Looking Above Water; Jarvis Island Revisited

Written by Chris Depkin, photographs by Jiny Kim

Chris Depkin surveys the wildlife at Jarvis Island

A Masked Booby (Sula
dactylatra ) chick awaits
its mother's return

Jarvis Island National Wildlife Refuge (NWR) has something to offer everyone.  As you can see by exploring previous blog entrees, the underwater world is exceptional by any standard. However, if you were to crawl out of the water, up onto and over the coral rubble that forms the beach, you would see a dazzling view of life on dry land equaling that of the surrounding coral reef community. After days on the open ocean all of your senses would be simultaneously assaulted by the sound of thousands of nesting seabirds, the sight of verdant island vegetation and the fragrance of life, reproduction and death. You see, Jarvis Island, only a little over one thousand acres in size, is the only land within thousands of square miles of open ocean. As such, this island provides the only suitable conditions for as many as 13 or more different seabird species of birds, in numbers often exceeding several hundred thousand, to mate and reproduce.

The isolated nature of Jarvis Island (> 200 miles from the next nearest island) makes visitation difficult and is generally accomplished only once every two years. On 01 April, two members of the US Fish and Wildlife Service, Jiny Kim and Chris Depkin, were dropped off on the north-west shore of the island. They spent the next 5 days and 4 nights exploring the terrestrial environs for the purpose of assessing the state of the seabird communities, looking for signs of unauthorized human presence, identifying and neutralizing any hazards to wildlife, mapping and inspecting the island’s vegetation communities for changes in distribution patterns and looking for recent, non-native plant introductions.

A White Tern (Gygis alba) finds
a perch to view its surroundings

Jarvis Island supports very few plant species most of which are low growing. There are no trees on the island. During previous visits, plant species were described as brown, and dried with little flowering, dead or not detected at all. Our first impression of the island was astonishment and wonder at both the diversity and extent of coverage of the vegetation. Well over half of the island was bright green with at least 8 species well represented and most either flowering or in seed, or both.

A Hermit Crab searches for food

However, conditions favorable for plant growth and reproduction (excessive rain fall) are not necessarily conditions suitable for seabird nesting. The unusual amount of rainfall at Jarvis is likely a result of the recent El Niño-Southern Oscillation event (ENSO) which can bring about large scale changes in regional weather patterns once every 3-5 years. These large scale changes, and in particular changes in sea surface temperature (SST), also affect the distribution, abundance, availability and predictability of prey items critical to successful nesting.

The region is just now emerging from the current El Niño event and our visit to Jarvis seemed to support the above. Although thousands of seabirds were present during this visit, the vast majority were in the very early stages of nesting, either sitting on eggs or standing around, on territory, getting ready.  Chris and Jiny documented the presence of very few chicks either alive or dead (dead chicks indicate earlier breeding attempts that failed) which indicates little or no nesting has occurred here over the last several months. Very preliminary and crude estimates suggest there were less than 150,000 birds present on the island during this visit. Previous visits place estimates well over one-million birds present during peak nesting.

After walking more than 30 miles during the 5 day period, locating and counting breeding birds and mapping vegetation distributions, Jiny and Chris were picked up where they were dropped off, not to return for another 2 years.

Jarvis Island is without question a rare jewel set in the vastness of the Pacific Ocean. On January 6th, 2009, President George W. Bush established the Pacific Remote Islands Marine National Monument.  Jarvis Island NWR along with Howland and Baker island, Johnston, Wake, and Palmyra Atolls, and Kingman Reef are all included in this new Marine Monument which contains 86,888 square miles of mostly open ocean and the above uplands. The areas designated by this new Monument are used by over 4 million breeding tropical seabirds and at least 10 million more that are pre-breeders or migrants passing through those waters on their way to Northern and Southern breeding grounds. Protecting these remote places cannot be overstated, important not only for the marine and terrestrial organisms that live there but for the enjoyment, benefit and educational opportunities afforded future generations.

The last bit of light before the sun sets over the Pacific