Bioaccumualtion Presentationx - mrsmailliw

swedishstreakMechanics

Feb 22, 2014 (3 years and 4 months ago)

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Bioaccumulation

The start of the problem


Many chemicals we use in our daily lives
are toxic.



Toxic
chemicals
include:

1.
pesticides
,


2.
engine
products and


3.
many
household cleaners.



Most
toxins are made by humans;


they do not
occur naturally.

Some of these toxins are
persistent
.



Persistent toxins can cause the following problems:

1.
Reproductive failure

2.
Birth defects

3.
Immune system disorders (cancers and weakness
to disease)

4.
Behaviour and learning disorders

5.
Death



Persistent toxins are also known as Persistent
Organic Pollutants (POPs).

Persistent Organic Pollutants
(POPs).


Water is the lifeblood of our planet


so
how can it be polluted?

W
aterways get polluted by:

1.
Runoff
from
pesticides

2.
Runoff
from
fertilisers

3.
Stock
effluent seepage and
dispersal

4.
Sedimentation
from land
clearance/erosion

Traveling through food chains


We (humans) may use toxins on land, but
they can travel through the soil in
groundwater into waterways and into
the ocean.



All
persistent toxins eventually end up
in ocean food chains.

Bioaccumulation vs
Biomagnification



Bioaccumulation refers to the
accumulation of a toxic chemical in the
tissue of a particular organism
.



Biomagnification refers to the
increased concentration of a toxic
chemical the higher an animal is on the
food chain.


The Effect of the Pollutant



Different organisms show varying
degrees of

sensitivity to toxins. Even
within a species,

sensitivity to a
particular toxin may depend on

age, sex,
food availability, reproductive condition


with
DDT, the egg shells of large birds
were so weak that they would be
crushed by the weight of the adult
birds.

Egg shells of large birds

A little goes along Way

From the article:
Blooms and Gloom


Dinoflagellates are microscopic and some
species can produce toxins


which can
harm an organism.



Question 2


??????

Answer 2


Biomagnification refers to the
increased concentration of a toxic
chemical the higher an animal is on the
food chain.



Own words????

Question 3


????

A
nswer 3
: Western Port Bay


a
) Food chains:

Detrius



tube worm


squirter

worm


black bream


pelican



b
) DDT increases from 1.4 to 22.8 in
this food chain


Tern, Pelican, Cormorant are all

Question 4


????

Carnivores
as they eat meat



The Black swan is the only bird that is
a
herbivore





Answer 4

Question 5


?????

A
nswer 5a:

DDT levels in various organisms


a
) Tern DDT level is less than the
Pelican or the cormorant because:


Tern is a 3
rd

order consumer

Pelican is a 4
th

order consumer

Cormorant can be a 4
th

order consumer

A
nswer 5b:

DDT levels in the Black Swan



Black Swan feeds on
eel grass
and not
detritus, therefore the DDT levels are
lower in the swan compared to other
birds

Question 6


????

A
nswer 6:

DDT in detritus is very high


decomposing organic matter is found in the
detritus


so any organism that had a high
DDT content in it and dies will leave this DDT
in the detritus

Question 7


????



Answer 7:

Which fish would you buy?



Black Bream = 2.1


Yellow
-
eye mullet =1.4


King George whiting = 1.2



Reason???

Question 8


????

Answer 8:

How does DDT find its way into
waterways???



1.
Runoff from pesticides

2.
Runoff from fertilisers

3.
Stock effluent seepage and dispersal

4.
Sedimentation from land
clearance/erosion


Question 9


????

A
nswer 9:

Non
-
degradable substances



Summarize how they accumulate


What we want instead is:














Biochallenge
answers page 468

Answer a


Birds of prey are further up the food
chain than the seed
-
eating birds and
would be more affected by the
accumulation of DDT


Answer b

The average thickness of the shells over
time has been reduced. The majority of
the dots are 1.4 in mid 1970, compared
to 2.0 in 1890

Answer c

A range of thickness observed in egg
shells in the same year could indicate:


Eggs were collected from different
regions


Some birds may not have consumed as
much DDT as others through their
feeding



Answer d

Based on the graph the DDT was most
likely used extensively in Australia just
before 1950

Evidence for this can be seen in the
increase in dots at index 1.2 and 1.4

The idea is: DDT causes thinning
of the shells of eggs

Answer e

Observation 1
supports
the idea that
DDT causes thinning of the eggshells

Observation 2
neither
supports or
disproves this idea

Observation 3
neither
supports or
disproves this idea




Answer f:
DDT levels in breast milk from
urban and rural areas in 1971 & 1979


In 1971 Urban and rural differences existed
because the DDT was entering the food chain via
agricultural use


treatment for termites in rural
areas



The change from 1971
-
1979 was that urban
numbers decreased from 2300
-
1200, and rural
numbers decreased from 17,000 to 1200


due to
the restrictions the government put on the way
to treat termites