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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
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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 • 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 © MIT
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. The Fens are entirely surrounded by urban development. © Muddy River Restoration Project
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 What’s in the water?
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 ofAquatic 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 <4.0 ppm: animals begin to stress out, bigger that require more oxygen may begin to die >6.0 ppm: lots of animals can survive in the pond/lake <2.0 ppm: animals cannot survive for more than a short period
Nitrate Mass die-off of fish in Narragansett Bay due to anoxia. • Naturally occurring 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 ofAquatic 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 out-compete native species for essential resources. • Characteristics of invasive species: • 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. Phragmites australis, invasive, outcompetes the native cattail, Typha latifolia
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.
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? 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
