Mussimila braziliensis, a coral species found only in Brazil, produces unique mushroom-like
formations known as chaperiões.
The Dusky damselfish (Stegastes fuscus) is one of the many species found only in
Brazilian waters.
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Setting sail
For three weeks this past February, Brazilian
marine scientists and international conservation experts teamed up to survey the
Abrolhos Bank as part of the Rapid Assessment Program (RAP) set up by Conservation
International, an NGO based in Washington. RAP has launched a total of 29 expeditions—exploring
land, freshwater and marine environments—which have resulted in the discovery of
hundreds of new species, improved biodiversity management by identifying priorities
at the local and global levels, and led to the creation of six protected areas in
five countries.
In contrast to the world’s two great areas of coral reefs—in the Indo-Pacific and
the Caribbean Sea—Brazil’s coral reefs are not very rich in biodiversity, but they
do harbour a large number of endemic species. The main focus of the Abrolhos survey
was less on finding new species and more on helping local managers understand how
different parts of the bank compare in terms of biodiversity and environmental threat.
Many of the sites we selected for our survey had never before been scientifically
inventoried.
The Abrolhos Bank is the single largest area of coral reefs in the southern Atlantic,
covering about 8,000 km2 off the southeastern corner of the Brazilian state
of Bahia. As far as we know, there is no other place on earth where you can see a
kind of coral reef pinnacle known as a chapeirão, which look like giant mutant
mushrooms, overgrown with fans of fire coral and round knobs of endemic brain coral.
Months of preparation went into the expedition. Weather was a major concern because
most of the bank consists of loose sediments which are easily stirred up by wave
action and create underwater “dust” storms. Fortunately, we ended up with 18 days
blessed by sunshine and light winds.
In the coming months, our science team will be analyzing the results to help us formulate
a list of recommendations and priorities for conserving the marine biodiversity of
the Abrolhos Bank.
www.conservation.org
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Dive into the turbid
waters of Brazil’s Abrolhos Bank to explore the mysteries of its marine biodiversity
with a team of leading scientists
Day
1: Nova Viçosa
Aboard two fishing boats, we’re chugging through the muddy waters of the Caravelas
River to the first survey site at Nova Viçosa reef. Once out of the river’s
mouth, the blue water teems with coral reef animals that only live in this part of
the world. On our first dive, I descend past a mat of anemone-like creatures commonly
called “baba-de-boi”, or bull’s slobber. Brush up against this animal’s mucus lining,
and you instantly understand how it got its name. Below this mat, I am surrounded
by a number of ancient and endemic corals that make this area such a priority for
global conservation.
Over the next three weeks our team of leading marine scientists will log about three
dives a day to document the bank’s marine biodiversity.
Days
2-3: Popa Verde
Our Brazilian
fish specialist, Rodrigo Moura, spies a lemon shark and what will be one of only
two shark sightings for the whole survey. For the shark-wary this is good news, but
to a marine conservationist it is worrisome. Sharks are important top predators in
the ocean. Remove them and you can disturb the ecological balance. Around the world,
they are increasingly rare from heavy demand particularly for their fins, meat and
liver oil. Fortunately, on this same dive I see a huge grouper—longer than I am—which
is a good sign. Large fish still thrive in the waters of Abrolhos.
Day
4: In the wake of Cabral
Exactly 500
years ago, the Portuguese mariner Alvares Cabral reported seeing lush tropical forest
from the same spot where we are anchored. Our view is very different. Logging has
destroyed all but about 8 per cent of this unique forest, prompting Conservation
International to classify it as one of the world’s top “hotspots” or priority areas
for conservation (see
p. 21).
Deforestation also takes its toll on the ecology of coastal waters. Erosion unleashes
a steady stream of sediments that can “choke” or even bury corals. Most of the corals
found on the Abrolhos Bank appear adapted to the turbid conditions that would kill
species in other parts of the world. We find one of the endemic coral, Scolymia wellsii,
in a pit five centimetres below the muddy sea floor!
Day
5: Corumbau
We are anchored
directly across from the fishing village of Corumbau where local elders claim they
once burned coral to produce house paint. Elsewhere along the Brazilian coast, there
are houses built of coral boulders. These practices have been abandoned but corals
and other living marine animals are still harvested illegally for sale in the curio
trade. One of the most coveted is the Brazilian snail, Strombus goliath, which can
reach lengths of 35 cm. During our entire survey we will see only one individual.
Day
8: Paredes
Today’s destination
is Brazil’s largest coral reef, Paredes. At first, the reef looks barren but in crevices
we find several interesting fishes and corals we haven’t yet seen during the survey.
At the bottom of a steep wall I see one of the world’s strangest looking marine fishes:
a batfish. Dull green and shaped like a swollen arrow, the batfish not only swims
but crawls along the sand like a reptile, using its fins as feet.
Day
13: California Reef
After hours
of searching, our boat’s depth finder picks up California reef—between 20 and 35
metres down. But it turns out to be well worth the search. Wrapped in a luxurious
growth of gorgonian corals, the reef’s pinnacles produce new records of corals and
fishes for the survey. What a surprise to find several colonies of the coral species
Porites branneri with bright red tentacles—a sharp contrast from its usual drab brown-and-white
colour.
Returning to our anchorage at Santa Barbara Island, we see boats fishing illegally
well inside the boundary of the Abrolhos National Marine Park. The morning before
we radioed in the name and identification number of one of these boats to the park
guard. That afternoon, we heard a naval officer speaking by radio with the alleged
offender, telling him that he shouldn’t get overly concerned as it was only a “tourist”
who provided the information.
In the evening, we decide to check out the local nightlife. Much like a submerged
city, a coral reef has towering structures of stone crawling with denizens, some
of whom spring to life only when the sun sets.
Thousands of polychaete worms wriggle around our underwater lights in a reproductive
frenzy known as swarming. On certain nights of the year, linked to the lunar cycle,
polychaete worms release masses of sperm and eggs. If I keep my light on too long
at a certain spot, I began to feel these worms scurrying inside my ear and brushing
my face. We have just observed the first known spawning event to take place in Brazil
in February.
Day
17: A look at the edge
We are as close
as we will get to the edge of the continental shelf. This is an ideal location for
observing “cleaning stations”. At certain rocky outcrops, small fish await the arrival
of the larger fish, much like a pit crew in a motorcar race. The large fish swim
up and stop while the smaller fish begin picking off their parasites.
Day
18: Wrapping up
The whole team
meets on deck to discuss our preliminary findings. It looks very likely that our
field collections will reveal many new species, possibly including 20 polychaete
worms and many records for this area, such as 20 new plant species and five new fishes.
We have also discovered that a species of reef coral once thought rare in Brazil,
Stephanocoenia michelenii, is actually common.
To our dismay, fish populations seem to be fewer in number than expected and many
of the individual fish tend to be small. The closer we come to fishing communities,
the worse the situation appears to be.
Several months of analysis remain before we release our final conclusions. The next
step will be to put this information in the hands of conservation managers. Beyond
the mud-choked waters of the Caravelas River lie essential areas of biodiversity.
We cannot afford to lose them simply because we couldn’t evaluate their extraordinary
wealth.
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Nature makes nothing in vain.
Aristotle,
Greek philosopher
(384-322 B.C.)
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