Incidental Catch of Marine Mammals by Foreign and Joint Venture Trawl Vessels in the U.S. EEZ of the North Pacific, 1973-88

During 1973-88, 3,661 marine mammals of 17 species were reported as incidental catch by U.S. fishery observers aboard foreign and joint venture trawl vessels in the U.S. Exclusive Economic Zone in the North Pacific Ocean and the Bering Sea. Northern sea lions (Eumetopias jubatus) accounted for 90% of the reported incidental mortality in the Gulf of Alaska and eastern Bering Sea. Nearly half of these sea lions were taken in trawl nets in the Shelikof Strait, Alaska, joint venture fishery during 1982-84. However, high incidental mortality rates (>25 sea lions per 10,000 metric tons of groundfish catch) also occurred in the foreign fisheries near Kodiak Island and in the Aleutian Islands area in earlier years. Estimated annual mortality of incidentally caught northern sea lions in Alaska declined from 1,000 to 2,000 animals per year during the early 1970s and 1982 to fewer than 100 animals in 1988. In the Bering Sea most sea lions incidentally caught were males, while in the Gulf of Alaska females were more frequently caught. Females may also have been dominant in the incidental catch of sea lions in the Aleutian Islands area, but age and sex composition data are limited. Incidental mortality of adult female sea lions by foreign trawl fisheries in these areas could have partially contributed to the reported declines in northern sea lion populations in Alaska during the 1970s, but it cannot alone account for the present decline in population size. (PDF file contains 64 pages.

Neonatal growth of Steller sea lion (Eumetopias jubatus) pups in Alaska

The growth rate of Steller sea lion (Eumetopias jubatus) pups was studied in southeast Alaska, the Gulf of Alaska, and the Aleutian Islands during the first six weeks after birth. The Steller sea lion population is currently stable in southeast Alaska but is declining in the Aleutian Islands and parts of the Gulf of Alaska. Male pups (22.6 kg [±2.21 SD]) were significantly heavier than female pups (19.6 kg [±1.80 SD]) at 1−5 days of age, but there were no significant differences among rookeries. Male and female pups grew (in mass, standard length, and axillary girth) at the same rate. Body mass and standard length increased at a faster rate for pups in the Aleutian Islands and the western Gulf of Alaska (0.45−0.48 kg/day and 0.47−0.53 cm/day, respectively) than in southeast Alaska (0.23 kg/day and 0.20 cm/day). Additionally, axillary girth increased at a faster rate for pups in the Aleutian Islands (0.59 cm/ day) than for pups in southeast Alaska v(0.25 cm/day). Our results indicate a greater maternal investment in male pups during gestation, but not during early lactation. Although differences in pup growth rate occurred among rookeries, there was no evidence that female sea lions and their pups were nutritionally stressed in the area of population declin

Ecology of Juvenile Walleye Pollock, Theragra chalcogramma: Papers from the workshop "The Importance of Prerecruit Walleye Pollock to the Bering Sea and North Pacific Ecosystems" Seattle, Washington, 28-30 October 1993

The Alaska Fisheries Science Center (AFSC), National Marine Fisheries Service (NMFS), hosted an international workshop, 'The Importance of Prerecruit Walleye Pollock to the Bering Sea and North Pacific Ecosystems," from 28 to 30 October 1993. This workshop was held in conjunction with the annual International North Pacific Marine Science Organization (PICES) meeting held in Seattle. Nearly 100 representatives from government agencies, universities, and the fishing industry in Canada, Japan, the People's Republic of China, Russia, and the United States took part in the workshop to review and discuss current knowledge on juvenile pollock from the postlarval period to the time they recruit to the fisheries. In addition to its importance to humans as a major commercial species, pollock also serves as a major forage species for many marine fishes, birds, and mammals in the North Pacific region. (PDF file contains 236 pages.

Relationship between fish size and otolith length for 63 species of fishes from the Eastern North Pacific Ocean

Otoliths commonly are used to determine the taxon, age, and size of fishes. This information is useful for population management, predator-prey studies, and archaeological research. The relationship between the length of a fish and the length of its otoliths remains unknown for many species of marine fishes in the Pacific Ocean. Therefore, the relationships between fish length and fish weight, and between otolith length and fish length, were developed for 63 species of fishes caught in the eastern North Pacific Ocean. We also summarized similar relationships for 46 eastern North Pacific fish species reported in the literature. The relationship between fish length and otolith length was linear, and most of the variability was explained by a simple least-squares regression (r 2 > 0.700 for 45 of 63 species). The relationship between otolith length and fish length was not significantly different between left and right otoliths for all but one fish species. Images of otoliths from 77 taxa are included to assist in the identification of species. (PDF file contains 38 pages.

Alternative Substrates and Fertilization Routine Relationships for Bedding Pot Plants: Impatiens wallerana

This study was carried out searching for alternative substrates to traditional peat based on river waste and Sphagnum and Carex peat from Argentinean peatlands and used to grow Impatiens wallerana bedding plant. The aim of this study was i) to characterize physical and chemical effects from seven growing media on I. wallerana plants grown under different fertilization rates and ii) to describe the physiological mechanisms in plants, involved in the use of such substrates. Particle stability was lower for the six alternative substrates compared to the Canadian peat-base control substrate. However, with a high fertilization dose it is possible to reach non significant differences in plant growth compared to the control substrate. It is suggested, for future research, that nitrogen signalling associated to cytokinin synthesis by roots is involved.Fil: Thibaud, J.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Floricultura; ArgentinaFil: Loughlin, T. Mc.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Floricultura; ArgentinaFil: Pagani, A.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Floricultura; ArgentinaFil: Lavado, Raul Silvio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Di Benedetto, Adalberto Hugo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Floricultura; Argentin

Who has to 'lean in' for equal gender representation in leadership roles?

Even though women surpass men in university graduation rates and other skill-based gains, the Conference Board of Canada (2011) found it will take over 151 years for women and men to achieve parity in middle management, let alone senior leadership. Sheryl Sandberg's book, Lean In (2013), invigorated a worldwide conversation about the representation of women in leadership roles

An interdisciplinary approach to volcanic risk reduction under conditions of uncertainty: a case study of Tristan da Cunha

The uncertainty brought about by intermittent volcanic activity is fairly common at volcanoes worldwide. While better knowledge of any one volcano's behavioural characteristics has the potential to reduce this uncertainty, the subsequent reduction of risk from volcanic threats is only realised if that knowledge is pertinent to stakeholders and effectively communicated to inform good decision making. Success requires integration of methods, skills and expertise across disciplinary boundaries. This research project develops and trials a novel interdisciplinary approach to volcanic risk reduction on the remote volcanic island of Tristan da Cunha (South Atlantic). For the first time, volcanological techniques, probabilistic decision support and social scientific methods were integrated in a single study. New data were produced that (1) established no spatio-temporal pattern to recent volcanic activity; (2) quantified the high degree of scientific uncertainty around future eruptive scenarios; (3) analysed the physical vulnerability of the community as a consequence of their geographical isolation and exposure to volcanic hazards; (4) evaluated social and cultural influences on vulnerability and resilience; and (5) evaluated the effectiveness of a scenario planning approach, both as a method for integrating the different strands of the research and as a way of enabling on-island decision makers to take ownership of risk identification and management, and capacity building within their community. The paper provides empirical evidence of the value of an innovative interdisciplinary framework for reducing volcanic risk. It also provides evidence for the strength that comes from integrating social and physical sciences with the development of effective, tailored engagement and communication strategies in volcanic risk reduction

A 3D <i>in vitro</i> model reveals differences in the astrocyte response elicited by potential stem cell therapies for CNS injury.

Aim: This study aimed to develop a 3D culture model to test the extent to which transplanted stem cells modulate astrocyte reactivity, where exacerbated glial cell activation could be detrimental to CNS repair success. Materials & methods: The reactivity of rat astrocytes to bone marrow mesenchymal stem cells, neural crest stem cells (NCSCs) and differentiated adipose-derived stem cells was assessed after 5 days. Schwann cells were used as a positive control. Results: NCSCs and differentiated Schwann cell-like adipose-derived stem cells did not increase astrocyte reactivity. Highly reactive responses to bone marrow mesenchymal stem cells and Schwann cells were equivalent. Conclusion: This approach can screen therapeutic cells prior to in vivo testing, allowing cells likely to trigger a substantial astrocyte response to be identified at an early stage. NCSCs and differentiated Schwann cell-like adipose-derived stem cells may be useful in treating CNS damage without increasing astrogliosis

A multi-well plate model of reactive gliosis for high throughput screening of potential CNS therapies

Reactive astrogliosis is an important feature of CNS damage and disease which involves changes in astrocyte phenotype and morphology. In particular, CNS trauma can lead to the formation of a glial scar, a three dimensional (3D) mesh of astrocyte processes that can form a physical and chemical barrier to neuronal regeneration, which is a potential target for CNS drug and cell therapy. However, reactive gliosis is difficult to isolate and monitor in typical animal models of CNS damage. In monolayer culture systems astrocytes adopt a highly reactive phenotype, limiting the range of available models suitable for research in this area. Our previous 3D cell culture systems allow astrocytes to be maintained with a relatively unreactive phenotype until stimulated, whereupon a classical reactive astrocyte response can be monitored. The aim of the current work is to adapt this approach in order to develop a multi-well plate system to provide a reliable, consistent model of reactive gliosis for high throughput screening and research. Once baseline viability and phenotype of primary rat astrocytes were investigated in these models, reactivity was triggered using treatments such as TGFβ1, as seen in Figure 1, hypoxia and low glucose. Outputs included confocal microscopy and 3D image analysis, Western blotting and RT-PCR to quantify markers such as GFAP and CSPG in test and control gels. Using GFP-labelled astrocytes permitted monitoring of cytoplasmic volume and shape, giving an additional measure of astrocyte hypertrophic response within stimulated conditions. The robust protocol that we have developed can form a basis to investigate astrocyte biology in a highly controlled environment, and to model phenotypic features of astrocytes in both damaged and undamaged CNS. A reproducible multi-well plate system will provide an experimental platform which allows potential CNS therapies to be screened at high-throughput, and the effects of potential modulators of astrocyte reactivity to be investigated simply and systematically