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FACULTY OF NATURAL SCIENCES
Rich Knight, Biodiversity & Conservation Biology
UWCknight.rich[at]gmail.com
Pollution
Litter
Oil Spills
Pesticides
Fertilizers
Light
Global Warming
WHAT ARE THE WHAT ARE THE ENVIRONMENTAL FACTORS ENVIRONMENTAL FACTORS
CAUSING LOSS OF CAUSING LOSS OF BIODIVERSITY?BIODIVERSITY?
100s of different pesticides exist
Many are worldwide contaminants as they have been carried in the air and water
Have been seen as agent of evolutionary change in some species
PESTICIDESPESTICIDES
These pesticides all have
Chemical stability
High mobility
High solubility
Toxicity
A well known example of a chlorinated hydrocarbon pesticide is DDT
PESTICIDES: CHLORINATED PESTICIDES: CHLORINATED HYDROCARBON PESTICIDES HYDROCARBON PESTICIDES
(CHS) (CHS) 11
Discovered in 1939
First used to kill mosquitoes
Used to control against pests such as the elm bark beetle
DDT does not just affect the target species
DDT is still used in some developing countries
PESTICIDES: DDT PESTICIDES: DDT 11
Has been seen to bioaccumulate and biomagnify throughout the trophic levels in the environment
An example is seen in a study by Boykins (1967) 2
Worms were absorbing DDT
The worms kept the DDT 18 months after spraying
Birds absorbed the DDT from the worms when they ate
DDT caused bird mortality
Seen in the artic and sub-artic 3
DDT increased from Ringed and Square flipper seals to Polar bears
Polar bear milk contained increased levels of DDT
PESTICIDES: DDTPESTICIDES: DDT
This is not just affecting animals and plants
In Kibaha in Tanzania DDT was found in crops 4
The crops were eucalyptus, cashew, plums and casava which are eaten by humans
In Mato Grosso, Brazil the DDT in the soil is leaking into the underground water 5
In Turkey DDT has been found in 12 edible fish 6
These are concerns for public health
PESTICIDES: DDTPESTICIDES: DDT
Some animals such as a few of the bird species that showed eggshell thinning are recovering since DDT was banned 1
In Grey Seals since the use of DDT has been stopped the gynaecological problems that the seal populations had have decreased and pregnancies have increased 7
PESTICIDES: DDTPESTICIDES: DDT
These are the alternatives to the CHs 1
Have been seen to kill herbivorous birds 1
Affects birds that feed on sprayed insects 1
Rainbow trout that were exposed to methiocarb had lemmellar edema and the epidermis became separated from the lamellae 8
One of these is called Dioxin which causes cancer and birth defects in lab animals, this is still in use 1
Many of these substances have now been banned
PESTICIDES: CARBAMATES AND PESTICIDES: CARBAMATES AND ORGANOPHOSPHATESORGANOPHOSPHATES
The estimate of oil input into the environment is 3.2 million tons a year
Most of this is from land waste put into the ocean or into rivers
Evaporation and combustion allow petrol compounds into the air which are then cycled into the sea
More noticeable is the large media events of the ocean oil spills
OIL POLLUTION OIL POLLUTION 11
The worst spill was seen in the Persian gulf
This was during the war to liberate Kuwait in 1991
1,700,000 tons of oil was released into the sea
Not far off was the spill in 1979 from a Mexican platform
500,000 to 1,400,000 tons of oil was spilt
Better publicised are the oil tanker spills such as the Exxon Valdez in Alaska and Amoco Cadiz in France
OIL POLLUTION OIL POLLUTION 11
Spill occurred on March 24th 1989
The tanker hit a reef off the coast of Alaska
41,000 tons of crude oil was spilt
40-45% of the oil spilled ended up on the coast
Death Toll
350,000-500,000 sea birds
200 bald eagles
3,500-5,500 sea otters
350 Harbour seals
14 killer whales
OIL POLLUTION CASE STUDY: OIL POLLUTION CASE STUDY: THE EXXON VALDEZ THE EXXON VALDEZ 11
A misguided clean up operation was started
Activities lasted four years
Shores were washed with hot water and oil and tar was collected
Unfortunately the hot washing killed many of the shores invertebrates and pushed the oil onto unaffected beaches
The coast that had been cleaned was more damaged than the unclean part
OIL POLLUTION CASE OIL POLLUTION CASE STUDY: STUDY:
THE EXXON VALDEZ THE EXXON VALDEZ 11
Long term affects
Fry of the pink salmon were sterile 1
Sockeye salmon could not be harvested, their numbers increased allowing many fry to starve to death 1
Mussels and clams are still poisoned 9
Sea otters have only managed to regain half of their numbers 9
People have had to move away from the coastline as they relied on the fish and seals for food 10
OIL POLLUTION CASE OIL POLLUTION CASE STUDY: STUDY:
THE EXXON VALDEZTHE EXXON VALDEZ
Differs from habitat to habitat
In open ocean oil slicks kill plankton and fish and effect sea mammals and sea birds
At the coast, sandy beaches can hide oil for months and rocky coasts become coated with the oil and kills almost all the organisms, this can last for years
In estuaries and salt marshes the effect of an oil spill are felt the hardest, here the oils can affect the environment for decades as it gets buried in the anoxic sediments to be exposed again at a later date
OIL POLLUTION: IMPACTS ON THE OIL POLLUTION: IMPACTS ON THE WILDLIFE WILDLIFE 11
Sea birds suffer the most when oil is spilled into the ocean
Many sea birds dive into the ocean to get food, every time they dive they pass through the oil slick
This causes their feathers to become oily which in turn inhibits their flight and buoyancy
Oil soaked feathers are not good insulators so the birds get cold
Trying to remove the oil by preening causes more problems like toxic effects on the liver, kidneys and pancreas
OIL POLLUTION: IMPACTS ON THE OIL POLLUTION: IMPACTS ON THE WILDLIFE WILDLIFE 11
Used as insulators and fire retardant
Have made way into aquatic systems
Long lived
High solubility in lipids
Food chain magnification
Impairs reproductive success in birds and seals and affects polar bears
POLYCHLORINATED BIPHENYLS POLYCHLORINATED BIPHENYLS 11
Found in petrol and cigarette smoke and given off after combustion of fossil fuels 1
Pollute aquatic environment 1
PAHs are activated by cytochrome P450 and form compounds that damage or mutate DNA, RNA or proteins 11
Some bond with the DNA, RNA or proteins and can cause cancer 11
POLYNUCLEAR AROMATIC POLYNUCLEAR AROMATIC HYDROCARBONS HYDROCARBONS
Heavy metal pollution has been going on for about 8000 years 12
Archaeologists have found evidence of copper extraction and smelting in the Faynan orefield in Jordan 12
Athenian civilisations managed to pollute the air with 2300 tons of copper every year, these figures were calculated from the ice sheets in Greenland 12
Other examples; mercury, lead and nickel 1
Many show food chain magnification 1
Affects fish, marine birds 1
For example gold mining uses mercury to separate the gold and the waste is poured into local water 1
An obscure example is the use of a paint on the hulls of ships that contains tin, it is toxic to marine organisms and is banned in some countries 1
HEAVY METALSHEAVY METALS
Naturally occurs in soils
Where desert regions are farmed selenium leaches into the local water
An example of this was seen in California at the Kesterson National Wildlife Reserve
Caused reproductive failure in some birds and birds that did manage to breed hatched deformed chicks
Also caused death
SELENIUM SELENIUM 11
For example, caesium, strontium and
phosphorous
All show bioconcentration and biomagnification
A well known example of this kind of pollution
was seen at the disaster of Chernobyl
RADIOISOTOPES RADIOISOTOPES 11
The Chernobyl disaster occurred in the Ukraine in 1986
There had been a nuclear reactor at the site since 1977
The explosion occurred due to a safety test
The explosion exposed the core
Radioactive fission products and debris rose 1 km into the air
The pollution was carried north-west on the wind
The graphite fire lasted 9 days
RADIOISOTOPES – RADIOISOTOPES – CHERNOBYL CHERNOBYL 1313
The soviet government at the time did not admit that there was anything wrong
Only noticed by Swedish workers who saw the smoke
A tunnel was dug underneath the core to place a concrete slab and a cooling system
The core was placed in a 300,000 ton concrete and steel box
Before the box was in place six tonnes of uranium dioxide and fission products along with xenon, krypton, iodine, tellurium and caesium were released into the atmosphere
RADIOISOTOPES – RADIOISOTOPES – CHERNOBYL CHERNOBYL 1313
The effects of the radiation widespread
Caesium has a long half life and is absorbed into the body like potassium so it quickly got into the food chain 13
Radiation got in to the ground water 13
There was a rise in thyroid cancer 13
More than 20 species show genetic damage 14
Radiation reduces antioxidants and immune response in animals 15
Has increased levels of partial albinism
Has affected breeding successes of animals 15
RADIOISOTOPES – CHERNOBYL RADIOISOTOPES – CHERNOBYL
Now the concrete and steel box that is containing the radiation is breaking down
Work is being carried out to repair the box
A large arch is being constructed to contain the radiation and the concrete box
The three undamaged reactors need to be decommissioned
Need to dispose of the radioactive waste that was dug into the ground in 1986
RADIOISOTOPES – RADIOISOTOPES – CHERNOBYL CHERNOBYL 1414
Plastics pollute the land and sea
On the Sargasso sea surface there are about 3500 large pieces of plastic making up 290 grams per km2 16
Animals are known to eat plastics
Sea turtles are notorious for eating plastic bags assuming they are jellyfish
Laysan albatrosses have been seen to feed plastic bags to their chicks 1
In a study by Moser and Lee (1992) 1033 birds were collected from 1975-1989 17
21 of the 38 bird species had plastic in their stomach
The amount of plastic in the birds stomach increased over time
Some birds selected for particular colours or shapes
PLASTIC PLASTIC
There is no easy answer
Man will continue to pollute and the environment will carry on suffering
Some governments regulate the use of pesticides
Oil tankers are now built with a double hull 1
An international dumping convention in 1972 agreed to by 64 countries states that deliberate dumping of CHs, PCBs, some heavy metals, plastics, petroleum and radioactive waste must be stopped 1
THE ANSWERTHE ANSWER
This pollution occurs when we switch lights on outside at night
Estimates show that two thirds of the population are living in areas above the accepted light pollution level 18
Light pollution affects many species in ways we are only just understanding
Trees increase their growing season in the presence of outdoor lighting and are then susceptible to winter frosts 19
The Hawk moth (Deilephilia elpenor) shows decreased ability to see colours in artificially lit environments 20
Artificial light at night increased tumour growth and decreased survival in female rats 21
LIGHT LIGHT POLLUTIONPOLLUTION
Large topic much talked about recently
Estimate that 18% of the species in Central America, Australia, South Africa and Europe will disappear 22
Earth warmer now than in the last 40 million years 23
Problems:
Change may occur so rapidly that plants and animals cannot adjust
Compounded by habitat fragmentation and degradation
The new conditions may be more suitable for invasive species
Has caused distribution shifts in species
GLOBAL CLIMATE CHANGE GLOBAL CLIMATE CHANGE 11
Species are moving pole-wards, global meta-analysis predicts that ranges will move north by 6.1km per decade and spring will become 2.3 days earlier
Shown by non-migratory butterfly species, 63% of 35 species have shifted their range northward by between 35-240km 24
Species are adjusting their breading seasons
Shown by native amphibian species in Britain 25
Species are moving higher in altitude
Species are becoming extinct
Shown by Bufo periglenes 26 (an anuran (newt) species)
GLOBAL CLIMATE CHANGEGLOBAL CLIMATE CHANGE
Study by Beebee (1995)
The time that five species entered a pond was recorded over 17 years
Bufo calamita and Rana esculenta spawned earlier each year
The three newt species arrived 5 weeks earlier in 1994 than in 1978
Pond arrival time of T. vulgaris and spawning of R. esculenta gets 9-10 days earlier every 1 °C increase in temperature
GLOBAL CLIMATE CHANGE –GLOBAL CLIMATE CHANGE –SPECIES ALTERING BREEDING SPECIES ALTERING BREEDING
SEASON SEASON 2525
Study by Pounds et al. (1997)
The Golden toad (Bufo periglenes) lived in the Monteverde cloud forest
It is not conclusive but evidence suggests that the climate changed in the years preceding the disappearance of the Golden Toad
The toad relied on the cool, wet cloud forest and water bodies for breeding
GLOBAL CLIMATE CHANGE – GLOBAL CLIMATE CHANGE – SPECIES BECOMING EXTINCT SPECIES BECOMING EXTINCT 2626
In South Africa, modelling studies have predicted large shifts in biomes
Requires extremely rapid shift in distributions – often faster than is physically possible (Midgley et al predict significant numbers of fynbos species will die due to lack of movement)
Not all species that are unable to follow shift in optimal climate will die out (rear edge conservation)
However, remainder populations are less viable, and more susceptible to additional effects (invasion, fragmentation)
Inevitably means change in population structure, lower complexity, reduced ecosystem function until new climax community is formed (could be many thousands of years)
GLOBAL CLIMATE CHANGE – GLOBAL CLIMATE CHANGE – POTENTIAL HABITAT SHIFTS POTENTIAL HABITAT SHIFTS
Image source: SANBI website. http://www.sanbi.org/climrep/4.htm
This is an enormous topic and not everything is covered here
The human population is doing a lot to pollute the environment
The effects of this pollution are not fully understood
IN CONCLUSIONIN CONCLUSION
1. Cox, G. W. (1997) Conservation Biology (2nd ed) concepts and applications. Pp 223-232
2. Boykins (1967) The effects of DDT contaminated earthworms in the diet of birds. Bioscience 17:37-39
3. Bowes, G. W. and Jonkel, C. J. (1975). Presence and distribution of polychlorinated biphenols in artic and sub-artic marine food chains. Journal of Fish Research Board, Canada 32: 2111-2123
4. Marco, J. A. M. and Kishimba, M. A. (2006). Pesticides and metabolites in cassava, eucalyptus, plum and cashew leaves and roots in relation to a point source in Kibaha, Tanzania. Chemosphere 64: 542-548
5. Villa, R. D. et al. (2006). Dissipation of DDT in a heavily contaminated soil in Mato Gosso, Brazil. Chemosphere 64: 549-554
6. Coelhan et al. (2006). Organochlorine levels in edible fish from the Marmara sea, Turkey. Environmental International 32: 275-280
7. Bergman, A. (1999). Health condition of the Baltic grey seal (Halichoenis grypus) during two decades. APMIS 107: 270-282
8. Altinok, I. et al. (2006). Effects of water quality and fish size on toxicity of methocarb, a carbamate pesticide, to rainbow trout. Environmental Toxicology and Pharmacology 22: 20-26
9. BBC news at News.bbc.co.uk/1/hi/world/americas/3333369.stm (accessed July 2006)
10. BBC news at News.bbc.co.uk/1/hi/ programmes/from_our_own_correspondent/301097.stm (accessed July 2006)
11. Oh, E. et al. (2006). Comparison of immunological and genotoxilogical parameters in automobile emission inspectors exposed to PAHs. Environmental Toxicology and Pharmacology 21:108-117
12. Grattan et al. (2006). The local and global dimensions of metalliferous pollution derived from a reconstruction of an eight thousand year record of copper smelting and mining at a desert mountain frontier in Southern Jordan. Journal of Archaeological Science (in press)
REFERENCESREFERENCES
13. BBC news at Bbc.co.uk/dna/h2g2/A2922103 (accessed July 2006)
14. BBC news at News.bbc.co.uk/1/hi/in_depth/europe/2006/chernobyl/default.stm (accessed July 2006)
15. Moller, A. P. and Mousseau, T. A. (2006). Biological consequences of Chernobyl: 20 years on. Trends in Ecology and Evolution 21: 200-207
16. Carpenter, E. and Smith, K. L. (1972). Plastics on the Sargasso sea surface. Science 175: 1240-1241
17. Moser and Lee. (1992). A fourteen year survey of plastic ingestion by Western North Atlantic sea birds. Colonial Waterbirds 15: 83-94
18. Cinzano, P. et al. (2001). The first world atlas of the artificial night sky brightness. Monthly Notices of the Royal Astronomical Society 328:689-707
19. International dark sky association at www.darksky.org (accessed July 2006)
20. Johnsen et al. (2006). Crepuscular and nocturnal illumination and its affects on colour perception by the nocturnal hawk moth, Deilephilia elpenor. Journal of Experimental Biology 209: 789-800
21. Cos, et al. (2006) Exposure to light-at-night increases the growth of DMBA-induced mammary adenocarcinomas in rats. Cancer Letters 235: 266-271
22. Thomas, C. D. et al. (2004). Extinction risk from climate change. Nature 427: 145-148
23. Easterling, D. R. et al. (1997). Maximum and minimum temperature trends for the globe. Science 277: 364-367
24. Parmesan, et al. (1999). Poleward shifts in geographical ranges of butterfly species associated with regional warming. Nature 399: 579-583
25. Beebee, T. J. C. (1995) Amphibian breeding and climate. Nature 374: 219-220
26. Pounds, J. et al. (1999) Biological response to climate change on a tropical mountain. Nature 398: 611-614
REFERENCESREFERENCES
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