Programa CIMAR
http://hdl.handle.net/1834/1361
2024-03-29T11:18:30ZDistribución de quistes de Alexandrium catenella y otros dinoflagelados en sedimentos de la zona sur-austral de Chile
http://hdl.handle.net/1834/4126
Distribución de quistes de Alexandrium catenella y otros dinoflagelados en sedimentos de la zona sur-austral de Chile
Lembeye, Georgina
During the expeditions Cimar - Fiordos 2, 3 and 4 (1996, 1997 and 1999), samples of marine sediments were collected in Southern Chile, between Melinka (Lat. 43° 45' S) and Beagle Channel (Lat. 54° 56' S) to study the distribution and abundance of dinoflagellate cysts, particularly the toxic dinoflagellate Alexandriurn catenella. Samples were collected from 33 stations at depths of 1 to 15 meters. The study included photographic record and taxonomic identification of cysts to genus and, whenever possible, to species, with emphasis on the identification of cysts of A. catenella. Cysts from samples collected in cruises 3 and 4, were incubated in f/2-Se culture medium at 13 °C with controlled photoperiod (14:10, L:D), to induce germination and confirm species identification. Through this method, it was possible to establish monoclonal cultures of A. catenella. Cysts of dinoflagellates of at least 18 different forms or species were detected within the samples analyzed. The nine species of dinoflagellates identified belong to 5 genera (Protoperidium, Protoceratium, Scrippsiella, Polykrikos and Alexandrium). The cysts of A. catenella were present in samples of 11 stations. They were most abundant at estero Quitralco (Aysén Region), and at Puerto Engaño (Magallanes Region), with 76,7 ± 23,7 y 72,7 ± 33,8 cysts/mL, respectively. Environmental factors, including oceanographic and geographic conditions, and the characteristics of sediments, may affect the distribution and abundance of the cysts of A. catenella. Those locations may become sources for the generation of toxic blooms in the Aysén and Magallanes Regions.
2004-01-01T00:00:00ZDistribución de clorofila a y feopigmentos en los canales australes chilenos comprendidos entre Puerto Montt y la laguna San Rafael, Chile
http://hdl.handle.net/1834/3147
Distribución de clorofila a y feopigmentos en los canales australes chilenos comprendidos entre Puerto Montt y la laguna San Rafael, Chile
Ramírez, B.; Pizarro, E.
La distribución de clorofila a y su relación con feopigmentos se describe para 98 estaciones localizadas en los fiordos chilenos comprendidos entre 41º a 46º S. Además, es relacionada con la disponibilidad de luz y con la información existente de temperatura, nutrientes, oxígeno y de biomasa planctónica. Las mayores concentraciones de clorofila (>5 mg m–3) se detectaron hasta 25 m, coincidente con una baja concentración de feopigmentos y 50% de luz. Sus más bajas concentraciones (<0,5 mg m–3), fueron detectadas entre 50 y 100 m y asociadas con altos valores de la proporción feopigmento-clorofila. Se establecen cuatro zonas de abundancia de clorofila. La primera tiene concentraciones entre 1,5 y 5 mg m–3, localizadas en seno Reloncaví y golfo de Ancud. La segunda zona tiene baja concentración y se ubica en el golfo Corcovado. La tercera zona corresponde a los canales Moraleda, Jacaf y Puyuguapi. El primero con las máximas concentraciones de toda el área. El canal Jacaf, al oriente del Moraleda también tiene elevadas concentraciones. En cambio, los canales oceánicos (Baeza y King), tienen bajas concentraciones y solo es moderada en el punto de encuentro con el Moraleda. La cuarta zona tiene bajos valores (0,5 a 1,5 mg m–3) y se extiende desde la isla Meninea hasta la laguna San Rafael. El canal Moraleda facilita el crecimiento del fitoplancton porque su cuenca es fertilizada por las aguas oceánicas y la gradiente térmica, detectada en los primeros 25 m, facilita la permanencia de las poblaciones fitoplanctónicas en los niveles fóticos. Las cuencas de seno Reloncaví y golfo de Ancud presentan el mismo patrón de gradiente térmico, pero sus nutrientes son de origen antropogénico.; The distribution of chlorophyll a and its relationship with phaeopigments is described for 98 stations located in the Chilean fjords between 41° to 46° S. The distribution is associated to availability of light and to existing information on temperature, nutrients, oxygen and plankton biomass information. The highest chlorophyll a concentrations (>5 mg m–3) were detected down to 25 m, which is coincident with low phaeopigment concentrations and 50% of light. The lowest concentration of chlorophyll (<0.5 mg m–3) was detected between 50 and 100 m, with high rate values of chlrophyll-phaeopigments.
Four zones were identified based on chlorophyll abundance. The first, with moderate levels (1.5 to 5 mg m–3), located between Reloncaví Inlet and Gulf of Ancud. The second zone has the minimum concentration and it is located in the Corcovado Gulf. The third zone belongs to the Channels Moraleda, Jacaf and Puyuguapi. The former with the maximum concentrations of the whole area. The Jacaf Channel to the East of Moraleda, also with high levels of chlorophyll. The oceanic channels (Baeza and King) have low concentrations, and moderate only at the point where it meets with Moraleda. The fourth zone has also minimum concentrations of chlorophyll (0.5-1.5 mg m–3), extending from Meninea Island to Laguna San Rafael. The Moraleda Channel facilitates the growth of phytoplankton cells, because its basin becomes fertilized by oceanic waters and the thermal gradient, detected in the first 25 m depth, helps the permanency of phytoplankton populations within the photic levels. The basins of the Reloncaví Inlet and Gulf of Ancud shows the same thermal gradient pattern, but its nutrient content are of anthropogenic origin.
2005-01-01T00:00:00ZCapacidad de transporte de la constricción de Meninea para un flujo de dos capas y el efecto de la corriente de marea
http://hdl.handle.net/1834/3104
Capacidad de transporte de la constricción de Meninea para un flujo de dos capas y el efecto de la corriente de marea
Salinas, S.; Hormazábal, S.
En la primavera de 1995, se instaló un anclaje con dos correntómetros sobre el umbral de la constricción de Meninea para un análisis inicial de corrientes. El experimento fue parte del programa multidisciplinario Cimar 1 Fiordos. Durante 61 días se obtuvo las mediciones cada 30 minutos. Los correntómetros estaban instalados a 25 m y 40 m bajo la superficie del mar, en la profundidad de 60 m. La velocidad promedio fue de 15,9 cms-1 hacia el norte en el correntómetro superior y de 2,0 cms-1 hacia el sur en lo profundo. La variabilidad de las corrientes fue dominada por la corriente de marea de tipo semidiurno M2. Debido a la corriente de marea, crece la capacidad de transporte de la constricción con respecto al sistema de dos capas. El tiempo de residencia de las aguas al sur de la constricción es del orden de los 10 meses.; In the spring of 1995 an array of two current meters was deployed over the sill in the Meninea contraction for an initial examination of currents. The experiment was part of the multidisciplinary program Cimar-Fiordo 1. For 61 days data were recorded every 30th min. The current meters were placed 25 and 40 m below the sea surface, the bottom depth was 60 m. The mean velocity was 15.9 cms-1 to the north and 2,0 cms-1 to the south in the deepest one. Tidal currents M2 dominated the current’s variability. Owing to the tidal current the transport capacity of the Meninea contraction relative to the two water masses increases. The residence time for the water on the southern side of the contraction is about 10 months.
2004-01-01T00:00:00ZPropagación de la onda de marea en canales adyacentes a Campos de Hielo Sur
http://hdl.handle.net/1834/1579
Propagación de la onda de marea en canales adyacentes a Campos de Hielo Sur
Fierro, J.; Castillo, M.; Valenzuela, C.
During the research cruise Cimar-Fiordo 2, carried out in late 1996, sea level was recorded in three stations located in channels, Messier (Puerto Edén), Wide (Punta Beresford) and Concepción (Caleta Patria). The measurements were of short term, starting in October 20th and finishing in December 13th, 1996. The sea level in those stations, was analyzed in the time and frequency dominion, and some tide non harmonic values were calculated. Results showed that tides evident influence in sea level signal, with a clear mixt semidiurnal behavior, and a daily inequality between high and low waters. The highest tide range was observed in puerto Edén, showing the effect of the local orography configuration while the wave propagates into the channel, and experiences non linear effects modification. The low frequency sea level signal is perceptible even it has very small amplitude. However, due to the series short length it was not possible a proper resolution of the low frequency energy spectrum. From the spectral analysis, was clearly advisable that tides is the most energetic phenomenon that shows its biggest expression particularly in the semidiurnal frequency in all stations.
2003-01-01T00:00:00Z