Download - Conservation of BIODIVERSITY
Conservation of BIODIVERSITY
• Biodiversity can be assessed and conserved at several levels: – Molecular/Genetic (rare genes and alleles) – Population – Species – Assemblage – Ecosystem – Global
BIODIVERSITY
• Molecular/genetic is the level at which natural selection and evolution occurs – Loss of genetic diversity impedes “adaptability” – Loss of populations similarly handicaps a species’
chance of surviving uncertain circumstances in the future.
Loss of BiodiversityLoss of Biodiversity
• Many reasons, often confounded
• Historic extinctions – p/t extinction (250 mya) – k/t extinction (65 mya)
• Holocene extinctions: 10,000 years ago to present
EXTINCTIONEXTINCTION
• “Given evolutionary turnover, extinction is inevitable. Like death for the individual, nothing is more certain in the future of a species than its ultimate removal.”
P. Martin and R. G.Klein IN Quarternary Extinctions:
A Prehistoric Revolution
1984
Current ExtinctionsCurrent Extinctions
• Current biodiversity crisis – Human mediated
• Correlated with Homo sapiens expanding range and density
• Ever-quickening rate of extinctions
– Has led to increase of 1000 – 10,000% above the rate of background extinctions
Current ExtinctionsCurrent Extinctions
• Current biodiversity crisis – Before 1800
• Islands: many unique island assemblages decimated – Gigantic flightless birds
– Gigantic tortoises
– Dwarf elephants/hippos
• Continents: severe extinctions among megafauna – North american mammals
– South american marsupials
Current ExtinctionsCurrent Extinctions
• After 1800: – Extinctions on islands continue
• Birds, endemic mammals, reptiles
– Extinctions among smaller continental fauna increase in pace
• Habitat destruction/conversion • Unregulated trade • Bounties on “undesirable” species
Conservation of HerpetofaunaConservation of Herpetofauna
• Amphibians and reptiles face many of the same threats that face other non-human organisms: – Habitat modification and destruction – Introduction of exotic species – Pollution – Commercial exploitation – Traditional and modern medicine – Pets – Research and teaching– Traffic mortality– Persecution
Habitat modification and Habitat modification and destructiondestruction
• The most significant problem • Absolutely correlated with increasing human population
size • Extensive and worldwide; all biomes, but tropical
rainforests hit hardest • “At the current rate of deforestation, within 30 years
there will remain neither extensive tropical forests, nor their endemic amphibian and reptile fauna”
•
from Pough et al. 2001
1) Habitat destruction
a) Deforestation of tropical forests
b) Destruction of coral reef ecosystems
c) Wetland alteration for development
d) Temperate regions altered for agriculture
e) Habitat fragmentation
Habitat modification and Habitat modification and destructiondestruction
• >95% of central California’s marshes were drained and converted before 1900. – Rana aurora draytonii (California red-legged
frog), once California’s most common frog, all but disappeared
– Thamnophis gigas (giant garter snake), slowly declined, now almost extinct
Habitat destruction:
Habitat modification and Habitat modification and destructiondestruction
• In Florida, habitat conversion may have been responsible for a decline in Ambystoma cingulatum – 200-300 per night between 1970-1972 – <1 per night after habitat conversion in 1990-
1992
• Anniella pulchra declines correlated with introduced plant spp.
Habitat modification and Habitat modification and destructiondestruction
• Often works in tandem with weedy or introduced species – In Arizona, alteration of hydrologic regime enables
crayfish, game fish and bullfrogs to persist where they otherwise couldn’t
– Argentine ants expanding range into U.S. deserts by utilizing lawns and other landscaping features. Decline in Phrynosoma coronatum and P. cornutum correlated with spread of fire ants
Habitat Fragmentation
Introduced speciesIntroduced species• Declines (and extinctions) in many island species
attributable to introduced exotics – Dogs and cats: Cyclura carinata in Caicos Islands – Cats: Brachylophus iguanas in the South Pacific – Goats: Crotalus unicolor on Aruba Island – Sheep, goats, rats: Sphenodon in New Zealand – Introduced fish in California’s high elevation lakes:
Rana muscosa and Thamnophis spp. – Fire ants impacting Texas horned lizard (P. cornutum)
and Coast horned lizard (P. coronutum)– Small Indian Mongoose: 7 species of reptile and
amphibian from Puerto Rico
Introduced Species: HerpsIntroduced Species: Herps
• Bullfrog: western U.S, C. and S. America, England, France, Asia, many other places
• Boiga irregularis: Guam – Wiping out geckos and skinks (all birds, bats,
many small mammals already gone)
• Introduced herp assemblages at ports-of-call
Introduced Herps by State Introduced Herps by State (Simberloff et al. 1996)(Simberloff et al. 1996)
05
10152025303540
PollutionPollution
– Acid rain: • Ambystoma tigrinum in the Rocky Mountains • Bufo calamita in Britain
– Selenium/agriculture runoff: • Thamnophis gigas in California’s Central Valley
– Pesticide wafting: Rana and Bufo spp. in the Sierra Nevada
PollutionPollution
• Solid Waste: marine turtles
• PCB’s: effect endocrine systems of aquatic frogs and turtles
• Acidic runoff from mines: Rana tarahumarae in Arizona
Pollution • Biomagnification
– The increase in the concentration of bioaccumulated toxic chemicals in organisms higher on the food chain due to preferential storage of the toxic chemical in edible body parts
• There is abundant evidence that some carnivores at the ends of longer food chains (crocodiles, alligators, snakes) suffered serious declines in fecundity and hence in population size because of this phenomenon
Anthropogenic eutrophication
• Nutrients released, triggering chain of events
Directly Impacts aquatic turtle, alligator, snake populations
Over-harvesting
Commercial collecting: FoodCommercial collecting: Food
• Frogs: U.S., Europe, SE Aisa, Africa – Late 1800’s: extreme
decline in availability of California red-legged frogs partially attributable to collecting pressure
– 1976- 2.5 million KG frog legs imported into U.S.
– Annual consumption in France: 2.7-3.6 million KG frog legs
Commercial collecting: FoodCommercial collecting: Food
• Declines in Iguana iguana and Ctenosaura similis
• Monitors, pythons, tortoises, sea turtles
Commercial collecting: SE Commercial collecting: SE Asian Turtle CrisisAsian Turtle Crisis
• 12 million turtles sold per year in China’s food markets
• China’s and Vietnam’s turtle populations depleted: now imported from all around the world, including the U.S.
• Many of China’s turtles were only known from the food markets: no natural history or distribution information available
• Many of those turtles have not been seen in markets for years
Commercial collecting: SE Commercial collecting: SE Asian Turtle CrisisAsian Turtle Crisis
• Low reproductive rate combined with great importance placed on age of turtle has dire consequences for natural populations
The bycatch problem:
Commercial exploitation for Commercial exploitation for skinsskins
• Civil war: Thousands of American alligators killed for skins
• Legal importation of 304,189 pairs of Boa constrictor boots and 176,204 pairs of Python reticulatus into U.S in 1981 (all harvested from the wild)
• >1 million crocodile skins per year from 1980 to 1985
• >12 million tegu skins during same period
Commercial exploitation for Commercial exploitation for skinsskins
• Most species harvested for skins are long-lived
• Until recently all have been harvested from the wild
• Some progress being made to establish farms for commercially important species
• The vast majority of skins are still collected from wild animals
Traditional and Modern Traditional and Modern MedicineMedicine
• Bufo alvarius and Phyllomedusa bicolor used in shamanistic rituals
• Snake venom used in antivenin and anticoagulant drugs
• Batrachotoxin used in research to probe for voltage-sensitive sodium channels
• Rattlesnake “shaker muscle” used in physiology studies
PetsPets
• In Florida, 119,831 herps removed from the wild between 1990-1992
• 74,000 box turtles exported as pets between 1992-1994
• Habitat destruction often accompanies collecting for pets
• Very little record kept regarding #’s of animals collected as pets from the wild
Pet trade• “In the United States, the retail trade in live reptiles,
amphibians, and related products is worth a minimum of two billion dollars annually” -Joseph Franke MS and Teresa Telecky
• If you wish a reptile as pet make sure you are dealing with dealer that can be trusted. Find out where the animals come from
ResearchResearch
• For scientific collections: usually very small impact
• For bio and medical training – In early 1970’s 15 million leopard frogs
collected from the wild – 1970-1971: 10 tons of leopard frogs collected
from one western state – 250 lbs collected 4 years later
Traffic Mortality – Roadkill!
Increases mortality of individuals and also decreases gene flow
Matthew Aresco, a 4th year PhD student in the Department of Biological Science at Florida State University built a temporary fence to divert turtles (and other wildlife, > 41 species) away from the road and into a culvert that joined the two lakes. Over the past 2.5 years he has monitored the temporary fence at least twice per day and maintained it at his personal expense (at least $2000 out-of-pocket).
Species such as frogs, snapping turtles, large softshell turtles, alligators, and most mammals can climb over this low fence. The fence only covers 2000' - 3000' of the "killing zone".
Permanent guidewall and culvert system recently constructed at Paynes Prairie on US Highway 441 south of Gainesville, Florida.
http://www.rattlesnakeroundup.com/index.html
Persecution
Rattlesnake RoundupsRattlesnake Roundups• Occur in several
southeastern states • Run by either non-profit
Jaycee’s clubs or for-profit companies
• 5 Crotalus spp. are targets; other harmless snakes taken incidentally
• Collecting methods often unethical
•
Rattlesnake RoundupsRattlesnake Roundups
Snakes often stockpiled by collectors for long periods of time
At roundup, measured, weighed, poked fun at, submitted to stresses and injuries
Often skinned alive, in public
Rattlesnake RoundupsRattlesnake Roundups
• Justified as a way to “educate the public”
• Also, to collect venom for research/antivenin industry
• Claims that there’s no effect, or a beneficial effect, on native populations
• However, effects of roundups on wild populations largely undocumented
Rattlesnake roundupsRattlesnake roundups
• The only organized events in the U.S. in which profits are made off the unregulated harvest of a vertebrate group
•
• WHY?
Declining Amphibians-HistoryDeclining Amphibians-History
• In 1989, at an international herp conference, workers expressed concern that their study organisms weren’t as common as they once were
Declining Amphibians-Declining Amphibians-
• Species extinctions and population declines around the world prior to 1990
• Subsequent studies have documented declines as they happen
• Few patterns emerged, other than that the most precipitous declines were among Anurans
Declining Amphibians-Declining Amphibians-
• Many of the same causes found for other biodiversity losses: – Habitat loss – Pollution, acid rain – Exotic species – Collecting
Amphibian Decline:What’s happening to all the frogs?
http://www.amphibiaweb.org/aw/declines/extinct.html#declines
Evidence of a complex problem
Two specimens of deformed frogs (Rana pipiens) from Vermont with missing parts of their hind limbs
Deformed Pacific Treefrog, Hyla regilla, from Oregon, with supernumerary hind limbs
What’s causing these Deformities/Declines?
predation and/or cannibalism, whereby some predator (even other tadpoles) may be nipping the limbs off of tadpoles
1) predation and/or cannibalism?
Retinoic Acid:Main effects of RA on amphibian limbs-
Methoprene?
Atrazine:
Diazinon:Suppresses cholinesterase (nervous system)
2) CHEMICAL POLLUTANTS?
Hayes found hermaphroditism in frogs at levels as low as 0.1 ppb. Even with today's limits, levels of 40 ppb atrazine have been measured in rain and spring water in parts of the Midwest, while atrazine in agricultural runoff can be present at several parts per million.
3) Parasites? http://www.jcu.edu.au/school/
phtm/PHTM/frogs/ampdis.htm
Ribeiroia ondatrae (trematodes)
Ribeiroia cercariae
Johnson et al. exposed tadpole Pacific tree frog (Hyla regilla) to the cercaria of a trematode parasite, Ribeiroia. They found that as the number of parasites per tadpoles rises, the percentage of abnormalities increases while survival decreases.
http://news-info.wustl.edu/tips/page/normal/961.html
Parasites cont.
Spirometra erinacei (tapeworm)
Pathogens?
Chytrid Fungus (Batrachochytrium dendrobatidis)
Mucor amphibiorum Infected frogs and toads have
fungi disseminated through their internal organs and skin
Infected frogs may:
• have discoloured skin • be sloughing, or peeling, on
the outside layers of its skin. This can vary from obvious peeling of skin (particularly on the feet), to a roughness of the frog's skin that you can barely see
• sit out in the open, not protecting itself by hiding
4) Climate Change?
Increase in temperature seems to be impacting amphibian populations
5) Habitat Loss
7) Exotic species
• Bullfrog
UV Radiation
• UVB Radiation?– Blaustein vs Adams
and Corn
Laws and Regulations: CITESLaws and Regulations: CITES
• Convention on International Trade in Endangered Species of Wild Fauna and Flora established by IUCN in 1973 – Regulates international trade in species of concern – Mandates that international trade in endangered
species is unlawful – Nearly 600 species of amphibian and reptile are
covered
Laws and Regulations: ESALaws and Regulations: ESA
• Signed into law by Nixon in 1973 – Far-reaching law; protects both domestic and foreign
animals and plants – Prohibits “take” of species of concern – Mandates that FWS and NMFS monitor populations
and develop a recovery strategy
Laws and Regulations: ESA Laws and Regulations: ESA listing processlisting process
• Anyone can petition to list a species – Must provide sound scientific basis for listing – FWS or NMFS reviews petition, may conduct
additional research, must make findings according to predetermined time schedule
– Decision to list or not published in Federal Register, including basis for decision
Laws and Regulations: ESA Laws and Regulations: ESA recovery processrecovery process
• FWS or NMFS drafts a Recovery Plan for the species in question – Delineates tasks and criteria needed for the recovery
of a species – Solicits public and expert comment on draft Recovery
Plan – Revises draft, issues final recovery plan
• Includes dollar estimates needed for recovery • Not a binding document
– Species is delisted or downlisted as criteria from Recovery Plan are met
– Critical habitat may be designated later
ESA: Herp Listing StatusESA: Herp Listing Status
99
15
49
0
25
50
75
100
Endangered
EmE
SAT
Threatened
ESA: Insular and Continental Amphibians and Reptiles
48
98
8
0
25
50
75
100
island
continental
marine
ESA Listed Amphibians by ESA Listed Amphibians by StateState
Was
hingto
n
Oregon
Alabam
a
Arizona
Nevad
a Wyo
min
gTexas
Califo
rnia
012345678
Alaba
ma
Arizon
a
Califo
rnia
Florid
a
Idah
o
Miss
ouri
Nevad
a
New M
exico
Ore
gon
Texas
Virgin
ia
Wes
t Virg
inia
ESA Listed Reptiles by StateESA Listed Reptiles by State
0
2
4
6
8
10
12
14
ESA: Herps with Recovery PlansESA: Herps with Recovery Plans
13
31 32
123
0
25
50
75
100
125
amphibians (42%) reptiles (26%)
recovery plans
listed species
ESA: Herps with Critical HabitatESA: Herps with Critical Habitat
19
134
0
20
40
60
80
100
120
140
14% w/Critical Habitat
Yes
No
ESA: U. S. Listings of Herps by ESA: U. S. Listings of Herps by YearYear
1
10
100
1000
10000
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
# L
iste
d Amphibians
Reptiles
All species
ESA Listed Amphibians and ESA Listed Amphibians and Reptiles by GroupReptiles by Group
1714
41
24
2
37
19
0
5
10
15
20
25
30
35
40
45
Anura
Urodela
Chelonia
Crocodylia
Rhynchocephalia
Sauria
Serpentes
% of ESA Listed Species by % of ESA Listed Species by GroupGroup
100
0
10
20
30
40
50
60
70
80
90
100
Anura
Urodela
Chelonia
Crocodylia
Rhyncocephalia
Sauria
Serpentes
Human Population Density & Human Population Density & # ESA Listed Herps# ESA Listed Herps
Rept. = 0.3426x + 1.3969
R2 = 0.2383F 1,36 = 11.26, p = 0.002
Amph.= 0.0453x + 0.5344
R2 = 0.0108F 1,22 = 0.24, p = 0.63
0
0.5
1
1.5
2
2.5
3
-6 -4 -2 0 2 4
ln state population density
ln #
lis
ted
American alligator:American alligator:an ESA success storyan ESA success story
• American alligator was listed as threatened under precursuer to ESA in 1967.
• All subsequent “take” was illegal • Captive breeding and farming “ranches”
proliferated • Eggs collected in wild, incubated, then released
when hatched • Alligator recovered, delisted in 1987 • Now subject of 60 million $/ year industry
State laws and herpsState laws and herps
• Usually protected by state game and fish agency
• Funding through sales of fishing and hunting licenses (P-R act and D-J act, respectively)
• Often need fishing or hunting license to collect
• Often may not collect for sale • Bag limits, quotas imposed • States may have ESA-type
legislation
What can I do?
• Adopt a conservation ethic• Work directly in the area of conservation
– Help conduct research– Assist with conservation organizations– Become involved politically
• Educate yourself, family & friends about the importance of herps in the ecosystem
• Educate yourself, family & friends about the importance of having better “green” life choices– Try to have a lifestyle that incorporates sustainable methods– Support companies that work towards sustainability & are
supportive of the environment– Elect officials that support environmental policies
Conservation GroupsConservation Groups
• Conservation International
• The Wildlife Society
• Society for Conservation Biology
• The Wilderness Society
• Center for Biological Diversity
Conservation JournalsConservation Journals
• Conservation Biology • Biological Conservation • Southwest Naturalist • Journal of Wildlife
Management, Wildlife Society Bulletin
• Chelonian Conservation and Biology
When it comes to conservation and all the things of your life keep in mind these words
I am only one, but I am one.I cannot do everything, but I can do Something.I will not let what I cannot do interfere with what I can do.
Edward Everett Hale