Transcript 'A stench from its inky surface putrescent with the

"A stench from its inky surface putrescent with the oxidizing processes to which
the shadows of the overreaching trees add stygian blackness and the suggestion of
some mythological river of death. With this burden of filth the purifying agencies
of the stream are prostrated; it lodges against obstruction in the stream and rots,
becoming hatcheries for mosquitoes and malaria. A thing of beauty is thus
transformed into one of hideous danger."
Texas Department of Health 1925
"There are three kinds of lies. Lies, damned lies, and statistics!"
Mark Twain
Under carefully controlled laboratory conditions an organism does what it damn
well pleases.
Harvard Law
"What's the use of their having names", the gnat said, "if they won't answer to
them?"
"No use to them," said Alice; "but it's useful the people who name them, I
suppose.“ Through the Looking Glass – Lewis Carroll
Cyclomorphosis
Cyclomorphosis is, as the name indicates is a cyclic change in body form. This occurs
primarily in female lemnetic species such as Daphnia pulex and Daphnia rosea. A population of
cyclomorphic species has a homogeneous “normal”or rounded head, form in the fall, winter and
early spring. As the water becomes warmer the populations develops, however, there is a
commonly progressive increase in the longitudinal axis produced by a general elongation of the
head and the appearance of a “helmet”. Characteristically, the helmets become fully developed by
midsummer, when they may be quite bizzarre. Beginning in late summer or early autumn, the
morphology of the head progressively reverts so that the “normal” condition prevails by late
autumn. In the words of Coker (1939), “The changes in form are not simple functions of external
conditions or of any inherent cycle, but rather of a combination of internal and external conditions in
a way that becomes exceedingly baffling the more we know about it.”
Theories about helmet shapes:
Under conditions of low dissolved oxygen Cladocera often produce hemoglobin to
facilitate the transfer of oxygen. Studies have been done which strongly suggest that given the
choices of red/pink Cladocera and a normal colored Cladocera, fish choose the red/pink Cladocera.
There would therefore appear to be a selective disadvantage to becoming red/pink. One theory
suggests that the increased size of the helmet of Cladocera functions to increase surface area over
which oxygen can be extracted from the water and therefore changing helmet dimensions would be
a function of reduced dissolved oxygen.
Another theory suggests that as the water temperature increases the density of the water
decreases and therefore animals such as Cladocera have to expend more energy to keep from
sinking. Since the food of the cladocerans is mostly algae and since algae live near the surface,
decreasing the amount of energy necessary to stay higher in the water column would be a selective
advantage. One way to counter the tendency to sink would be to increase the helmet dimensions.
Normal helmet shape
for fall, winter , spring
D-H are all Daphnia retrocurva
Poikilotherm – having a body temperature that varies with the environment,
cold blooded as are amphibians, reptiles, fishes, insects
Homiotherm – having a constant body temperature, warm-blooded as are mammals
and birds
Q10 law or VanHoft’s Law which states that a doubling of temperature between 10
and 20 ºC increases the metabolic rate by 2 fold.
Inverse metabolic rate law – the smaller the organism the greater the metabolic rate
on a per gram basis. Therefore, it takes more energy to support 10, 1 gram organisms
than it does 1, 10 gram organism. If a rhinoceros had the metabolic rate of a mouse it
would have to endure boiling temperature at its surface in order to dissipate heat
generated as a result of metabolic processes.
Physoclist, physostome, no gas bladder
Diurnal
Diel
Nocturnal
At 25 °C and well fed a
female Ceriodaphnia dubia
will have its first brood (4 to
6 neonates)on day 4 after
its release from the brood
pouch. On day 5 it will
have a second brood (7 to
10 neonates) and on day 7
it will have its third brood
(15 to 20 neonates) All of
these offspring will be
female unless something
happens to induce the
Obligate filter feeders
sexual part of cyclic
parthenogenesis.
Food
Very Early Stages of Development Embryo (0 hours old)
Embryo +3 Hours
Embryo +5 Hours Old
Embryo +8 Hours
Eye spots
Embryo +11.5 Hours
Embryo +13.5 Hours
Embryo +14 Hours
Embryo +14.5 Hours
Embryo +16.5 Hours
Embryo +17.5 Hours
Young C. dubia In Last Embryonic Membranes
Compound eye
Ocellus or simple eye
First antennae
First Antennae of Female Ceriodaphnia dubia
First Antennae of Male Ceriodaphnia dubia
First Antennae of Male Ceriodaphnia dubia
Female With Fertilized Egg In Brood Pouch
Female With Fertilized Egg In Brood Pouch
ephippium
Embryo – resting egg
Ephippium With Resting Egg
Densities so great they form windrows along the
shoreline of lakes.
Ephippia
Sampling Devices
Ekman Dredge
Ponar Dredge
Surber Sampler
Kick Net
½ meter net – macrozooplankton
Microzooplankton closing net
Artificial Substrates
Diatometer
Distributions
random
clumped
Mean, Variance, Standard Deviation and Confidence Limits
Data Set 1
Data Set 2
10
5
10
80
10
0
10
1
10
0
10
0
10
0
10
7
10
3
10
4
Total
100
100
n
10
10
Ave
10
10
Variance
0
St. Dev
0
C.I.
10+/-0
611
24.7
10+/-17.8
Variance = (xi2) - (xi)2/n
Standard Deviation (St. Dev) = square root of the variance
n-1
Confidence Interval (CI) = Mean  tvalue (St. Dev.) The t value is chosen based on sample size and  or probability
n
level
t value for 95% Confidence Interval and n=10 is 2.262
1-/2 n-1 d.f.
If  = 0.05
Data Set 3
10
12
14
Calculate the mean, variance
standard deviation and 95%
Confidence limits for Data Set 3
17
T value for n-1 degrees freedom
2.262
28
Mean = 13.5
2
Variance (s2) = 55.17
6
Standard deviation = 7.43
21
Mean  5.3 (13.5  5.3)
10
15
If you have an n of more than one you can
calculate a mean and confidence intervals
about the mean
Data Set 4
30
56
18
22
4
Calculate the mean, variance
standard deviation and 95%
Confidence limits for Data Set 3
T value for n-1 degrees freedom
2.262
Mean = 20.9
12
Variance (s2) = 134
15
Standard deviation = 11.6
22
Mean  20.9 (20.9  8.2)
11
19
If you have an n of more than one you can
calculate a mean and confidence intervals
about the mean
1000
Failing to reject the null hypothesis does not
mean that there is not a difference!!!!
Ho: There is no difference in the mean
number of benthic organisms above
and below the outall.
Ha: There is a difference in the mean
number of benthic organisms above
and below the outfall.
0
Correlation and Regression
The purpose of correlation analysis is to measure the intensity of association observed
between any pair of variables and to test whether the association is greater than can be due to
chance alone. Once established, such an association is likely to lead to reasoning about causal
relationships between variables. Students of statistics are told at an early stage not to confuse
significant correlation with causation.
Regression deals primarily with the means of one variable and how their location is
influenced by another variable. Regression comes close to implying cause and effect relationships.
Thus, where a correlation coefficient tells us something about a joint relationship between variables,
a regression coefficient tells us that if we alter the value of the independent variable then we can
expect the dependent variable to alter by a certain amount on average.
The correlation coefficient r can range between -1 and +1 and the value of r tells us
something about the degree of relationship between the two variables.
The coefficient of determination r2 used in regression analysis (the square of the
correlation coefficient) tells us how much of the variation in the dependent variable can be
explained by its association with the independent variable. An r2 of 0.90 indicates that 90% of the
variation in the dependent variable can be explained by its relationship with the independent
variable.
In a sample size of 200, an r of 0.2 would be significant at the 1% level of significance,
but it would only indicate that 4% of the variation in Y could be explained by its relationship with the
X variable. A verdict of statistical significance shows merely that there is a linear relationship with a
non-zero slope. It tells us nothing about the importance of the relationship.
Mid-Term Grade Distribution
Maximum possible points at this time is 360.
Maximum accumulated points at this time is 356.5,
therefore there is a curve of 3.5 points at this time.
This does not include any of the laboratory grade.
To get an A you need to accumulate 486 points, B
432 points; C 378 points. The total number of
points possible is 540.
Animal Control
Russia
Shakespeare
Eugene Schiefflein
Passer domesticus
Aggresive
Insectivorous
Coevolution
Wolf
Lymantria dispar
Polyploidy
Fungi
•Pretty Flowers
weevil
Prolific
Dieldrin
Evapotranspiration
Tamarisk
Argentina
Conroe
China
Table decorations
Coyote
Jackrabbit
Wild Currants
Dimilin
Gypsy Moth
White amur
Gooseberries
Mongoose
Professor Ettiene Leopold Trouvelot
Japan
Bombyx mori
Agent Orange
Homo sapiens – this animal is a real mess
dichotomous key
Lepomis megalotis
Operculum
Operculum
Lepomis cyanellus
Starlings (Sturnus vulgaris)
It is the first of February, and everyone is talking about starlings. Starlings came to this country on
a passenger liner from Europe. One hundred of them were deliberately released in Central Park.
According to Edwin Way Teale, their coming was the result of one man’s fancy. That man was
Eugene Schieffelin, a wealthy New York drug manufacturer. Schieffelin formed a club called The
American Acclimatization Society who had as their goal the introduction into the US all the birds
mentioned by William Shakespeare. The birds were released in Central Park in New York and first
nested under the eaves of the Northwest wing of the Museum of Natural History. The birds
acclimated splendidly, in less than 60 years the 100 or so birds released into Central Park
increased to more than a million and by 1954 had reached Alaska. “The king forbade my tongue
to speak of Mortimer. But I will find him when he is asleep, and in his ear I’ll holler ‘Mortimer!’ Nay
I’ll have a starling shall be taught to speak nothing but Mortimer, and give it to him to keep his
anger still in motion” was the only line in Henry IV that provoked such a reckless act. These birds
are controlled in England and other parts of Europe by the normal array of competitors, predators
and diseases with which the bird evolved. These controls were not present in the US so the bird
spread rapidly, and out competed many of our native birds. You’ll begin to hear pneumatic
cannons on our campus a little later in the spring as attempts are made to drive off the starlings
and boat tailed grackle that roost on our campus.
Anne Dillard in her book Pilgrim at Tinker Creek writes, “Starlings are
notoriously difficult to “control”. The story is told of a man who was
bothered by starlings roosting in a large sycamore tree near his
house. He said he tried everything to get rid of them and finally took
a shotgun to them killing three. When asked if that discouraged the
birds, he reflected a minute, leaned forward, and said confidently,
‘Those three it did.’
Roosting in hordes of up to a million , starlings can devour vast stores of seed and fruit, offsetting
whatever benefit they confer by eating insects. In a single day, a cloud of omnivorous starlings can
gobble up 20 tons of potatoes.
In 1960 a Lockheed Electra plummeted seconds after taking off from Logan Airport in Boston, killing
62 people. Some 10,000 starlings had flown straight into the plane, crippling its engines. Any bird
in the wrong place can pose such a danger, but it is the ever-present starling that pilots fear the
most.
Starlings have proved themselves to be virtually ineradicable, though millions of dollars have been
spent trying to do so. Few creatures have inspired so much folly. In 1948, the superintendent of
sanitation in Washington, D.C., having failed to rout the birds with balloons and artificial owls, tried
exposing them to itching powder. The police used mechanical hawks. An Interior Department
consultant proposed placing grease around starling feeding sites, hoping they would track the gook
back to their nests and cover their own eggs, preventing them from hatching.
The most innovative solution, though, was advanced by the U.S. Department of Agriculture in 1931.
“When the breasts of these birds have been soaked in a soda-salt solution for 12 hours and then
parboiled in water, which is afterwards discarded, they may be used in a meat pie that compares
fairly with one made of blackbirds or English sparrows.” But cautioned the gamy taste was not for
everyone.”
In the early 1960’s a Federal Government experiment with poisoned pellets killed thousands of
starlings in Nevada. From 1964 to 1967 nine million starlings were poisoned in California’s Solano
County in an effort to protect feed lots. During that same time period the California Department of
Agriculture experimented with irradiating captive starlings with lethal doses of cobalt-60. In
Providence Rhode Island officials set off Roman candles near flocks.
Passer domesticus
There are several different versions regarding the introduction of the English sparrow.
The sparrow entered the US as a gesture of friendship. As the steamship
Europa steamed up the Hudson River the birds were released as a gesture of friendship
to the U.S. In reality the English sparrow was introduced numerous times before it
finally took hold. Including introductions from guess who? Yep, Eugene Schieffelin.
Native to the Old World, the bird was first introduced into the United States
about 1850 to combat cankerworms (inch worms…. moths that defoliate trees, both
fall and spring cankerworms feed on a wide variety of trees including apple, ash,
beech, elm, hickory, linden, maples and oaks) and it rapidly became widespread.
Aggressive as well as prolific, it has largely replaced many native birds in urban areas.
In 1912 The English Sparrow As a Pest? Farmers
Bulletin #493, by USDA noted they eat more than ½
their own weight in grain or other food a day. It
contained recipe for house sparrows.
•By 1887, some states had already initiated efforts to eradicate HOSPs. States such as
Illinois (1891-1895) and Michigan (1887-1895) established bounty programs. According to
Keith Kridler, since the bounty on "English" Sparrows was only a few cents per bird in
many states, young children killed these birds to earn money for "hard candy." The children
quickly learned to wait for the eggs to hatch and thus quadruple their bounty. County clerks
often felt sorry for these children, and paid out the bounty on any species of sparrow. A
3/16/1892 article in an Indiana PA paper stated "The different county treasurers of Illinois
have paid out in round figures $8,000 as bounty money under a law allowing 2 cents for the
head of each sparrow killed during December, January and February in that State. This
shows that about 450,000 sparrows were killed, but the frisky bird seems more numerous
than ever."
•On 09/06/1888, The Cartersville Courant-American newspaper noted "The English
Sparrow, with its grown and growing progeny, is a conspicuous nuisance. Can they be no
way devised to abate him, if not totally, at least partially?"
•An 1883 article in The Messenger (Indiana, PA, 06/27/83) said "The little sparrow has
been declared an outlaw by legislative enactment and they can be killed at any time. They
were imported into this country from Europe some years ago as a destroyer of insects,
but it has been found they are not insectivorous. Besides they drive away all our native
song birds and give no equivalent. Let them all be killed."
•In 1903, W.L. Dawson wrote "Without question the most deplorable event in the history of
American ornithology was the introduction of the English Sparrow." (The Birds of Ohio,
1903)
Think about it!
By there very nature rabbit populations are cyclic. By killing the rabbits the cycle is sometimes
exacerbated. When the rabbit population crashes the reproduction of coyotes goes down but for
those that are living don’t throw up their paws, fall over and die. They turn to alternative food –
like eat more chicken, goats or sheep. Once they learn to like chicken, goats or sheep they
continue to hunt them even when the rabbit population increases. If you have problem coyotes
deal with them. Bounties have been used to control coyote programs for over 150 years despite
a lack of evidence that they lead to long-term reductions in populations.
Wolves
Coyotes
Reintroduction health of bison herds in
Yellowstone increasing. Hunting alllowed?
Coyote populations doing just fine .
60-70 percent of diet rabbits.
Fox
Ground Nesting Game Birds
Top
Dog
Professor Ettiene Leopold Trouvelot – 1855 arrived in America
Professor Trouvelot wanted a hardy caterpillar which would feed on oak leaves and
spin a cocoon of silk. He thought such a useful creature might be produced by crossing
the American Silk Moth, Bombyx mori, which feeds on mulberry and produces a large
cocoon, with the Gypsy Moth, Lymantria dispar, which feeds on oak leaves. He was
apparently culturing the gypsy moths on trees in his backyard when some of them
escaped. Trouvelot understood the potential magnitude of this accident and notified
local entomologists, but no action was taken. After the “accident”, outbreaks began to
occur in Trouvelot’s neighborhood and in 1890 the State and Federal Government
began their attempts to eradicate the gypsy moth. Trouvelot apparently lost interest in
entomology and became interested in astronomy. About 10 years after the accident He
became famous for his illustrations of astronomical details of Venus and was
eventually given a position at Harvard University in Astronomy. A crater on the moon
was named in honor of Trouvelot and he won the French Academy’s Valz prize for his
astronomical research.
The gypsy moth is now one of North America’s most devastating pests. In one of their
record breaking years they defoliated almost 13 million acres; in 1993, they devoured a
mere 1.8 million acres. This species originally evolved in Europe and Asia where it has
existed for thousands of years. Each year about 1 million acres of forest are sprayed
aerially with pesticides in order to suppress outbreaks of gypsy moth populations.
Though some areas are treated by private companies under contract with private land owners,
most areas are sprayed under joint programs of the state and USDA Forest Service. Millions
of dollars of tax money have been spent trying to eradicate and/or control the gypsy moth.
More recently, the Asian gypsy moth—traveled as stowaways on boats from Russia to the
West Coast in 1991 and from Germany to North Carolina in 1993. The Asian moths eat more
voraciously than the Europeans and, because the females can fly, may spread four to five
times faster. This gypsy moth is known to feed on the foliage of hundreds of species of plants
in North America but its common hosts are oak and aspen. Gypsy moth hosts are located
throughout most of the conterminous US but the highest concentrations are in southern
Appalachian Mountains, the Ozark Mountains, and the Northern Lake States. Every year
isolated populations of are discovered beyond the contiguous range of the gypsy moth. Most
die out but it is inevitable that the gypsy moth will continue to expand in the future.
New studies suggest that Dimilin (RUP) one of the most effective pesticides against the gypsy
moth, does more damage to the environment than previously thought. Dimilin, also destroys
insects vital to the health of the forest ecosystem. Dimilin is the cheapest and most efficacious
way to kill gypsy moths but the chemical has also become the “bad boy” of pesticides because
of its non-target effects. Studies indicate that of all the arthropods in the tree canopy, the
macro-Lepidoptera larvae which includes the butterflies and big moths suffer the greatest loss.
These arthropods, and others don’t seem to recover for longer than a year after spraying, play
a critical role in the forest ecosystem as food for bats and birds. Dimilin is also incredibly
toxic to aquatic invertebrates compared with alternatives. An imported fungus is also being
utilized to try and control the Gypsy Moth.
Under the Toxic Substances Control Act (ToSCA) the risk of
chemicals to human health and the environment are supposed to be
evaluated before a chemical is allowed into commerce. Many of the
100,000 chemicals in commerce have never been evaluated because
they were already in commerce when the ToSCA was passed in 1976.
Approximately 2,000 new chemicals come into commerce in the US
each year.
The ecological risk assessment is done by calculating the ratio
between the Predicted Environmental Concentration (PEC) and the
Predicted No Effects Concentration (PNEC). For fish medicines*based on acute data the ratio of these two parameters is <1 the
environmental effects are considered low or non-existent. If the ratio
is greater than 1 or the log Kow is >3 or the DT50 in water is greater
than 4 days further studies including chronic toxicity are carried out.
*the various factors DT (dissipation time), Kow organisms tested vary
depending on the environmental compartment into which the
chemical might go (air, water, soil, etc.)
Log Kow for selected environmental contaminants…..
DDT 6.19 (1,548,816 times more in octanol than in water).
DDD 5.5
DDE 5.7
PCBs congeners range from 4.65 to 7.36 (22,908,676) with the higher the chlorination the greater the log Kow
Synthetic musk compounds used in detergents, shampoos, perfumes Kow 6
Triclosan log Kow 4.76, methyl triclosan log Kow 5.2, Triclocarban log Kow 4.9
2,3,7,8-TCDD (dioxin) Kow 6.80 contaminate in 2,4,5,T
Dibenzofuran Kow 5.17 contaminate in 2,4,5,T
Chloroform Kow 1.97
Benzene Kow 2.13
The use of dimilin (diflubenzuron) is expected to cause adverse
acute and chronic effects to both freshwater and estuarine/marine
invertebrates, including endangered species. Chitin inhibitor.
To lessen the environmental risks posed by diflubenzuron, EPA is
requiring the following risk mitigation measures:
Row crops and orchard uses must include a 150 foot buffer zone for
aerial applications and a 25 foot vegetative buffer strip to decrease
runoff in all cases (buffer strip will also serve as a buffer zone for
spray drift from ground applications);
Aerial applications must include the most current spray drift
language; and
All products must CONTAIN a hazards statement warning about
possible adverse effects to aquatic organisms.
White Pine Blister Rust – Cronartium ribicola
2,3,7,8-Tetrachloro-dibenzoIntroduced into the
US from timber shipments from Europe. It is a
p-dioxin
heteroecious (requires two hosts) parasite. The two hosts are the white pine
Agent valuable
Orange and
has wild
beencurrant
linkedand
to gooseberries of
tree which is commercially
cancers and other diseases in
the Genus Ribes.
Dioxins:
Congeners
several
epidemiological
studies.
One spore is found Congener:
associated
with
white
pine tree and this spore must
a member
of the the
same class,
or group.
The
Agent
Orange
cancers
and
Each
individual
PCDD
or
PCDF
is
termed
a
congener.
be transmitted to the intermediate host, the wild currant or gooseberry
diseases
include
prostate
cancer,
There
are
75
PCDD
congeners
and
135
PCDF
congeners.
before the spores infectious to the white pine tree, are formed.
respiratory cancers, (lung,
The spores that infecttrachea/bronchus,
the white pine treeslarynx),
may travel
long distances;
softhowever, the spores that
carry
the infection
from the wild currants and
tissue
sarcoma,
non-Hodgkin
gooseberries to the white
pine trees
seldom travel
more than 1000 feet. The
lymphoma,
Hodgkin
disease,
control strategy for this disease was to eradicate the wild currant and
chronic lymphocytic leukemia
gooseberry bushes within 1000 feet of white pine trees.
(CLL), and multiple myeloma.
9
O
8
O
7
9
1
6
2
8
3
7
2
O
6
4
Dibenzodioxin
PCDD
3
4
Dibenzofuran
PCDF
Cl
O
Cl
Cl
Cl
O
Cl
Cl
2378-TCDD
1
Cl
O
Cl
We used 2,4,5-Trichlorophenoxy acetic acid and 2,4-Dichlorphenoxy acetic
acid. Agent Orange
2378-TCDF
Unlike PCBs dioxins have no uses they are contaminants of
manufacturing
Kudzu Vine Brought to the U.S. in 1859 from China or Japan....
Hairy, wide leaves with fragrant purple flowers
Grows to 60 feet
Edible roots
Originally planted in eroding soils
Deciduous, nitrogen fixing bacteria associated with roots
Protein concentration about like alfalfa, leaves have been made into breakfast cereal
Now blankets everything including tall trees in the deep south
Hydrilla sp
Most native aquatic vegetation enhances aquatic ecosystems. Some of the benefits that are
derived include fish and waterfowl habitat, sediment stabilization, and improved water quality with respect
to nutrient removal and water clarity. However, many introduced species can have negative impacts.
Aquatic ecosystems are often destroyed as a result of the increased biomass, dense canopy production,
and the loss of diversity due to aggressive, weedy growth patterns that overwhelm native vegetation.
One such non-native aquatic plant that causes excessive negative impacts is hydrilla (Hydrilla
verticillata. Hydrilla is native to Southeast Asia and Australia. It was first discovered in the U.S. in the
1960s. Two distinct biotypes; one monoecious (both sexes on the same plant), and dioecious (one sex
per plant) exist in the U.S. Monoecious Hydrilla was discovered in 1982 in the Potomac River, just outside
Alexandria, VA. It has since been found in other parts of Virginia, in addition to North Carolina, Delaware,
Maryland, California, and Washington. Hydrilla is also found in Texas and in fact is in Lake Ray Roberts,
North Lake, Lake Conroe, among others.
Once Hydrilla invades an aquatic ecosystem, the plant spreads rapidly either by root crown,
and stolon growth or by drifting fragments or turions. Hydrilla also produces an underground tuber,
another reproductive strategy for survival. Monoecous Hydrilla produces viable seed, whereas dioecious
Hydrilla in the U.S. produces only female flowers. Hydrilla can rapidly produce a dense canopy , shading
out desirable native vegetation and reducing plant diversity.
To improve Hydrilla management, the U.S. Corps of Engineers’ Aquatic Plant Control Research
Program supports studies in four main technology areas. Biological control, chemical control, ecological
control, and simulation technologies. Biological control (fungal pathogens, insects), chemical control
(exposure time for herbicides, and use at the operational level) , ecological control investigates
parameters determining the distribution, The simulation technology has been developing growth models
for Hydrilla and specific control techniques such as herbicides, harvesting, and/or triploid grass carp.
Polyploid – an individual or species whose chromosome number is a multiple other
than two of the haploid number of chromosomes.
Polyploidy – a condition in which an individual posses one or more sets of
homologous chrmosomes in excess of the normal diploid sets as, triploidy,
tetraploidy, hexaploidy, octaploidy, and 16, 32, 64 etc. ploidy. Colchicine
Heterosis – hybrid vigor, increased size, faster growth rates, resistance to disease,
etc.
Homologous chromosomes – a pair of chromosomes which have identical genes on
their alleles
Water Hyacinth (Eichhornai crassipes)
Hyacinth was allegedly first brought from Brazil as table decorations for the 1884 Cotton States
Exposition in New Orleans. A woman brought one from the exposition home to Florida and put it
in her backyard fish pond. Within 10 years the colorful plant had become a public menace.
Unchecked by natural enemies and nourished by Florida’s nutrient rich waters, the water
hyacinth, which can double its population size in two weeks, rapidly displaced native aquatic
plants and took over.
Transported by boat propellers, river currents, birds, and wind the plant was soon widely spread.
The hyacinth is very plastic in its habitat. It has a tenacious ability to multiply. It floats on the
surface and extends its roots 6 to 24 inches into the water. It can survive under extreme
conditions. If water dries up it extends its roots into the bottom mud. The dense mats block the
surface exchange of oxygen from the atmosphere to the water which can lead to anaerobic
conditions. The mass can become so dense as to cause floods during spring runoff.
Control of hyacinth….
Efforts to control the water hyacinth began in 1898 with the “help” of the Army Corps
of Engineers which was authorized by Congress to remove hyacinth from navigable
waters of Florida, Mississippi, Alabama, Louisiana, and Texas. The methods they
used were:
1. Mechanical chopper
2. Within two years the COE found a chemical sodium arsenite, which did the job
more efficiently. Even though sodium arsenite was recognized as a deadly
chemical, the COE used the chemical for hyacinth control for about 35 years
between 1902 and 1937.
3. In 1937 a new crusher boat was introduced that had a large conveyor belt. Plants
were harvested and transported to shore to dry. It did not operate well in shallow
water and the cleared areas were quickly re-inhabited by plants that were not
removed.
4. In the mid 1940s the hebicide 2,4-D became available and has been used
extensively.
5. Amazingly, the integration of mechanical removal along with herbicide application
is being used to control infestations.
More recently scientists have sought to join forces with nature to control
hyacinth. There are several predators (herbivores) which in large enough
numbers could eliminate the constant attention and manpower necessary in
mechanical and chemical control.
A species of weevil from Argentina is being used. This species feeds
exclusively on hyacinths so there is “no danger” it will attack beneficial
plants. There is a small snail from Puerto Rico that has been examined but
it feeds on plants other than hyacinth. Other mites, fish, turtles have been
tested as biological control mechanisms.
Studies at the University of Florida in Gainsville analyzed the chemical
content and nutritional value of hyacinth as cattle feed. Found that it cannot
occupy more than 25% hyacinth or the cattle’s weight will go down. Another
problem is that cattle apparently don’t like its taste.
More than a century of control efforts with expenditures of millions of dollars
with minimal success.
Waif – something found without an owner
and especially by chance………
Fire Ants
Seven species of fire ants (Solenopsis) are distributed throughout the warm
temperate regions of the Americas. Shortly after World War I a dark form S.
saevissima from Argentina became established in Mobile, Alabama and slowly
spread to surrounding regions. In the 1930’s a smaller reddish form of Solenopsis
appeared in the same region, apparently representing a second major introduction.
The latter form aggressively made its way beyond the State’s borders swamping out
by interbreeding and internecine warfare (violent death marked by slaughter) the
established black phase. At present the North American populations are chiefly the
red phase, tending to replace native forms as well as the dark phase.
In 1957 the U.S. Department of Agriculture requested congressional approval for
control of the fire ant. The request was granted and a 2.4 million dollar allocation was
approved with the stipulation that matching funds be made available. Most states and
many individuals did respond with matching funds, but very often control programs
went ahead without them. A massive operation was set up with great speed. The first
spraying using 2 pounds of dieldrin (chlorinated hydrocarbon, on the POPs list, log
Kow 5.17) or heptachlor (chlorinated hydrocarbon on the POPs list, Log Kow 5.5) per
acre began in November 1957. Over two and one-half million acres were aerially
treated. Not until the operation was well underway were wildlife and health authorities
notified. Immediate opposition to the program resulted-opposition was to grow to a
national controversy. Fish, wildlife, livestock, and poultry suffered losses, the
destruction of wildlife bordered on the catastrophic. The insect was not considered
more than a nuisance in any of the southern states; it did not destroy crops, wildlife,
However, chemicals did eliminate vertebrates from some areas, it did cause residue
problems, it did contribute to insect outbreaks themselves requiring control. It did not
eradicate the fire ant; the ants re-infested most of the treated areas. The Plant Pest
Control Division of the Dept. of Agriculture had clearly made a massive mistake; the
operation was a failure from its inception.
Between 1962-1978 Mirex was used as a bait to kill fire ant colonies. Mirex was
banned for use (it is on the POPs list, Log Kow 5.28) by EPA because it was shown to
pose serious human health hazards. Mirex is converted to Kepone (Log Kow 4.07) by
photolysis.
The imported fire ant now infests more than 230 million acres in Alabama, Florida,
Georgia, Louisiana, Mississippi, North and South Carolina, and Texas. Somewhere in
the neighborhood of 175 to 200 million federal dollars have been spent trying to first
to eradicate and now control this pest.
Economic-When soybean combines cut through fire ant mounds their blades and
rollers must be replaced two or three times a season compared to once every four
years under good conditions. Farmers have been known to leave valuable crops in
the field to protect their machinery. Citrus growers in Florida are spending about
$110/acre/year to replant some varieties of young trees that die because they are
girdled by fire ants. Studies by two U of Florida researchers found that infestations of
fire ants actually increased on insecticide treated plots that originally had low
infestation levels. The amount of increase on treated plots was somewhere between
200 and 3000 percent. Because the imported fire ants colonize better than other ants
Home control can be achieved by using boiling water on the mounds. Tends to kill
the grass around the mounds. Farmland and Rangeland controls using synthetic
growth hormones like Pro-Drone that prevents the larvae from developing into
normal workers. Large areas of Texas have been treated. Some researchers believe
that the Pro-Drone will act like the broad spectrum pesticides and actually increase
the infestation. Baits designed for yard use are available Amdro just enter
http://fireant.tamu.edu/ in your search engine for the latest information.
Researchers are looking for predators, fungi, or bacteria in native Brazil for control
mechanisms. In Brazil the fire ant is not a significant problem. Clearly something in
Brazil is controlling the density of fire ants. Our native fire ant species is a minor
nuisance at home, but a major pest in India where it was inadvertently introduced.
Former Texas Agriculture Commissioner Regan Brown told a national fire ant
symposium that, “This is not an infestation it is an invasion.” This is the same guy
who, on national TV, stuck his fist into a fire ant mound and then spent the rest of the
interview trying to get the dam things off of him.
Zebra Mussel (Dreissena polymorpha)
The Zebra mussel is a fingernail sized mussel native to the Caspian Sea. First discovered in the
US in 1986 in the St. Clair River near Detroit where larvae were probably discharged along with
freshwater ballast, these incredibly prolific bivalves have spread explosively throughout the Great
Lakes. Female Zebra mussels can produce up to a million eggs per year, which develop into
microscopic, free swimming larvae that form shells and attach to any surface.
Unchecked by natural predators—in Europe they are eaten by fish and diving ducks-the mussel can
reach population densities of >90,000 per square meter. They clog pipes and shut down water
intake systems (steam electric plants). They pile up on boats, buoys, and piers crowding out native
species. One utility estimated it will cost 50 to 100 million dollars to scrape the mussels from
cooling pipes at their power plants. One “beneficial” effect is that the mussels have made Lake Erie
noticeably clearer by filtering water through its feeding apparatus.
The exotic Zebra mussel probably invaded the Mississippi Basin via canals linking Lake Michigan to
the Illinois River, a major tributary of the Mississippi. First reports in the basin were from these
canals in 1989 and 1990, so it is not surprising that the densest and most extensive populations are
from the Illinois River (up to 94,504/m2). The percentage of native mussels infested with Zebra’s
increase from 3% up river to 99.5% down river. Judging from researchers in the area the Zebra
mussels threatens the 23 native species of mussels. Freshly dead native mussels (with meats
inside) were found so heavily infested with zebras that their shells could not be forced closed.
Others were held shut by byssal threads (mechanism by which Zebra mussels attach themselves to
the substrate). Mussels that can neither close nor open will not survive. Researchers recommend
that action be taken now to cryogenically preserve gametes or fertilized eggs of native riverine
mussels or to move adults to hatcheries where they can be maintained and perhaps propogated.
Native mussels might be stocked in the future if the Zebra mussel populations every crash.
Data: 26,000 acre lake (surface acres)
“Weed” in the lake is Hydrilla veticillata, native of the old World tropics i.e., Africa
Weed is spreading at the rate of 15% per year.
Home owners around the lake have collected money and tried:
Mowing machines, and Eli Lily Co. spread chemicals, nothing has stopped the spread.
Lake is also used as a drinking water source for a major metropolitan area (provides about
40% of its drinking water).
Home owners and marina owners claim they are losing 10s of millions of dollars in lost
revenue and property values. Weed has choked off recreational area use of shore lines and
coves. The weed often traps swimmers and two have drown.
Home owners have the opportunity to buy 240,000 grass carp (white amur,
Ctenopharyngodon idellas) for $250,000 they have raised from private sources ($1.04 per
fish). The grass carp has been imported from the Soviet Union, and is being tried as a water
hyacinth control as well.
What Lake is it? You work for the Texas Fish and Game Commission and you have to decide
whether or not to let them bring in these fish. A law exists that prohibits the import of piranha
and walking catfish in addition to the grass carp. The Legislature would have to be convinced
to do this. Bass fisherman say that importing the fish will make the best large mouth bass
lake in the State the worst.
Characteristics of the grass carp:
1. Known to eat vegetation other than Hydrilla.
2. Requires running water to breed successfully.
3. Resembles a big silver colored goldfish and can weigh up to 100 pounds.
Texas legislature was convinced to approve a 5 year study beginning in 1981:
1. By 1984 all significant vegetation in Lake was gone
2. Grass carp are eating leaves off of willow trees, and 2-3 inches of grass up from the
shoreline.
3. Largemouth bass are harder to catch (lack of cover and declining population?). Bass
catch is down 25%, crappie catch is down 60%; grass carp catch is way up, corn and
dog food used as bait, fish is a vegetarian (20 to 25 lbs each), claims are made they
are good to eat. Water fowl populations are way down.
4. Grass carp now found in the Trinity and San Jacinto Rivers. Where they came from
no one is sure.
5. Some Parks and Wildlife biologists believe:
a. the carp will die out in 5 to 10 years because they need running water to spawn.
b. Hydrilla which still has roots in the lake bottom will return
c. Pressure now on to use grass carp in Houston Lake, Lake Jacsonville, Lake
Livingston, Lake Worth, and Lake Plaestine.
Triploid carp are available at $5.00 per fish. A triploid grass carp is now in effect on this
lake. If a grass carp is caught it must immediately be returned to the water.
There have been repeated instances over time where organisms, for a variety of reasons,
have been imported into the U.S. In some cases the organisms were brought in on a whim
(starlings), in the name of science (gypsy moth), to attack a specific problem (English
sparrow) or as an accident.
The current epidemic of the spread of bird flu is an example of how quickly things can
spread due to both natural conditions as well as our ability to travel almost anywhere in the
world.
The zebra mussel entered the US in the ballast of a ship as have many other hitchhikers, the
reverse movement from the US to other countries is also possible. A law is before Congress
(2008) to require ballast to be dumped and filled with saline water before ships can enter
territorial waters.
One underlying problem associated with almost all of these introductions is that at “home”
they are generally well behaved (their populations are controlled by many forces they have
evolved with) when introduced into a foreign area without the control mechanisms the
populations almost always explode.
Sometimes we introduce new species in an attempt to solve problems created by previous
introductions but end up making the situation worse. In Hawaii and several Caribbean
Islands for instance, mongoose were imported to help control rats that had escaped from
ships and were destroying indigenous birds. Since the mongoose were diurnal, and the rats
were nocturnal they tended to ignore one another. Instead the mongoose also killed native
birds and further threatened endangered species.