Any study of coral reef ecology must also consider the impact of the terrestrial environment on the health of the reef ecosystem. Clearing land for farming -- sugar cane is the most common crop in North Queensland -- leads to a significant increase in sediments in the estuaries and bays at the coast. Additional problems arise when the runoff includes chemicals such as fertilizers, herbicides and pesticides.

Coral reefs require clear water to grow and thrive. Although the coral polyp (the animal that produces the calcium carbonate skeleton we easily recognize on coral reefs) can feed on plankton in the water, the zooxanthelle within the polyp is actually a photosynthetic algae. As we learned in high school biology (hopefully), photosynthesis requires sunlight. Increased sediment particles from erosion upstream result in muddied waters, sediment settling on the corals, and ultimately kills the coral polyps. For similar reasons, coral reefs require low nutrients. An increase in nutrients may increase algal blooms that smother the corals. Thus, it is important to preserve the native ecosystems on land to protect the Barrier Reef ecosystems in the water.

During a hike through the Conway State Forest, we examined the different levels of a rainforest: canopy, mid-level, lower-level, and floor. Each level can be considered a different ecosystem, each interdependent upon the other. Because the dense overhead canopy blocks most of the sunlight at the floor, plants have broad leaves to absorb the relatively scant sunlight. Surprisingly, there is little detritus on the floor of the rainforest. Efficient decomposition by fungi and insects recycles the nutrients very quickly. Although the incredible diversity of rainforest inhabitants indicates that the soil is rich and fertile, the majority of the biomass of a rainforest is within the plant life growing from the soil. When the rainforest is razed for farm land, the soil quickly loses fertility and farmers must fertilize crops -- leading to runoff and algal blooms among the coral reefs. Additionally, the loss of sufficient ground covering increases subsequent erosion of top soil.

The Australian and Queensland governments are working to design and implement management plans that take into account the interconnectedness of both terrestrial and aquatic ecosystems. It is a work-in-progress.