South Brazil Bight IMMA

Size in Square Kilometres

118 006 km2

Qualifying Species and Criteria

Bryde´s whale – Balaenoptera edeni

Criterion C (2)

Atlantic spotted dolphin – Stenella frontalis

Criterion C (2)

Sei Whale – Balaenoptera borealis

Criterion A; B (2)

Humpback whale – Megaptera novaeangliae

Criterion C (1)

Sperm whale – Physeter macrocephalus

Criterion A

Blue whale – Balaenoptera musculus

Criterion A

Fin whale – Balaenoptera physalus

Criterion A

Marine Mammal Diversity 

Criterion D (2)

Balaenoptera edeni, Stenella frontalis, Tursiops truncatus, Delphinus delphis, Orcinus orca, Balaenoptera borealis, Megaptera novaeangliae, Physeter macrocephalus, Balaenoptera musculus, Balaenoptera physalus, Balaenoptera bonaerensis, Balaenoptera acutorostrata, Eubalaena australis, Stenella longirostris, Stenella attenuata, Steno bredanensis, Stenella clymene, Sotalia guianensis, Feresa attenuata, Peponocephala electra, Pseudorca crassidens, Globicephala macrorhynchus, Grampus griseus, Kogia sima, Ziphius cavirostris

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The South Brazil Bight (23–28.5°S) is the most productive portion of Brazil’s continental Shelf. The IMMA extends to the 2,000m contour line and is characterised by the confluence between recurrent upwelling of nutrient-rich South Atlantic Central Waters and temperate and tropical waters. The IMMA encompasses marine habitats on both the continental shelf and slope, both of which are of particular importance for species such as the Bryde’s whale (Balaenoptera edeni), the only resident baleen whale of Brazil, the Atlantic spotted dolphin (Stenella frontalis), the humpback whale (Megaptera novaeangliae) and the sei whale (Balaenoptera borealis). The IMMA hosts a minimum of 25 cetacean species, comprising at least 60% of all marine cetacean species in Brazil. The IMMA also encompasses areas of regular occurrence of four species that are threatened on the IUCN Red List: the sperm whale (Physeter macrocephalus), the blue whale (Balaenoptera musculus), the fin whale (Balaenoptera physalus) and the sei whale.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

Four species that occur regularly in the South Brazil Bight (SBB) and contiguous continental slope are classified as having some degree of extinction risk globally (IUCN Red List) and/or nationally (Ministry of Environment of Brazil): the sperm whale (Physeter macrocephalus) is assessed as “Vulnerable” on the IUCN Red List of Threatened Species (Taylor et al., 2019) and nationally (MMA, 2022); the blue whale (Balaenoptera musculus) listed as “Endangered” on the IUCN Red List (Cooke, 2018a) and “Critically Endangered” nationally (MMA, 2022); the fin whale (Balaenoptera physalus) listed as “Vulnerable” by the IUCN (Cooke, 2018b) and “Endangered” nationally (MMA, 2022); and the sei whale (Balaenoptera borealis) listed as “Endangered” by the IUCN (Cooke, 2018c) and nationally (MMA, 2022).

Criterion B: Distribution and Abundance

Sub-criterion B2: Aggregations

Sei whales were observed in the Santos Basin relatively often in winter months from 2015 to 2021 (n = 80 groups) during a systematic monitoring program (Petrobras, 2021). They occurred mainly along the continental slope, but were concentrated in the northern portion of the IMMA and around a submarine canyon, with group size varying from 1 to 32 whales. Groups with more than 10 whales were observed on 9 occasions (11.3% of the groups). The aggregations in this subtropical region are most likely for breeding purposes, since a recent migration event was recorded between this IMMA, which has characteristics of a tropical/subtropical breeding ground, and the Falkland Islands (Malvinas), a known Sei Whale feeding ground (Weir et al., 2020).

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

Humpback whales (Megaptera novaeangliae) observed in the IMMA are engaged in typical reproduction-related behaviour, including the formation of competitive groups and male singing (Reiter, 2021; Morete et al., 2022). Six percent (n = 34) of all humpback whale observations (n = 566 groups) recorded during winter boat-based surveys in the region were groups with calves (Petrobras, 2021).

Sub-criterion C2: Feeding Areas

There is strong evidence that the oceanographic processes occurring in the Southern Brazil Bight IMMA, especially those associated with the Cabo Frio and shelf-break upwellings, are responsible for high productivity in the region, which sustains large stocks of fish consumed by Bryde’s whales (Balaenoptera edeni), and possibly other species as well (see also Brandini et al., 2018).

The Bryde’s whale (Balaenoptera edeni) is the only baleen whale that remains all year long in the waters of Brazil (Zerbini et al., 1997; Milmann et al., 2020). Records are common in the South Brazil Bight, especially near Cabo Frio, State of Rio de Janeiro, and Ilhabela, State of São Paulo (Siciliano et al., 2004; Gonçalves et al., 2016). Photo-identification studies reveal numerous resightings of identified individuals in Cabo Frio region and along the coastal areas of the SBB, with individuals showing some degree of site fidelity (Figueiredo et al., 2014). Surface feeding events on Brazilian sardines (Sardinella braziliensis) were often observed in the area (Siciliano et al., 2004; Mello-Neto et al., 2017). This species of sardine is a major fishing resource in South Brazil Bight and its life cycle is connected to oceanographic processes of SBB, such as the Cabo Frio upwelling (Bakun & Parrish, 1990). Moreover, higher encounter rates of Bryde’s whales and other non-migratory cetaceans of the Cabo Frio region were associated with peaks of Chlorophyll a concentration on the shelf and low SSTs (Tardin et al., 2019), conditions that are typical of upwelling environments.  Globally the taxonomy and systematics of the Bryde’s whale species complex is unclear, and until multiple issues are clarified the Society for Marine Mammalogy’s Committee on Taxonomy provisionally classifies all Bryde’s whales globally as B. edeni (see Committee on Taxonomy 2023 for details). Bryde’s whales off South America have been commonly classified in the past as B. edeni, but a genetics study published in 2015 suggests that only individuals of B. brydei occur on the South American coast, including in this IMMA (Pastene et al., 2015, Milmann, et al. 2020).

Atlantic spotted dolphin (Stenella frontalis) sightings are common in the SBB, occurring in waters ranging from 20 to almost 1,000 m of depth (Moreno et al., 2005). Niche modelling analyses show that the SBB is a core region for the distribution of an isolated southern population of these dolphins (Amaral et al., 2015). The species feeds on a variety of fishes, cephalopods and crustaceans in the SBB IMMA (Melo et al., 2010; Lopes et al., 2012). Their prey includes pelagic and demersal organisms from inshore and offshore habitats. Among the most common items of the diet are regionally abundant fishes, such as Porichtys porosissimus, and squid such as Loligo plei. This squid is dominant on the continental shelf of the SBB and may be regarded a keystone species in this marine ecosystem (Gasalla et al., 2010). Stable isotope analyses show that Atlantic spotted dolphins feed on prey associated with the SACW (Bisi et al., 2013).

Globally the taxonomy and systematics of the Bryde’s whale species complex is unclear, and until multiple issues are clarified, the Society for Marine Mammalogy’s Committee on Taxonomy provisionally classifies all Bryde’s whales globally as B. edeni (see Committee on Taxonomy 2023 for details). Bryde’s whales off South America have been commonly classified in the past as B. edeni, but a genetics study published in 2015 suggests that only individuals of B. brydei occur on the South American coast, including in this IMMA (Pastene et al., 2015; Milmann et al., 2020).

Criterion D: Special Attributes

Sub-criterion D2: Diversity

The SBB is a highly dynamic environment in which the convergence of subtropical and temperate water masses and two submarine canyons combine to enhance regional productivity and promote high cetacean diversity (Di Tullio et al., 2016). Recent systematic survey effort in the Santos Basin encompassing intensive sampling effort from both coastal and oceanic waters over six years has significantly improved the level of knowledge about cetacean ecology in this region, (see Dalpaz et al., 2021; Petrobras, 2021). The surveys resulted in the documentation of 25 species within the IMMA’s boundaries. The diversity might be even higher if strandings and other species that probably occur in the region are taken into account. It is noteworthy that the slope of the SBB has two submarine canyons with known occurrence and concentration of diverse species of cetaceans (Petrobras, 2021). The recently documented cetacean diversity in the IMMA represents  approximately 60% of all the species that have ever been documented in Brazilian waters.

Supporting Information

Amaral, K.B., Alvares, D.J., Heinzelmann, L., Borges-Martins, M., Siciliano, S. and Moreno, I.B. 2015. ‘Ecological niche modeling of Stenella dolphins (Cetartiodactyla: Delphinidae) in the southwestern Atlantic Ocean’. Journal of Experimental Marine Biology and Ecology, 472:166-179.

Bakun, A. and Parrish, R.H. 1990. ‘Comparative studies of coastal pelagic fish reproductive habitats: the Brazilian sardine (Sardinella aurita)’. ICES Journal of Marine Science, 46(3):269-283.

Bisi, T.L., Dorneles, P.R., Lailson-Brito, J., Lepoint, G., Azevedo, A.F., et al. 2013. ‘Trophic Relationships and Habitat Preferences of Delphinids from the Southeastern Brazilian Coast Determined by Carbon and Nitrogen Stable Isotope Composition’. PLoS ONE 8(12):e82205.

Brandini, F.P., Tura, P.M. and Santos, P.P.G.M. 2018. ‘Ecosystem responses to biogeochemical fronts in the South Brazil Bight’. Progress in Oceanography, 164: 52-62.

Committee on Taxonomy. 2023. List of marine mammal species and subspecies. Society for Marine Mammalogy,, consulted on 4th March 2024.

Committee on Taxonomy. 2023. List of marine mammal species and subspecies. Society for Marine Mammalogy,, consulted on 4th March 2024.

Cooke, J.G. 2018a. Balaenoptera musculus (errata version published in 2019). The IUCN Red List of Threatened Species 2018: e.T2477A156923585. Accessed on 19 April 2023.

Cooke, J.G. 2018b. Balaenoptera physalus. The IUCN Red List of Threatened Species 2018: e.T2478A50349982. Accessed on 19 April 2023.

Cooke, J.G. 2018c. Balaenoptera borealis. The IUCN Red List of Threatened Species 2018: e.T2475A130482064. Accessed on 19 April 2023.

Dalpaz, L., Paro, A.D., Daura-Jorge, F.G., Rossi-Santos, M.R., Norris, T.F., Ingram, S.N. and Wedekin, L.L. 2021. ‘Better together: analysis of integrated acoustic and visual methods when surveying a cetacean community’. Marine Ecology Progress Series, 678:197–209.

Di Tullio, J.C., Gandra, T.B.R., Zerbini, A.N. and Secchi, E.R. 2016. ‘Diversity and distribution patterns of cetaceans in the Subtropical Southwestern Atlantic outer continental shelf and slope’. PLoS One, 11(5): e0155841.

Figueiredo, L.D., Tardin, R.H., Lodi, L., De Sá Maciel, I., Dos Santos Alves, M.A. and Simão, S.M. 2014. ‘Photo-id catalog points to some degree of Bryde’s whales (Balaenoptera edeni) site fidelity to Cabo Frio region, southeastern Brazil’. Brazilian Journal of Aquatic Science and Technology, 18(2): 59-64.

Gasalla, M.A., Rodrigues, A.R. and Postuma, F.A. 2010. ‘The trophic role of the squid Loligo plei as a keystone species in the South Brazil Bight ecosystem’. ICES Journal of Marine Science, 67:1413–1424.

Gonçalves, L.R., Augustowski, M. and Andriolo, A. 2016. ‘Occurrence, distribution and behaviour of Bryde’s whales (Cetacea: Mysticeti) off south-east Brazil’. Journal of the Marine Biological Association of the United Kingdom, 96(4):943-954.

Lodi, L. and Tardin, R. 2018. ‘Site fidelity and residency of common bottlenose dolphins (Cetartiodactyla: Delphinidae) in a coastal insular habitat off southeastern Brazil’. Pan American Journal of Aquatic Sciences, 13(1):53-63.

Lopes, X., Santos, M.C.O., da Silva, E., Bassoi, M. and Santos, R.A. 2012. Feeding habits of the Atlantic spotted dolphin, Stenella frontalis, in southeastern Brazil. Brazilian Journal of Oceanography, 60(2):189-198.

Maricato, G., Tardin, R., Lodi, L., Wedekin, L. Daura-Jorge, F.G., Maciel, I., Maria, T.F. and Alves, M.A.S. In press. ‘Identifying suitable areas for common bottlenose dolphins in anthropized waters’. Marine Biology.

Marta-Almeida, M., Dalbosco, A., Franco, D. and Ruiz-Villareal, M. 2021. ‘Dynamics of river plumes in the South Brazilian Bight and South Brazil’. Ocean Dynamics, 71:59-80.

Melo, C.L.C., Santos, R.A., Bassoi, M., Araújo, A.C., Lailson-Brito J., et al. 2010. ‘Feeding habits of delphinids (Mammalia: Cetacea) from Rio de Janeiro State, Brazil. Journal of the Marine Biological Association of the U.K., 90:1509–1515.

Mello-Neto, T., Maciel, I.S., Tardin, R.H. and Simão, S. 2017. ‘Twisting movements during feeding behavior by a Bryde’s whale (Balaenoptera edeni) off the Coast of Southeastern Brazil’. Aquatic Mammals, 43(5):501-506.

Milmann, L., Siciliano, S., Morais, I., Tribulato, A.S., Machado, R., Zerbini, A. and Ott, P.H. 2020. A review of Balaenoptera strandings along the east coast of South America. Regional Studies in Marine Science, 37:e101343.

Morete, M.E., Marques, M.L., de Souza, R.C.F., Tristão, I.A., Motta, M.C., Martins, C.C.A., Cardoso, J. and Francisco. A. 2022. Is the reproductive area of the humpback whale (Megaptera novaeangliae) in Brazilian waters increasing? Evidence of breeding and calving activities around Ilhabela, São Paulo, Brazil. Latin American Journal of Aquatic Mammals, 17(1):63-67.

MMA. 2022. Portaria MMA N°148, de 7 de junho de 2022. Anexo 2. Ministério do Meio Ambiente (MMA) [Ministry of Environment of Brazil], Brasília, Brasil. Available at: Acessed on 18 april 2023.

MPA. 2011. Boletim estatístico da pesca e aquicultura. Ministério de Pesca e Aquicultura, Brasília

Pastene, L.A., Acevedo, J., Siciliano, S., Sholl, T.G.C., de Moura, J.F., Ott, P.H., and Aguayo-Lobo, A. 2015. Population genetic structure of the South American Bryde’s whale. Revista de Biologia Marina y Oceanografia. 50, no. 3:453-464.

Pastene, Luis A., Jorge Acevedo, Salvatore Siciliano, Thais GC Sholl, Jailson F. de Moura, Paulo Henrique Ott, and Anelio Aguayo-Lobo. “Population genetic structure of the South American Bryde’s whale.” Revista de biología marina y oceanografía 50, no. 3 (2015): 453-464.

PETROBRAS. 2021. Relatório Consolidado 1 – Ano 6. Projeto de Monitoramento de Cetáceos na Bacia de Santos (PMC-BS). Relatório técnico elaborado pela SOCIOAMBIENTAL Consultores Associados para a PETROBRAS. Florianópolis-SC. Available at: (Accessed: 8 December 2022)

Siciliano, S., Santos, M.C.O., Vicente, A.F., Alvarenga, F.S., Zampirolli, É., Brito, J.L., Azevedo, A.F. and Pizzorno, J.L.A. 2004. ‘Strandings and feeding records of Bryde’s whales (Balaenoptera edeni) in south-eastern Brazil’. Journal of the Marine Biological Association of the United Kingdom, 84(4):857-859.

Tardin, R.H., Chun, Y., Jenkins, C.N., Maciel, I.S., Simão, S.M. and Alves, M.A.S. 2019. ‘Environment and anthropogenic activities influence cetacean habitat use in southeastern Brazil’. Marine Ecology Progress Series, 616:197-210.

Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. and Pitman, R.L. 2019. Physeter macrocephalus (amended version of 2008 assessment). The IUCN Red List of Threatened Species 2019: e.T41755A160983555. Accessed on 30 January 2023.

Weir, C.R., Oms, G., Baracho-Neto, C.G., Wedekin, L.L. and Daura-Jorge, F.G. 2020. Migratory movement of a sei whale (Balaenoptera borealis) between Brazil and the Falkland Islands (Malvinas). Marine Mammal Science, 36(3):1050-1057.

Zerbini, A.N., Secchi, E.R., Siciliano, S. and Simões-Lopes, P.C. 1997. ‘A review of the occurrence and distribution of whales of the genus Balaenoptera along the Brazilian coast’. Report of the International Whaling Commission, 47:407-417.


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