Each year, my sixth grade students travel to Marine Lab in Key Largo. There, the students spend three days snorkeling and learning about the coral reef, sea grass, and mangrove habitats. This presentation highlights topics covered at
M Is for Marine Lab Sunshine State Standards SC.6.L.15.1 Benchmark Description: Analyze and describe how and why organisms are classified according to shared characteristics with emphasis on the Linnaean system combined with the concept of Domains. SC.6.E.6.1 Benchmark Description: Describe and give examples of ways in which Earth's surface is built up and torn down by physical and chemical weathering, erosion, and deposition. SC.6.E.6.2 Benchmark Description: Recognize that there are a variety of different landforms on Earth's surface such as coastlines, dunes, rivers, mountains, glaciers, deltas, and lakes and relate these landforms as they apply to Florida. SC.6.L.14.3 Benchmark Description: Recognize and explore how cells of all organisms undergo similar processes to maintain homeostasis, including extracting energy from food, getting rid of waste, and reproducing.
Biodiversity is the diversity of plants and animals within a habitat; a high level of biodiversity usually translates to a healthy habitat. Of all underwater ecosystems, coral reefs have the highest biodiversity.
Coral comes in many different shapes, sizes, and colors. Many people are surprised to learn that it is classified as an animal, not a plant. Interestingly, coral is made of small polyps, and coral reefs are formed when many polyps connect to make colonies.
More than one million visitors pass through the gates of John Pennekamp State Park each year, and with these visitors come revenue. Visitors are charged to enter the Park, and camping, boat ramp, and pavilion fees also apply.
Nearly half of coral reefs in the U.S. are in poor or fair condition, and the rest of the world’s reefs are in the same boat. Threats to coral reefs include coastal development, fishing, recreational activities, sedimentation, and global warming.
Although hurricanes can be devastating to life on land, life underwater is remarkably sturdy against this natural disaster. Many animals, such as manatees, move into the mangroves for protection during strong storms. Other animals instinctively move to deeper water.
John Pennekamp State Park opened in 1963 and was the first underwater park in the United States. Included in the park grounds are 178 square miles of coral reefs, seagrass beds, and mangrove swamps. John Pennekamp was a conservationist and news editor instrumental in preserving the Key Largo area.
Limestone is created by a buildup of coral, algae, shells, and debri. The plethora of limestone on Key Largo is actually remnants of coral that existed many years ago, when Key Largo was underwater. Limestone creates hard corals that provide fragile polyps with protection.
Mangroves thrive in conditions in which no other plant could survive: off the chart salt levels, thick mud, and extreme heat. They protect the shoreline from erosion and storms and serve as a nursery for fish. Red, black, and white mangroves are all found in John Pennekamp State Park.
Coral reefs need nutrition, too! The small polyps of coral use algae to get energy through photosynthesis. The algae cells get much more energy than they need from the sun, so they release their leftovers to the coral polyps.
Sea grasses are like land plants except they do not possess the strength to support themselves without the natural buoyancy of water. Just one acre of sea grass can support up to 40,000 fish and 50 million invertebrates; therefore, they are an important indicator of the overall health of a coastal area.
Tentacles are used by many filter feeders, including coral, to trap food. Many tentacles release a sticky mucus that helps speed along this process. Jellyfish, squid, octopi, and snails are other examples of filter feeders that utilize tentacles.
Remarkably, strong storms are actually healthy for an underwater ecosystem. Every spring, storms and strong winds stir up nutrients from the deep sea, and these nutrients benefit systems such as the coral reef. This process is called upwelling.
Coral reef ecosystems are incredibly fragile. Water temperature must remain between 68 and 86 degrees F, or the symbiotic relationship between zooxanthellae and the coral will fail. In this case, bleaching will occur and the coral colony will die.
Hard corals, such as brain, star, and pillar, have firm exoskeletons that protect their fragile bodies. On the other hand, soft corals such as sea fans lack an exoskeleton; these corals sway to and fro with the ocean currents.
Zooxanthellae are tiny algae cells that live inside most coral polyps. Zooxanthellae and coral have a mutualistic relationship; the coral provides a safe home for the cells, and the cells give oxygen and help take away wastes. Surprisingly, zooxanthellae give coral its color, since coral itself is colorless.