RESUMO
The Port of Salvador (12°58'S, 38°30'W) receives cargo ships from different regions such as southeast Asia, North Atlantic, Mediterranean, Africa, North and South America. Thus, the presence of this port enhances the probability of new species arriving and establishing in Todos os Santos Bay (TSB), in which the port is located. Ascidians are sessile filter-feeding invertebrates with short lived larvae and thus are good indicators of bioinvasion. We surveyed the ascidian fauna on three different occasions: August 1999, June 2004 and December 2007. Nineteen species were identified belonging to the following families: Ascidiidae (Phallusia nigra, Ascidia cf. multitentaculata, A. nordestina, A. papillata, A. scalariforme, A. cf. tapuni, A. tenue), Corellidae (Rhodosoma turcicum), Pyuridae (Microcosmus anchylodeirus, M. exasperatus, M. helleri, Pyura vittata, Herdmania pallida), and Styelidae (Polycarpa cf. reviviscens, P. spongiabilis, P. tumida, Polycarpa sp., Styela canopus, Cnemidocarpa irene). Only A. nordestina, A. papillata, A. scalariforme and P. spongiabilis are possibly native to this region, while P. tumida and C. irene were classified as introduced. Microcosmus anchylodeirus, H. pallida, P. vittata, M. exasperatus, M. helleri, S. canopus, A. cf. multitentaculata, A. tenue and P. nigra were classified as cryptogenic. Most are widely distributed in all oceans and their native geographic distribution is unknown, while A. cf. multitentaculata and A. tenue occur only in the Atlantic, with disjunct distributions. Polycarpa cf. reviviscens, P. tumida and M. anchylodeirus are registered for the first time on the coast of Brazil. Colonial ascidians from this collection are still being studied. The large number of cryptogenic and introduced species indicates the necessity of monitoring TSB for expansion of these populations and the need for the establishment of control programs.
RESUMO
The Port of Salvador (12°58'S, 38°30'W) receives cargo ships from different regions such as southeast Asia, North Atlantic, Mediterranean, Africa, North and South America. Thus, the presence of this port enhances the probability of new species arriving and establishing in Todos os Santos Bay (TSB), in which the port is located. Ascidians are sessile filter-feeding invertebrates with short lived larvae and thus are good indicators of bioinvasion. We surveyed the ascidian fauna on three different occasions: August 1999, June 2004 and December 2007. Nineteen species were identified belonging to the following families: Ascidiidae (Phallusia nigra, Ascidia cf. multitentaculata, A. nordestina, A. papillata, A. scalariforme, A. cf. tapuni, A. tenue), Corellidae (Rhodosoma turcicum), Pyuridae (Microcosmus anchylodeirus, M. exasperatus, M. helleri, Pyura vittata, Herdmania pallida), and Styelidae (Polycarpa cf. reviviscens, P. spongiabilis, P. tumida, Polycarpa sp., Styela canopus, Cnemidocarpa irene). Only A. nordestina, A. papillata, A. scalariforme and P. spongiabilis are possibly native to this region, while P. tumida and C. irene were classified as introduced. Microcosmus anchylodeirus, H. pallida, P. vittata, M. exasperatus, M. helleri, S. canopus, A. cf. multitentaculata, A. tenue and P. nigra were classified as cryptogenic. Most are widely distributed in all oceans and their native geographic distribution is unknown, while A. cf. multitentaculata and A. tenue occur only in the Atlantic, with disjunct distributions. Polycarpa cf. reviviscens, P. tumida and M. anchylodeirus are registered for the first time on the coast of Brazil. Colonial ascidians from this collection are still being studied. The large number of cryptogenic and introduced species indicates the necessity of monitoring TSB for expansion of these populations and the need for the establishment of control programs.
RESUMO
The Port of Salvador (12°58'S, 38°30'W) receives cargo ships from different regions such as southeast Asia, North Atlantic, Mediterranean, Africa, North and South America. Thus, the presence of this port enhances the probability of new species arriving and establishing in Todos os Santos Bay (TSB), in which the port is located. Ascidians are sessile filter-feeding invertebrates with short lived larvae and thus are good indicators of bioinvasion. We surveyed the ascidian fauna on three different occasions: August 1999, June 2004 and December 2007. Nineteen species were identified belonging to the following families: Ascidiidae (Phallusia nigra, Ascidia cf. multitentaculata, A. nordestina, A. papillata, A. scalariforme, A. cf. tapuni, A. tenue), Corellidae (Rhodosoma turcicum), Pyuridae (Microcosmus anchylodeirus, M. exasperatus, M. helleri, Pyura vittata, Herdmania pallida), and Styelidae (Polycarpa cf. reviviscens, P. spongiabilis, P. tumida, Polycarpa sp., Styela canopus, Cnemidocarpa irene). Only A. nordestina, A. papillata, A. scalariforme and P. spongiabilis are possibly native to this region, while P. tumida and C. irene were classified as introduced. Microcosmus anchylodeirus, H. pallida, P. vittata, M. exasperatus, M. helleri, S. canopus, A. cf. multitentaculata, A. tenue and P. nigra were classified as cryptogenic. Most are widely distributed in all oceans and their native geographic distribution is unknown, while A. cf. multitentaculata and A. tenue occur only in the Atlantic, with disjunct distributions. Polycarpa cf. reviviscens, P. tumida and M. anchylodeirus are registered for the first time on the coast of Brazil. Colonial ascidians from this collection are still being studied. The large number of cryptogenic and introduced species indicates the necessity of monitoring TSB for expansion of these populations and the need for the establishment of control programs.
RESUMO
Despite limited natural dispersal, some species of ascidians can be transported vast distances via oceanic petroleum platforms, ship hulls and ballast water and therefore may be good indicators of bioinvasion. Usually non indigenous species (NIS) are abundant in harbors. This is caused in part because of the higher propagule delivery rate in these areas. An alternative explanation of why invasion is enhanced in harbor and marinas is that environmental degradation commonly found in these habitats favors the establishment of NIS. Most surveys for introduced species were not comprehensive and targeted mainly ports and marinas. Angra dos Reis is an excellent system that provides an opportunity to compare the potential distribution of introduced and native species of Ascidiacea between port and natural environments. Here, we compared the colonization of experimental subtidal plates placed in harbors and marinas with the colonization of plates placed in nearby natural areas. With 27 taxa (15 identified to species), species richness was greater in port environments (25 versus 8). Six taxa were common to both environments while 19 taxa were exclusively found in ports. Among the identified species in ports, three were introduced, five were cryptogenic and only one was native. Only three species were found exclusively in the natural sites and all were cryptogenic. The presence of introduced species only in the port areas of Angra dos Reis reinforces the need for continued, periodic monitoring in the region for early detection of new, potentially invasive, species as well as for better understanding of abnormal population growth of the already known species. Management to reduce the transfer of exotics to natural habitats must be implemented.
RESUMO
Despite limited natural dispersal, some species of ascidians can be transported vast distances via oceanic petroleum platforms, ship hulls and ballast water and therefore may be good indicators of bioinvasion. Usually non indigenous species (NIS) are abundant in harbors. This is caused in part because of the higher propagule delivery rate in these areas. An alternative explanation of why invasion is enhanced in harbor and marinas is that environmental degradation commonly found in these habitats favors the establishment of NIS. Most surveys for introduced species were not comprehensive and targeted mainly ports and marinas. Angra dos Reis is an excellent system that provides an opportunity to compare the potential distribution of introduced and native species of Ascidiacea between port and natural environments. Here, we compared the colonization of experimental subtidal plates placed in harbors and marinas with the colonization of plates placed in nearby natural areas. With 27 taxa (15 identified to species), species richness was greater in port environments (25 versus 8). Six taxa were common to both environments while 19 taxa were exclusively found in ports. Among the identified species in ports, three were introduced, five were cryptogenic and only one was native. Only three species were found exclusively in the natural sites and all were cryptogenic. The presence of introduced species only in the port areas of Angra dos Reis reinforces the need for continued, periodic monitoring in the region for early detection of new, potentially invasive, species as well as for better understanding of abnormal population growth of the already known species. Management to reduce the transfer of exotics to natural habitats must be implemented.
RESUMO
Despite limited natural dispersal, some species of ascidians can be transported vast distances via oceanic petroleum platforms, ship hulls and ballast water and therefore may be good indicators of bioinvasion. Usually non indigenous species (NIS) are abundant in harbors. This is caused in part because of the higher propagule delivery rate in these areas. An alternative explanation of why invasion is enhanced in harbor and marinas is that environmental degradation commonly found in these habitats favors the establishment of NIS. Most surveys for introduced species were not comprehensive and targeted mainly ports and marinas. Angra dos Reis is an excellent system that provides an opportunity to compare the potential distribution of introduced and native species of Ascidiacea between port and natural environments. Here, we compared the colonization of experimental subtidal plates placed in harbors and marinas with the colonization of plates placed in nearby natural areas. With 27 taxa (15 identified to species), species richness was greater in port environments (25 versus 8). Six taxa were common to both environments while 19 taxa were exclusively found in ports. Among the identified species in ports, three were introduced, five were cryptogenic and only one was native. Only three species were found exclusively in the natural sites and all were cryptogenic. The presence of introduced species only in the port areas of Angra dos Reis reinforces the need for continued, periodic monitoring in the region for early detection of new, potentially invasive, species as well as for better understanding of abnormal population growth of the already known species. Management to reduce the transfer of exotics to natural habitats must be implemented.