Read the following passage about The Unprecedented Coral Reef Crisis and mark the letter A, B, C or D on your answer sheet to indicate the b...
Đề bài
Read the following passage about The Unprecedented Coral Reef Crisis and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
The planet's coral reefs are undergoing an unparalleled environmental catastrophe, marking the most devastating bleaching phenomenon ever documented. Since early 2023, this catastrophic event has impacted over 80% of global reef systems, substantially surpassing previous historical occurrences. Marine biologists have observed that tropical and subtropical waters are experiencing extraordinary thermal stress, transforming once-flourishing underwater ecosystems into ghostly, colorless landscapes. This alarming deterioration represents a critical juncture for oceanic biodiversity, threatening the delicate balance that has sustained marine life for millennia.
The underlying mechanism involves corals expelling their essential zooxanthellae—microscopic algae residing within coral tissues—when water temperatures exceed tolerable thresholds. These symbiotic organisms typically provide corals with vital nutrients through photosynthesis while lending them their characteristic vibrant hues. Climate change has accelerated oceanic warming to unprecedented levels, triggering this defensive response across vast expanses of reef territories. Consequently, corals lose both their primary food source and distinctive coloration, leaving them vulnerable to starvation and disease.
The ramifications extend far beyond aesthetic degradation, jeopardizing approximately one-third of all marine species dependent on reef habitats. Millions of coastal inhabitants rely on these ecosystems for sustenance, income, and storm protection. Previously considered thermal refugia—areas historically resistant to temperature fluctuations—are now succumbing to bleaching, eliminating potential sanctuaries for coral survival. The eerie silence replacing the usual bustling activity signals an ecosystem approaching collapse.
Scientists emphasize that without substantial reductions in greenhouse emissions, recovery prospects remain bleak. The current trajectory suggests continuous deterioration, potentially resulting in irreversible damage to these invaluable ecosystems. This crisis underscores humanity's profound impact on oceanic environments, demanding immediate, comprehensive action to mitigate further destruction and preserve remaining reef systems for future generations.
https://www.theguardian.com/z
Question 23: According to the passage, which of the following is NOT MENTIONED as an effect of coral bleaching?
A. Decline in tourism revenue
B. Threat to marine biodiversity
C. Loss of storm protection for coastal communities
D. Impact on livelihoods of coastal residents
