than 100° F
during the course of a year.
Estuarine
organisms are naturally adapted to withstand these ranges in salinity, tides,
and temperatures. They must, however, have a balanced flow of fresh and
saltwater. This balance can be upset if
1) there is too much freshwater, as when causeways are constructed impeding the free flow of
tides,
or if 2) there is too little
freshwater, as in the diversion or damming of a river. Estuarine-dependent
marine life may die if the precarious balance of fresh and saltwater is not
maintained.
WHY ARE ESTUARIES SPECIAL?
“The cradle of the ocean” is a most appropriate title
for estuaries. More than 70 percent of
Florida’s recreationally and commercially important fishes, crustaceans, and shellfish spend part of their lives
in estuaries, usually when they are young. Many fishes
and crustaceans migrate offshore to spawn or breed. The eggs develop into larvae (immature forms) that
are transported into estuaries by tides
and currents. The shallow
waters, salt marshes, sea-grasses, and mangrove roots provide excellent hiding
places from larger, open-water predators. Some species grow in estuaries for a
short time; others remain there for life.
Shrimp, for example,
spawn offshore. The larvae then move toward inshore waters, changing form by
molting as they progress through various stages of development. As young
shrimp, they burrow into the sea floor at the mouth of the estuary as the tide
ebbs, then ride into the estuary on the incoming tide. If successful in
reaching the estuary after this hazardous journey from the sea, the young
shrimp find seagrasses and algae to conceal them from predators. Because many
larger animals cannot survive in the lower salinity of the estuary, the young
have the added protection of a “salt barrier.” Once the shrimp approach
maturity, they leave the estuary for the sea to spawn, and the cycle begins anew.
Estuaries are among the
most productive ecosystems in nature. Rivers and streams drain into estuaries,
bringing in nutrients uplands. Plants
use these nutrients, along with the sun’s energy, carbon dioxide, and water
to manufacture food. Among the most important plant forms that contribute to
estuaries are microscopic algae called phytoplankton. Other plant forms include
marsh grasses, mangroves, seagrasses, and macroalgae. When these larger plants
die, they are broken down into detritus and are colonized by microbes
(bacteria, fungi, and other organisms). During decomposition, detritus becomes
smaller and smaller and the nutrients and small particles become food for
thousands of organisms. Larger animals feed directly on these tiny particles or
on smaller animals that fed on detritus.
As long as nutrient-rich freshwater flows and tides interact
without human interference, our estuaries will remain productive. Snook, trout,
mullet, jack, grouper, redfish, silver perch, spot, cattish, sheepshead, spiny
lobster, shrimp, crabs, oysters, and clam’s are examples of the diverse marine
animals dependent upon healthy estuaries. Estuaries also provide breeding and
nesting areas, or rookeries, for many coastal birds, including several
endangered species such as brown pelicans. Estuaries’ role as the ocean’s
nurseries cannot be overemphasized.
Florida’s Estuaries
Florida is
undergoing tremendous growth and development pressure which is impacting marine
fisheries habitat components important in maintaining viable commercial and
recreational fisheries. Florida Department of Natural Resources, Bureau of
Marine Research scientists are locating and calculating the acreage of existing
estuarine habitat components such as salt marshes, mangroves, and seagrasses.
Information used to map and monitor Florida’s coast is available from LANDSAT satellite and other satellite
information sources. The scientists are also noting trends in habitat change by
analyzing aerial photographs from the 1940’s, 1950’s, and 1980’s. Results of
the habitat trend analyses have shown substantial losses of fisheries habitat
throughout Florida. One study area on the east coast included the Indian River
from Sebastian Inlet south to the St. Lucie Inlet. Over a forty year period, an
86 percent decline in the availability of mangrove habitat to fisheries was
documented in addition to a 30 percent loss of seagrass acreage. Tampa Bay, in
southwest Florida, has experienced an 81 percent loss of seagrasses and a 44
percent loss of mangrove and salt marsh acreage over a 100 year period.
Estuarine habitat
loss is a serious problem in Florida’s coastal zone.. It is difficult to put a price on, estuaries, but without question they are one of our greatest natural
resources. This resource, however, can be destroyed. The coast’s appeal is very
evident; 78 percent of Florida’s estimated 11 million residents live in the
coastal zone. Dredge and fill operations for waterfront homesites and seawall
construction destroy mangrove shoreline and underwater grassbeds. Though these
activities may temporarily enhance real estate value, ultimately they may
decrease long-term value as the natural amenities disappear, the water becomes
foul, and wildlife leaves. These activities often eliminate habitat and feeding
areas for young fish, shrimp, and crabs. Without estuaries many important
fisheries will disappear.
Estuaries are special. Help protect them.
Marsh Flow-way Project removing nutrients
The
St. Johns River Water Management District's 1,850acre marsh flow-way project is
designed to filter suspended sediments rich in phosphorus and nitrogen from Lake
Apopka.
An
overabundance of phosphorus and nitrogen in the lake is the principal cause of
the lake's poor condition.
The
lake's pea green color, caused by chronic algal blooms, has prompted many to
refer to Lake Apopka as a dead but it is much too alive. The profusion of algae serves to choke off
many of the normal life forms present in a healthy lake system.
These
algal blooms indicate an overly-enriched condition in the lake where phosphorus
and nitrogen, elements common in fertilizer, serve to feed the algae.
The
flow-way, located on the northwest corner of the lake, is on a site where
vegetables were once grown. Functioning
much like a swimming pool filter, it removes phosphorus and nitrogen from the
lake as water passes through the grassy marsh in a shallow sheet flow.
The
sediments contained in the lake are constantly re-suspended in its shallow,
turbulent basin. They will be filtered
from the water as it passes through the marsh flow-way before returning to the
Apopka-Beauclair Canal and Lake Apopka.
Rention time of water in the flow-way varys from 3-25 days to determine
optimum water depth and flow rate for the full marsh flow-way project.
Environmental
scientists at the District estimate 90 percent of the phosphorus in the lake is
in particulate form and that much of the suspended sediments can be filtered
out.
During
the next two years, the District will fine-tune the flow-way.
Dr.
Mike Coveney, technical program manager for Lake Apopka's restoration, predicts
the full marsh flowway system will remove and store 30 metric tons of
phosphorus per year from the lake, and the total volume of Lake Apopka could
pass through the marsh flow-way twice each year.
In
the final 5,000-acre marsh flow-way, water from Lake Apopka will be filtered
for 10 days. Ninety percent of that
treated water will be returned to the lake, while 10 percent will go
downstream. Only treated water from the
marsh will be released to go down-stream.
Land
for the initial marsh flow-way cost $5,000,000. Construction on the 1,850acre project began in December 1989 and
took one year to complete.
(1850
Acres)
Chronology of Lake Apopka Restoration Efforts
June 1995
Lake Apopka Restoration Act passed,
directing SJRWMD to develop an environmentally sound, economically feasible method to restore Lake Apopka.
Junel987
Legislature
passes SWIM Act, naming Lake Apopka a priority for restoration.
August 1987
Marsh
Flow-way concept formalized.
March 1988
Interim
SWIM plan developed for Lake Apopka.
June 1988
First
$5,000,000 appropriated for Marsh Flow-way land acquisition.
DER
delegates to SJRWMD authority to
regulate agricultural discharges into Lake Apopka.
June 1989
Second $5,000,000 appropriated
for Marsh Flow-way land acquisition.
September 1989
DER
approves Lake Apopka SWIM plan.
December 1989
Construction
begun on Marsh Flowway Demonstration
Project.
Junel990
Final
$5,000,000 appropriated for Marsh Flow-way land acquisftion.
November 1990
Marsh
Flow-way Demonstration
Project
begins operation.
For more Information about the Lake Apopka restoration project, call JIM Conner at (407) 897-4347, or the Public Information Division at (904) 329-4500.
Lake Apopka Vital Statistics
Location:
Approximately 15 miles
north of Orlando in Lake and Orange counties.
Size: Fourth
largest lake in Florida with a surface area of 30,800 acres and a volume of 54 billion gallons.
Depth:
Lake Apopka's water stage is 66.5 feet above sea
level. The average depth is 5.4 feet.
Deepest point is 16 feet
along south shore. Ninety percent of
the flat and shallow lake bottom is covered
by a layer of sediment averaging 46 inches thick. This black muck
sediment is composed of dead algae and plant material.
These
sediments are constantly stirred up by wave
and wind action, reducing the clarity of the water. This resuspension keeps the sediments in the lake water so that they can be filtered out as the water passes through the marsh flow-way.
Lake
Apopka is classified as 'hypereutrophic' in that it has an average of .22 mg@ of phosphorus and 4.5 mg of nitrogen (typical level is.05 mg/L
for phosphorus and 1.0 mg/L
for nitrogen).
Recreational Activity: Once heralded as
one of the best bass fishing lakes anywhere, only one of 21 fish camps open in
1956 still remains open. Recreational activity is nearly
non-existent. There is little
recreational fishing and swimming is discouraged.
Marsh Flow-way Vital Statistics
Total Area: The
Demonstration Project is 1,850 acres, including
950 acres of wetlands, of which 635
acres comprise the flow-way. The full marsh project will be 5,050
acres, including 4,150 acres of wetlands.
Water Flow: The
Demonstration Project's rate of water flow from the lake varies from 30-300 cubic
feet/second. h takes 3-25 days for the water to pass through
the marsh flow-way, These flow rates will
help determine the optimum nutrient storage levels
for the full marsh project.
The full marsh project is
designed for a watatilow from the lake of
510 cubic feet/second, with the
water taking 10 days to make its
way through the flow-way. It is estimated the full marsh project
will extract 30 metric tons of
phosphorus from the lake each year.
Land Cost: Land
for the Demonstration Project cost
$5,000,000. Land acquisftion for the full marsh project is estimated
at $15,000,000.
Benefits: The Marsh Flow-way is designed to:
· Reduce muck farm
discharges through land acquisition;
Restore fish and
wildlife habitat;
· Protect downstream lakes;
· Improve water quality.
Flow-way project's filtering improves water
clarity
The
Marsh Flow-way Demonstration project's natural filtering process is having a
visible effect on water quality and clarity.
In
initial tests, the marsh has removing more than 40 percent of phosphorus
and 50 percent of nitrogen from the water exceeding designers' projections.
More
than 90 percent of all suspended
solids-which phosphorus and nitrogen binds to-are removed as the lake water
passes through the marsh.
The
difference between water entering the marsh flow-way and that leaving R is startling.
District
environmental scientists use a black and
white secchi disk to measure water clarity. They record the depth at which the disk is
no longer visible in the murky water.
Secchi
comparisons between the center of Lake Apopka and the pump station at the end
of the marsh flow-way show water
clarity at the pump station is up to ten
times greater than at the center
of the lake.
Followup-2/2000
Lake's waters, future clearing
Kevin Spear of The Sentinel Staff Published in The Orlando Sentinel on March 01, 2000
Not long
ago, scientists working to restore massive Lake Apopka warned success might not
come in their lifetimes -- not for at least 50 years.
On
Tuesday, St. Johns River Water Management District officials whittled more than
a few years off the timetable.
Henry
Dean, water district executive director, said the lake might be swimmable in 10
years -- perhaps even in as few as "seven or eight" years.
"Nature has a way of restoring itself," said Dean, whose
prediction came during a boating tour to introduce the 50-square-mile lake to
Orange County Chairman Mel Martinez.
A water
district scientist later tried to downplay the possibility of Lake Apopka
making such a stunning recovery.
Ed Lowe
said much restoration work remains before many swimmers or skiers will jump out
of their boats into water that, for now, still bubbles with the gases of
rotting bottom muck.
Still,
Lake Apopka is showing signs it may shake off its label as one of the most
polluted lakes in Florida.
Ken
Thompson and his uncle, John Anderson, both of Orlando, have fished for 30
years in the waters gushing out of the dam at the lake's north end.
"The
fish look better, the shade of water looks better," Thompson said, angling
for catfish and speckled perch. "The lake is coming back."
Jim
Thomas, president of Friends of Lake Apopka, agrees that the lake is noticeably
improved.
"The
color is obviously different. You can see it as soon as you get
there."
Thomas
said it is reasonable to expect the lake to "return to the valuable
fishery it was" within seven to 10 years.
So far,
restoration work has cost about $130 million during the past two decades, with
most of that spent to buy 18,000 acres of shoreline farms that had drained into
the lake.
Although
other restoration work had been done, the buyouts halted much of the polluted
runoff in the late 1990s, and that was when scientists began to detect
promising changes.
A few years ago, Lake Apopka waters allowed only about 6 inches of
visibility. Today, that has increased to 18 inches.
A few
years ago, Lake Apopka would glow a vivid green when struck by the right angle
of sunlight. Today, the lake has less of the green algae that flourished from
farm pollution. The lake now gets a brown tint from muck that stirs from the
bottom.
Even the muck, which can have the
feel of mayonnaise and the stench of rotten eggs, has shown signs of compacting
into a firmer layer.
Cleaner water has allowed more sunlight to strike the lake bottom,
nourishing the growth of eel grass and other aquatic plants.
In the
mid-1990s, when the water district planted a short stretch of shoreline with
eel grass, the plants died.
But a few
years ago, eel grass began to appear on its own in small patches. Today, the
lake has more than 50 patches of eel grass, which harbors young fish.
For all of
the signs of recovery, the water district has been beset with unexpected
disasters at Lake Apopka.
In late
1998, the water district flooded former farmland along the shore. Then hundreds
of white pelicans and other birds died of pesticide poisoning from foraging on
the flooded fields. The district drained the fields early last year and is
still looking for sources of the contamination.
Shutting
down the farm fields also is thought to have played a key part in last year's
invasion of mice that struck homes and businesses in northwest Orange
County.
To help
meet the prediction of making the lake swimmable in a decade or less, those
fields will have to be flooded again and other measures must be completed.
Restoration costs could grow to $150 million.
In 1999,
his first year as Orange County chairman, Martinez criticized the water
district's handling of restoration work, citing bird deaths and the mouse
invasion.
His tour
of Lake Apopka brought a change in attitude.
"It's
a more encouraging picture than I anticipated," he said.
Posted Feb
29 2000 9:54PM
By
Michael Zimmerman
Scientific
experts on a high-level panel have come up with what they think might be a
dramatic cure for the greenhouse effect.
Unfortunately, while their solution is in keeping with a basic law of
ecology, their idea runs afoul of an equally basic law of medicine.
The
experts, a panel of top scientists gathered by the National Research Council
(NRC), have endorsed a plan to fertilize the planet's oceans with iron. After all, iron is supposed to promote the
growth of tiny marine algae known as phytoplankton. Phytoplankton, like all green plants, take up carbon dioxide, one
of the most troublesome greenhouse gases. and release oxygen. So the thought is that a dramatic increase
in phytoplankton will lead to the removal from the atmosphere of a large
percentage of the offending carbon dioxide.
Why
iron? As every gardener knows, and as I
teach my introductory ecology students very early on, the answer is quite
simple. In 1840, the great German
chemist Justice von Liebig conducted a series of experiments and published a
paper that established the "law of the Minimum." That ecological axiom states that
"growth of a plant depends on the amount of foodstuff which is presented
to it in limiting quantity." Even
more simply, plant growth is always limited by a particular environmental factor. Add more of that factor and plants will grow
until some other factor becomes limiting.
The NRC scientists. recognizing that iron appears to be the factor
limiting the growth of phytoplankton, want to add more iron to the
phytoplankton's habitat.
So
confident are the scientists of their solution that one of the leading
proponents of this remedy, John Martin of Moss Landing Marine Laboratories in
California, has been quoted as saying, "You give me a half a tanker full
of iron, I'll give you another ice age."
Needless
to say, no one on the NRC panel wants quite that much iron. Also, needless to say, no purposeful human
manipulation of the natural environment of this magnitude has ever before been
undertaken. And because the
phytoplanklon are at the bottom of the ocean's food chain, fed on by tiny
zooplankton that, in turn. are eaten by the fish and mammals of the sea, the
ecological consequences of the addition of iron might be enormous. This
uncertainty alone might be reason enough not to pursue such a massive
manipulation.
But,
in fact, there is a far better reason not to proceed along the lines of the NRC
panel's recommendations, and that reason comes from medicine rather than
ecology. Doctors have long recognized
that it is far less productive to treat the symptoms of a disease rather than
the underlying causes. While aspirin,
for example, might be wonderful at bringing down a fever caused by a bacterial
infection, it will not help remove the offending bacteria. With the fever reduced, the patient may seem
to be improving only to suffer a
massive and perhaps deadly relapse when
the bacteria reach immense quantities.
Fertilizing
the oceans with iron is like feeding aspirin to a sick patient. Increased quantities of phytoplanklon might
well reduce the amount of carbon dioxide in the atmosphere, but they will not
get at the root of the greenhouse problem.
And given the politics, both national and international, of attempting
to rein in emissions of offending gases, any program that appears to make such
control less immediately pressing is sure to add ammunition to those who would
rather not take any action at all. As
with an untreated bacterial infection, continuing to use our atmosphere as a
repository of unwanted pollutants is a prescription for suicide.
Regardless
of how much increased phytoplankton growth can be coaxed out of our oceans, the
amount of carbon dioxide that will be absorbed will never be infinite.
Ultimately,
then, we will still need to control our profligate habits if we expect to live
in harmony on this planet. Fertilizing
the oceans, while delaying the problem, will increase its magnitude and,
ultimately, will make finding an acceptable solution even more difficult. By delaying, we are doing what we do so
well: Bequeathing to our children our own most difficult problems. We should have the moral strength to act in
a more responsible fashion
Michael
Zimmerman is professor of biology
Overlain College in Ohio
One of the most controversial offspring of the
energy crisis of 1973 and 1979 is the subsidized production of alcohol from
corn, for auto fuel. Burning alcohol
rather than gasoline reduces smog and our petroleum imports, but ethanol has
also acquired a reputation of being damaging to automobile engines and a
heavily subsidized alternative to straight gasoline.
Norm Hinman, a biochemical engineer specializing
in ethanol at SERI says the first problem was solved several years
ago:"Every auto manufacturer will warrant its engines on a ten percent
ethanol blend". He agrees that the
current corn-fed approach, producing 850 million gallons of ethanol yearly is
not going to make much of a dent in the 112 billion gallons of gasoline that
the nation's engines burn every year (1990). But he predicts that ethanol
production will soon be increased to five billion gallons per year (Another
type of alcohol already is well established in one small but influential
population of engines: cars in the Indianapolis 500, which burn pure methanol. "It's safer and you can get more energy
with it because it's susceptible to high compression" says Indy technical
inspector Dave Kyle.)
The corn to alcohol process is simple as can be,
requiring only the fermentation of the sugars already in the kernels, along
with sugars produced from the starches.
SERI is heading down a different road using lignocellulose, or plant
fiber, as a feed stock rather than corn kernels. The difficulty is that lignocellulose does not ferment until it
is broken down into certain sugars and this is difficult to do economically. Current Biotechnology can break three quarters
of the fibers into sugars, using acids, enzymes, and yeast strains. (The leftover lignin is useful in
industry). A full-scale plant, Hinman
says, would look like a cross between a corn wet milling factory and an oil
refinery.
Hinman says lignocellulose is worth using because
it is inexpensive and available in vast quantities, as a residue from current
food and fiber harvests. Take corncobs,
which are tossed out of corn harvesters onto fields every fall. All those cobs, Hinman points out, could produce
five billion gallons of ethanol a year.
At a gathering cost of $20 to $50 per dry ton,
Hinman figures that lignocellulose processing could produce the equivalent of
130 billion gallons of gasoline a year, more than the current consumption
(1990). "That would produce a lot
of jobs in the US rather than in Saudi Arabia". He explains that even this high level of use would not mean
sweeping up every branch and cornstalk and rice hull but would leave millions
of tons of surplus fiber in forests and fields for natural recycling. Because the ag-waste approach would
piggyback on certain harvests, it would require no extra deforestation. Some biomass proposals, however, call for
converting millions of acres for forest and wilderness to energy crops.
As the technology stands now (1990), Hindman says,
the production would cost $1.35 a gallon.
He admits that this figure is far from the wholesale price of gasoline,
about 50 cents (1990-oh how it's changed!), but the progress has been rapid: in
1984 the cost was three times higher.
He is aiming for an unsubsidized, wholesale cost of sixty cents a gallon
or ethanol, which would match the per-BTU cost of gasoline. "I think its doable" he says
"I look at the progress we've made and think we can do it within ten years.
If you listened to biologist Lewis Brown long
enough, you might conclude that we should cover one percent of New Mexico and
Arizona with saltwater ponds. Put to
use producing algae, they could take care of about a thirtieth of the nation’s
energy needs, Brown says, in the form
of high-value liquid fuel.
The algae he has been experimenting with, as
manager at SERI’s biotechnology branch, is first cousin to that in the ocean’s
upper layers. This algae, he says,
absorbs about 1/3 of all the carbon absorbed by plants worldwide. The ideal alga is selected for its
single-minded production of oil. With
the water removed more than ½ of the algae by weight is oil.
Brown has in mind building thousands of racetrack
shaped ponds just six inches deep. Algae
could flourish in the intense southwestern sunlight, and Brown estimates that
each acre could produce 150-400 barrels of refined fuel. In effect, these ponds would mimic the
ancient shallow seas that produced so much petroleum. Here however, tubes would bubble large amounts of carbon dioxide
through the water to boost algae growth. (What would this do to the pH of the
water???)
“Carbon dioxide is not the enemy.” Brown says,
“without it plants won’t grow and we’d all die.” When questioned about proposals to discard vast quantities of
carbon dioxide underground or at sea, he responds, “Why not give it to us and
we’ll make use of it”? He explains that
algae in ponds is forty times more efficient at taking up carbon dioxide than
algae in the open ocean. A quarter of a
percent of Arizona and New Mexico, he estimates, would absorb all the carbon
dioxide that power plants produce in those states. Natural gas, he says, burns so cleanly that its combustion
exhaust could be piped directly into its ponds.
Brown concedes that the recycled carbon would
enter the atmosphere eventually, as the algae-grown liquid fuel was burned in
cars, but points out that this approach would extend the carbon’s usefulness
before the harm started. How about
water lost to evaporation from the ponds?
“These farms could operate on existing brackish water supplies for many
decades,” he says. And the water that
becomes too salty from evaporation could go back underground.
Experimental ponds are operating near Roswell, New
Mexico. The projected cost is $1.60 per
gallon (Taxes NOT included) for the fuel, so don’t expect commercialization
just yet.
The algae and lignocellulose proposals came under
the heading of biomass. Power
production from biomass, using energy stored during photosynthesis, is well
advanced in some industries. The
utility company in Burlington, Vermont, operates a 62 megawatt wood fired
powerplant, and dozens more such small plants are being built or planned.
Bay Killlers
#6
Bay
Killers 6
BY RONNIE WACKER Sea Frontiers v37#6 12/91
Mario
Carrera rests the bull clam rake on the gunwale of his 16-foot skiff and scans
the silver-blue waters of Long Island Sound. “You see why I’m a bay man?” he
asks. “This is a beautiful way of life.” His outstretched hand sweeps across
the horizon. “It’s independence. It’s freedom. It’s being your own boss.”
Then
he plunges the long-handled rake into the muck ten feet below the boat. “It
gives you a chance to pray, and there is no better cathedral than what God has
made.” Camera holds the rake still for
a moment. “I will be very sorry when this ends.”
This
is what he is afraid of, that it is all coming to an end, working the bays for
fish and clams and scallops. On the day that I accompanied him, he was doing
something I’m sure he would not have dreamed of doing when he first went out,
13 years ago: He was taking clams from polluted waters.
Now
27, a onetime aerospace engineer—for years he went clamming during high-school
and college vacations—he worked this year as chief of a crew authorized by New
York State to gather clams from the befouled waters of Echo Bay near New
Rochelle for transplant into the Peconic bays in the tip of Long Island, where
most—not all, but most—of the waters are still clean. Three weeks in the clean
water rinses away the contaminants, and the clams can be harvested a second
time, now fit for eating.
Gary
Quarty, a seasonal fisherman, has recently trawled for shrimp off Tampa, Key
West, and Panama City, Florida, but now is about ready to quit fishing altogether.
“I don’t want to be the guy to catch the last fish,” he says.
He’ll
try again this year, but he doesn’t expect much. One reason is the slump in
Texas and Louisiana production: Shrimpers from those states have been coming
over to Florida and taking immature juveniles. The result, says Quarty, is that
much of this year’s Florida catch won’t be big enough to keep.
So
after 20 years of fishing, he now works for a landscaper and wonders what to do
with rest of his life. He has no bitterness toward the Texas and Louisiana
shrimpers: He blames home builders whose pink and white confections line the
Florida shoreline, and what he sees as theft wanton disregard for nature. “In
Tampa,” he says, “it’s a violation to clear out mangrove trees, but developers
just tear them out and pay the fines. As far as the government is concerned,
it’s easier to blame the fishermen for overfishing and cut back on fishing
limits than to get to the root cause—loss of habitat for the fish.”
Nat Bingham, who trolls
for salmon on the 38-foot, wood-hulled Elliott
M out of Fort Bragg on California’s north coast, worries that the area is
losing its fisheries because water in northern rivers has been diverted from
San Francisco Bay down long pipelines into desert lands to the south. This has
dried up spawning beds and reduced salmon and steelhead fisheries to a fraction
of their former landings.
Bingham, grandson of the
late Hiram Bingham, a famous explorer and former governor of Connecticut, left
New England for the west coast in his twenties. He has fished for salmon for
more than 25 years and headed the Pacific Coast Federation of Fishermen’s Associations
for the last eight. He accuses the Central Valley Project, a federal-state
network of dams and reservoirs, of enriching huge corporate farms by selling
irrigation water at far below cost, while destroying the fish and success of
small salmon-fishing businesses. It’s taxpayers’ dollars, he says, that
subsidize vast “agribusiness” farms growing water-intensive crops in the
desert. One river, the Trinity, lost 85 percent of its water into the
agribusiness pipelines, says Bingham, and with it went 85 percent of the salmon
that once spawned there.
Like the canaries
in a coal mine, whose death warned the miners of trouble ahead, dwindling fish
catches everywhere should be clanging alarm bells for all of us, according to
marine biologists of the National Marine Fisheries Service (NMFS). The state
of U.S. urban bays, estuaries within 10 miles of population centers of over
100,000 people, is bad and getting worse.
The
estuaries, where fresh water from inland meets the ocean’s brine, nurture many
small and infant fish. They are showing the results of years of concentrated
abuse. The worst degradation occurs, as might be expected, in the most urbanized
and most populous areas: on the east coast, in Boston, New York, and New Jersey
harbors, Long Island Sound, and Chesapeake Bay. Pictures of garbage floating in
Boston Harbor are credited with helping George Bush win the presidency. On the
west coast, San Francisco, Santa Monica, and San Pedro bays are in serious
trouble. In the northwest, Puget Sound is victim of some of the worst
industrial discharges in the region.
At
the National Symposium on Fish Habitat Conservation last March, NMFS biologist
James R. Chambers reported that all fisheries dependent upon estuaries—that is, 75 percent of all edible species—have been
reduced to the lowest levels in their history.
In
Chesapeake Bay, landings of hickory shad are down 96 percent since the 1960s.
Alewife and blueback-herring landings are down 92 percent, and American shad
is down 66 percent The Maryland oyster harvest has declined 90 percent from
peak levels reached years ago.
In
the northwestern United States, Columbia River salmon and steelhead runs are
down 75 and 84 percent; the Snake
River coho-salmon population is believed to be gone and the river’s
sockeye-salmon stock is dwindling. Puget Sound’s English-sole landings are down
from 2.4 million pounds some years ago to 700,000 pounds in the last reported
year. Califomia has lost 90 percent of its historic chinook-salmon spawning
habitat. In San Francisco Bay, there are few young striped bass, and the adult
striped-bass population is down 60 to 80 percent.
Commercial landings of
fish and shellfish along the U.S. southern Atlantic and Gulf of Mexico coasts
have declined by 42 percent since 1982. Nationally, 54 percent of all shellfish
beds have been closed because of pollution.
What is destroying the
world’s most important source of protein? Loss of habitat, toxic contamination
and overfishing says William B. Fox, chief of NMFS, on leave from the University
of Miami Rosenstiel School of Marine and Atmospheric Science.
Our estuaries are
polluted by discharges from industrial and sewage-treatment plants, and by road
runoff carrying the detritus of residential populations: road salt, rubber and
oil, pet feces and litter. And they are crushed by real-estate developers who
fill the spongy wetlands with sand and rock and top it all off with houses, factories,
and shopping centers—all producing still more pollution. For the past 200
years, we’ve been losing our wetlands at the rate of one acre a minute,
according to the U.S. Fish and Wildlife Service. What was once a treasure trove
of 200 million acres—each capable of producing ten tons of food a year—is down
to 100 million acres in the lower 48 states, and shrinking fast.
As bad as the threatened loss of food
supply, some scientists believe, is the toxic impact on humans of chemical
pollution. Effluents from chemical plants, synthetic fertilizers washed from
farm fields and lawns, paints, sprays, and solvents all are assaulting the
fish. Many scientists fear the pollutants may have the same long-range effect
on us.
Usha
Varanasi, who heads the environmental conservation division of NMFS’s
Northwest Fisheries Science Center, shares this fear. She has found liver
tumors in English sole from Puget Sound, in black and white croakers from Santa
Monica, San Pedro, and San Diego bays, and in winter flounder from Boston
Harbor. Her crews have found flatfish in Puget Sound with signs of retarded
ovarian development, reduced spawning ability, and lowered levels of sex hormones.
Even young salmon that travel through affected areas like the Duwamish waterway
in Seattle pick up the chemicals from sediments and are beginning to show an
AIDS-like weakening of the immune system. “If toxic chemicals have that effect
on fish,” says Varanasi, “what about the humans who eat the fish?”
Evidence
of public concern is widespread and growing. In a recent survey of the
sociology department at North Carolina State University, 92 percent of the
respondents agreed that when humans interfere with nature, it often produces
disastrous consequences, and 95 percent endorsed the statement “Mankind is
severely abusing the environment.” Eighty-two percent also agreed that there
are limits to growth beyond which our industrial society cannot expand.
In
response to growing public awareness of the threat, Congress passed the Clean
Water Act of 1987, creating a National Estuary Program (NEP), administered by
the Environmental Protection Agency (EPA), to identify environmental problems
in estuaries of national significance. NEP currently is studying 18 sites,
jointly with local and state agencies and citizens’ groups, to develop
comprehensive estuarine management.
The
common factor in all bay pollution, according to EPA, is development. Three
quarters of all Americans now live within 50 miles of salt water. This means
more homes, septic systems, industry, marinas, restaurants, and other supports
of civilization to follow the migration. It also means more beaches close each
summer because of high fecal coliform count in the water, or medical waste and
other filth floating on the tide. And more “dead sea” zones, devoid of
dissolved oxygen, where no fish can live.
And
it means more algal blooms that come and go mysteriously, attacking finfish,
shellfish, and the vacationers who swim among them. Their exact cause is
unknown, although they usually appear close to developed shoreline.
Last
August (1991), a red tide came ashore along the Florida coast south of Tampa,
killing millions of fish and creating a pervasive stench that devastated the
tourist economy. In 1988, a similar bloom struck the Albemarle-Pamlico estuary
behind North Carolina’s outer banks. Swimmers suffered burning eyes and
breathing problems. Shellfish eaters reported 48 cases of neurotoxic poisoning.
For 18 months, shellfishing was banned along 240 miles of shoreline for an economic
loss of nearly $25 million.
The Peconic Bay system, in eastern Long Island,
suffered a similar economic blow in 1985, 1986, and 1987, when a brownish algae
spread through the water, strangling a $2 million-a-year scallop crop. Oyster
and clam harvests also shrank, and tourism slumped, denting a $229 million
recreational industry. Then, as mysteriously as it had arrived, the brown tide
left, in 1988. New bug scallops were planted, beginning a two-year growth
cycle. Bay men were looking forward to a scallop bonanza this year—and then the
brown tide returned, threatening another disastrous year for the fishermen.
Except for brown tide,
the Peconic bays’ clean waters are afwight spot in an otherwise dismal picture.
Named one of the “Last Great Places” in the western hemisphere by The Nature
Conservancy, the 1 10,000-acre estuary consists of rolling farmland, beaches,
creeks, woodlands, and wetlands. These recreational attractions swell its
115,000 population to 280,000 in summer. All this open space, one-fourth of the
estuarine land area still available for development, concerns environmentalists
and government. Given its location, less than 80 miles from New York City and
the eastward march of population on Long Island, it is only a matter of time,
they worry, until the Peconic system shares the problems of neighboring urban
bays. They look to the federal estuary program to prevent this and are working
to make the system the 19th NEP member.
Just north of the
Peconic bays, Long Island Sound with 15 million people on its New York and
Connecticut shores was slow to show the effects of contamination because it is
deep and has good flushing action. But in recent years fish kills have occurred
with some frequency in “dead zones” where the oxygen has been squeezed out of
the waters as a result of enormous amounts of nutrients from sewage effluent
and storm-water runoff. Some 86 sewage-treatment plants, when all operating,
discharge a billion gallons of nitrogen- and phosphorus-laden effluent into the
sound every day.
Groups along both sides
of the sound have angrily protested the water condition. The National Audubon
Society took a campaign for public attention to the sound into 15 communities.
Fishermen, boaters, professors, schoolchildren, environmentalists, and
government officials who participated in the hearings talked, sometimes
emotionally, about the need for limits to growth, vigorous protection of
wetlands, clean beaches, healthy fisheries, changes in land-use policies to
protect water quality—and government funding for these projects.
A witness in Old Lyme, Connecticut recalled when
the sound’s water was so clean his mother used to cook spaghetti in it. A
middle-aged Long Island woman said wistfully, “I remember swimming in the
sound, having porpoises swim around me.” One father said he’s “mad as hell. I
never saw a diseased fish until the mid-1970s. Now I have to find out what is
safe to feed my kids.”
A Connecticut woman
reported that she and her son took 80 tires, 209 oil drums, and 23 bags of
glass from islands at the mouth of the Connecticut River, which flows into the
sound.
But a basic conclusion was that people
individually and collectively bear responsibility for the state of the bays. “They don’t pollute the sound,” said one
speaker in Middletown, Connecticut. “We do.
And thye are not going to clean it
up. We, as a community, must.” Another,
in New Haven said: “We need to see the personal connection between the
irritating leak under the [family car] chassis and the poisoning of Long Island
Sound from urban runoff.”
The public also has been
mobilized to save Chesapeake Bay, the largest estuary in the country, which
has suffered “a long, slow slide into degradation,” as Fran Flanigan, executive
director of the Alliance for Chesapeake Bay,’ puts it. The bay’s famous
Chincoteague oysters have almost disappeared, dwindling rockfish populations
resulted in fishing bans in Maryland and Virginia, perch are scarce, and
aquatic grasses that provide breeding grounds for fish have disappeared in
many parts of the bay.
The Alliance has pulled together more than
100 organizations—corporations, bay men, environmentalists, marina operators,
developers— to work on management of growth problems of the 64,000-square-mile
basin. The cooperation came about, says Flanigan, when “we finally recognized
that economic development and a healthy environment, far from being in
conflict, are mutually dependent.” In 1983, a three-state cooperative program
was launched and, since then, there has been some return of bottom grass, and
the striped-bass population appears to be improving. “But,’ says Flanigan,
“we’ve still got a long ways to go.”
People living around Puget Sound in Washington
hadn’t been very aware of pollution there until several migrating whales died
in bay waters, according to John Dorman, director of planning and compliance
for the Puget Sound Water Quality Authority. Then community protest spurred the
state to form the authority. Its studies showed toxic chemicals from
industrial discharges and storm runoff had settled in the bottom sediments.
EPA called one area of the sound—Commencement Bay—more polluted than the
infamous Love Canal zone near Niagara Falls.
. In spring 1991, Washington State adopted a Sediment Quality Standards
Act.
A
massive effort to change people’s behavior has helped prevent further
pollution, says Donnan, but his prognosis for cleaning up Puget Sound is only
fair. “We don’t know how well we can control storm-water runoff,” he says.
Along the Gulf of Mexico, loss of habitat
in urban bays is the result of canals and channels dug into the marshes for
transportation of oil and gas. The Barataria-Terrebonne estuary, between the
Mississippi and Atchafalaya rivers, had the most extensive coastal wetlands in
the United States but lost them at the rate of 40 to 60 square miles a year
from the 1950s-l970s.
Kay
Radlauer of the management committee for the NEP blames dikes and levees on
the Mississippi, along with the canals and channels, for the loss of wetlands.
“But,” she says, “the oil-industry recession has somewhat slowed the
degradation process.”
It’s
an ill wind...
Storm
runoff from New Orleans and Baton Rouge was threatening the Louisiana oyster
harvest, which accounts for 40 percent of all America’s oyster crop. Also,
about half of the state’s productive growing waters are closed at certain times
of the year. This infuriates Louisianans, who are proud of their cuisine.
“That’s
what it takes to get something done— people getting mad,” says Radlauer. “We
formed a coalition of businesses, local government, churches, environmental
groups, a broad base of people.” They got a dedicated trust fund for protection
of the wetlands through the state legislature, and Louisiana voters ratified
it by a 70 percent majority.
San
Francisco Bay, with 94 percent of its wetlands gone and more than 150 square miles of the estuary filled,
has the unwelcome distinction of being the country’s most manhandled estuary.
The Gold Rush in 1848 brought the first population boom to the bay and
eventually its first serious water pollution: raw domestic sewage. Since then,
humans have dug, filled, rechanneled, diverted, and dumped into the waters and
wetlands of this Pacific coast estuary.
Toxic
contaminants have decimated once-abundant fisheries for shrimp, salmon, and
Dungeness crab. But the most devastating blow to the San Francisco Bay system
has been the systematic diversion of fresh water from its tributary rivers,
through state and federal pipelines and reservoirs, to supply the huge corporate
farms in south-central California and the swimming pools of Beverly Hills, Palm
Springs, and like communities. The water loss, into the maws of the Central
Valley Project, is estimated at 65 percent. Studies have shown that a river
cannot lose more than 25 to 30
percent of its flow without disastrous ecological consequences.
At
times, the San Joaquin River is sucked so hard that it must flow backward. And,
says fisherman Bingham, that river, which once had a run of 115,000 to 140,000
king salmon every spring, now has zero. “The run was not just reduced,” he
says. “It is gone. Along with it went the historic salmon gillnet fishery of
the San Francisco Bay and delta that harvested San Joaquin stocks.” While water
for the fish was being cut back at the beginning of the drought, he says, no
agricultural cutbacks had been proposed. In fact, he continues, cotton acreage
actually increased. He concludes bitterly: “King Salmon has been lost to King
Cotton.”
The
only bright light Bingham sees on the horizon is the Central Valley Project
Improvement Act, sponsored by Senator Bill Bradley of New Jersey, which would
reallocate freshwater flows to give fish and wildlife an equitable share of
that now going to municipal uses in southern California and subsidized
agribusiness farms.
In the southern U.S. Atlantic region, estuarine
development has occurred along the narrow strip of the coast, unlike the urban
areas of the north which grew outward from core cities. The Albemarle/Pamlico
estuary in North Carolina, the first estuary NEP accepted for study, contains
four of the five fastest-growing counties in the state, with ten-year
population increases ranging from 30 to 91 percent.
Todd Miller, executive
director of the North Carolina Coastal Federation, calls non-point source
runoff the number one problem of the area. Coastline population growth has
changed the character of the rural area from fishing and agriculture to service
industries, tourism, and retirement communities, he says.
When
asked what could be done to save the Albemarle/Pamlico estuary from its extensive
pollution, environmentalist David McNaught, head of the Pamlico-Tar River Foundation,
drawled: “People can stop making so many babies. . . or ii they make them,
educate them not to be so wasteful.”
Wasteful
or greedy, pollution is not the only threat to our fish supply. Overfishing
also has shrunk the size of the catch in most U.S. coastal waters. This wasn’t
supposed to happen. The Magnuson Act of 1976, prohibiting foreign fleets from
fishing within 200 miles of the U.S. coast, was enacted to prevent high-tech
factory ships from scouring the coastal water bottoms. Amen-can fishermen were
delighted that U.S. grounds would be theirs again, but then they bought bigger
boats and sophisticated electronic fish-tracking equipment and started
slaughtering fish just as recklessly as the foreign fleets had been doing. The
impact has been that “an expanding number of vessels is attempting to catch a
shrinking number of fish,” says Fox of NMFS.
Urban
bays seem to be in such bad condition that it is difficult to believe that
progress has been made. But Brian Gorman of the National Oceanic and
Atmospheric Administration’s National Ocean Service maintains that federal
laws
have done much to prevent the bays from getting
worse. “With the cleanup that has been going on during the last ten years, the
coastal waters are actually cleaner than they were ten years ago. Seattle and
San Francisco are not getting worse, and the Chesapeake is actually improving.
We are not putting as much lead into the air as we were. U.S. environmental
laws are having some effect.”
But
it’s hard to be optimistic when you’re sitting at the culling board in Mario
Carrera’s skiff in Echo Bay. Watch him as he plunges the clam rake into the sparkling
waters and chugs the crossbar handle up and down into the mud. Then he hauls up
the long, steel pole and dumps the basket on the board.
Nestled
among the polluted clams are a beer can and a wine bottle. Other casts bring up
an automobile tire, old floor mats, and many more beer cans. “That’s the kind
of garbage we throw in our waters,” says Carrera. “We don’t think about what
we’re doing. It looks beautiful up here,” he says, motioning toward the waters
glinting in the sun, the greenery rimming the beach, sea gulls on-a rock facing
into the wind.
“But
look over there,” he says, waving his hand toward a sewage-treatment plant on
the shore. “What happens when we have heavy rains and that sewage overflows? We
are destroying our natural resources, polluting the waters, building on
shores where we shouldn’t be building. When it comes to land use, we are back
in the Neanderthal age.” Carrera shakes
his head. “It’s hard to believe what we’re doing to our world.”
Ronnie Wacker has written on social
behavior and environmental trends for
several newspapers and magazines, including the New
York Times, New York Newsday, Science
86, and McCall’s. She raised five sons on the shores
of one of the New York bays she writes about here. For the past three years, she
has been president of the North Fork Environmental Council, a New York regional organization acting to preserve the rural character of eastern
Long Island.
1.
Questions with Estuary reading
__________1. According to
the article, estuaries provide numerous ecological services of only indirect
value to humans. T or F
__________2. Where ar
Florida’s most expanse estuaries? (A)
east coast (B) west coast (C) panhandle
only (D) Lake Apopka southern shores
__________3. The amount of
freshwater entering the estuary by any route depends on (A) rainfall (B) watershed size (C) power plant runoff (D) all of these are correct (E) a and b are
correct.
__________4. What reduces salt stress in the mangroves (A) high
tides (B) low tides (C) fresh water (D) salt water
_________5. What has happened to
the fresh water runoff into Tampa Bay?
(A) dams impound rivers (B)
drought conditions occurred (C) sea
level rose allowing salt water to flow in
_________6. Terrestruial plants
canot contribute to the detritus of estuaries because they are not salt water
plants T or F
_________7. Estuaries comprise
the treasured quality of life enjoyed in the states coastal zones and is
probably responsible for the fast growing of the coastal counties in Northeast
Florida. (T or
F)
________8. When fresh water is
deprived to estuaries, salt wedhes may develop farther out into the estuary and
saltwater intrusion of coastal water supplies can result. T or F
________9. When fresh
water is deprived to estuaries, populations of nuisance species increase. T or F
_______10. The
department of Natural Resources lacks any authority over activities outside of
preserves where freshwater ordginates.
T or F
2 Florida Estuaries (What are Estuaries)
1.What
conditions do estuarine plants and animals have to put up with?
2. What
can upset the balance of estuarine
organisms?
3. Why are
estuaries special to Florida?
4.Where do
the young shrimp live and describe their journey?
5. List
some producers and consumers of the estuaries.
6. How is
Florida mapping their estuaries?
7. What
percent decline in estuaries has been noted from Sebastian inlet to St. Lucie
inlet along the Indian River?
8.What
value will the dredge and fill operations for homes have in the future?
3Lake Aopoka ESTUARIES AND MARSH FLOW PROJECT
9. What
is the Marsh Flow-way supposed
to do?
10. What do the algal blooms indicate?
11. What
will they do with the filtered water?
12. How deep is Lake Apopka?
13. How thick is the sediment along the bottom
of the lake?
14. What should the benefits of the Marsh
Flow-Way project be?
4 Symptoms Treating a Symptom...
1. What would the addition of iron to the ocean
do?
2. How would this work?
3. Why fertilize phytoplankton?
4. Would this cure the greenhouse effect?
5. After reading this article, should
scientists follow through with this idea?
5..Oil From Algae Energy...
1. List some positive and negative effects of
using ethanol in cars.
2. Where does Lignocellulose come from?
3. How much gas per year could be produced from
lignocellulose and at what price?
4. How much of our energy could be produced
from algae?
5. How much of the algae is oil?
6. What else would be used to feed the algae?
7. How much would a gallon of fuel cost?
8. Explain how would this recycle carbon?
6 THE BAY KILLERS
1. HOW LONG DOES IT TAKE TO RINSE AWAY
CONTAMINANTS FROM CLAMS?
2. BESIDES OVERFISHING, WHAT IS ANOTHER CAUSE
FOR A DECLINE IN FISH POPULATIONS?
3. WHAT IS RESPONSIBLE FOR THE DESTRUCTION OF
THE CALIFORNIA SALMON INDUSTRY?
4. WHAT PERCENTAGE OF ALL EDIBLE SPECIES OF
FISH ARE DEPENDENT ON ESTUARIES?
5. WHY ARE SO MANY SHELL FISH BEDS CLOSED?
6. HOW FAST ARE
WE LOSING OUR WETLANDS?
7. DO THE TOXIC CHEMICALS DUMPED INTO THE WATER
HAVE ANY MARKED EFFECT ON FISH? GIVE
EXAMPLES.
8. WHAT IS A COMMON FACTOR IN ALL BAY
POLLUTION?
9. WHAT IS A "DEAD ZONE" IN THE SEA?
10. WHAT AFFECT DOES THE DISAPPEARANCE OF
AQUATIC GRASSES IN THE CHESAPEAKE BAY HAVE ON FISHING?
11. WHAT IS AFFECTING 40% of the American oyster
crop?
12. HOW FAR HAS THE KING SALMON RUN BEEN CUT
DOWN? WHY?
13. WHY DIDN'T THE PROHIBITION OF FOREIGN
FISHING FLEETS PREVENT OVERFISHING?
14. HAS ANY PROGRESS BEEN MADE TO CLEAN UP THE
BAYS?
15.
WHERE DOES THE AUTHOR OF THIS ARTICLE LIVE?