New York’s Urban Ecosystem Lessons



Class Periods




Subject Areas


Students will graph precipitation data in NYC. They will then look at the connection between rainfall and salinity. Finally, they will consider the effect (if any) that rainfall has on oysters.


  • Graph precipitation data

  • Look at the connection between rainfall and salinity

  • Consider the effect of rainfall on oysters.

Before you get started

Tips for Teachers

The rainfall data is for 2015. Go to http://w2.weather.gov/climate/xmacis.php?wfo=okx to find it for any month or year. The graphs DO NOT match up. The rainfall data strongly influences the salinity but the snowmelt is an even bigger factor. Therefore, this worksheet could lead to a discussion of ALL the factors that can affect salinity.




The salinity of the harbor has a lot to do with the health of oyster spat. Large precipitation events can cause oysters to die off. However, rain is not the only factor. Every year the snow melt contributes vast quantities of fresh water to the harbor. This can also affect the salinity.

Instruction Plan



Get three beakers of 200 mL of water. Dump a pinch of salt into the first one, 1 tsp of salt in the second, and 2 tsp of salt into the third. Now taste all three. Which is the saltiest?

The level of saltiness in the water is called the salinity. If you wanted to make the last beaker taste lest salty, what could you do? Test your hypothesis and see if it works.



As a discussion, have the class make a hypothesis about what effect increased rain will have on SALINITY or the level of salt in the water.

Then have class complete the “When did it Rain handout?”



Discuss other factors that might affect salinity:

  1. Snowmelt

  2. Tides

  3. Hurricanes

  4. Etc.



Rain affects salinity. The more rain there has been, the less salty the water is. However, the salinity can also be affected by many other things. If the weather is hot, more water can evaporate to make the harbor more salty.  If tides are particularly high, the harbor will have higher salinity despite the rain. In the spring, snow melt will cause the salinity to drop because of the influx of freshwater.

Oysters prefer brackish and salty water. A salinity range between 10-28 parts per thousand (ppt) provides the best conditions for oysters. Oysters can die if salinity drops below 5 ppt for extended periods of time. Therefore, too much rain can be disastrous for oysters.

Discuss: What factors should you keep track of over time in order to monitor the salinity of oysters?



Students should read one of the two documents mentioned in the resources and discuss how climate change affects rainfall, salinity, and oysters.


CCLS - ELA Science & Technical Subjects

    • Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic.
    • Conduct short research projects to answer a question (including a self-generated question), drawing on several sources and generating additional related, focused questions that allow for multiple avenues of exploration.

CCLS - Mathematics

    • Display numerical data in plots on a number line, including dot plots, histograms, and box plots.

NGSS - Cross-Cutting Concepts

  • Cause and Effect

    • Cause and effect relationships may be used to predict phenomena in natural systems.

NGSS - Disciplinary Core Ideas

  • ESS2.C: The Roles of Water in Earth's Surface Processes

    • The complex patterns of the changes and the movement of water in the atmosphere, determined by winds, landforms, and ocean temperatures and currents, are major determinants of local weather patterns.
    • Water continually cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation and crystallization, and precipitation, as well as downhill flows on land.

NGSS - Science and Engineering Practices

  • Planning and Carrying Out Investigations (investigations that use multiple variables)

    • Conduct an investigation and evaluate the experimental design to produce data to serve as the basis for evidence that can meet the goals of the investigation.
    • Collect data to produce data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions.

NYC Science Scope & Sequence - Units

  • Grade 6, Unit 2

    • Weather and Atmosphere
  • Grade 6, Unit 3

    • Diversity of Life
  • Grade 6, Unit 4

    • Interdependence
  • Grade 7, Unit 1

    • Geology
  • Grade 7, Unit 4

    • Dynamic Equilibrium: Other Organisms

NYS Science Standards - Key Ideas

  • LE Key Idea 5

    • Organisms maintain a dynamic equilibrium that sustains life.
  • LE Key Idea 6

    • Plants and animals depend on each other and their physical environment.
  • PS Key Idea 1

    • The Earth and celestial phenomena can be described by principles of relative motion and perspective.
  • PS Key Idea 2

    • Many of the phenomena that we observe on Earth involve interactions among components of air, water, and land.

NYS Science Standards - Major Understandings

    • The dynamic processes that wear away Earth’s surface include weathering and erosion.
    • The majority of the lithosphere is covered by a relatively thin layer of water called the hydrosphere.
    • Water circulates through the atmosphere, lithosphere, and hydrosphere in what is known as the water cycle.
    • Regulation of an organism’s internal environment involves sensing the internal environment and changing physiological activities to keep conditions within the range required for survival. Regulation includes a variety of nervous and hormonal feedback systems.
    • The survival of an organism depends on its ability to sense and respond to its external environment.
    • Matter is transferred from one organism to another and between organisms and their physical environment. Water, nitrogen, carbon dioxide, and oxygen are examples of substances cycled between the living and nonliving environment.

NYS Science Standards - MST

    • Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to pose questions, seek answers, and develop solutions.
    • Students will apply the knowledge and thinking skills of mathematics, science, and technology to address real-life problems and make informed decisions.