For centuries, Okinawa's picturesque coral reefs have contributed to the island's economic profile and abundant tourism. Clear, warm waters typically characterize the island and allow reefs to flourish with marine life. Coral reef degradation, though, has taken over. Red soil runoff, coral bleaching, crown-of-thorns starfish, and human influences have deprived the reefs of the necessary sunlight and nutrients for survival. The stark decline in those underwater ecosystems directly affects both tourism and ocean-reliant economies. In an attempt to preserve the reefs (and the hub of Okinawa's tourism), some organizations have installed reef-monitoring systems and implemented regulations centered around reef conservation. This essay will discuss the historical changes in Okinawa's reefs, their causes, their effects, and the efforts of those who hope to save them.
A “Picture Perfect” Reef
While living on the island, my family and I would often spend sunny days snorkeling in its notoriously gorgeous waters. Expecting to see a forest of colorful corals and fish in all directions, I would excitedly dunk my snorkel-covered face beneath the waves. I instead saw fragments of a ruined kingdom. Pieces of broken and bleached coral lay scattered on the ocean floor, among them only a few lucky survivors and straggling marine animals. Because of its
subtropical climate, Okinawa’s reefs are usually teeming with life and more than 200 species find their home within them (JT 2000). So, the question looms: what happened?
When Man Moves In
After the end of World War II, Okinawa experienced an influx of American troops and an assimilation to mainland culture. When more people came in, much of the reefs went out. New developments along the coast such as buildings or military bases pollute the oceans and, consequently, destroy coral reefs. The Ryukyu Shimpo (2016) reports the construction of a new U.S. military base that causes direct harm to the reefs in Oura Bay, Nago. According to the article, concrete blocks weighing between 15 to 20 tons and military-vessel anchors destroy coral habitats.
Although a large contributor, the American military does not stand alone as the sole source of reef-detrimentation. By partaking in a modernized culture via construction or automobile usage, Okinawa’s inhabitants secreted greenhouse gases that warmed the atmosphere
and, in turn, the ocean. Exceeding 30 degrees celsius, sea temperatures rose one to two degrees celsius higher and became too warm to sustain coral life (Omori 2011).
Along with earth-warming gases, red soil runoff greatly contributes to the destruction of coral reefs. Livestock farms, for example, result in an overabundance of nutrients that end up draining into the ocean (UNU 2012). A direct result of this abnormal ratio of nutrients to seawater, typically clear waters become clouded and sunlight can no longer reach the zooxanthellae that use photosynthesis to give life to corals. The United Nations University also explains that this increase in nutrients leads to a growth in macroalgae, stymieing that of corals.
Mother nature gives, but she also takes. During a strong El Nino season in 1998, coral-bleaching episodes led to the endangerment of Okinawa’s staghorn corals (RS 2016). Coral reefs cannot readily or easily adapt to the drastic change in sea surface temperatures resulting from El Nino conditions.
In addition to periodic climate-change, the crown-of-thorns starfish plays a significant role in the dwindling Okinawan reefs. In fact, the Okinawa Churashima Foundation estimates that these starfish are the leading culprits of coral death, being especially destructive to the Acropora coral community. The corals did experience some recovery, but in total, the amount of reef that took root on the island decreased from 30% to 3% (Omori 2011).
A Colorless Catastrophe
Coral bleaching, an occurrence that turns once-colorful corals white, plagues Okinawa’s reefs. When corals lose their symbiotic relationship with zooxanthellae, they no longer receive
the necessary nutrients to survive and retain their vibrancy. In 1998, a mass coral-bleaching event in the Yaeyama district nearly wiped out the acropora coral community (UNU 2012). Later in August of 2013, another outbreak occurred and proved to be especially harmful; The Okinawa Churashima Foundation (2016) reported 11 different species of coral that became victims of the epidemic.
The Domino Effect of Reef-Loss
The loss of coral reefs directly and negatively affect both tourism and a fish-dependent economy. These reefs produce to countries worldwide, and The Okinawa Institute of Science and Technology (2013) estimates that it contributes roughly 3 trillion yen to Japan’s economy. Because of the drastic reduction in coral communities, though, those gold mines have lost significant value. An array of reef fish have experienced population declinations, with the grouper declining by 31%, the parrotfish by 41%, and the emperor fish by 14% (Omori 2011). Not only does this translate into a decline in marine markets, but also to a decline in tourist trips to the island—the runner-up for largest contributor to revenue (Omori 2011). Foreigners travel to Okinawa in hopes of diving into its warm waters and exploring the different reefs and marine animals that dwell within them, but when those attractions decrease, so do their visits.
Making a Change
Okinawa’s reefs once boasted picturesque beauty, and many ecologically-concerned citizens are taking the measures to return them to their former glory. Focusing on reef-preservation, the Okinawan government created laws like the Red Soil Runoff Prevention Ordinance in 1995 or the Law on Promoting Proper Management and Use of Livestock Excreta
in 2004 (UNU 2012). These laws ultimately reduce and control the amount of nutrients flooding into the ocean, allowing sunlight to properly aid in coral production.
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