114
B. Kjerfve eta!.
eluding 2,700 tons of fish, paricularly sardine and mullet; 200 tons of mussels from hard substrates, mostly Perna perna, and cockles, i.e., Anomalocardia brasiliana, from mud flats; and 100 tons of shrimp (Pennaeus
schimidtii). However, these catches are but 10% of the annual catches
recorded prior to 1970 (Almeida 1993).
8.9 Anthropogenic Impacts
Bafa de Guanabara is one of the most prominent coastal bays in Brazil. The
cities of Rio de Janeiro, Duque de Caxias, Sao Gon<;:alo, Niteroi, and many
smaller communities are located along its margins, and the greater metropolitan area of Rio de Janeiro has a population exceeding 11 million and
growing by 1.1% annually. The domestic runoff from the 8 million inhabitants who live in the bay catchment is still largely untreated. There are
more than 12,000 industries in the drainage basin. Two oil refineries along
the shore of the bay are responsible for the processing of 17% of the national oil. Bafa de Guanabara is traversed by the 6-lane 13-km-long RioNiter6i highway bridge, which was completed in 1975. At least 2,000 commercial ships dock in the port of Rio de Janeiro every year, which is second
only to the Santos in Brazil. The bay is also the home port to two navy
bases, has a shipyard, and a large number of ferries, fishing boats, and
yachts.
Dredging takes place continuously in the port to a design depth of 17m.
Due to urban development, including two commercial airports, residential
construction, and building of roads and bridges, coastal marginal lands
have been reclaimed. The bay surface area has been reduced by 10 %
during the past few decades.
In spite of the pollution control plan created by FEEMA (1979), the water
quality situation in the inner portion of Bafa de Guanabara has become
critical. Although there are six existing sewage treatment plants, only 15%
of the total amount of domestic and industrial waste discharged into the
bay was subjected to any form of sewage treatment in 1991. Six thousand
tons of garbage are generated daily in the area surrounding the bay (Silva
et al. 1990). Ferreira (1995) calculated that 18 tons of petroleum hydrocarbons enter the bay daily, 85% via urban runoff. Further, large amounts of
suspended solids, organic matter, and heavy metals are discharged into
Bafa de Guanabara and accumulate in the bottom sediments. High inputs
of nutrients have made the bay eutrophic (Rebello et al. 1988; Lavrado et al.
1991) at the same time that the fisheries yield has declined to 10 % of the
level three decades ago (FEEMA1990).
B. Kjerfve eta!.
eluding 2,700 tons of fish, paricularly sardine and mullet; 200 tons of mussels from hard substrates, mostly Perna perna, and cockles, i.e., Anomalocardia brasiliana, from mud flats; and 100 tons of shrimp (Pennaeus
schimidtii). However, these catches are but 10% of the annual catches
recorded prior to 1970 (Almeida 1993).
8.9 Anthropogenic Impacts
Bafa de Guanabara is one of the most prominent coastal bays in Brazil. The
cities of Rio de Janeiro, Duque de Caxias, Sao Gon<;:alo, Niteroi, and many
smaller communities are located along its margins, and the greater metropolitan area of Rio de Janeiro has a population exceeding 11 million and
growing by 1.1% annually. The domestic runoff from the 8 million inhabitants who live in the bay catchment is still largely untreated. There are
more than 12,000 industries in the drainage basin. Two oil refineries along
the shore of the bay are responsible for the processing of 17% of the national oil. Bafa de Guanabara is traversed by the 6-lane 13-km-long RioNiter6i highway bridge, which was completed in 1975. At least 2,000 commercial ships dock in the port of Rio de Janeiro every year, which is second
only to the Santos in Brazil. The bay is also the home port to two navy
bases, has a shipyard, and a large number of ferries, fishing boats, and
yachts.
Dredging takes place continuously in the port to a design depth of 17m.
Due to urban development, including two commercial airports, residential
construction, and building of roads and bridges, coastal marginal lands
have been reclaimed. The bay surface area has been reduced by 10 %
during the past few decades.
In spite of the pollution control plan created by FEEMA (1979), the water
quality situation in the inner portion of Bafa de Guanabara has become
critical. Although there are six existing sewage treatment plants, only 15%
of the total amount of domestic and industrial waste discharged into the
bay was subjected to any form of sewage treatment in 1991. Six thousand
tons of garbage are generated daily in the area surrounding the bay (Silva
et al. 1990). Ferreira (1995) calculated that 18 tons of petroleum hydrocarbons enter the bay daily, 85% via urban runoff. Further, large amounts of
suspended solids, organic matter, and heavy metals are discharged into
Bafa de Guanabara and accumulate in the bottom sediments. High inputs
of nutrients have made the bay eutrophic (Rebello et al. 1988; Lavrado et al.
1991) at the same time that the fisheries yield has declined to 10 % of the
level three decades ago (FEEMA1990).