Human impacts on Coral Reef UPSC NOTE

 

• The paper in Nature highlights that simultaneous efforts to reduce human impacts on both land and sea have contributed to less coral loss during a marine heatwave in Hawaii.

• These combined strategies also support the persistence of coral reefs after the heatwave.

• The study demonstrates the effectiveness of managing both land and sea activities to safeguard coral reefs.

• Coral reef ecosystems face various human impacts, including land-based disturbances like wastewater pollution and sea-based impacts such as overfishing.

Human impacts on Coral Reef

• Coral health is affected by prolonged warm ocean temperatures, known as marine heatwaves, which lead to coral bleaching and death.

• The study was conducted by Jamison Gove and colleagues from the National Oceanic and Atmospheric Administration (NOAA), Honolulu, Hawaii.

• The study used a unique 20-year time series (2003-2019) of land-sea human impacts in Hawaii.

• An unprecedented marine heatwave occurred in 2015, causing ocean temperatures to rise 2.2 degrees Celsius above normal.

• The analyzed human impacts included urban runoff, wastewater pollution, and fishing restrictions.

• Over the study period, some areas experienced increased coral reef cover, while others saw decreases or remained stable.

• Reefs with mitigated land and sea human impacts displayed higher coral cover before and during the heatwave.

• Reefs with fewer human impacts showed increased reef-builder cover (essential coral types) four years after the heatwave.

• More herbivorous fishes and reduced exposure to land-based impacts were associated with improved reef-builder cover.

• The authors used scenarios to model the impact of reduced human impacts on reefs.

• Reductions in both land- and sea-based human impacts were projected to result in a three- to sixfold greater probability of high reef-builder cover four years after a disturbance.

• The study's results emphasize the potential of integrated land-sea management for coastal ocean conservation.

• Such strategies offer coral reefs a better chance to persist in the changing climate.