94
Z.M.A.N. Leao and R.K.P. Kikuchi
ments (Leao and Ginsburg 1997). Furthermore, anomalous high sea surface temperatures affected 51-88 o/o of Mussismilia colonies in the Abrolhos
area during the summer of 1994. During the 1997 El Nino-Southern Oscillation (ENSO) event, maximum mid-March surface temperatures in 1998
were about 1 oc higher than normal (28.5 °C) in areas around the Abrolhos
reefs (13-18° S) and up to 80 o/o of Porites branneri, Mussismilia hispida,
M. harttii, Porites asteroides and Agaricia agaricites colonies were affected
(bleached or partially bleached).
The rapid deforestation of the Atlantic coastal rain forest has significantly increased runoff, and untreated sewage discharge from expanding
urban centers (i.e., Prado, Caravelas, Nova Vi~osa) has led to abnormally
high nutrients and algal growth at the expense of corals (Leao 1994, 1996).
Accompanying the expanding marine tourism industry in Brazil, the number of visitors of Abrolhos National Marine Park has increased over 400 o/o
between 1988 and 1992 (Leao et al. 1994). Since activities of tourists lack
orientation and control, boat anchors, non-biodegradable garbage disposal, removal of reef organisms, diving and fishing may seriously damage
the reef ecosystem. Reef walking on the exposed surface of fringing reefs in
protected areas of the Abrolhos Archipelago has been considered a major
cause of reef damage. The exploitation of coral by both artisanal and commercial fisheries as building material has existed since the 17th century
and the extraction of Millepora alcicornis for aquarium decoration may be
a major cause for the disappearance of this species (Pitombo et al. 1988).
Industrial projects are a constant threat to Abrolhos coral reefs if industrial
wastes are not properly disposed of and signals of heavy metal contamination in the southern part of Abrolhos might be due to chemical effluents
of a paper plant (Amado-Filho et al. 1997). Finally, offshore drilling in
southern Bahia State represents a threat to the reef ecosystem of Abrolhos
National Marine Park, owing to boat collision with the reefs, higher water
turbidity, or unpredictable oil spills.
Although our knowledge on the present conditions of Abrolhos reefs is
still scarce and some areas are virtually unknown, only reefs in coastal
areas with little urban development or relatively inaccessible offshore reefs
can be considered well preserved or pristine. Environmental institutions
concerned with the preservation of the coral reefs in Brazil have only
recently been founded, the Abrolhos National Marine Park, comprising
the Abrolhos Archipelago and the Outer Arc of chapeiroes and the Timbebas reef of the Coastal Arc, being one of the oldest (Fig. 6.1A). Management plans and conservation programs for the Abrolhos National Marine
Park have already been put into action (IBAMA/FUNATURA 1991). However, the park only represents one-fourth of the total Abrolhos reef area
and no restriction for recreational or even commercial use of reefs exists
Z.M.A.N. Leao and R.K.P. Kikuchi
ments (Leao and Ginsburg 1997). Furthermore, anomalous high sea surface temperatures affected 51-88 o/o of Mussismilia colonies in the Abrolhos
area during the summer of 1994. During the 1997 El Nino-Southern Oscillation (ENSO) event, maximum mid-March surface temperatures in 1998
were about 1 oc higher than normal (28.5 °C) in areas around the Abrolhos
reefs (13-18° S) and up to 80 o/o of Porites branneri, Mussismilia hispida,
M. harttii, Porites asteroides and Agaricia agaricites colonies were affected
(bleached or partially bleached).
The rapid deforestation of the Atlantic coastal rain forest has significantly increased runoff, and untreated sewage discharge from expanding
urban centers (i.e., Prado, Caravelas, Nova Vi~osa) has led to abnormally
high nutrients and algal growth at the expense of corals (Leao 1994, 1996).
Accompanying the expanding marine tourism industry in Brazil, the number of visitors of Abrolhos National Marine Park has increased over 400 o/o
between 1988 and 1992 (Leao et al. 1994). Since activities of tourists lack
orientation and control, boat anchors, non-biodegradable garbage disposal, removal of reef organisms, diving and fishing may seriously damage
the reef ecosystem. Reef walking on the exposed surface of fringing reefs in
protected areas of the Abrolhos Archipelago has been considered a major
cause of reef damage. The exploitation of coral by both artisanal and commercial fisheries as building material has existed since the 17th century
and the extraction of Millepora alcicornis for aquarium decoration may be
a major cause for the disappearance of this species (Pitombo et al. 1988).
Industrial projects are a constant threat to Abrolhos coral reefs if industrial
wastes are not properly disposed of and signals of heavy metal contamination in the southern part of Abrolhos might be due to chemical effluents
of a paper plant (Amado-Filho et al. 1997). Finally, offshore drilling in
southern Bahia State represents a threat to the reef ecosystem of Abrolhos
National Marine Park, owing to boat collision with the reefs, higher water
turbidity, or unpredictable oil spills.
Although our knowledge on the present conditions of Abrolhos reefs is
still scarce and some areas are virtually unknown, only reefs in coastal
areas with little urban development or relatively inaccessible offshore reefs
can be considered well preserved or pristine. Environmental institutions
concerned with the preservation of the coral reefs in Brazil have only
recently been founded, the Abrolhos National Marine Park, comprising
the Abrolhos Archipelago and the Outer Arc of chapeiroes and the Timbebas reef of the Coastal Arc, being one of the oldest (Fig. 6.1A). Management plans and conservation programs for the Abrolhos National Marine
Park have already been put into action (IBAMA/FUNATURA 1991). However, the park only represents one-fourth of the total Abrolhos reef area
and no restriction for recreational or even commercial use of reefs exists