1. Chemical Pollution and Animal Behaviour

Question 1

What effects can pollutants have on animals

Answer 1

Acute and or toxic effects such as fish kills due to reduction in DO caused by eutrophication.
May have more subtle effects such as chronic effects on developmental or physiological processes. Subtle effects on animal behaviour

Question 2

What are EDC’s

Answer 2

Endocrine disrupting Chemicls

Question 3

How do EDC’s affect animals

Answer 3

Affect development & physiology by interfering with normal endocrine functions – e.g. Imposex in dog whelks due to stimulation of androgenic hormones

Question 4

Where are EDCs found

Answer 4

• EDCs are ubiquitous in the environment
• Commonly found in human and animal tissues
• Organochlorine pesticides such as DDT found even in areas where its use has been banned
• Arctic fauna (e.g. polar bears) also found to have high tissue concentrations of EDCs

Question 5

Example of EDCs affecting animal behaviour

Answer 5

– Behavioural studies helped reveal problems with DDT/other pesticides
* 1958: Reduction in numbers of Florida bald eagles coincided with abnormal changes in behaviour
– Nesting, courtship, reproduction
– Effects due to endocrine disruption
* But DDT & other pollutants not recognised as EDCs for decades

Question 6

Types of effects from EDCs

Answer 6

– Synthesis, storage and release of hormones
– Transport of hormones
– Receptor recognition and binding
– Activate gene expression (Mimic effects of hormones)

Question 7

What does EDCs do to hormone production

Answer 7

Agonists stimulate endocrine system
– Overproduction of hormones
Antagonists inhibit endocrine system
– Underproduction of hormones

Question 8

What common behaviours do EDCs affect

Answer 8

Sexual behaviour, Communication,
Dominance, Aggression, Cognition

Question 9

Examples of how EDCs affect sexual & reproductive behaviour

Answer 9

– Male ringed turtle doves fed DDE significantly
reduced courtship and nesting behaviour
– Bengalese finches fed DDT delayed ovulation
– Exposure to methoxychlor shortened female mice maternal behaviour and reduced arousal in male mice.

Question 10

How does it affect chemosensory communication

Answer 10

Hormones influence the development of
scent-producing glands and olfaction
Mature male Atlantic salmon exposed to low
levels of cypermethrin for 5 days
Significantly reduced olfactory response to a
pheromone released by ovulating females

Question 11

Can animal behaviour be usefully applied to
toxicology studies?

Answer 11

Has been suggested that it might be a more
useful indicator or biomarker
Noninvasive and inexpensive

Question 12

Some studies have found that behaviour is
more sensitive to EDCs than developmental
and physiological parameters

Answer 12

Swimming behaviour in fish
* More sensitive to toxic stress than either lethality or
growth
Pheromonal communication in newts
* Highly susceptible to low concentrations of EDCs