coastal change Flashcards
How many people live near coral reefs?
Nearly a billion people live within 100 km of a coral reef, and the population growth in these areas is higher than global averages.
Why is sedimentation a primary stressor for coral reefs?
Sedimentation can smother corals, reducing their ability to feed, grow, and reproduce. It also reduces coral recruitment rates and increases post-settlement mortality.
How does sedimentation affect coral reefs’ ability to thrive?
Sedimentation reduces light levels by increasing turbidity, which lowers the availability of photosynthetically active radiation essential for coral health.
How do nutrients affect coral reefs?
While nutrients are typically beneficial, excess nutrients from fertilizers, sewage, and animal waste can lead to algal growth, blocking sunlight and depleting oxygen needed for coral respiration. Excess nutrients also support harmful microorganisms.
What role do seabirds play in supporting coral reefs?
Seabirds distribute nitrogen-rich nutrients through guano, which fertilizes surrounding seas, boosting the food chain and promoting healthy coral growth. Rat infestations reduce seabird populations, leading to lower nutrient levels and slower coral growth.
How does light pollution affect coral reefs?
Artificial light can disrupt natural coral growth patterns by masking moon cycles, potentially causing early spawning and reducing fertilization and survival chances for coral gametes.
What are the impacts of toxic substances on coral reefs?
Metals, organic chemicals, and pesticides from industrial discharges, sunscreen, and runoff can negatively affect coral growth, reproduction, and other physiological processes.
How do plastic pollution and microplastics affect coral reefs?
Plastic debris, such as bags, bottles, and fishing gear, can physically damage corals and block sunlight. Microplastics can be ingested by marine life, blocking digestion and potentially introducing toxins into the ecosystem.
How does coral harvesting affect reef ecosystems?
Over-harvesting of corals for the aquarium and jewelry trade can lead to decreased biodiversity and destruction of reef habitats.
What are the impacts of overfishing on coral reefs?
Overfishing can disrupt food web structures and affect the number of grazing fish that help prevent algal overgrowth on corals. Blast fishing, using explosives, can cause direct physical damage to reef habitats.
