BIOBUGS Urban Ecology :
Watersheds & Aquatic Wildlife
What is a watershed?
A
watershed is an area of land that drains
into a body of water.
 Every body of water has a watershed:
Rivers
Ponds
Lakes
Reservoirs
Bays
Oceans
Etc…
Boston Harbor Watershed
•293 square miles of
land © MIT
•Includes all or part of
45 towns and cities
•Includes the
watersheds of the
following rivers:
Charles, Mystic,
Neponset, Fore, Back,
and Weir
•Contains over a
million people
The Fens and the Muddy River
The Fens are a series of
freshwater wetlands that
were created when the
Charles River was dammed
in 1910.
Frederick Law Olmsted Sr., a
famous landscape architect,
re-routed the Muddy River to
create a series of parks
called the Emerald
Necklace.
© Muddy River Restoration Project
The Fens are entirely
surrounded by urban
development.
What’s in the water?
 Point
source pollutants
Sewage
Industrial waste
Oil spills
 Non-point
source pollutants
Agricultural waste
Sewage
Litter
Household chemicals
Oil and gasoline
Industrial particulates
Pesticides, herbicides, etc…
Lawn fertilizers
Pollutant Impacts: Litter
Pollutant Impacts: Nutrient loading
Pollutant Impacts: Oil
Other Pollutant Impacts
 Industrial
particulates (Nitrogen and Sulfur
deposits)
 Synthetic compounds (hormones, PCBs,
pesticides, etc…)
Global Human Impacts
 Global
warming
 Commercial fishing
 Habitat destruction
 Global shipping trade
 Aquaculture
 Exotic animal trade
 Introduction of exotic
species
Measuring the Health of
Aquatic Ecosystems
 We
can look at abiotic and biotic features.
 Abiotic factors are non-living features of an
ecosystem. They include:
weather (wind, rain, temperature, sunlight), dirt, rocks,
water bodies
 Biotic
factors are the living organisms of an
ecosystem. They include:
plants, microorganisms, insects, birds, mammals, etc.-both native and invasive species
Measuring the Health of
Aquatic Ecosystems

Abiotic features we will test today:
 Dissolved oxygen
 Nitrate
 pH

Abiotic features we will describe today:
 Visible pollution
 Potential pollution
 Abiotic
factors are short-term or "snapshot"
indicators of water quality.
Dissolved oxygen



measure of how much oxygen gas is dissolved in
a body of water
Measured in parts per million (ppm)
1 ppm = 1 milligram of substance (mg) dissolved
in 1 liter (l) of water
>6.0 ppm: lots of
animals can survive in
the pond/lake
<4.0 ppm: animals
begin to stress out,
bigger that require
more oxygen may
begin to die
<2.0 ppm: animals
cannot survive for
more than a short
period
Nitrate
Mass die-off of fish in
Narragansett
Bay due to
 Naturally occurring
anoxia.
nutrient needed by
plants to make
proteins and
enzymes
 Human activities add
nitrates to aquatic
systems
 These act as
fertilizers and result
in "blooms" of algae
 This starts a process
that may end in a
mass die-off of
animal life.
Aquatic nitrogen cycle
pH

measure of the acidity or
alkalinity of a liquid

pH scale ranges from 0
(most acidic) to 14 (most
basic); 7 is completely
neutral, pure water (H2O or
HOH)

extreme pH levels can
denature enzymes, making
vital biological reactions
impossible

Most organisms have an
optimal pH range of 6.5-8
Measuring the Health of
Aquatic Ecosystems

Biotic features we will analyze today:
 Aquatic macroinvertebrates
 Other wildlife
 Invasive species

Biotic factors are long-term indicators of water
quality.
Aquatic macroinvertebrates

Invertebrates are animals without
backbones. These include insects,
spiders, worms, molluscs,
crustaceans, and more…

Macroinvertebrates are ones that
we can see without the use of a
microscope (ie not plankton).

Aquatic macroinvertebrates can
tell us about the long-term water
quality of a freshwater ecosystem
because some are tolerant of
pollution while others are very
sensitive.
Invasive Species


Species that have been
introduced to an area that they
are not native to and outcompete native species for
essential resources.
Characteristics of invasive
species:




Phragmites australis, invasive,
outcompetes the native cattail,
Typha latifolia
Can tolerate a wide range of
environmental conditions
Rapid growth and reproduction
Low predation and disease
Often found in areas that have
high levels of human impacts and
disturbance, where native plants
are already under stress.
Data Collection
 We
are going to the field to collect data on
the Muddy River in the Fens.
 When
we get there you will work with your
research team to gather data on abiotic
and biotic features of the study site.
 We
will return to the lab to analyze our
data.
Results
Parameter
Invasive species:
ratio of invasives to
natives
Dissolved oxygen
Nitrates
pH
Macroinvertebrates
Result
Analysis

What is the water quality today?

What is the long-term water quality?

What has the biggest impact on the health of the
aquatic ecosystems we studied today?

What do you think the Muddy River looks like
after a heavy rain?
Impacts on the Charles River
and Boston Harbor

Scientists often make inferences about the "big
picture" based on data they collected on a small
part of a larger system.

What inferences can we make about the health
of A) Charles River and B) Boston Harbor based
on the data we collected today?

What other data would we have to collect to
know for sure?
Charles River: Would you swim in it?
Year
Grade
2009
Overall
Dry*
Wet
Boat
Swim
Boat
Swim
Boat
Swim
93
62
92
69
94
58
2008
B+
95
48
91
58
92
42
2007
B++
100
63
100
84
100
50
2006
B+
90
62
100
80
84
51
2005
B+
97
50
97
59
96
32
2004
B+
96
54
94
38
97
62
2003
B-
85
46
91
56
81
41
2002
B
91
39
100
71
86
21
2001
B
82
54
97
80
74
40
2000
B
92
59
94
82
91
46
1999
B-
90
65
100
71
85
62
1998
C+
83
51
98
85
74
31
1997
C
70
34
87
56
61
22
1996
C-
57
21
94
40
45
15
1995
D
39
19
A: always meets
standards
B: all boating and some
swimming
C: some boating and
swimming
D: some boating and
no swimming
F: no standards
How you can minimize your
impact on the oceans:










Reduce your energy consumption (lots of ways to do this…)
Don’t support destructive fishing practices
Recycle (especially plastic bags)
Walk more, drive less
Eat locally grown foods, try for organic
Bring your own bags when shopping
(for anything, not just food)
Reduce your water use
Use environmentally friendly cleaning products and bath
products
Buy more things second-hand
Consume less (or no) animal products
Charles River:
Long-term Water Quality
Charles River:
Long-term Water Quality
Charles River:
Long-term Water Quality