The Corogal: one of the big dredges in Culebra Cut, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

First U.S. battleships through Panama Canal: Missouri, Ohio, Wisconsin (postcard ca 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Tow boat fleet at Paraiso, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

View of Paraiso Yard showing dredging equipment, Panama Canal. (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Emergency dam at Pedro Miguel, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Lantern spillway and hydroelectric plant, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

U.S.S. Ohio, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Panama Canal Twenty-fifth anniversary 1914 - Aug. 15 -1939

Leonard Carpenter Panama Canal Collection. Photographs: Views of Panama and the Canal. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida. Booklet dedication: Published under the direction of a committee appointed by Brigadier General Clarence S. Ridley, Governor of The Panama Canal, to arrange suitable ceremonies, as authorized in Public Resolution No.5, 76th Congress, approved March 28, 1939, to celebrate the twenty-fifth anniversary of the opening of the Panama Canal to commerce. Prepared by Rufus Hardy, Executive Department, The Panama Canal. (120 page document)

Noise levels and sources in the Stellwagen Bank National Marine Sanctuary and the St. Lawrence River Estuary

Although ambient (background) noise in the ocean is a topic that has been widely studied since pre-World War II, the effects of noise on marine organisms has only been a focus of concern for the last 25 years. The main point of concern has been the potential of noise to affect the health and behavior of marine mammals. The Stellwagen Bank National Marine Sanctuary (SBNMS) is a site where the degradation of habitat due to increasing noise levels is a concern because it is a feeding ground and summer haven for numerous species of marine mammals. Ambient noise in the ocean is defined as “the part of the total noise background observed with an omnidirectional hydrophone.” It is an inherent characteristic of the medium having no specific point source. Ambient noise is comprised of a number of components that contribute to the “noise level” in varying degrees depending on where the noise is being measured. This report describes the current understanding of ambient noise and existing levels in the Stellwagen Bank National Marine Sanctuary. (PDF contains 32 pages.)

Penaeus indicus H. Milne Edwards, 1837: resumo das conclusões dos cruzeiros de pesca exploratória entre 1979 e 1983 no banco de Sofala em Moçambique

From 1979 to 1983, several surveys were carried out with research and fishing vessels at Sofala Bank in Mozambique. Their main objective was the assessment of shallow water prawn stocks, as this resource is of great economic importance for the country. A summary of the conclusions of these surveys regarding the species Penaeus indicus is presented. During the rainy season the species occurs closer to the shore than during the dry season. Estimates of biomass are very variable. The spawning peak seems to occur at the beginning of the rainy season (September-October). The spawning areas are located very close to the shore in the northern part of Sofala Bank and South of 17 degree 10'S in the 15-25 m depth interval.

Use of endoparasitic helminths as tags in delineating stocks of American plaice (Hippoglossoides platessoides) from the southern Gulf of St. Lawrence and Cape Breton Shelf

Endoparasitic helminths were inventoried in 483 American plaice (Hippoglossoides platessoides) collected from the southern Gulf of St. Lawrence, NAFO (North Atlantic Fisheries Organization) division 4T, and Cape Breton Shelf (NAFO subdivision 4Vn) in September 2004 and May 2003, respectively. Forward stepwise discriminant function analysis (DFA) of the 4T samples indicated that abundances of the acanthocephalans Echinorhynchus gadi and Corynosoma strumosum were significant in the classification of plaice to western or eastern 4T. Cross validation yielded a correct classification rate of 79% overall, thereby supporting the findings of earlier mark-recapture studies which have indicated that 4T plaice comprise two discrete stocks: a western and an eastern stock. Further analyses including 4Vn samples, however, indicated that endoparasitic helminths may have little value as tags in the classification of plaice overwintering in Laurentian Channel waters of the Cabot Strait and Cape Breton Shelf, where mixing of 4T and 4Vn fish may occur.

The relationship between smolt and postsmolt growth for Atlantic salmon (Salmo salar) in the Gulf of St. Lawrence

The interaction of ocean climate and growth conditions during the postsmolt phase is emerging as the primary hypothesis to explain patterns of adult recruitment for individual stocks and stock complexes of Atlantic salmon (Salmo salar). Friedland et al. (1993) first reported that contrast in sea surface temperature (SST) conditions during spring appeared to be related to recruitment of the European stock complex. This hypothesis was further supported by the relationship between cohort specific patterns of recruitment for two index stocks and regional scale SST (Friedland et al., 1998). One of the index stocks, the North Esk of Scotland, was shown to have a pattern of postsmolt growth that was positively correlated with survival, indicating that growth during the postsmolt year controls survival and recruitment (Friedland et al., 2000). A similar scenario is emerging for the North American stock complex where contrast in ocean conditions during spring in the postsmolt migration corridors was associated with the recruitment pattern of the stock complex (Friedland et al., 2003a, 2003b). The accumulation of additional data on the postsmolt growth response of both stock complexes will contribute to a better understanding of the recruitment process in Atlantic salmon.

Raúl Adolfo Ringuelet (1914 1982): Una síntesis de su trayectoria con énfasis en sus contribuciones a la Ictiología y Limnología.

Historia de la Ciencia fue una materia ofrecida en 2003, por el curso de Posgrado en Ciencias Ambientales (PEA) de la Universidad Estadual de Maringá, PR, Brasil, dictada por la profesora Luiza Marta Bellini. Durante el curso de la misma, se discutía sobre la historia y filosofía de vida de los científicos que brillaron o, por el contrario, pasaron desapercibidos por la historia del pensamiento humano. Al final del término de la materia, se logró compilar un libro llamado Ecólogos e suas histórias: Um olhar sobre a construção das ideas ecológicas (Pelicice et al., 2010). El capitulo diez del libro, es un comentario sobre algunos pioneros que contribuyeron para el desarrollo de la Limnología fluvial en Sudamérica. Dos fueron tratados en ese capítulo, Harald Sioli y Juan José Neiff (ver Arenas‐Ibarra et al., 2010). Sin embargo, la idea principal del capítulo era incluir también a los doctores Argentino Aurelio Bonetto y Raúl Adolfo Ringuelet, pero cuestiones relativas al formato y espacio de cada capítulo, impidieron mantener la integridad original de éste y el mayor conocimiento de las contribuciones de estos dos destacados investigadores argentinos en tierras brasileras. Si bien esta omisión fue compensada en parte por el artículo de Arenas‐Ibarra & Souza‐Filho (2010) en el que se resaltan las figuras de Bonetto y Rzóska como precursores de la Limnología fluvial, quedó aún pendiente este reconocimiento por parte de los autores de este documento a Raúl Ringuelet. Con motivo de que en el transcurso de este año se cumplieron treinta años del fallecimiento del Dr. Raúl Adolfo Ringuelet, decidimos, por invitación de Hugo Luis López, publicar el material recopilado durante la materia cursada en la Universidad Estadual de Maringá (UEM, Brasil), actualizándola con nuevos datos proporcionados por Hugo López y Juan José Neiff. Este trabajo es una síntesis de las ideas de Raúl Adolfo Ringuelet, quien sin duda se encuentra entre los pioneros de la ictio‐limnología local y sudamericana.

Movement of American lobster (Homarus americanus) in the southwestern Gulf of St. Lawrence

A total of 42,445 American lobsters (Homarus americanus) were tagged in thirty-one sites throughout the southwestern Gulf of St. Lawrence between 1980 and 1997. Results from the recapture of 8503 tagged lobsters showed small distances traveled between the release and the recapture position for animals ranging in size from 51 to 152 mm carapace length. The average distance traveled ranged from 2 km in parts of Baie des Chaleurs and western Cape Breton to 19 km in central Northumberland Strait. Lobsters moved generally along the shore (93% of the dispersion was in areas between the shore and the 20-m bathymetric contour). As a result, lobsters traveled longer distances in sites characterized by a gradually sloping bottom where the distance between the shore and the 20-m contour line was extensive in contrast to areas characterized by rapidly changing depths and by a relatively small amount of habitat shallower than 20 m. In the majority of sites (14 of 19) there was no significant difference between males and females in the average distance they traveled. In four of the five sites females moved farther than males. In general, the average distance traveled by berried females was shorter than that traveled by males or nonberried females. No relationship was observed between the distance traveled and the size of the animal. There was no strong evidence of a relationship between the average distance traveled and the number of days at liberty. In general, lobsters in the southwestern Gulf of St. Lawrence traveled short distances and dispersion was restricted to the nearshore habitat. Further, the distance traveled was not correlated to size, sex, or years at large. These findings show that there is little interaction between American lobsters from different fishing areas at the benthic level and that American lobster movements should have minimal consequences for management of the species in the southwestern Gulf of St. Lawrence.