Ecotoxicology Final
By far, the major source of CO2 from Brazil
deforestation for ag use
Toxic metal expected in outflows from tanneries
Chromium
Element that is reduced in sediments and is associated with methylation of mercury (helps drive the process).
sulphur
Correlations between human disturbance, species diversity, & susceptibility to exotic spp. Invasions (from Brazil lecture)
Streams more affected by humans more susceptible to invasions. Highest species richness in leas disturbed streams.
Critical habitat to protect in order to protect stream biota
Riparian zones
Impacts of industry on Rio de Janeiro coastal water quality
decrease in dissolved oxygen, increased algae, incresed heavy metals
A herbicide formerly used on marijuana, used in Brazil and used in the US for defoliating soybeans (and cotton
Paraquot
Crop that is consuming the highest quantities of water in Brazilian agriculture
Sugar cane
Sensitivity of aquatic invertebrates to paraquat
lethal to insects, prawn, snails, zooplankton
Major causes of population decline in condors, including life history & human impacts.
DDT, collecting, Animal trade, collisions with power lines, lead poisoning, shooting. Slow population growth.
How the condor populations are being assisted
captive breeding and release
Primary source of lead that has impaired recovery of condors.
lead shot/ bullet fragment ingestion
How the individual birds are assessed; body fluid that is tested for lead in live birds (and mammals).
blood samples
Evidence that lead shot was the source of the problem in condors.
isotope ratios, found shot in birds
Principal clinical signs of lead toxicosis in condors.
weight loss, weakness, reduction in movement, uncoordination, nervous system, kidney, and circulatory system impacts
General detoxification method for condors if their lead body burden is high
chelation
How the birds are managed in captivity to reduce interactions with people and human changes in environment after release
puppet rearing, parent rearing, isolation, aversion therapy
Approximate number of California condors in the wild today
100
Long term solutions to the problem lead toxicosis in condors
get rid of lead shot, acquire more hunting-free zones
Why specialized species including polar bears are particularly at risk from climate change
narrow nitch. Cascade effect of warming in arctic
How being at the top of a food chain results in an animal having to deal with the summation of effects on other trophic orders (polar bear talk)
Cascade effect
Why climate change increases the period of fasting in female polar bears
Pregnant females fast for longer. Can’t den on fast ice if it’s melting
How climate change alters the food web so that polar bears may have less to eat.
Decreased sea ice – water interface

Preferred environment of algae

Algae main food of Atlantic Cod

Atlantic Cod Prey for many species

Seals prey on cod

Seals are main prey of polar bears

How climate change alters the access to prey that are there when the bears are hunting on the ice
Seals have more air holes
Reason why GPS tracking does not always work
Substrate in the way of satellite reception
Why studies of the Hudson Bay coastal polar bears may be a good predictor of future conditions
Southern most population
Trends in body condition & body fat over time in polar bears
Bears were returning to land in poorer condition
Factor in survival – lose between 0.7 and 0.85 kg/day when fasting, fat loss is 93% of mass change
Related to ringed seal numbers
change in fish populations and change in bear hunting environment
The major causes of deer overpopulation in the US.
Restricted seasons & game laws
– Introductions
– Tree planting/forested landscaping
– Decline in predators
– Moderate climates (Global warming
How global warming influences deer population size.
– Moderate climates
– Mild winters
 Increase deer body mass
& winter survival  population
growth
How overpopulated deer aggravate global CO2 burdens
reduced vegetation??
Some major diseases associated with high deer populations.
Tick-borne zoonoses
– Lyme disease and ehrlichiosis
Bovine tuberculosis
– Mycobacterium bovis
Chronic Wasting Disease (“Mad Cow”)
– Transmissible spongiform encephalopathy
How woody plants evolve to rely on toxins more earlier in life than later in life
once too big to be browsed, makes sense to produce fewer toxins
How browsers may favor and then later degrade plant diversity
forage on dominant species, those get reduced, browse resistant species do better, then become dominant
How overpopulated deer may increase silt & nutrients in water
reduced ground cover-> increased erosion
How over-browsing favors conifers & reduced soil nitrogen.
Reduced leaf litter favors conifers
Duration of relatively low deer abundance needed for recovery of the plant community
long time
Current “control” methods to reduce deer impacts on the environment
hunting, sharp shooting, fencing, repellents, sensors, birth control
How gill raker spacing influences ecological impacts & nutrients free in the water
Influences ability to filter small algae
Origin of Asian carp before they became an exotic pest species in the US
Eastern Asia. Brought in for management of aquaculture water quality
Four major exotic species with major adverse impacts in the Great Lakes.
Sea Lamprey, Zebra Mussels, Round Goby, Eurasian Ruffe
Meaning of oligotrophic & mesotrophic, which lakes have which condition, & why this influences whether an exotic carp will become established in sufficient numbers to become a pest species.
nutrient availability impacts phytoplankton which in turn impacts fish survivability
Meaning of stoichiometry in terms of energy budgets
Balance of what goes in and what goes out and what is used for growth and reproduction. Equations need to account for all energy and all matter.
Why feces were removed from the aquaria in this study.
They eat their own feces
Current assumption as to the efficiency of bighead carp in filtering small algae
not particularly efficient
How long ago the Great Lakes were covered by glaciers
9-14,000 years ago
Two Great Lakes with the longest and two with the shortest water retention times; & how this may affect exposures of aquatic biota to persistent contaminants
Superior/ Erie
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