enwc 201 final exam university of delaware module 4

dr. kyle mccarthy

wildlife diseases are connected to

-conservation of threatened and endangered species

-recreational use of wildlife

-public health/loss of life (pet and human)

-agriculture (livestock)

disease

a disturbance to the normal function or structure of an organism (mange or rabies is what we typically think of, but starvation or trauma can be diseases as well)

epizootic

a type of disease that appears at an unexpected rate, synonymous w epidemic in humans (like white nose syndrome in bats)

infectious things can be

viruses, bacteria, fungi, parasites (internal and external)

• pathogen: a disease causing agent

• protein: incorrectly folded protein = a prion

pathogen

a disease causing agent

noninfectious things can be

toxins (manmade, plant, fungal, or bacterial), physiological, nutritional, congenital, degenerative, cancer

• mercury (product of coal/fossil fuel power generators)

  • heavy metal toxin

• bio-accumulation: more mercury put into ecosystems

• bio-magnification: increased concentration we see as we move up trophic levels

mercury

example of non-infectious toxin

bio-accumulation

ex: more mercury put into ecosystems

bio-magnification

ex: increased concentration of mercury we see as we move up trophic levels (100% of mercury makes it up even tho only 10% of the energy)

what methods reduce harmful chemicals in fish (not including mercury)?

bake, broil, steam, or grill fish (not frying, frying traps juices/pathogens)

reservoir

any living/nonliving substance that may perpetuate a pathogen in nature (ex: white footed mouse)

reservoir host

a host that acts as a reservoir for the pathogen but does not suffer ill effects from the disease (also white-footed mouse)

host

an organism on/in which another organism lives

vector

an organism that carries pathogens from one host to another or from a reservoir to a host

• biological (mosquitoes - pathogen inside body and regurgitates into host)

• mechanical (flies - pathogen on outside of body)

biological vector

pathogen inside body

mechanical vector

carries pathogen around on outside of body

disease and agriculture examples

-brucellosis in cattle

-bird flu outbreaks (tyson chicken farms, culled 73k birds over the wknd)

disease and endangered species examples

common loon, lake erie

• avian botulism type - E

• quagga and zebra mussels

• algae beds

• invasive round goby fish (goby fish eat algae, loons eat goby fish)

• > 1k loons killed on one lake

serengeti lion

• canine distemper from pet dogs in african villages not cared for well

• black back jackal get canine distemper from the dogs

• interact w lions and lions get canine distemper (in 1994, a single outbreak killed 1/3 of population: 1k lions)

why are we seeing the emergence of so many diseases?

more people → more habitat alteration → more stress on animals → more human/wildlife interaction → INCREASE IN DISEASES

example of stress impacting an animal

-near alaska oil tanker spilled, drunk captain

-high stress on sea otters, oil penetrates waterproof coat

• hypothermia → die so humans had to clean off and re release

• stress from otter/human interaction caused latent herpes to come around (existed but fought off by immune system)

  • became more prevalent

  • otters got mouth sores/couldn’t eat, dying bc of that

zoonoses

an animal disease that can be transmitted to humans but we are not necessary for that to happen in the life cycle of the disease (antonym: anthroponoses, goes human → animal)

• hookworms can infect humans but don’t need to

• lyme disease

anthroponoses

a human disease that can be transmitted to animals but they are not necessary for that to happen in the life cycle of the disease (antonym: zoonoses, goes animal → human)

lyme disease is an example of

a zoonoses

-cause: bacteria (borrelia burgdorferi)

-transmitted: deer and lone star ticks

-symptoms: rash, fever, swollen lymph nodes

• further complications: meningitis, facial palsy, heart abnormalities, arthritis

west nile virus is an example of

a zoonoses

-cause: virus

-transmitted: culex mosquito

-reservoir: birds

-vector: mosquito

• 40-50% of horses that get WNV aren’t vaccinated and die

• humans don’t have a vaccine for this

-symptoms: most ppl don’t get sick, 1 in 5 get west nile fever, 1 in 150 develop a severe infection (like meningitis)

-treatment: no specific treatment available

other examples of zoonoses

-H5N1 in birds in alaska

• seems to have disappeared for now, could spread to poultry, high fatality in humans, migratory flyways can spread disease between continents

-SARS

• originated in hong kong, 8422 cases and 916 deaths in 37 countries, high fatality in humans, outbreak contained in 2003 but not eradicated, persists in bat poop

-EBOLA

• children contracted from playing near contaminated bat feces/urine

introduced species: the starling

-american acclimatization society wanted to bring home starlings, brought starlings from europe and took 100 starlings and let them go in NYC

-now 200 mil today from those initial 100

conservation implications of introduced species

-good, bad, and ugly

conservation implications of introduced species GOOD

industrialized ag is all introduced species

makes the US billions of $$$/yr

conservation implications of introduced species BAD

unplanned introduced

not every introduced species is successful

all that succeed have ecological impact

conservation implications of introduced species UGLY

lion fish taking over reefs so we have to make robots to take them out of oceans

how many endangered species are threatened by introduced/invasive species?

20%

ex: zebra mussels introduced via ballasts of ships

• fill pipes we put in lakes to take water out, clog boat engines, etc

• shoreline sharp and not walkable

ex: shipworms (cost 200 mil/yr) and purple loosestrife (45 mil/yr)

introduced predators example - snakes

-brown tree snakes (boiga irregularis) made their way to guam on cargo ships after WWII

-ate birds of guam, 15 species extirpated (extinct on guam)

• 5 of those were endemic so now they’re just gone gone

-eating skinks, rats, bats, geckos, anoles

-started bombing guam w poisoned frozen rodents

-biggest fear is spreading to other islands so now they check wheels of planes before take off, etc

introduced predators example - snail

-giant african snail → hawaii

-rosy wolfsnail introduced to prey on giant african snail but now

• 15 endemic snails extinct

• 56 of 61 partulid snails on french polynesia

• fluffy the bird slayer

• highest percent effect

introduced competitors examples

-mussels (not directly preying on other mussels)

• 40-75% native mussels in great lakes classified as extirpated/of special concern

-argentine ant (both predator and competitor)

• horned lizards disappearing

introduced competitors - invader interactions

-sometimes an invader interacts to increase the effect of another invader

-sometimes an invader interacts to decrease the effect of another invader

invader increasing effect of other invader example

kelp decimated by urchins but then by bryozoan (europe, weakens kelp) and codium (asian, weakens kelp)

invader decreasing effect of other invader example

-warty comb jelly eats plankton

-fisheries for plankton crashed

-carnivorous jelly ate warty comb jelly, they didn’t eat plankton before, carnivorous jellies died out bc no more warty comb jellies to eat

morphological/behavioral impacts of invaders

-some natives respond w morphological or behavioral changes

• snail shell lengthen

genetic/evolutionary impacts of invaders

-hybridization and introgression affects genetics (mallards vs other ducks, breeding together)

• mallard can swamp out native species

ecosystem impacts of invaders

-some have larger/more noticeable impacts

-eating emergent marsh vegetation

• nutria: escaped from fur farms (looks like beaver)

  • eats native vegetation

  • erosion

• beaver

  • eats native vegetation

  • erosion

criteria for successful invasion

-a route in, pathway of invasion

• snakes on plane, spiders on cargo ships, weeds on boat trailers, intentional introductions, a new road into the forest

-any path that can transport species beyond their native range

what determines propagule pressure

-quantity, quality, and frequency of arriving organisms

invading species characteristics

-high fecundity, dispersal ability, generalists (broad tolerance), novelty

-luck can be a factor

-community where species established has just as many important factors

how are species introduced

-unintentionally

• dumping ballast water, shipping, necklace gift, etc

-intentional

• common carp, one of the most damaging aquative invasive species due to wide distance and severe impacts in shallow lakes and wetlands

• mongoose to hunt rats eating crops

• pet trade

  • burmese python in everglades (someone’s pet let go bc they didn’t want it to eat their kid/dog)

delaware invasive species

-total number exotic plants reported

• new castle: 372 species

• sussex county: 219 species

• kent county: 193 species

kudzu -spreading 150k acres/yr in US

mile-a-minute weed

norway maple

hemlock wooly adelgid (microscopic thing from china that kills our hemlocks)

• 80% of trees dead in 15-20 years

• many species rely on hemlock

• new species replace hemlock

• ecosystem restructured

what is climate change

the long-lasting pattern of climate over months and years

greenhouse effect

causing our climate change

• radiation converted to heat, reflected back to earth by greenhouse gasses

• allows us to live bc we need heat

• too many gasses = too much heat reflected back

cretaceous CO2

-anoxic (lacking O2) and wet era

-angiosperms (flowering plants) spread

• grow rapidly, die and don’t decompose well bc too wet, buried under other soil/plants, C captured out of atmosphere in plant starts to become our fossil fuels (oil, carbon/coal, etc)

limestone deposits…

…form carbon sinks

asteroid + volcanoes effect

-dinos die

-mass extinction

-separates cretaceous from tertiary

tertiary CO2

-tertiary trees build C into trunks

-bring down to current CO2 levels we have rn

-tree trunks = C sinks

glacial cycling

-ice ages vs no ice ages cycle

-10k yrs ago last ice age stopped

industrial revolution

-150 yrs ago

-started using fossil fuels

temp and ice heat map

-increase in temps, realized across globe

-blue and purple only bc changes in ocean circulation

rising temperatures impact on species

-loss of species and habitat

-shifts in time/space among species

habitat and species loss example

-coral can’t handle thermal stress very well

• increased coral bleaching

• white skeleton coral bc spit out intracellular endosymbionts

-range of tolerance and ability to adapt play a big role in how well species will survive climate changes

• moose migrating north

• moose need to survive through winter and make it to spring

  • winter ticks surviving better in southern ranges so moose weren’t surviving

time shifts

-timing of events

phenology

-specific things happening in the spring

time shifts can cause

-it to be warmer earlier, trees leafing out earlier

-some plans later bc require cold fall days to make buds

-end up with a mismatch in phenology

what can a mismatch in phenology cause?

-repro rates to drop

-starvation

-etc bc timing of predators vs food source

ice decrease in glacier national park occurs why

-occurs bc of feedbacks

-melting of sea ice → lowered albedo (absorbs more sunlight) → increase in absorbed sunlight → melting of sea ice

impacts from melting ice and snow on flooding

-freshwater storage loss

-habitat loss

-flooding

freshwater storage loss bc ice melt

-ice/snow = good way to store freshwater

-some places increase snowpack, some places decrease, melting rapidly (can’t capture in irrigation canals and lakes, floods so we have to let some go)

habitat loss bc ice melt

-in north, most rapid impact of climate change

-polar bears need ice to hunt seals

flooding bc ice melts

-increased rapid ice melt

-alter habitat for species, animals die, change habitat for long term in future in terms of nutrient availability

precipitation increase and decrease depends on where in the world

• lake mead, colorado river

  • 14 yrs of drought

precipitaton changes can lead to

-bc of rain/precipitation

-changes to disturbance patterns

• floods

• droughts

• erosion

-habitat and species loss

• flycatchers rely on riparian habitat (near river)

• humpback chub rely on certain water species

sea levels are increasing bc of ice albedo feedbacks

-at least 26-82 cm rise depending on where, could be much higher (conservative estimate) (10+ inches)

impacts of sea level rise (SLR)

-loss of land

-increased storm flooding

-salt water intrusion

-loss of habitat and species

• key deer, florida keys

  • may not have florida keys too much longer in the future bc of sea level rise

  • plants moveinward as SLR but some topography prevents

• erosion and plovers

  • live on thin strip of beach between vegetation and high tide line

    • zone keeps moving up w sea levels except zone dissipating bc dykes and piers protecting houses

the ocean is becoming

more acidic

-carbonic acid, decreased pH in ocean, similar to acid range

impacts of sea level acidification

-species w Ca in bodies

-acidity binds to free available Ca

-base of foodweb eroded bc Ca not available to animals

-pulling C from atmosphere faster than it went in during cretaceous

anthropogenic equation

-overexploitation + habitat degradation + introduced species + diseases + pollution + climate change

extinction types

-ecological

-local

-global

ecological extinction

-low density, no longer interacts w each other to reproduce like iberian lynx

local extinction

-species lost in only an area or region (extirpation) like brown bear in california

global extinction

-all of earth

• thylacine tiger, largest marsupial carnivore

cascade effects on extinction

-sea otters coast of cali

-controlled no sea urchins

-kelp extinct bc of sea urchin explosion

-things that fed on kelp extinct

characteristics of species most vulnerable to extinction

-rarity, narrow range of tolerance, large area requirements, low reproduction, specialization

-bad luck, wrong place, wrong time

patterns of endangerment help us to

classify what and where is endangered/extinct

what is the red list

systematic listing, extensive review of all data available about that species

red list classifications

-extinct

-extinct in the wild

-threatened

• critically endangered (cuban crocodile)

• endangered (ethiopian wolf - 291 adults left in the wild and fragmented populations)

• vulnerable (west indian manatee)

-near threatned

-least concern (grey wolf)

-no data/not evaluated (luzon broad-toothed rat, ammonite striped rabbit, ahmanson’s sportive lemur)

extinction crisis

-extinctions have happened for non-human reasons

-we are entering holocene mass extinction event

-loss of species we don’t realize are halfway there

-living planet report, every 2 yrs

• not a census, population size changes

• declined by average of 58%