Marijke Wilhelmus is a freelance web designer whose love of marine life spurred her to go on a yearlong trek around the world to discover examples of sustainable living and preservation projects in remote areas above and below the surface of the ocean. Seed asked Marijke to document her travels by sending regular dispatches chronicling the different characters she meets and the innovative and practical ways of life she witnesses.
To see all of Marijke's dispatches from her travels, click here.
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Lake Punawai, Hualalai Resort, the Big Island, Hawaii
At the Hualalai Resort, situated on the stunning Kailua-Kona Coast of Hawaii's Big Island, humans have built a lake that functions as a "living machine" capable of filtering water, producing food, and sustaining populations of birds, fish, and plants native to this island chain.
Lake Punawai, whose name means "source of spring water," is situated at the fifth hole of the resort's Jack Nicklaus-designed championship golf course.
Originally the manmade pond was created as a visually pleasing water feature for the course, one that would keep it free of algae without using excessive amounts of energy and especially water, which is a scarce commodity on the dry side of the Big Island.
Lake Punawai as seen from above
Apart from the views it provides, the 3.5 million-gallon lake hosts a thriving ecosystem complete with native birds, a wetland vegetation habitat and enough fish and shrimp to keep the resort's restaurant stocked—on a weekly basis, around 40 to 50 moi (also known as threadfish) and 20 pounds of shrimp are harvested.
The lake is built on the "living machines" principle. Living machines are contained, manmade ecosystems made up of thousands of species of living organisms specifically chosen to perform certain functions. A good, working living machine, like Lake Punawai, digests sediments, manages nutrients, and uses little energy—it is an example of phytoremediation, the treatment of environmental problems using plants.
In the foreground, the native Hawaiian sedge 'Ahu'awa
During the construction of Lake Punawai, two islands, called "restorers," were installed along with six airlifts and a subsurface gravel filtration system. Water is pulled through the bottom gravel filtration and up to the center of the two restorers. An air compressor, which operates at 3.5 horsepower, runs constantly and provides supplemental aeration for the fish.
After installation, sludge-eating bacteria were introduced as well as moi (threadfish), ama'ama (mullet), kahala (amberjack), opea (shrimp), awa (milkfish), and oleoe (oysters). Native Hawaiian flora were planted on both islands and the area around the pond. Now the lake is balanced and requires little to no maintenance. There is no need to remove bottom sediments, because there are none; they are consumed by the numerous detritivores and organic-matter-consuming bacteria established in the lake in the early days of the project.
An endangered Hawaiian Stilt, or Ae'o, paces around the shore of the lake
Early one morning I met David Chai, the resort's director of natural resources. At that time of day, the setting was stunning. I was excited to spot native Hawaiian plants like the 'Ahu'awa, a native Hawaiian sedge, as well as the beautiful island palm Loulu. I also spotted an endangered Ae'o, a native Hawaiian Stilt. This bird, which is endemic to the islands, is tall and slender, and stands on very long pink legs. To date, 16 new Ae'os have been hatched and raised at the Hualalai. Alongside the Hawaiian Stilt live other native birds like the 'Auku'u, or Juvenile night heron, and the nene, the Hawaiian goose, which is the state bird.
While hiking around the lake, I observed the living machine at work: several 'ama'ama, or mullets, filtered the water while they searched for food.
Contact Marijke Wilhelmus here.

