Quenching California’s Thirst For Water

California drought

The past four years have been among the driest in California’s recorded history. (Photo credit: Frederic J. Brown/Getty Images)

The past four years have been among the driest in California’s recorded history. This January marked one of the driest months on record. In March, the Sierra Nevada snowpack, a key source of fresh water for the region, was at 5 percent of its historical average of 28.5 inches. The Sierra Nevada’s Tuolumne River Basin supplies water for the Turlock and Modesto irrigation districts and the Hetch Hetchy Regional Water System, which provides water to San Francisco and surrounding areas. [Read more…]

Celebrating Earth Day Every Day


Earth Day was founded in 1970 by Senator Gaylord Nelson.  (Photo credit: Loskutnikov/Shutterstock)

April 22 marks the 45th annual celebration of Earth Day. Senator Gaylord Nelson of Wisconsin founded Earth Day in 1970 to bring environmental issues to the top of the national agenda. Until then, there were little to no legal or regulatory mechanisms to protect the environment. [Read more…]

Glacial Retreat and Biodiversity

Alaskan glacier

Glacial retreat, a consequence of climate change, may have a large impact on biodiversity. (Photo credit: Digital Vision/Getty Images)

As a result of climate change, glaciers around the world are melting. What impact might this have on biodiversity? [Read more…]

Hawaiian Agriculture and Its Impact on the Environment

Hawaii’s mild climate is ideal for year-round agriculture. (Photo credit: USDA)

Hawai’i has been associated with agriculture for as long as the islands have been inhabited. In some ways, the Hawaiian Islands are a perfect place to farm. A mild climate allows a year-round growing season. The average high temperature in July is 25° C (77° F), and the average low in January is 21° C (71° F).  Plenty of rainfall creates rich soil as nutrients from plant material get incorporated into the earth below.

Even so, early Polynesian settlers had to pick their farming sites carefully. The islands were once active volcanoes, and the lava flows range from hundreds of thousands of years old to brand new. The ancient flows make for good farmland now, but all of the land is patchy due to the newer lava flows lying on top of older flows in some places. Also, some areas get copious amounts of rainfall, and some areas receive almost no consistent rain. Too much rain washes nutrients right out of the soil and too little rain won’t allow crops to grow. Archeological studies have concluded that rainfall and soil types were deciding factors for the early settlers when choosing where to farm.

The first Polynesian voyagers, arriving from other Pacific islands, brought with them produce such as bananas ( mai’a in Hawaiian) and taro (kalo). Taro is farmed in lo’i, which are irrigated fields similar to rice paddies.  Because taro needs a continuous supply of fresh water, taro lo’i diverted water from streams. The water was then returned to the stream for use by the next farmer. They also created fishponds along the coast to raise seafood.  Each of the lo’i along the stream would add nutrients to the water, and the same stream would eventually add nutrients to the fishponds. For hundreds of years before the arrival of westerners, Hawaiians lived closely with the land and were able to sustain themselves. They divided up land with island ecology in mind. The land divisions, called ahupua’a, created pie-shaped slices of land from the mountains to the ocean.

When Captain Cook, the first westerner, arrived on the islands in 1778, he found not only taro and banana but sweet potatoes, pigs, chickens, ginger, sugar, coconut, and uniquely Polynesian crops like breadfruit (ulu), kawa and ti plants.  Eventually, rice was introduced and taro farming declined.  Sweet potato crops were devastated by the introduction of disease. The era of big sugar plantations began in 1834. Macadamia nut and pineapple plantations followed, using thousands of acres of land. In 1922 James Dole bought the entire island of Lana’i, using much of it for growing pineapple.  In 1959, Hawai’I became the 50th state.

Today, there are about 7,500 farms in Hawai’i, which use more than a million acres of land. Tropical plant and flower nurseries are one of the top money makers for Hawai’i, but this business has also caused the introduction of alien species. The coqui frog, a tiny little frog with a big voice, is well loved in its native Puerto Rico. It has been accidentally introduced in Hawai’i, where it has not received a warm welcome. Large populations of the frogs have been established on several of the islands, and, while they do not harm crops, they have cost many tourism dollars and lowered the property value of many homes. When groups of coqui sing in the evenings, the noise is above the decibel standards for hearing safety. In addition, nurseries now often have to certify that their plants are “coqui-free” which has created additional expenses for these companies.

Insects, too, have hitched a ride across the ocean from other tropical locales in the nursery trade. Interestingly, Hawai’i has one of the best quarantine programs in the world to prevent non-native species from establishing themselves. Even back in 1888 King David Kalakaua recognized the importance of quarantining products brought to the islands. He quarantined imported coffee to prevent the introduction of disease to the coffee crop. Today, tropical plants from other places are not allowed to be sold in Hawai’i. What is allowed, however, is to ship plants to the islands with the intention of bringing them them to the mainland United States or other global destinations. Sometimes, however, the plants have passed customs inspections in Hawai’i and then have been illegally distributed on the islands.  Now bug infestations, such as non-native fruit flies, prevent some companies from buying plants from Hawai’i.

Hawai’i has moved a long way away from its subsistence farming roots. It is currently 42nd in the United States for agricultural product sales, and imports at least 90% of its products. One estimate says that Hawai’i only has enough food for its current population to last 7 days. Still, agriculture is important to Hawai’i. It is the 3rd largest revenue producer, after tourism and the U.S. military. Agriculture adds almost 3 billion yearly to the state’s economy, and provides 42,000 jobs. High-tech aquaculture firms have replaced traditional fishponds. However, the pineapple and sugar industries that were once so vast are rapidly shutting down due to cheaper production in other places worldwide.  Lanai’s pineapple fields, for instance, have returned to grassland. Feral pig and goat populations on all the inhabited islands have endangered native plant populations. Many of the native species are endemic to Hawai’i, meaning they are found nowhere else in the world.

Modern challenges to farming on the islands center on the high cost of land. Many farmers must lease their land so they are reluctant to buy expensive equipment when there is a chance they may lose the land they farm on. Cost of irrigation, workers, and transport of the harvest all add to the cost of farming. One of the possible solutions to both preserve the environment and increase agriculture revenue is agri-tourism. Tourists are increasingly looking for cultural and unique hands-on experiences during their vacations.  Flower farms, cattle ranches, coffee and macadamia nut plantations, and fruit orchards have all started exploring this option. Chefs that cook with local foods are also using tourism to support agriculture. Marketing products as Hawaiian is also helping sales. Macadamia nuts and coffee are two products that are especially associated with Hawai’i. Coffee grown in Hawai’i is the only coffee grown in the United States, and macadamia production in Hawai’i is second in the world.  Products labeled “grown in Hawai’i” can command a higher price around the world than the same products grown elsewhere. Farms dedicated to preserving traditional farming techniques are also on the rise. Traditional farmers must also be environmental activists, lobbying for water once used for plantations to be returned to streams for taro lo’i.  The lo’i are popping up again on the islands, as more island residents recognize the wisdom of traditional diets and farming practices that preserve Hawai’i’s unique environment.

More to Explore

Hawai’is Agriculture Facing the Future 
To Hawai’i Travel Guide: Agriculture of Hawai’i
Hawaii Department of Agriculture
History of Agriculture in Hawai’i
Hawaiian Soils Reveal Clues to Cultural History

Making a Difference: Get Involved with the Environment

trail construction

Southwest Conservation Corps crew members help to build a mountain bike trail in Salida, Colorado.

You can only learn so much environmental science indoors. Sometimes, you just have to go out and get mud on your boots. Luckily many nonprofit environmental groups offer programs in which you can do just that—and make a difference while doing it.
[Read more…]

Points of View: Pipelines and Oil Sands

oil sands

Oil sands are mixtures of oil, clay, sand, and water. Many large deposits of oil sands are located in Canada.

The world needs oil. Oil is best known for its use as a fuel, but it also is used to make plastics, lubricants, and many chemicals. For decades, oil has been inexpensive and has been treated as an almost inexhaustible resource.

[Read more…]

Society and the Environment: Gold from Ghana

Geologists and miners inspect core samples at an underground gold mine in Obuasi, Ghana.The world market price of gold rose from $260 to $1,730 per ounce between 2001 and 2012. Most people don’t think about it, but the environmental and social consequences of this price increase have been substantial. This is especially true in countries where many people live in poverty. The situation in Ghana illustrates the complex interplay of societal and environmental processes that can lead to local crises or, alternatively, show cause for …hope.

[Read more…]

Points of View: Genetically Modified Foods


A scientist examines experimental samples ofgenetically modified fruit trees.

Genetically modified (GM) foods have been on sale in the world’s supermarkets since 1994. We do not recognize them because the U.S. Food and Drug Administration (FDA) does not require that GM foods be labeled as such.
[Read more…]

Points of View: The Three Gorges Dam

China’s Yangtze River is the third longest river in the world after the Nile and the Amazon. The Yangtze River flows through the Three Gorges region of central China, which is famous for its natural beauty and historical sites. For thousands of years, the area’s sheer cliffs have inspired paintings and poems. This idyllic region seems like the sort of place that would be protected as a park or reserve. But in fact, it is the site for the Three Gorges Dam—the largest hydroelectric dam project in the world. Now that the dam is fully operational, the Yangtze River forms a reservoir that is 595 km (370 mi) long—as long as Lake Superior. In other words, the reservoir is about as long as the distance between Los Angeles and San Francisco!

[Read more…]

Society and the Environment: Hurricane Katrina and New Orleans

New Orleans

Over 80 percent of New Orleans was submerged by floodwater when Hurricane Katrina struck in August, 2005.

The city of New Orleans was built on the Mississippi River Delta, about 160 kilometers upriver from the Gulf of Mexico. This city is vulnerable to flooding from the Mississippi River, Lake Pontchartrain to the north, and heavy rainfall from tropical storms. In addition, hurricanes that pass over the coast can create storm surges—waves up to 9 meters.

[Read more…]