Download Shattered Shells: Pacific Ecosystems in World War II

Shattered Shells:
Pacific Ecosystems in
World War II
A fairy tern near the Midway Atoll. (Kennerknecht)
12 November 2011
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An island is like a giant petri dish. Islands have limited resources. They’re fragile. They
are small and isolated, with a limited number of resources to support hundreds of species of
birds, mammals, reptiles, fish, and insects. Once damaged, islands can take years to recover—it
is possible that an island ecosystem may never recover from a disturbing invasion.
For eons, Pacific islands thrived because there was little human interaction—poachers
would occasionally come and upset population balances, but years of isolation following the
disturbance would allow populations to return to relatively normal levels with few lasting effects.
However, the human invasion of “paradise” during World War II was a particularly painful blow
to the delicate island webs—a blow that changed the nature of the islands forever. The flora and
fauna of the Pacific’s island ecosystems suffered habitat loss and drastic environmental change
both during and after U.S. troop occupation in World War II through troop establishment and
operations; the introduction of invasive species; and abandoned explosives, chemicals and
military structures.
Before delving into the damages inflicted during the war, it is crucial to understand that
the ecological damage in the Pacific went largely unrecognized in the years immediately
following the war. In the 1940s, ecological impairment was considered a normal side-effect of
war and was essentially disregarded, making analysis of ecological damage difficult. According
to Judith A. Bennett, associate professor of history at the University of Otago in New Zealand,
many island populations were illiterate or did not regularly record ecological change, so
comprehension of ecosystem conditions before and after the war is hard to gauge (201). There is
some pre-war data for bird populations on Midway Island, but it is limited (199). Literate
colonial administrations did not record alterations in the environment until several years after the
war in the Pacific ended, so the “scale of damage is elusive” (198). The Allies who occupied
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Pacific islands during the war were also hesitant to admit any ecological complications,
presumably to avoid accountability for damages (198). Even with this limited knowledge, it is
still quite apparent that the islands suffered from the disturbance of war.
Following the progression of war chronologically, the damages to island populations
began as soon as the first U.S. soldier set foot on the pure, white sand. The Midway Atoll is a
good example of what happened on most Pacific islands as troops arrived, and it is one of the
few cases where there are measurable data. On Midway, construction of barracks and other
structures began immediately—the islands were flattened for roads, airfields, storage, and
buildings. Except for a few isolated and heavily wooded areas, the surfaces of the two main
islands of the atoll were smoothed and paved, filled for underground installations, or covered by
buildings (104). Such construction went on for eighteen months, day and night, covering the
breeding season of every species on the island at least once and affecting both nocturnal and
diurnal birds (Fisher 104). Ground- and burrow-nesting birds, such as the many species of terns,
albatrosses, shearwaters, and petrels, suffered from displacement. Their traditional nesting sites
were made inaccessible or otherwise undesirable, and many birds were destroyed in their
burrows during construction, their eggs crushed by bulldozers (Fisher 104; Bennett 199). An
account from the construction period relates a common problem for U.S. soldiers:
Everywhere a man drove a cat or a bulldozer, the vast populations of birds stood
in the way…Small gray babies nestled in little hollows made for them by their
elders and refused to move out. […] Washington had sent word that goonies
[albatrosses] must not be hurt, so for a while Gallagher [an official] had to detail
an extra man to walk in front of every vehicle, awkwardly requesting the birds to
step aside, setting the young out of harm’s way one at a time. Gallagher protested
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that too much time was being lost; with Ventres’ [a higher official] permission, he
gave orders to run over the creatures. This didn’t work any better, for the dead
birds raised such a terrible smell that they had to be picked up one by one and
disposed of. (qtd. in Fisher 105)
Although unceasing construction during the U.S. occupation of Midway was quite harmful, the
mere presence of military structures was still a hazard for most bird populations. Foxholes, pits,
and gun emplacements trapped several species of local birds, whose fates were usually to starve
to death (Bennett 199). Albatrosses were found caught in fences and tangled in barbed wire.
Loss of nesting sites reduced breeding potential for ground- and shrub-nesting birds (Fisher 105).
Trying to return to their long-time nesting places, albatrosses would often gather on airfield
runways. Nearly every plane that took off or landed ran over a large flock of the displaced birds,
killing the birds as well as damaging parts of the plane.
A white tern and its chick. These burrow-nesting birds suffered from habitat loss. (Leary)
Some vehicles would travel off-road, driving through colonies of terns, shearwaters, and petrels,
destroying their nests and eggs (Fisher 106).
Then there were the men themselves—the inflated amount of people on the islands was a
source of stress for the surviving birds. Animal stress is defined as “a symptom resulting from
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exposure of an animal to a hostile environment” (Stott 1). In the case of the Midway bird
populations, such stress would have entailed upsetting individuals’ homeostasis, meaning their
bodies would not be able to function normally. Their behavior may have changed or failed to
change based on the transforming environment, compromising their chance of survival. They
were not habituated to living among humans, so their survival was at an even greater risk with
stress. The men’s actions also contributed to the disturbance of local fauna. Birds’ eggs were
often gathered to “feed bored, hungry men” (Bennett 199). Because the troops became frustrated
with the habits of the disoriented birds, grounds crews pummeled many of the birds to death,
particularly when the birds got in the way their work (199).
The whales located near many of the islands also suffered from human action. Whales,
particularly the humpbacks, had a difficult time maneuvering through mines and floats scattered
in the ocean (Bennett 202). One of the most tragic causes of whale population reduction was the
misjudgment of young submarine captains: whales were often identified as enemy subs—the
subsequent shooting and killing of the harmless creatures caused countless dead whales to float
ashore during the war years and after (202). Even more despicably, some submarine captains
would just want to test out their skills, targeting the whale even when he knew it was not an
enemy vessel (202).
The combination of construction, established structures, and human action resulting from
the U.S. occupation of Midway and other atolls during the war had multiple negative effects on
the plant and animal populations. With threatened bird populations, as in Midway, the entire
ecosystem also suffered. Habitats were destroyed or made undesirable. Tropical forests were
leveled, altering the environment of the island. The foolish actions of troops did not improve
conditions.
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If the military occupation of the islands in the South Pacifc was threatening, then the
inadvertent introductions of foreign species were even worse. According to Dr. Caut of the
University of Paris-Sud 11 in Orsay, “the invasion of ecosystems by alien species is currently
viewed as one of the most important causes of native biodiversity loss” (Caut 1). One of the
worst pests to enter the islands during the war was the black rat, Rattus rattus. According to
American zoologist Dr. Harvey Fisher, it was first introduced to the islands in 1943. Although
the U.S. military partly controlled its spread through traps and poison bait, the survivors still
wreaked havoc on the delicate island ecosystems (106). By 1945, the rat population in Midway
was estimated to be about 100 rats per acre (106). Rats would raid native birds’ nests and eat
their eggs. The rats were a menace even to the troops, so much that the men were often forced to
kill the rats for their own protection (Bennett 199). Once the troops left Midway, the limited
human control was abandoned, allowing the rat population to increase unhindered. In a paper
published in 1949, Dr. Harvey Fisher mentioned that the invading rat’s presence was a particular
threat to the Christmas Island Shearwaters and Bulwer’s petrels because their populations on
Midway were already small. He believed that if rat predation continued unchecked, these two
rare species were in danger of local extinction (107). He was correct—those two species of birds
disappeared from the atoll for many years. According to Dr. Robert Pyle’s 2009 survey
publication, small numbers of breeding pairs from both the shearwaters and the petrels, probably
having migrated from another island, have been found in recent years on Midway, but
reestablishment appears to be slow and difficult (1). The Laysan Finch and Laysan Rail were not
so lucky—the rats’ establishment completely eradicated these birds’ presences in the Midway
ecosystem, although they are still found on some other Pacific islands (1).
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Multiple species of “weeds,” or invasive plants, found their way to the islands. Seeds and
burrs attached to the clothing and equipment of the soldiers; weeds thrived where construction
and human activity disturbed the native vegetation. In Dr. Bennett’s book, she describes how
most of these “weeds” were native to the American tropics and naturalized in Hawaii before the
war began (210). Several of the Old World weeds were already present in New Guinea before
the war, but the spread of the weeds, mirroring the westward and northward flow of U.S. “island
hopping,” caused them to be even more fully spread and established throughout the Pacific
theater (210-211). 135 different invasive species found their way to the Micronesian islands and
were particularly successful on the islands most ravaged by war and soil disturbance (210).
“American rope,” or “mile-a-minute” (Mikania micrantha), was one of the more aggressive of
these weeds. It was most likely introduced by American troops as a source of fast-growing
camouflage. While this weed may have been useful for the military, it was a true nuisance to the
native flora of the Pacific islands, particularly in western Melanesia, “where poor logging
practices encourage[d] its spread” (211). It is a “perennial vine with heart-shaped leaves…it can
reproduce by seeds that cling to clothing [as well as reproducing] vegetatively” (211). American
rope is native to South American rainforests, so it found a perfect niche in the Western Pacific
islands where it had little competition. It grows about 15 inches each day and climbs over native
saplings, deforming the saplings’ growth and often killing them (211). Invasive species are an
underrated problem in any environment, but they are especially threatening on an island where
native species’ highly specific niches can be easily usurped by an exotic fiend. Much of an
ecosystem’s vitality is based on the health and composition of its flora, so threatened plants have
implications for all organisms connected to the system.
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The giant African snail (Achatina fulica) was probably the most destructive invader of
the islands because it had a direct negative impact on the island peoples as well as ecosystems.
The huge invertebrates were first introduced in Japan, brought from Africa to “supplement the
diet” (Bennett 212). This was quickly revealed to be a mistake. Being hermaphroditic, the snails
bred like lightning, producing up to 150 eggs per year during their 4 years of reproductive
maturity (211). Because the pests devastated Japanese gardens, the Japanese government led a
successful extermination program that effectively eliminated the snails from Japanese territory—
except in Okinawa (212). From there, the snails spread via Japanese and U.S. movements
through the Pacific islands, thriving in the warm tropical climate and ravaging the native
islanders’ gardens (212).
A giant African snail. (dreamstime)
The snails made quite an impact on the island ecosystems—the giant African snail can carry
three fungus-like pathogens, two of which thrive in warm, tropical regions. These pathogens
cause disease in plants, which upsets the entire ecosystem (212). In the islands, the snail
appeared to have no natural enemies. The snail populations would undergo boom-and-bust
phases in different locations, making it arduous to track and eliminate them (212). The
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nightmarish pest almost made it to the United States in 1948, which startled the U.S. government
enough that they sent entomologists to Africa to find a natural predator (212). Nevertheless, the
snail continued to spread across the Pacific. Since the 1950s, attempts to provide exotic
predators, such as the cannibal snail Euglandina rosea, have diminished its numbers somewhat,
but at the price of the extinction of native snails in Tahiti and Hawaii (213). Such inadvertent
elimination of a species can cause the most harmful problems in an ecosystem. Species can
suffer from invasion and still return to normal levels if there are survivors, but extinction is
irreversible. There is no recovery.
Efforts to control or eliminate alien species in the Pacific have been made, but their
success varies. Invasive species removal can be tricky: “successful eradication can have
unexpected and unwanted consequences for native species and ecosystems” (Caut 1). If a nonnative species is removed from an ecosystem too quickly, its absence can cause the previously
suppressed native species populations to increase drastically. This causes further damage to the
ecosystem and is referred to as the “surprise effect” (1). Dr. Caut found ways to adapt current
control programs by following the characterization of trophic relationships between the invasive
species in question and associated native species, taking a more holistic approach to alien species
control that had success in black rat control on Surprise Island, New Caledonia (1). Such
methods, however, are still being developed and perfected since each ecosystem is unique and
requires different measures for safe removal of aliens.
The United States has been involved in invasive species removal in the Pacific, mostly
concerning its own territory, Guam. Congress passed legislation dealing with quarantine
protocols on cargo leaving Guam in order to keep the slightly venomous brown tree snake,
another pest introduced to some Pacific islands in the WWII era, from reaching Hawaii
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($A146m). Other studies and efforts were and are being made to eradicate other invasive species
throughout the Pacific, but foreign species are still threatening the viability and health of the
islands.
In addition to introducing a plethora of unwelcome species that are nearly impossible to
eliminate, the U.S. military left behind weapons, chemicals, and ruins that continue to be a curse
to the islands. Munitions storage was a problem while the troops occupied the islands, but they
were even more of a nuisance after V-J Day. U.S. ships returning to the mainland did not want
dangerous munitions and chemicals as cargo, so much of this excess was dumped on the islands
and in the sea (Bennett 203). Where there were storage facilities, the military attempted to store
munitions away from living areas because of their destructive potential, but there was only so
much that could be done to prevent disaster—the nature of the climate, terrain, and vegetation in
most Pacific islands was a threat to safe storage. The warmth of the tropical sun was a hazard for
munitions manufactured in considerably cooler climates (203). Terrain made drainage poor,
often causing munitions to sink into the mud (203). Grasses during the dry months were prone to
catch fire, which often happened after an accidental explosion. Such storage facilities, while
dangerous, were also a hindrance to the ecological community in that they covered jungles and
beaches, disrupting natural territory and sometimes reshaping it. Some dynamite was simply
dumped into swamps, which was unhealthy for the swamp-dwelling organisms (203).
Chemical dumping was also unhealthy for the island ecosystems, particularly in the
oceans. On the island of Suva, engineers from New Zealand excavated soapstone and rock
during the war to install gasoline storage. They dumped the spoils into the next-door Walu Bay.
So much was excavated that some worried the resulting slick would be conspicuous to enemy
planes (Bennett 200). Where Americans excavated for similar purposes on other islands, the
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change of the coastline was even more extensive. According Dr. Bennett, it is not currently
possible to gauge the damage done, since no studies were conducted either before or after the
change in landscape: “How the changed shoreline and hillside affected the ecology is anyone’s
guess” (201).
Sunken ships are one of the more serious sources of pollution in the Pacific Ocean from
World War II. It is estimated that there are over 400 World War II-era tankers sitting at the
bottom of the Pacific Ocean (“World War II”). Oil damage is harmful to crustaceans and
mollusks, though usually on a temporary basis (Bennett 209). A native from the island of Tulagi
described some of the damage he could see wash ashore in 1942: “The shells, clams, crabs in the
sea died ashore in the course of the poison of the oil [sic]” (qtd. in Bennett 201). However,
heavy metals from corroding, sunken vessels were and still are a major threat to fisheries and the
ocean ecosystem at large. Details of the munitions on board are not readily available or known,
but it can be expected that some of these vessels leaked ammonium picrate and powdered
aluminum, both of which poison fish stocks (209). Legal liability for this is difficult to establish
because the ownership of the sunken vessels passes to the country of their final resting place, but
these ships are a responsibility too difficult for the tiny island administrations to handle (209).
Different island leaders have made pleas to the United States and other Allied countries for
assistance in removal of the sunken ships, but many of their pleas have been ignored (209).
These leftovers from the war continue to be major threats to the stability of the islands
and ocean ecosystems. Although some of the oil the ships carried escaped soon after they sank,
much of their storage is still contained within the wrecks. One notable example of a location
seriously threatened by tanker spillage is Chuuk Lagoon in Micronesia. A graveyard of various
Japanese ships sunk by a U.S. attack during World War II lies at the bottom of the lagoon. Many
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of these ships are now coral-encrusted, providing a home for over 266 species of reef fish
(“Tropical”). The three oil tankers in Chuuk Lagoon alone hold 32 million liters [8.45 million
gallons] of oil that, if allowed to escape the vessels, would devastate the local island beaches and
destroy the mangrove forests that many local fish use as breeding grounds (“Tropical”).
Unfortunately, local fishing by means of explosives and different vessels dropping anchor in the
lagoon have destabilized the wrecks, causing two of the three oil tankers to leak oil (“Tropical”).
In 2008, the Hoyo Maru was responsible for creating an oil slick three miles long (“World War
II”). There are still millions of gallons of oil in these vessels that could be released in time. Safe
removal of the oil is possible: in 2003, the United States pumped 3 million gallons of fuel from a
sunken tanker in Micronesia’s Ulithi Lagoon (“World War II”). The Micronesian government
has asked Japan for assistance in pumping out the oil in the Chuuk Lagoon wrecks, but no action
has been taken, and the wrecks are threatening to disintegrate to the point where saving the
lagoon would be impossible (Willacy). The consequences of such a release of oil are ghastly to
imagine.
World War II had a negative impact on the environment in the Pacific theater. The initial
human invasion, the exotic species introduced, and the physical and chemical remnants of war
changed the ecological balance immediately and continuously. Some recovery efforts have been
made, such as in native species reintroduction attempts, but there is much more that can and
needs to be done to improve ecological conditions—if the United States and other countries are
willing to accept responsibility for damages. The Pacific still stirs images of sunny, warm, sandy
beaches to Western culture, but the cruel reality of how little of that isolated paradise actually
remains untouched is largely dismissed. The Pacific islands are more than a vacation spot for the
rich—they are an integral part of our biosphere. If the human race can’t take care of the tiny
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suffering islands, the entire world environment is weakened. And a threatened environment is a
poor host for dependent organisms such as ourselves.
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Bennett, Judith A. Natives and Exotics World War II and Environment in the Southern Pacific.
Honolulu: University of Hawai'i Press, 2009. Print.
Caut, Stéphane, Elena Angulo, and Franck Courchamp. "Avoiding Surprise Effects on Surprise
Island: Alien Species Control in a Multitrophic Level Perspective." Biological Invasions
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Fisher, Harvey I. “Populations of Birds on Midway and the Man-Made Factors Affecting Them.”
Pacific Science 3 (1949): 103-110. Print.
Kennerknecht, Sebastian. Fairy Tern Near Midway. 2006. Flickr. 19 Nov. 2011.
Leary, Pete. White tern chick. 2011. Pete at Midway. 19 November 2011.
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Willacy, Mark. "WW2 Wrecks Threaten Micronesian Environment." AM. Australian
Broadcasting Corporation, 12 Apr. 2011. Web. 19 Nov. 2011.
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by Invasive Rats." Biological Invasions 12.9 (2010): 3351-61. EBSCO. Web. 19 Nov.
2011.
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Environmental History of Warfare. Corvallis: Oregon State University Press, 2004. Print.
"New Bill Proposed to Deal with Guam Brown Tree Snakes." CongressDaily (2004): 11.
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