honolulu

The pandemic was good for Hanauma Bay

October 8, 2025 By EarthWise Leave a Comment

Hanauma Bay is a marine sanctuary near Honolulu that is a popular snorkeling spot and is home to vibrant marine life and well-preserved corals. Its popularity grew in the 1970’s and 1980’s and its visitor attendance peaked at an estimated 10,000 people a day. A new management plan in 1990 reduced visitation, improved facilities, established an education program, and banned the feeding of fish. In 2019, average daily attendance was still about 3,000 people – about a million a year – and the impact on the reef ecosystem was considerable.

In 2020, because of the Covid pandemic, the preserve was completely closed to the public for seven months. This provided a unique natural experiment to study the effect of removing human interference from a natural ecosystem.

Researchers from the Hawaii Institute of Marine Biology found that the reef in Hanauma Bay quickly returned to having better water quality, more monk seal sightings, greater fish abundance, and significant changes in fish behavior. The fact that the ecosystem responded quickly indicated that everyday human presence can have a real and measurable effect on reef health.

The research serves as a valuable case study for marine managers around the world. Putting limits on the number of visitors to reefs – especially those that are currently unregulated – could help restore lost ecological function and reduce human-induced pressure while still maintaining access. Tourism to reefs generates billions of dollars annually, so there needs to be ways to protect reefs without making them entirely off limits.

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When crowds left, reefs came alive at Hanauma Bay

Photo, posted December 13, 2011, courtesy of Dalton Reed via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change And Heat-Related Deaths | Earth Wise

July 14, 2021 By EarthWise Leave a Comment

According to a new study recently published in the journal Nature Climate Change, more than one-third of the world’s heat-related deaths each year are attributable to human-induced climate change.

Researchers from the London School of Hygiene and Tropical Medicine in the UK and the University of Bern in Switzerland analyzed data from 732 locations in 43 countries. They took observed temperatures and compared them with 10 computer models simulating a world without climate change. By applying this technique to their data, the researchers were able to calculate for the first time the actual contribution of anthropogenic climate change in increasing mortality risks due to heat.

The research team found that 37% of all heat-related deaths between 1991 and 2018 were attributable to the warming of the planet due to human activities. This percentage was highest in South America, Central America, and South-East Asia.

In the United States, 35% of heat deaths were found to be a result of climate change. New York had the most heat-related deaths at 141, and Honolulu had the highest percentage of heat deaths attributable to climate change at 82%.

But scientists caution that this is only a small portion of the climate’s overall impact. Many more people die from other extreme weather amplified by climate change, including severe storms, floods, and droughts. Heat-related death figures will grow exponentially as temperatures rise.

According to the research team, the study’s findings highlight the need to adopt stronger climate change mitigation strategies, and to implement interventions to protect people from the adverse consequences of heat exposure.

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Global warming already responsible for one in three heat-related deaths

Photo, posted April 14, 2017, courtesy of Karim Bench via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rising Seas And Wastewater Leakage | Earth Wise

April 28, 2021 By EarthWise Leave a Comment

Global mean sea level has risen nearly 9 inches since 1880, with over two inches of that over just the last 25 years. The rising water level is primarily due to two factors: additional water in the oceans coming from melting glaciers and ice sheets; and the thermal expansion of seawater as it warms. Climate models estimate that over the course of the century, global sea levels will rise at least a foot even if efforts to reduce greenhouse gas emissions are quite successful and, in the worst case, levels could rise as much as 8 feet.

Faced with this situation, the greatest concerns are, initially, increasing amounts of coastal flooding and erosion and, as things get worse, inundation of coastal regions making many places uninhabitable and creating millions of climate refugees.

Recently, computer modeling studies have focused on an additional imminent problem: the flooding of coastal wastewater infrastructure, which includes sewer lines and cesspools.

A new study by the University of Hawaii at Manoa is the first to provide direct evidence that tidally driven groundwater inundation of wastewater infrastructure is already occurring in urban Honolulu. The study shows that higher ocean water levels are leading to wastewater entering storm drains and the coastal ocean. The result is degradation of coastal water quality and ecological health.

The researchers used chemical tracers to detect groundwater discharge and wastewater present at multiple low-lying areas during spring tides. During high tides, storm drains become channels for untreated wastewater to flood streets and sidewalks.

People tend to think of sea-level rise as a future problem, but there are already serious effects going on today that are only going to get worse.

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Sea-level rise drives wastewater leakage to coastal waters

Photo, posted August 23, 2011, courtesy of Eric Tessmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.