TRAVEL TIMES (link to directions)
Depart Lehigh 9:00 AM; Arrive at Lacawac Sanctuary 11:00 AM
Depart Lacawac 2:00 PM; Arrive at Lehigh 4:15 PM.

SCIENTIST-INSTRUCTORS
Bruce Hargreaves, Kelly Maloney, Tom Daniel

THEME
Scientific investigations of a lake ecosystem. You will learn from scientists working at Lacawac Sanctuary about hypotheses they are testing through observations, measurements, and controlled experiments to learn about chemical, physical, and biological processes.

SCHEDULE
  9:00 Bus departs from Lehigh (students bring lunch; raincoat or jacket suggested if rain or cool weather  is predicted; hat and sunscreen are helpful).
10:45 Arrive at Lacawac, hike to Carriage House, use nearby bathrooms, hear orientation and divide into three groups.
11:15 Start first of 3 rounds of activities.
12:00 Eat lunch in Lodge, plus a chance to observe planktonic animals under the microscope.
12:30 Start second of 3 rounds of activities with groups rotating to next site.
  1:10 Meet at dock to change groups for last round of activities.
  1:50 Meet at lodge for bathroom use and wrap-up session before return trip.
  2:15 Hike from lodge to bus for departure to Lehigh.
  4:15 Bus arrives at Lehigh

BACKGROUND INFORMATION (also try this link for photographs and more information)

Scientists and students from Lehigh University have been investigating the lake ecosystem at Lacawac Sanctuary since 1988. Lake ecosystem is a term used by scientists who study ecology and the environment. An ecosystem includes living and nonliving things which interact. A lake ecosystem includes the surrounding watershed (from which water can flow into a lake), the atmosphere above it, the lake water and its bottom (rocks and mud), and all the organisms living in the watershed and the lake. Lehigh researchers are currently studying effects of sunlight (especially ultraviolet radiation, UV) and weather on lake water and the organisms that live in the lake. (Link to photos of lake and weather instruments plus current and past data).

IMPORTANT. Lacawac Sanctuary is dedicated to preservation, education, and research. Visitors and scientists are asked to be careful not to harm the special environment. This means that you should observe but not pick or otherwise harm flowers or other plants in the forest or the lake, including mosses growing near the shore. When walking in the woods you should stay on the trail. Some plants are quite rare and special and many of these are also small. Naturally you should also not leave any trash or other signs of your visit. For your safety you must follow directions when you are in boats. These include wearing your personal flotation device (PFD) at all times, remaining seated, and keeping a hand on the boat when stepping in or out.

Lake Lacawac is about 11-12 meters deep near the center and about 500 meters wide. It was formed 10,000 years ago when glaciers retreated from this region at the end of the last ice age. Its small watershed covers about the same total area as the lake and is covered mostly by forest consisting of deciduous trees (which lose leaves in winter) and evergreen trees. Around the edge of the lake on the North and West sides is a special kind of wetland call a bog. The plants that grow there, such as sphagnum moss, need soil that is always soggy. Blueberry bushes also grow near the lake. In the lake there many aquatic plants which grow near shore. Several produce beautiful flowers during the summer. All the forest and lake plants get energy from the sun in the process of photosynthesis. Underwater the most abundant photosynthesizer is the "cousin" to plants known at algae. Ecologists use the term phytoplankton for the microscopic algae that swim or float in the lake.

The animals living in the Lacawac Sanctuary forest include insects, millipedes, salamanders, turtles, snakes, birds, and mammals. Large birds include turkeys, herons, osprey, hawks, and rare piliated woodpeckers. Large mammals include deer and bear; small mammals are rodents (mice, chipmunks, and squirrels). Deer and rodents are herbivores, which means that they eat plants. In the forest the deer are so abundant that almost no small plants (including tree seedlings) can survive. You can see a great distance in the forest because of this.

In Lake Lacawac there are fish, frogs and salamanders, snakes, turtles, and mammals. The largest aquatic animals are the snapping turtle (up to two feet across), and several aquatic mammals (raccoon, muskrat, and beaver). The snapping turtle eats fish and probably an occasional swimming ducks; the aquatic mammals eat plants and the numerous algae-eating mussels which grow on the bottom (a cousin of the mussels, clams, and oysters which grow in bays and oceans). Aquatic fish-eating snakes, can often be seen basking in the sun near the dock or swimming near shore. Herons and osprey catch fish from the lake while ducks eat snails and plants growing near the shore. Deer also wade into the lake to eat some of the plants. The smallest animals in the lake are the zooplankton. Some of the these can be seen with the naked eye but most require the use of a microscope. Most zooplankton eat bacteria and algae.

Scientists sometimes make continuous measurements to record changes in the natural environment. These can be used to help interpret the measurements in a field experiment. At Lacawac we operate several special "weather stations". On the lake is a floating weather station which measures the effects of the atmosphere (sunlight, rainfall, wind, temperature, and relative humidity). It also measures underwater properties (water temperature at many depths and the total depth of the lake with a pressure sensor near the bottom). Near the dock is a system which records rainfall and evaporation from an evaporation pan. To learn more about the rate of evaporation it also records local wind speed, the temperature and humidity of the air, and soil moisture in the nearby forest. Near the entrance to Lacawac Sanctuary (where the bus probably parked) is our ultraviolet radiation system which measures the solar rays which can cause sunburn in humans and which can also affect lake water and organisms living in the lake ecosystem.

ACTIVITIES (40 minutes each with 3 groups in rotation through 3 activities).
Approximate size of each group:   36 STAR people  = 12 per group plus one Lacawac instructor.

Activity A (40 minutes at dock and in 4 boats on lake; physics, chemistry, biology).
Record measurements of lake temperature and dissolved oxygen at the surface and near the bottom of the lake. Collect microscopic animals (zooplankton) in a plankton net.  Examine the floating weather station. How does weather (the combined effects of sun, wind, rain, air temperature) affect the lake’s temperature and dissolved oxygen? How do living organisms (bacteria, algae and plants, animals) affect the lake’s temperature and concentration of oxygen.  You will have a chance to look at some of the small animals using microscopes during the lunch period.

Activity B (40 minutes at dock and nearby; physics, biology).
Evaporation and Precipitation are part of the water cycle.  Examine the evaporation pan and mini-weather station. Record and compare measurements of water temperature of pan and lake surface. Why do they differ? What affects the rate at which water evaporates from the lake? From the pan? From the forest soil?  Typically about 0.2 mm of lake water evaporates each hour.  This represents a volume of several tablespoons from the pan but 8,000 gallons from the lake.  We will investigate runoff from the watershed using buckets of lake water.  Most of the rain that falls on the watershed never reaches the lake.  What happens to it?  When plants move water from the soil through their leaves to the air the process is called transpiration.

Activity C (40 minutes near lake at spring and bog edge; physics, chemistry, biology).
Measure and record temperature and conductivity of well water from the kitchen faucet (supplied by a well--a pipe extending into a hole drilled in the ground), and of water samples from the shallow spring east of the dock, from the lake, and from the bog  (previously collected west of the dock). You may also have a chance to study the deep lake water collected during Activity A.  Examine the color of the water in clear sample jars. Conductivity measures the concentration of minerals dissolved in the water. Color indicates the presence of dissolved organic matter produced by the decay of living organisms. Why do these samples differ in conductivity and color? How do they compare to our drinking water back in Bethlehem? Where does that water come from?