[common frogs mating]

...Cold and Clammy, But You Gotta Love Us !

Animals as Environmental Animals as Environmental Sentinels of Human Sentinels of Human

PollutionPollution

Feature Creatures = Feature Creatures = AmphibiansAmphibians

By Leslie A. Dierauf, VMDBy Leslie A. Dierauf, VMDSanta Fe, New MexicoSanta Fe, New Mexico

SentinelsSentinels (O’Brien, (O’Brien, 1993)1993)

““...organisms whose known ...organisms whose known characteristics can be measured to characteristics can be measured to

assess the extent of assess the extent of environmental…implications…and environmental…implications…and to provide early warning of those to provide early warning of those

implications.”implications.”

PollutionPollution

Contamination of the earth’s Contamination of the earth’s environment with materials that environment with materials that

interfere interfere

with health, quality of life, with health, quality of life,

or the natural functioning of or the natural functioning of ecosystems.ecosystems.

At Air/Water Interface

[southern leopard frog]

On Land, Living In Outdoor Environs

Three Ways In Which Amphibians Are Affected By Their Environment

Bullfrog skin Eggs w/tadpoles Tadpole w/gills

Human Population Growth:Human Population Growth:Its Effects on SentinelsIts Effects on Sentinels

Loss or modification of habitat Loss or modification of habitat PredationPredation Introduction of non-native speciesIntroduction of non-native species Air and water quality impactsAir and water quality impacts Climate changesClimate changes

Air Quality EffectsAir Quality Effects

Greenhouse gas productionGreenhouse gas production Volatile organic compoundsVolatile organic compounds Aerosolized pesticides & other Aerosolized pesticides & other

chemicalschemicals Particulate matter and Particulate matter and

silt/sedimentationsilt/sedimentation

Water Quality & Quantity Water Quality & Quantity EffectsEffects

HerbicidesHerbicides PesticidesPesticides Heavy metalsHeavy metals Other materials in run-offOther materials in run-off Decreased pH & Increased salinityDecreased pH & Increased salinity Lowering of water tablesLowering of water tables Loss of freshwater spring flowsLoss of freshwater spring flows

Trematode Life-CycleTrematode Life-Cycle

Deformed Frog

Larval Form of TrematodeEncysts in Leg Bud of Tadpole

Snail Ingests TrematodeBird Eats Tadpole

Digestive JuicesRelease EncystedLarvae

Golden Toads - Monteverde CloudforestNorth Central Costa Rica

Climate Change EffectsClimate Change Effects

Increased ultraviolet lightIncreased ultraviolet light Acid rainAcid rain Global warmingGlobal warming DiseaseDisease

UVB Radiation Effects on Developing Eggs

Maintaining Biological Maintaining Biological DiversityDiversity

Strawberry Poison Dart Frogs Mating

Bridging the Gap - Who?Bridging the Gap - Who?

Public Health VeterinariansPublic Health Veterinarians

EpidemiologistsEpidemiologists

Applied and Basic Research ScientistsApplied and Basic Research Scientists

Small Animal Veterinarians (pocket pets)Small Animal Veterinarians (pocket pets)

Exotic Animal CliniciansExotic Animal Clinicians

Wildlife VeterinariansWildlife Veterinarians

Zoo VeterinariansZoo Veterinarians

Ecosystem Health VeterinariansEcosystem Health Veterinarians

Bridging the Gap - How?Bridging the Gap - How?

Amphibian PhysiologyAmphibian PhysiologyReproductive PhysiologyReproductive PhysiologyParasitologyParasitologyDisease DiagnosisDisease DiagnosisPhysical Environs AlterationsPhysical Environs AlterationsReproducible ResultsReproducible Results

Organism & Organism & Its Response Its Environment To the Environment

DiseaseDiagnosis

Ecosyst’m PathologyHealth Epidemiol’y

Morbidity & Mortality

Envir’l TreatmentHealth & Care

Life Hx

Environ’lFactors

KeenObservat’n

PopulationDynamics

HabitatHealth

FieldStudies

Bridging the Gap - Why?Bridging the Gap - Why?Healthy Environs Mean Healthy Animals Healthy Environs Mean Healthy Animals and Humansand Humans

Veterinarians have unique skills to communicate science simplyVeterinarians have unique skills to communicate science simply

Multi- and Inter-disciplinary research efforts recognize the Multi- and Inter-disciplinary research efforts recognize the value of animals as sentinelsvalue of animals as sentinels

Veterinarians are trained in systematic observation & reasoningVeterinarians are trained in systematic observation & reasoning

Attention to individual cases may help explain Attention to individual cases may help explain whether, how, and why a population is changingwhether, how, and why a population is changing

Use of clinical evidence and clinical judgementUse of clinical evidence and clinical judgement

Long-term monitoring and consistencyLong-term monitoring and consistency

Some Suggested Causes of Some Suggested Causes of Amphibian Declines & Amphibian Declines & DeformitiesDeformities

Habitat Modification and/or Destruction Predation--Introduced Non-Native Competitors Volatile Organic Compounds/Skin, Eggs, Tads Air- & Water-Borne Chemicals, Heavy Metals... Acid Rain and Increased UVB Exposure Retinoids, such as Retinoic Acid Climate Change and Emerging Diseases Trematodes, Ribeiroia spp.Encysting at Legbuds Fungi, such as Chytrid Bactrochochytrium spp. Iridescent Viruses, such as Iridovirus (ATV)

AmphibianAmphibianUp-to-Date WebsitesUp-to-Date Websites

www.avma.org/netvet/amphib.htm(American Veterinary Medical Assoc)www.uga.edu/srelherp (Savannah River Ecology Lab)www.usgs.gov (USGS, Biological Research Service)www.mp2-pwrd.usgs.gov/frogwatch(Frogwatch--Local Reports of Nation)cmgm.stanford.edu/~meisen/herp/(Stanford University Research)www.fws.gov/r9endspp/esysgal.htm(U.S. Fish and Wildlife Service)