5 resultados para Antonello, da Messina, 1430?-1479

em Aquatic Commons


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Proper release of marine fishes has become increasingly important to anglers. The use of fisheries management tools such as size limits, bag limits and closed seasons as well as stronger conservation ethics have resulted in more and more fish being released. In order to maintain healthy fish populations, each angler is responsible for fishing legally, carefully handling fish that are hooked and releasing fish that are not harvested so they can spawn or perhaps be caught again. (PDF contains 4 pages.)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The on-offshore distributions of tuna larvae in near-reef waters of the Coral Sea, near Lizard Island (14°30ʹS, 145°27ʹE), Australia, were investigated during four cruises from November 1984 to February 1985 to test the hypothesis that larvae of these oceanic fishes are found in highest abundance near coral reefs. Oblique bongo net tows were made in five on-offshore blocks in the Coral Sea, ranging from 0–18.5 km offshore of the outer reefs of the Great Barrier Reef, as well as inside the Great Barrier Reef Lagoon. The smallest individuals (<3.2 mm SL) of the genus Thunnus could not be identified to species, and are referred to as Thunnus spp. We found species-specific distributional patterns. Thunnus spp. and T. alalunga (albacore) larvae were most abundant (up to 68 larvae/100 m2) in near-reef (0–5.5 km offshore) waters, whereas Katsuwonus pelamis (skipjack tuna) larvae increased in abundance in the offshore direction (up to 228 larvae/100 m2, 11.1–18.5 km offshore). Larvae of T. albacares (yellowfin tuna) and Euthynnus affinis (kawakawa) were relatively rare throughout the study region, and the patterns of their distributions were inconclusive. Few larvae of any tuna species were found in the lagoon. Size-frequency distributions revealed a greater proportion of small larvae inshore compared to offshore for K. pelamis and T. albacares. The absence of significant differences in size-frequency distributions for other species and during the other cruises was most likely due to the low numbers of larvae. Larval distributions probably resulted from a combination of patterns of spawning and vertical distribution, combined with wind-driven onshore advection and downwelling on the seaward side of the outer reefs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Length-based methods (LBMs) were used to study the growth of Trisopterus minutus capelanus in the Strait of Sicily (Messina Strait). A total of 16,304 'merluzzetto' or poor cod collected by experimental trawling off the southern coast of Sicily during spring, summer, autumn 1986 and winter 1987 were measured in order to estimate the length structure of the population. Length-frequency distribution were analyzed and normal components were discriminated. Von Bertalanffy growth parameters were derived from the mean length of the normal components. The growth parameters obtained by weighted non-linear regression were: K=0.462 (yr super(1)), L sub( infinity )=222.3 (TL,mm) and t sub(o)=-0.679 yr. The resulting growth performance index ( Phi ') was 4.36, a value slightly lower than those derived for Western Mediterranean (mean Phi '=4.45) and Adriatic ( Phi '=4.58) populations and slightly higher than that derived for Hellenic waters ( Phi '=4.27). On the basis of the von Bertalanffy parameters estimated, an array of age-specific instantaneous natural mortality rate (M sub(t)=0.5-1.1) and an average value of total natural mortality rate (Z=2.1 yr super(1)) were estimated and used in the Thompson and Bell yield per recruit (Y/R) analysis in order to evaluate the status of the fishery and forecast the effects of changes in the fishing pattern. Results indicate that this resource is overexploited and that Y/R could be increased by postponing the age at first capture from 0.5 to 1.0 yr. Even a slight reduction in fishing mortality could improve the performance of the fishery. At the present level of exploitation, and assuming a constant recruitment, the spawning stock biomass per recruit (SPR) is well below the conservative threshold of 30% of the pristine or unexploited SPR.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Si bien existen varios ensayos biográficos que enfocan diferentes momentos de su vida (ANÓNIMO, 1963, BAHAMONDE, 1962, LÓPEZ et al., 2015, NION, 2015, PEQUEÑO, 2015, SÁNCHEZ CARRILLO, 2001), hasta donde tenemos conocimiento, no se ha publicado aún una bibliografía completa de la obra del Dr. FERNANDO DE BUEN Y LOZANO (Fig. de tapa). Bibliografías parciales se encuentran, entre otros, en los autores arriba citados. Aquí nos atrevemos a hacer el intento, aunque en forma defectuosa, ya que muchas de sus publicaciones no las hemos podido consultar directamente (se señalan con un asterisco, *). En parte nos hemos basado en una compilación hecha por el propio DE BUEN, que abarca los años 1915 a 1949 (Fig. 1), aunque no siempre con los datos necesarios para una completa información sobre la publicación; en lo posible intentamos complementarla. En sus casi cincuenta años de actividad científica, llegó a producir casi 300 títulos, de variado contenido, aunque siempre relacionados con el medio acuático, sea marino o dulceacuícola. Esta producción se puede dividir en cuatro períodos, que comienza con su etapa española, europea y africana (marroquí), entre 1915 y 1937, durante la cual publicó más de 140 títulos. Como consecuencia de la Guerra Civil Española, en 1939 se radica en México, donde permanece desde el 12 de Julio de 1939 hasta Noviembre 1946, país al que regresa entre 1953 y 1957. Durante este período escribe unos 70 artículos. Entre esas dos etapas mexicanas, estuvo brevemente radicado en el Uruguay, desde el 26 de Noviembre de 1946 hasta 1953, sin duda la etapa de menor producción científica, con una docena trabajos. A ésta sigue el último período de su vida, en Chile (Fig. 2), la que lamentablemente termina trágicamente, en 1962. Durante este período publica más de 60 publicaciones, de los cuales, aparentemente, seis quedan inéditas. Cabe señalar que durante estas tres etapas de exilio americano, si bien sus publicaciones están mayoritariamente relacionadas con el país de residencia, hay algunas excepciones. Preivo a estas estadías en América, hay que mencionar tres europeas, fuera de España, a saber: en el Museo Oceanográfico de Mónaco (1919), en el Instituto Centrale di Biologia Marina, Messina, Italia (1919), y en el Laboratorio Arago, Banyuls sur Mer, Francia (1939). En general, puede considerarse que FERNANDO DE BUEN fue un investigador solitario, ya que solamente seis, de sus casi 300 trabajos, fueron publicados en colaboración: dos con su hermano SADÍ DE BUEN (#31 y 32), dos con F. FRADE (#115 y 116), y dos con MANUEL ZOZAYA (#162 y 176). En su obra científica hemos podido identificar la descripción original de 12 géneros, 9 subgéneros, 54 especies y 11 subespecies, como se indican en la Tabla I.