Comprehensive Study Notes on Climate Change and Coastal Ecosystem Interconnected Coastal Ecosystems

Climate Change Impacts on Coastal Ecosystems

• Climate change functions as a chain reaction within the environment, significantly impacting interconnected coastal habitats.
• Primary affected ecosystems include:
  • Coral reefs.
  • Mangroves.
  • Seagrass beds.

Biological and Environmental Consequences of Warming Waters

• Warmer Water: An increase in sea water temperature serves as a primary driver for coral bleaching.
• Stronger Storms: Increased storm intensity can physically damage the structural integrity of coral reef systems.
• Altered Rainfall and Seawater Conditions: Changing precipitation patterns can significantly alter the salinity of coastal areas.
  • Impact on Plants: When terrestrial or coastal plants are exposed to unsuitable water conditions or drought, they dry out and die.
  • Impact on Marine Life: Shifts in salinity can be fatal for fish that are biologically specialized for specific natural water environments.

The Reef-Mangrove-Seagrass Connection

• These three ecosystems are biologically and physically linked, creating a critical interdependency:
  • Coral Reefs: Provide essential shelter and structural habitats for a diverse range of marine species.
  • Mangroves: Serve as vital nursery grounds for young fish. Activities such as mangrove planting are highly beneficial for ecosystem health.
  • Seagrass Beds: Provide extensive feeding areas and serve as additional nursery habitats.
• Interconnected Life Cycles: Many marine organisms utilize more than one of these habitats during various stages of their life cycles.
• Management Implications: Protecting only one ecosystem while allowing others to degrade is insufficient. Conservation efforts must be holistic because these ecosystems collectively provide:
  • Biodiversity.
  • Fisheries productivity.
  • Natural protection for coastal communities.
• Consequences of Degradation: If these habitats are destroyed, human communities lose both their primary food sources and their natural buffers against storms.

The Biology of Corals and the Bleaching Process

• Coral Biology:
  • Corals are animals, not plants.
  • They maintain a mutualistic relationship with microscopic algae called Zooxanthellae.
  • Zooxanthellae live inside the coral tissues, photosynthesize, and provide the majority of the coral's energy.
• The Mechanism of Bleaching:
  • Bleaching occurs when seawater temperatures rise approximately $1$ to $2\,^\circ\text{C}$ above the normal range.
  • High temperatures disrupt the photosynthesis process in the algae.
  • Disruption leads to the formation of Reactive Oxygen Species ($\text{ROS}$), which are harmful oxygen species.
  • To protect itself from $\text{ROS}$, the coral expels the algae.
  • Once the algae are gone, the coral loses its main energy source and its vibrant color, leaving behind a white skeleton known as bleached coral.

Social and Economic Impacts of Coral Loss

• Coral Structure: Reefs are formed by thousands of tiny jellyfish-like animals called polyps that connect to form colonies.
• Triggers for Stress: Global warming, water pollution, and various environmental disturbances stress corals, leading to bleaching.
• Reversibility: Bleached corals are not necessarily dead; they can recover if water temperatures cool down or if pollutants are removed. However, if conditions do not improve, the corals die.
• Statistics and Global Value:
  • Approximately $25\%$ of all marine life depends on the habitat created by coral reefs.
  • Over $500,000,000$ people worldwide rely on reefs for food, tourism, employment, and protection from extreme weather.
  • The estimated economic value of reefs is nearly $\$30,000,000,000$.
• Frequency of Events: Global bleaching events are occurring more often and with greater intensity. The current event is considered the worst on record.
• Human Consequences:
  • Fisheries: As reef structures decline, fish populations decrease, leading to lower catches, lower income, and reduced food security for fishing communities.
  • Coastal Protection: Weakened reefs provide less protection from waves, which increases coastal erosion and susceptibility to storm damage.

Climate Change Effects Across Biological Levels

• Individual Level: Causes internal stress, behavioral changes (such as reduced movement or irritability), and reduced survival rates.
• Population Level: Changes the geographic range of species, alters reproduction cycles, and shifts the timing of biological events.
• Ecosystem Level: Leads to the disruption of habitats and the breakdown of food webs.
• Community Level: Results in the loss of food, water, income, and physical protection.

Human Pressures and Urbanization

• Human activity acts as a secondary pressure on ecosystems alongside climate change.
• Urbanization: Population growth leads to increased demand for housing, water, food security, electricity, transport, and infrastructure.
• Land Use: High population density, such as in Manila, leads to the conversion of agricultural land into industrial hubs, stripping organisms of their natural habitats.
• Environmental Degradation: Lack of careful planning leads to habitat loss, pollution, waste accumulation, and the overuse of natural resources.
• Ecosystem Resilience: These pressures reduce the ability of an ecosystem to recover after an impact.
• Distinction in Population Dynamics:
  • Population Growth: A normal increase in the number of people requiring resources and infrastructure.
  • Overpopulation: Occurs when the human population exceeds the environment's capacity to provide resources and absorb waste sustainably. It is influenced by consumption patterns, waste management, and the government's ability to provide services (e.g., comparing the service capacity of China vs. the Philippines).

Strategies for Climate Response: Adaptation and Mitigation

• Adaptation: Adjusting to the current impacts of climate change to reduce harm and maintain normal functions.
  • Examples: Disaster preparedness, early warning systems, planting drought-tolerant crops, and mangrove restoration to buffer against storm surges.
• Mitigation: Addressing the root causes of climate change by reducing greenhouse gas emissions to limit future warming.
  • Examples: Renewable energy, forest conservation, reforestation, sustainable transportation, and reducing fossil fuel use.
• Blue Carbon: This refers to carbon stored in coastal and marine ecosystems. These ecosystems offer a double benefit:
  • Mitigation: They store carbon in tissues, roots, and sediments (keeping it out of the atmosphere).
  • Adaptation: They reduce erosion and storm damage, helping communities adjust.
• Hybrid Solutions: Projects like mangrove restoration and forest conservation serve as both adaptation and mitigation simultaneously.

Collective Responsibility and Action

• Climate action is a shared responsibility across multiple levels of society:
  • Individuals: Can conserve energy, reduce waste, and make responsible consumption choices.
  • Schools and Communities: Can engage in ecosystem restoration and strengthen local disaster preparedness.
  • Institutions and Governments: Hold the power for large-scale land use planning, habitat protection, implementing sustainable energy, and supporting climate-resilient livelihoods.

Questions & Discussion

• Question: A student (11, I) was asked if they had questions regarding the connection between human activity, population growth, and ecosystem resilience.
• Response: The student indicated they had no questions.
• Closing Instruction: The speaker emphasized the importance of humanity-focused subjects (like those in Gen Zai or Humanities) even for those in the STEM industry, noting that scientists must remain human-centric in their approach to solving environmental problems. Students were reminded to work efficiently on their tasks and contribute significantly to their projects.