Environmental Problems of Bermuda
General
Bermuda has many environmental issues
to deal with. In fact, it is a microcosm of the whole Earth. The difference
being, of course, that the resources on Earth are finite and we know of
no other source of them. However, Bermuda can, and does, import whatever
is not available. Some of the environmental issues that Bermudians have
to contend with are:
-
water issues (there is virtually no
fresh water available except rainwater)
-
efficient trapping of rainwater
-
water conservation
-
desalinization (expensive!)
-
resource conservation in general
-
solid waste disposal
-
landfills? (it is a small set of islands!
- about 21 square miles)
-
incinerators? (and pollute the air
and possibly the drinking water?!?)
-
recycling!
-
hazardous waste disposal (same problems
as solid waste)
-
sewage disposal
-
automobile issues
-
crowded roads
-
air pollution
-
overfishing
-
oil spills
-
possible extinction of native/endemic
species due to introduced species
Native versus Introduced Species
General
What happens when a species is introduced
to an ecosystem? Sometimes, not much because the new environmental conditions
are not optimal and the introduced species dies out. However, it is more
often the case that the introduced species can survive under the
new environmental conditions and thrives because it has no natural
enemies in the new area. As a result, other, native organisms can be adversely
affected by this tip in the balance of the ecosystem.
In Bermuda
I will focus on two species in particular,
the Bermuda Cedar and the Bermuda Petrel (the Cahow), which are both endemic
to Bermuda.
When settlers first came to Bermuda
it was covered with a lush forest of Bermuda Cedar. These trees served
multiple purposes in the ecosystem: providing a habitat, food, and windbreak
for other organisms. Bermuda Cedar wood was cut and used extensively at
home and was considered one of Bermuda's prized exports for many years.
This overuse did contribute to the decimation of the species. However,
the final blow came in the 1940's when a scale insect was accidentally
introduced to Bermuda that killed most of the cedars. Fast-growing Casuarina
pines were planted to take the place of the lost cedars. The problem with
that solution was that the new trees did not afford the other flora much
protection from the wind, as the cedars had. Fortunately, some of the trees
were resistant to this insect and survived (sometimes barely!). Over the
last twenty years, these resistant cedars have been used in replanting
efforts to bring the population back up to a viable size. The most amazing
part of this is that some of the "dead" cedars which were left standing
have started to come back to life. A native Bermudian told me a story of
a cedar tree that had been dead for 30 years that, over a period of ten
years, totally remade itself. It is amazing what nature is capable of doing!
The Cahow is an ocean dwelling bird
that comes to land once a year to mate. They are named for the sound that
they make. When the Spaniards first came to Bermuda, cahows were extremely
abundant. Their combined noise was so frightening that Bermuda got the
reputation of being the Isle of Devils. The British did not seem to mind
the cahows and figured out that they were very good to eat. Cahows have
a very low reproductive rate and are very picky about their nesting site.
It has to be on an island where cahows have already nested before and it
has to be a deep (or long) burrow so that the nesting can go on in complete
darkness. They compete with the White-Tailed Tropicbird (Longtail) for
nests when times are tough. Longtails are bigger than cahows and will peck
a Cahow chick to death if it is in the way. In the mid-1600s Cahows seemed
to go extinct. People though this for 300 years, until specimens started
being reported in 1900. Finally in 1951, Dr. Robert C. Murphy and Louis
S. Mowbray discovered the Cahows' breeding grounds on some tiny islands
in the Bermuda archipelago (in Castle Harbour). Why did cahows "go extinct"?
There are various reasons. Unsustainable harvesting of them by colonists
was certainly a contributing factor. Ultimately, however, their downfall
was caused by introduced species, particularly hogs, cats, and dogs. The
hogs were left here by early Spanish sailors as a source of meat on future
stops. The cats and dogs were brought by settlers as pets. The probelm
is that these mammals, especially the hogs, would dig up the Cahow eggs
from their underground nests and eat them. So, the Cahows that nested on
remote islands that had no mammals survived! Since the rediscovery of Cahows,
an intensive conservation program has been implemented and there are now
about 50 breeding pairs.
The other perfect example of havoc
wreaked by an introduced species is the Great Kiskadee. This bird is considered
a pest, not only because of its loud call of "kiskadee, kiskadee", but
also because it feeds on citrus crops. (I have to admit I was not too bothered
by them and actually thought they were kind of neat!) Ironically, the Great
Kiskadee was brought in to control the population of the Anole lizard which
had been imported to control the population of Mediterranean fruit flies
which had accidentally gotten in. Both the fruit fly and the lizard have
a predeliction for citrus as well.
Solutions
General
Bermuda has taken measures to preserve
the balance of its ecosystems, both land and sea. To find out about some
of Bermuda's Environmental
Awareness Programs visit that section of the webpage Bermuda
Online.
David Wingate and Nonsuch Island
David Wingate was a young boy when
the Cahow was rediscovered, but he was fortunate enough to be present.
He had a great interest in birds and knew from the moment he saw his first
cahow that his goal in life was to help bring this species back from the
brink of extinction. Ten years after this epiphany, Mr. Wingate was able
to begin fulfilling his dream. In 1961 he moved onto a small island called
Nonsuch (probably named after the Tudor palace in England - it means "there
is no other like it") and became the warden of this uninhabited, outer
island. Nonsuch Island had been inhabited by various groups over the years.
It was used for grazing livestock, as a quarantine station and hospital
for victims of yellow fever, and even as a school for delinquent boys.
Mr. Wingate set out to recreate the pre-colonial, natural ecosystem of
Bermuda on Nonsuch, because he knew that this was the only way to truly
save the Cahow. Now, more than thirty years later, Nonsuch Island is a
"Living Museum" that represents every natural habitat of the Bermuda archipelago.
In terms of the Cahow, the work is never done. Some of the measures taken
to bring back these beloved birds have been to build gates so that Longtails
can not get into Cahow nests, to build "government housing" (man-made burrows)
for Cahows, and even blasting recorded Cahow calls on a boombox to attract
the timid birds to the island. Our group had the privilege of taking a
guided tour of Nonsuch Island with Mr. Wingate himself. He is a fascinating
man who is totally dedicated to his cause and truly understands how important
balance is to ecosystems. Here are some pictures from our trip:
1)
2)
1)Approaching Nonsuch Island 2) The dock at Nonsuch
(a sunken ship serves as a wave breaker)
3)
4)
3)David Wingate 4)Mr. Wingate standing at one end
of man-made Cahow nest and holding a gate to keep out Longtails
5)
6)
5) Mr. Wingate and group standing at the other end
of the Cahow burrow 6) Trash that has washed up onto the beach of Nonsuch
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