RESUMO
Non-indigenous bryozoans are frequent components of biofouling assemblages in harbour environments worldwide. We performed a survey of artificial hard substrates in six harbours spanning 16 degrees of latitude along the coast of Argentina, from Ingeniero White (38º47' S) to Ushuaia (54º48' S). Microeciella argentina n. sp., distributed in warm-temperate waters of northern Patagonia and Buenos Aires Province, is described. The non-indigenous species (NIS) Callopora dumerilii, Smittoidea spinigera and Stephanollona boreopacifica are recorded here for the first time in the Southwest Atlantic. Their occurrence in fouling assemblages of warm-temperate harbours and their previous absence in these areas suggest that they probably arrived in Argentina by international shipping traffic. Callopora dumerilii is native to Europe and the northeast Atlantic. Smittoidea spinigera and Stephanollona boreopacifica are native to China and Korea, respectively. The morphological differences between S. spinigera and the Californian species S. prolifera, which is invading European harbours in the North Sea, are discussed. Bugula neritina, Bugulina flabellata, Cryptosula pallasiana and Fenestrulina delicia, common in harbours of Buenos Aires Province, are here recorded in Patagonia, highlighting the importance of regional shipping traffic to secondary spread of NIS. Arachnidium fibrosum, Buskia socialis, Anguinella palmata, Aetea cultrata, Bicellariella edentata and Exochella moyanoi, previously known from Brazil, and Hippothoa divaricata, are here recorded in Argentina. This study shows that warm-temperate harbours in Buenos Aires Province and northern Patagonia are particularly prone to the introduction of non-indigenous bryozoans.
Assuntos
Briozoários , Animais , NaviosRESUMO
The problem created by invasive non-native species through ships' ballast water has caused the International Maritime Organization (IMO), through the Ballast Water Management (BWM) Convention and many countries to develop their own laws to prevent their introduction. One of the most important non-native species in Argentina, the golden mussel (Limnoperna fortunei), causes a significant economic impact on the Plata Basin. Argentina has a great amount of maritime and fluvial ports that receive ships from different regions of the world. Particularly, the San Lorenzo-San Martín Port Complex (here termed SLOR), placed in the terminal portion of the Paraná Basin, receives ocean ships with great loading capacity, which increases the possibility of invasions and the need of an adequate environmental management. This work proposes to estimate the potential vulnerability of SLOR port, in relation with the origin of the ballast water and its volume. For this purpose, an adaptation of the risk assessment model of the GloBallast Program was used. The results suggest that SLOR has important similarities with different fluvial ports of the world, especially in Brazil and China. However the amount of ships coming from the nearest estuary waters, where the diversity of invasive species has major effects, is also important. This article provides the necessary information to conduct the efforts through surveys and enforcement regulations, and could be the foundation for future research using global data that could provide basic information for other fluvial ports with similar features.