9. Analyse the Moreton Bay food web to show feeding relationships between organisms in an ecosystem and how energy flows into and out of an ecosystem.
The Moreton Bay food web is a complex network of feeding relationships between organisms that inhabit the marine ecosystem. The food web consists of various trophic levels, including producers, primary consumers, secondary consumers, and tertiary consumers. Each level is dependent on the level below it for energy.
Producers, such as phytoplankton and seagrasses, are the foundation of the food web. They convert sunlight into chemical energy through photosynthesis. Primary consumers, such as zooplankton, sea snails, and sea urchins, feed on the producers. Secondary consumers, such as fishes, crabs, and marine mammals, feed on the primary consumers. Tertiary consumers, such as sharks and dolphins, feed on the secondary consumers.
Energy flows through the food web in a unidirectional and linear manner. Producers produce energy, which is transferred to primary consumers when they consume the producers. This energy is then transferred from primary consumers to secondary consumers when they eat the primary consumers. The energy is transferred further to tertiary consumers when they eat secondary consumers. With each transfer, energy is lost as heat through metabolism and respiration.
Decomposers, such as bacteria and fungi, play a crucial role in the ecosystem by breaking down dead organisms and organic matter, releasing nutrients back into the ecosystem for use by producers, starting the cycle again.
The Moreton Bay food web illustrates how energy flows through an ecosystem and how organisms are interdependent on each other for survival. Any disruption to one level can have significant impacts on other levels and the entire ecosystem. For example, overfishing of species at the top of the food chain can lead to an increase in the population of their prey species, which can result in a decrease in the population of primary consumers and ultimately, producers. This disruption can have a cascading effect throughout the ecosystem, impacting biodiversity and ecosystem stability.
Analyzing the Moreton Bay food web involves understanding the feeding relationships within the ecosystem and how energy flows through it. Let's break this down step-by-step:
Step 1: Identify the organisms in the food web. The Moreton Bay food web consists of various organisms, including primary producers (plants and algae), primary consumers (herbivores), secondary consumers (carnivores), and tertiary consumers (top predators).
Step 2: Determine the feeding relationships. Begin by identifying the primary producers. In Moreton Bay, primary producers include macroalgae, seagrasses, and phytoplankton. Herbivores, such as small fish, crustaceans, and benthic grazers, consume these primary producers.
Step 3: Identify the secondary consumers. Small fish and crustaceans serve as secondary consumers, feeding on herbivores. These secondary consumers are often preyed upon by larger fish, such as snappers, groupers, and pelagic fish, as well as by larger crustaceans like the eastern rock lobster.
Step 4: Determine the tertiary consumers or top predators. The apex predators in the Moreton Bay food web include sharks, such as bull sharks, and marine mammals like dolphins. These animals are at the top of the food chain and have no natural predators.
Step 5: Trace the flow of energy. Energy flows through the food web in the following way: sunlight is captured by primary producers (plants and algae) through photosynthesis, converting it into chemical energy. This energy is then consumed by primary consumers (herbivores) when they eat the primary producers. The energy continues to flow through the food web as secondary and tertiary consumers consume one another.
Step 6: Consider energy loss. As energy moves through each trophic level, there is energy loss. This is known as the 10% rule, where only approximately 10% of the energy from one trophic level is transferred to the next. The remaining energy is lost as heat or used for metabolic processes. This energy loss explains why there are usually fewer individuals at higher trophic levels in an ecosystem.
By analyzing the Moreton Bay food web, we can understand the feeding relationships between organisms and how energy flows within the ecosystem. This knowledge helps us comprehend the intricate balance within ecosystems and highlights the dependencies among different species.