Radio Expedition Sensitive to Environment at Ducie Island

The recent VP6DX radio expedition to remote Ducie Island accomplished more than a record number or contacts world-wide. The nineteen visitors also worked to minimize any impacts and to remove any trash present on the atoll where they stayed for about two weeks during mid-February.

Looking west along the beach on Acadia Island, the main islet covering the NW, N, and E shores, Ducie Atoll. Photograph by Angela K. Kepler, courtesy of Pacific Biodiversity Information Forum.

There were several environmental goals during their visit, said Eric Scace, a member of the expedition team from the northeast United States. These included:

"1) to leave the island cleaner than it was when we arrived, by collecting trash left by previous visitors and some flotsam.

"Trash and recyclables were removed from the island daily. This included our own trash and stuff picked up each day off the island. (We tried to do a little bit every day, along with a complete sweep of the areas around our campsites on our last days.) That all went into the hold of the ship, and I wasn't there to make a total count. Some items were big: a couple of old fishnet radio beacons were the biggest. We partially disassembled them to make them easier to transport back to the ship and stow for disposal back home.

2) "to avoid damage/change to the basic structure of the island: reefs, shoals, rocks, soil, wooded areas, etc.

3) "to remove all of our own materials and trash, especially all plastics and non-organic materials. Ashes were scattered to avoid concentrations, and human waste was buried at a site not used by plants.

4) "to avoid disturbing plants and animals (with the exceptions of fish caught for food and firewood burned), and to tolerate as much as possible those critters which choose to visit our sites. In practice, this meant avoiding a lot of hermit crabs when walking around at night!

5) "to segregate and recycle used materials from the island and from on-board ship activities back in New Zealand. All plastics/non-organic trash from the island and generated on-board ship was also captured for disposal in New Zealand. Used engine oil from the generators was captured during oil changes for recycling in New Zealand."

Expedition members also undertook efforts to reduce any hazards associated with the several antenna arrays erected to provide radio communications.

"We took care to keep all antennas (with one exception) in open areas (hard limestone or loose large old coral), and there were no ground nests (or remnants of ground nests) in the areas of our camps or antennas at the time of construction," Scace said. “We saw no interactions between birds of any kind and the antennas, other than one or two adult fairy terns perched on horizontal cross-arms."

The two bird species noted to have fledglings during the mid-February visit were Fairy Terns and Brown Noddies, Scace said. "The team photographer took photos of most birds seen at the island, so those might be helpful to others interested in make a more positive identification."

"At one camp, about ten days into the operation, a curious fledgling noddy walked into the camp area. We marked off an area around him so that he would remain undisturbed (we were mostly concerned that the resident hermit crabs not bother him at night)... and found him more curious about us than we were about him. He spent a couple of evenings in his marked off patch of coral, and a few days later was not seen again. I saw two other fledglings testing their not-yet-functional wings near the lagoon's edge in open areas of limestone. One of these I saw several times over the course of two days. Initially I wondered whether these individuals were in trouble, as they were not near any obvious nest and not clearly supervised... but it seemed like this was a normal part of their life cycle... they were not lethargic or displaying obvious signs of distress or weakness, did not appear to be bothered by hermit crabs, and disappeared on their own schedule without a trace (e.g., no carcass on the site)."

Scace said he “was actually very surprised at overall very low number of birds at Ducie during the visit. Besides these two species, there was a handful of frigate birds (only one or two on the ground, none making displays of their red sacs) and a few transient boobies (maybe a dozen individuals over the course of 3 weeks). In one area I could hear at night a group of chattering birds whose calls sounded very duck-like, but never saw an individual that I could associate with the sound; I think these were gathered in heavy underbrush. I saw one hawk-like silhouette on a branch, which definitely surprised me... but I had no field guide to use to make an identification. There was very little bird chatter in general, far less than on other equatorial/tropical uninhabited Pacific Islands on which I have worked (Jarvis, Mellish Reef, Clipperton) or south Indian Ocean islands (St. Brandon in September, for instance, where one hears fairy terns and noddies talking all the time, day and night). I can't comment, based on a single visit in February, whether this was just due to the time of year, due to location, or due to the nature of food sources in that region."

The expedition noted further details for the natural history of the atoll.

"There are no rats/mice on Ducie Island or any other kind of mammal (other than us radio operators and ship's crew)," Scace said. “No sign of turtles or turtle nesting in the areas I visited ... no roaches ... no biting insects. The largest insect we saw was a spider. Other animals included hermit crabs (three shades of red), two varieties of land crab, a very small ghost-like land crab (about 2 cm across), a very small gecko-like lizard (about 4 cm long), and a wide variety (but not annoying population) of small flying insects (about gnat-sized in general)."

Scace couldn't say the expedition did not have any impact on the environment.

"Of course the ship burned diesel fuel during its trip, and we burned gasoline in our generators to make electricity. We ate some fish caught in the waters around the island and on the sea voyage. We burned dead twigs and branches in a camp fire in order to cook our food. We dug latrines in loose coral and buried our feces. Probably, if one ran the numbers, the 19 of us (13 radio operators and 6 ship's crew) used less fossil fuels than we would have used back in our home countries during the same period. So maybe the net planetary impact for these people was less.

"All of us who visited Ducie Island loved its beauty. As a radio expedition, by all external measures the trip was a big success. But for the 19 of us privileged to live on the island for a time, we took away memories and friendships to be treasured for the remainder of our lifetimes. It's hard to describe the sense of wonder in seeing the full moon rise offshore while in an eclipse, to smile at the antics of the fearless and inquisitive fairy terns, to suddenly notice a row of coral trout watching you, or the simple visual delight of looking across the lagoon at dawn or sunset. We felt we were the luckiest people on the planet, to be able to undertake a project for the benefit of a hobby that we love, to do so with people we enjoyed, and to live for a time in such a beautiful corner of the planet. And, as a co-leader of this project, I hope the team's behavior was such that we would be welcome to undertake a similar radio expedition in other intriguing corners of the world."