Variations in eastern North Pacific demersal fish biomass based on the U.S. west coast groundfish bottom trawl survey (2003–2010)

In response to declining biomass of Northeast Pacific groundfish in the late 1990s and to improve the scientific basis for management of the fishery, the Northwest Fisheries Science Center standardized and enhanced their annual bottom trawl survey in 2003. The survey was expanded to include the entire area along the U.S. west coast at depths of 55–1280 m. Coast-wide biomass and species richness significantly decreased during the first eight years (2003–10) of this fishery-independent survey. We observed an overall tendency toward declining biomass for 62 dominant taxa combined (fishery target and nontarget species) and four of seven subgroups (including cartilaginous fish, flatfishes, shelf rockfishes, and other shelf species), despite increasing or variable biomass trends in individual species. These decreases occurred during a period of reduced catch for groundfish along the shelf and upper slope regions relative to historical rates. We used information from multiple stock assessments to aggregate species into three groups: 1) with strong recruitment, 2) without strong recruitment in 1999, and 3) with unknown recruitment level. For each group, we evaluated whether declining biomass was primarily related to depletion (using year as a proxy) or environmental factors (i.e., variation in the Pacific Decadal Oscillation). According to Akaike’s information criterion, changes in aggregate biomass for species with strong recruitment were more closely related to year, whereas those with no strong recruitment were more closely related to climate. The significant decline in biomass for species without strong recruitment confirms that factors other than depletion of the exceptional 1999 year class may be responsible for the observed decrease in biomass along the U.S. west coast.

Dietary variations in three co-occurring rockfish species off the Pacific Northwest during anomalous oceanographic events in 1998 and 1999

Stomach samples from three rockfish species, yellowtail (Sebastes f lavidus), widow (S. entomelas), and canary (S. pinniger) rockfish, seasonally collected off the Pacific Northwest in 1998 and 1999, provided quantitative information on the food habits of these species during and after the 1997–98 El Niño event. Although euphausiids were the most common major prey of all three predators, gelatinous zooplankton and fishes were the most commonly consumed prey items during some seasonal quarters. The influence of the El Niño event was evident in the diets. Anomalous prey items, including the southern euphausiid species Nyctiphanes simplex and juveniles of Pacific whiting (Merluccius productus) frequently appeared in the diets in the spring and summer of 1998. The results of stomach contents analyses, based on 905 stomach samples from 49 trawl hauls during seven commercial fishing trips and from 56 stations during research surveys, were consistent with the timing of occurrence and the magnitude of change in biomass of some zooplankton species reported from zooplankton studies in the northern California Current during the 1997–98 El Niño. Our findings indicate that the observed variations of prey groups in some rockfish diets may be a function of prey variability related to climate and environment changes.

Geographic and seasonal variations in maturation and growth of female Pacific cod (Gadus macrocephalus) in the Gulf of Alaska and Bering Sea

This study investigates the temporal stability of length- and age-at-maturity estimates for female Pacific cod (Gadus macrocephalus) in the Gulf of Alaska and eastern Bering Sea. Females reached 50% maturity (A50) at 4.4 years in the Gulf of Alaska and at 4.9 years in the eastern Bering Sea. Total body length at 50% maturity (LT50) was significantly smaller (503 mm) in the Gulf of Alaska than in the eastern Bering Sea (580 mm). The estimated length- and age-at-maturity did not differ significantly between winter and spring in either the Gulf of Alaska (1999) or Bering Sea (2003) areas. The results of this study raised the spawning biomass estimate of female Alaskan Pacific cod from 298×103 t for 2005 to 499×103 t for 2006. The increased spawning biomass estimate resulted in an increased over-fishing limit for Pacific cod.

Estudo de viabilidade técnica, econômica e ambiental preliminar da aplicação da tecnologia de Tratamento Térmico de Resíduos e Materiais Multifásicos-TTRM a resíduos de terra diatomácea de usina genérica de produção de biodiesel.

O cenário mundial de matriz energética apresenta dados crescentes de contribuição das energias renováveis. No Brasil, o governo tem realizado esforços para aumento da parcela de combustíveis renováveis, e com isso isso também para o aumento da produção de biodiesel. O principal processo de fabricação de biodiesel com seu polimento em via seca gera quantidades significativas de resíduos, dentre eles, o resíduo de terra diatomácea, com potenciais características de inflamabilidade. Em contrapartida existe a Política Nacional de Resíduos Sólidos com objetivos de não geração, redução, reutilização, reciclagem e redução de periculosidade dos resíduos, e envio para aterro somente de resíduos sem qualquer possibilidade viável de tratamento. O presente trabalho objetiva realizar um estudo de viabilidade técnica, econômica e ambiental preliminar da aplicação da tecnologia de Tratamento Térmico de Resíduos e Materiais Multifásicos - TTRM a resíduo de terra diatomácea - RTD de usina genérica de biodiesel. Foram utilizados como base para o estudo: os resultados dos testes da PETROBRAS e da ALBRECHT realizados em escala de bancada de laboratório e em planta piloto que simularam a aplicação do TTRM ao RTD; premissas técnicas; premissas operacionais; e dados econômicos de referência. Foram estabelecidos cenários específicos para o estudo da aplicabilidade e realizada análise de sensibilidade para os principais fatores da composição dos custos. Observou-se para este estudo preliminar que: na dimensão técnica o TTRM demonstrou ser aplicável; na dimensão econômica, os indicadores são positivos em sua totalidade no cenário esperado, mesmo após análise de sensibilidade com variações de 25% dos principais parâmetros de entrada do estudo de viabilidade; na dimensão ambiental o TTRM demonstrou ser uma alternativa que incorpora os conceitos para uma gestão alinhada com a Política Nacional de Resíduos Sólidos, seja na redução da periculosidade do resíduo, na potencial minimização da geração dos resíduos ou no reuso e reaproveitamento resíduos.

Episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystem, with particular reference to fish populations in N.W. England

This is the episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystems, with particular reference to fish populations in North West England produced by the North West Water Authority in 1985. This report looks at the biological, physical and chemical information collected over a five year period from over 100 sites on upland streams in the North West Region of which drained rocks of low buffering capacity. In both Lake District and South Pennine sites striking differences were found between the composition of invertebrate communities inhabiting acid-stressed and less acid-stressed streams. Electric fishing surveys showed that acidic streams (geometric mean pH <5.5) generally had abnormally low densities of salmonids ( < 0 .2m2) and that 0+ fish were very few or absent. The latter indicates recruitment failure. Salmon were more sensitive than trout to low pH.

Year 1 operational report: Improving employment and income through development of Egypt’s aquaculture sector(IEIDEAS) project

Implementation of the SDC funded project ‘Improving Employment and Income through Development of Egypt’s Aquaculture Sector’ commenced on 1st December 2011 and will continue until late 2014. This report summarizes the results of the first 10 months until 30th September 2012. The project was based on a value chain analysis carried out by WorldFish in September 2011. The information in the VCA acts as the baseline for the main project parameters. It established that the aquaculture value chain is a significant employer (14 FTE per 100 tonnes of annual production), particularly in rural areas and there was scope to increase employment of youth and women.