13 - Ecotoxicology Flashcards
How did different zebra fish respond to a stimulus (pulse of water?)
Different swimming speeds (velocity)
Some continued same velocity, others went from still -> moving, some had a short pause, others a long pause
What is behaviour? Implies…
The way in which an animal or person acts in response to a particular situation or stimulus
Implies:
- sensory input
- cognitive response
- motor response
Common ways to study behaviour in ecotoxicology
- Feeding: avoidance/attraction, prey capture
- Predator avoidance: novel tank, simulated predator
- Social interaction: schooling, grooming
- Reproduction: male aggression, nesting
How did prey capture vary among treatment group
No diff in latency to capture across treatments, but control group (salt water ctrl) was much more variable
Some control fish were bolder when hunting, some more shy
In exposed groups, shy behaviour was erased (behavioural ablation)
What types of compounds were fish exposed to in the prey capture assay
Salt water control
Weathered oil
Source Oil
+/- dispersant
Slides 11, 12
What were the results on changes to male aggression in fish exposed to mirror?
Saltwater and weathered oil groups had higher variability in aggression response than source oil and source oil + dispersant
Slides 13, 14
What effects do unconventional crude oils have on zebrafish? Treatment groups in this study?
Exposure eliminated steady-state swim phenotype
Treatments:
- embryo media (ctrl)
- dilbit (bitumen)
- mixed sweet blend
- medium sour composite
Slides 16, 17, 18
Examples of types of classes of compounds found in EPCOR’s secondary water clarifiers
Herbicides, insecticides, NSAIDs, antibacterials, anti-epileptics
Explain ducks over-wintering in secondary clarifiers
Should be going south for the winter
Water is warm in the clarifier, so they remain there for the winter
Drink the water
Some birds step onto the concrete when they are wet, get stuck and die
Duck abundance in the clarifier varied…
- over the winter
- increased with temperatures (as T decreased, more birds found on pond)
How did duck behaviours on the pond vary from normal?
Behaviours were ‘normal’
Moved more bc of rakers (cleaning devices)
In a mild winter, how do secondary clarifiers benefit mallards?
Mild winter = winter haven
- access to regional feeding sites
- reduced migration distance and risk
- early arrival on breeding grounds
In a severe winter, what kind of consequences are there for mallards wintering in secondary clarifiers?
Severe winter = ecological trap
- high cost of foraging
- high cost of body maintenance
- crowding = stress and disease
- potential exposure to toxic compounds
Describe the sub-lethal toxicity experiment on ducks (treatment, experimental design)
- 3 treatment groups with 2 replicates each
- individuals were weighed daily (28d)
- dosed with 10mL/kg of treatment daily:
1. municipal tap water
2. secondary clarifier effluent water (SCEW)
3. Ethynylestradiol (E estradiol) - blood samples taken weekly
In the sub-lethal toxicity experiment, what factors were affected and unaffected by treatment
- growth unaffected by treatment
- tissue development unaffected
- subtle changes in bone and cartilage development
- prevalence of infrequently used behaviours (pecking and resting) decreases… infreq used beh tend to be important
