Threatened green sea turtles are frequently seen inside
the lagoon and basking on beaches, and 2007–2008
marked the first turtle nesting in many years. Endangered
hawksbill sea turtles (Eretmochelys imbricata) are infrequently seen in the lagoon. About 65 endangered
Hawaiian monk seals (Monachus shauinlandsi) are usually present at Midway at any time, and pup levels have
increased significantly since the establishment of the
NWR in 1996. Approximately 150–200 Hawaiian spinner
dolphins use Midway’s lagoon; bottlenose dolphins are
commonly seen outside the reef; and striped dolphins,
spotted dolphins, and rough-toothed dolphins have also
been reported. Endangered humpback whales and other
whales are also occasionally seen off Midway.
Terrestrial wildlife and habitats
Humans have greatly changed Midway Atoll from its original form. The combined effects of dredging and filling, seawall construction, and importation of herbs and many plant
species has greatly expanded the original acreage and made
Midway a different place, but one that is still a wildlife habitat of worldwide importance. The earliest botanical
descriptions of Midway were made in 1902, and since then
more than 265 different terrestrial taxa have been identified.
Nine of these are endemic to the NWHI and another 17 are
indigenous to the HI. One endemic plant species, Cenchrus
agriminoides var. laysanensis, is listed as endangered. Ecological restoration efforts are underway to eradicate invasive and noxious weeds, control others, and restore some
habitats with native species. Since the first insect (a moth)
was described from Midway in 1894, more than 300 species
of arthropods and land snails have been found on Midway,
mostly introduced aliens.
Almost two million breeding seabirds of 15 species make
Midway one of the most important breeding areas of seabird
conservation in the Pacific. Midway hosts the world’s largest populations of both the Laysan albatross (396,936
nesting pairs) and black-footed albatross (23,963 nesting
pairs) in 2009, accounting for 67 and 39% of the world’s
totals, respectively. One or two endangered short-tailed
albatross generally visit Midway each year, but none have
nested yet. Midway’s breeding populations of white terns,
black noddies, and red-tailed tropicbirds constitute the largest colonies in the Hawaiian archipelago. After eradication
of rats in the mid-1990s, the Bonin petrel colony at Midway
had rebounded to more than 32,000 pairs by 2005.
In 2004, 20 endangered Laysan Ducks, were
transported to Midway from their only home at the
time, Laysan Island, within the Hawaiian Islands
National Wildlife Refuge (now also within the
Papahānaumokuākea MNM). Biologists wanted to establish a second “insurance” population of this endemic duck
once found throughout the Hawaiian Islands whose distribution had declined during the past two centuries to the
single hyper-saline lake at Laysan Island. The ducks have
adapted well to Sand Island, surprising biologists by
breeding during their first year on Midway, with at least
10 ducklings surviving. An additional 22 ducks were
transported to Midway in 2005, most of which were introduced to Eastern Island. Over the last several years there
were declines due to disease, but duck populations have
now rebounded to their highest levels at Midway. The atoll
also serves as an over-wintering area for several arctic
migrant shorebirds, including the globally rare Bristlethighed curlew. Predator-free islands are required for this
large but vulnerable shorebird because they become
flightless during their winter molt. Many other migratory
birds also visit Midway, some regularly and some rarely.
Current investigations
The provisions of the MNM include the total ban of commercial fishing by 2011, control of access and introduction
of alien species, and monitoring, safeguarding, and restoring the many endemic, threatened and endangered species
that depend upon Midway and the other atolls and reefs
within the MNM for their survival. A management plan
for the Monument has been coordinated and approved,
and a research plan will soon be completed.
Some research will be devoted to tracking and promoting recovery of depleted, endangered or threatened species
as well as fish targeted by commercial fishers that will
become fully protected in 2011. Because general visitation
will be allowed only at Midway within the Monument,
there will be considerable monitoring and controlling of
visitors to prevent harm to fish and wildlife, collecting of
fish and wildlife, preventing the introduction of invasive
and alien species, and minimizing the effects of trash and
pollution. Much of the Monument marine habitats including offshore habitats at Midway still remain relatively
unexplored, and so some effort will be devoted to exploration for new species and habitats to determine which need
to be afforded special status and additional protection.
Research will also be conducted to learn more about how
relatively pristine reefs function and what lessons can be
learned from comparisons with the status of stressed reefs
outside the Monument. In addition, research efforts will
continue to determine whether reef growth at Midway is
keeping pace with erosion and subsidence, and whether
additional measures will help to reduce adverse effects,
such as selective removal of the large populations of sea
urchins that are now eroding key shallow reefs that serve
as natural breakwaters for protecting the entire atoll.
Floating marine debris discarded or lost by distant fishing fleets in East Asia continues to accumulate regularly at
Midway. Since 1996 when cleanup efforts were initiated,
42,821 kg has been removed from Midway which ranks
fifth in total quantity removed. Evidence of increased
accumulation rates on the shores and reefs of the NWHI
may be attributed to the southward movement of the Subtropical Convergence Zone in the north central Pacific.
Controversies and gaps in current knowledge
A review of the field methods supporting the Darwin Point
hypothesis (Grigg, 1982) revealed it relied primarily on
MIDWAY ATOLL (HAWAIIAN ARCHIPELAGO)
705
the lagoon and basking on beaches, and 2007–2008
marked the first turtle nesting in many years. Endangered
hawksbill sea turtles (Eretmochelys imbricata) are infrequently seen in the lagoon. About 65 endangered
Hawaiian monk seals (Monachus shauinlandsi) are usually present at Midway at any time, and pup levels have
increased significantly since the establishment of the
NWR in 1996. Approximately 150–200 Hawaiian spinner
dolphins use Midway’s lagoon; bottlenose dolphins are
commonly seen outside the reef; and striped dolphins,
spotted dolphins, and rough-toothed dolphins have also
been reported. Endangered humpback whales and other
whales are also occasionally seen off Midway.
Terrestrial wildlife and habitats
Humans have greatly changed Midway Atoll from its original form. The combined effects of dredging and filling, seawall construction, and importation of herbs and many plant
species has greatly expanded the original acreage and made
Midway a different place, but one that is still a wildlife habitat of worldwide importance. The earliest botanical
descriptions of Midway were made in 1902, and since then
more than 265 different terrestrial taxa have been identified.
Nine of these are endemic to the NWHI and another 17 are
indigenous to the HI. One endemic plant species, Cenchrus
agriminoides var. laysanensis, is listed as endangered. Ecological restoration efforts are underway to eradicate invasive and noxious weeds, control others, and restore some
habitats with native species. Since the first insect (a moth)
was described from Midway in 1894, more than 300 species
of arthropods and land snails have been found on Midway,
mostly introduced aliens.
Almost two million breeding seabirds of 15 species make
Midway one of the most important breeding areas of seabird
conservation in the Pacific. Midway hosts the world’s largest populations of both the Laysan albatross (396,936
nesting pairs) and black-footed albatross (23,963 nesting
pairs) in 2009, accounting for 67 and 39% of the world’s
totals, respectively. One or two endangered short-tailed
albatross generally visit Midway each year, but none have
nested yet. Midway’s breeding populations of white terns,
black noddies, and red-tailed tropicbirds constitute the largest colonies in the Hawaiian archipelago. After eradication
of rats in the mid-1990s, the Bonin petrel colony at Midway
had rebounded to more than 32,000 pairs by 2005.
In 2004, 20 endangered Laysan Ducks, were
transported to Midway from their only home at the
time, Laysan Island, within the Hawaiian Islands
National Wildlife Refuge (now also within the
Papahānaumokuākea MNM). Biologists wanted to establish a second “insurance” population of this endemic duck
once found throughout the Hawaiian Islands whose distribution had declined during the past two centuries to the
single hyper-saline lake at Laysan Island. The ducks have
adapted well to Sand Island, surprising biologists by
breeding during their first year on Midway, with at least
10 ducklings surviving. An additional 22 ducks were
transported to Midway in 2005, most of which were introduced to Eastern Island. Over the last several years there
were declines due to disease, but duck populations have
now rebounded to their highest levels at Midway. The atoll
also serves as an over-wintering area for several arctic
migrant shorebirds, including the globally rare Bristlethighed curlew. Predator-free islands are required for this
large but vulnerable shorebird because they become
flightless during their winter molt. Many other migratory
birds also visit Midway, some regularly and some rarely.
Current investigations
The provisions of the MNM include the total ban of commercial fishing by 2011, control of access and introduction
of alien species, and monitoring, safeguarding, and restoring the many endemic, threatened and endangered species
that depend upon Midway and the other atolls and reefs
within the MNM for their survival. A management plan
for the Monument has been coordinated and approved,
and a research plan will soon be completed.
Some research will be devoted to tracking and promoting recovery of depleted, endangered or threatened species
as well as fish targeted by commercial fishers that will
become fully protected in 2011. Because general visitation
will be allowed only at Midway within the Monument,
there will be considerable monitoring and controlling of
visitors to prevent harm to fish and wildlife, collecting of
fish and wildlife, preventing the introduction of invasive
and alien species, and minimizing the effects of trash and
pollution. Much of the Monument marine habitats including offshore habitats at Midway still remain relatively
unexplored, and so some effort will be devoted to exploration for new species and habitats to determine which need
to be afforded special status and additional protection.
Research will also be conducted to learn more about how
relatively pristine reefs function and what lessons can be
learned from comparisons with the status of stressed reefs
outside the Monument. In addition, research efforts will
continue to determine whether reef growth at Midway is
keeping pace with erosion and subsidence, and whether
additional measures will help to reduce adverse effects,
such as selective removal of the large populations of sea
urchins that are now eroding key shallow reefs that serve
as natural breakwaters for protecting the entire atoll.
Floating marine debris discarded or lost by distant fishing fleets in East Asia continues to accumulate regularly at
Midway. Since 1996 when cleanup efforts were initiated,
42,821 kg has been removed from Midway which ranks
fifth in total quantity removed. Evidence of increased
accumulation rates on the shores and reefs of the NWHI
may be attributed to the southward movement of the Subtropical Convergence Zone in the north central Pacific.
Controversies and gaps in current knowledge
A review of the field methods supporting the Darwin Point
hypothesis (Grigg, 1982) revealed it relied primarily on
MIDWAY ATOLL (HAWAIIAN ARCHIPELAGO)
705