Mg. Diaz-Peralta, Christian

Growing coastal urbanization together with the intensification of maritime traffic are major processes explaining the increasing rate of biological introductions in marine environments. To investigate the link between international maritime traffic and the establishment of non-indigenous species (NIS) in coastal areas, biofouling communities in three international and three nearby local ports along 100 km of coastline in south-central Chile were compared using settlement panels and rapid assessment surveys. A larger number of NIS was observed in international ports, as expected in these ‘invasion hubs’. However, despite a few environmental differences between international and local ports, the two port categories did not display significant differences regarding NIS establishment and contribution to community structure over the studied period (1.5 years). In international ports, the free space could be a limiting factor for NIS establishment. The results also suggest that local ports should be considered in NIS surveillance programs in Chile.

We cultivated the Pacific oyster (Crassostrea gigas) simultaneously in three types of cultivation device sets deployed in two sites: a sheltered site and a non-sheltered site in the coast of the central area of Chile. Oysters were cultivated in polypropylene trays, nylon cones and lanterns suspended at 2, 5 and 8 m depth from long-lines. Organism sampling was performed monthly from June, 2014 to May, 2015, measuring temperature, salinity and chlorophyll a. Growth was measured by shell length, wet meat weight and meat yield. At the end of cultivation, there were significant differences in the growth of oysters with higher growth in lanterns at 2 m at Punta Lobería (non-sheltered site). Higher growth was also found at 2 m in Coliumo bay (sheltered site). Better growth seems associated with the stability of salinity and chlorophyll a. This is the first study that demonstrates the viability of oyster cultivation in non-sheltered environments on the coast of central Chile.

Choosing an alternative species of mussel for the aquaculture industries, will be possible if it has equal or greater yield than the mussel cultivated. This study compares the growth of the chilean native mussel Mytilus chilensis with the non-native Mediterranean mussel Mytilus galloprovincialis and evaluate if environmental variables and cultivation depth affects mussels growth. Mussel were seeded in summer, with the same mean total weight and shell length for both species. At the end of the experiment, shell length (SL), condition index and gonadosomatic index were compared over month, depth and species. Highly significant differences were found in shell length between month and depth and between month and species (p < 0.05). The linear relationship between the gonad weight and wet meat weight in M. chilensis present a higher gonad weight for the same wet meat weight than M. galloprovincialis. It can be concluded that at the end of the harvest size cultivation M. chilensis presents a greater gonad weight, condition index and gonadosomatic index.

The spatial distribution of heavy metals content (Ba, Cd, Cu, Pb, Sr and Zn) in sediments of the Baker Fjord and surrounding channels in the central region of the Chilean fjords (47°45'S, 48°15'S) is analyzed. The aim of the study was characterized the patterns of abundance and distribution of these metals in surface sediments. The area corresponds to a poorly studied zone with low human activity. Distribution patterns would be influenced by rainfall conditions (local erosion), fluvial (continental sediments carried by rivers), glacier (glacier flour) and estuarine circulation. Cluster analysis allows differentiation among the sampled sites and group with similar characteristics. Finally, the concentrations found were contrasted with average values of metamorphic rocks and show with some certainty that the values found for calendar for this area and the greatest concentrations are the result of natural enrichment.