Comparative Microbial Dynamics in Crassostrea virginica and Crassostrea ariakensis

Considerations to introduce the Suminoe or Asian oyster Crassostrea ariakensis along the East Coast have raised many questions regarding ecology, economics, and human health. To date, research has focused primarily on the ecological and socioeconomic implications of this initiative, yet few studies have assessed its potential impact on public health. Our work compares the rates of bioaccumulation, depuration and post harvest decay of indicator organisms (such as E. coli) and Vibrio sp. between Crassostrea virginica and Crassostrea ariakensis in the laboratory. Preliminary results suggest that the rates of bioaccumulation of E. coli in Crassostrea ariakensis were significantly lower than those for Crassostrea virginica, depuration of E. coli was variable between the two species, and Crassostrea ariakensis post harvest decay rates of Vibrio sp. were significantly lower than Crassostrea virginica. This research provides coastal managers with insight into the response of Crassostrea ariakensis to bacteria, an important consideration for determining appropriate management strategies for this species. Further field-based studies will be necessary to elucidate the mechanisms responsible for the differences in rates of bioaccumulation and depuration. (PDF contains 40 pages)

A review of the ecological effectiveness of subtidal marine reserves in Central California, Part I: Synopsis of scientific investigations

Marine reserves, often referred to as no-take MPAs, are defined as areas within which human activities that can result in the removal or alteration of biotic and abiotic components of an ecosystem are prohibited or greatly restricted (NRC 2001). Activities typically curtailed within a marine reserve are extraction of organisms (e.g., commercial and recreational fishing, kelp harvesting, commercial collecting), mariculture, and those activities that can alter oceanographic or geologic attributes of the habitat (e.g., mining, shore-based industrial-related intake and discharges of seawater and effluent). Usually, marine reserves are established to conserve biodiversity or enhance nearby fishery resources. Thus, goals and objectives of marine reserves can be inferred, even if they are not specifically articulated at the time of reserve formation. In this report, we review information about the effectiveness of the three marine reserves in the Monterey Bay National Marine Sanctuary (Hopkins Marine Life Refuge, Point Lobos Ecological Reserve, Big Creek Ecological Reserve), and the one in the Channel Islands National Marine Sanctuary (the natural area on the north side of East Anacapa Island). Our efforts to objectively evaluate reserves in Central California relative to reserve theory were greatly hampered for four primary reasons; (1) few of the existing marine reserves were created with clearly articulated goals or objectives, (2) relatively few studies of the ecological consequences of existing reserves have been conducted, (3) no studies to date encompass the spatial and temporal scope needed to identify ecosystem-wide effects of reserve protection, and (4) there are almost no studies that describe the social and economic consequences of existing reserves. To overcome these obstacles, we used several methods to evaluate the effectiveness of subtidal marine reserves in Central California. We first conducted a literature review to find out what research has been conducted in all marine reserves in Central California (Appendix 1). We then reviewed the scientific literature that relates to marine reserve theory to help define criteria to use as benchmarks for evaluation. A recent National Research Council (2001) report summarized expected reserve benefits and provided the criteria we used for evaluation of effectiveness. The next step was to identify the research projects in this region that collected information in a way that enabled us to evaluate reserve theory relative to marine reserves in Central California. Chapters 1-4 in this report provide summaries of those research projects. Contained within these chapters are evaluations of reserve effectiveness for meeting specific objectives. As few studies exist that pertain to reserve theory in Central California, we reviewed studies of marine reserves in other temperate and tropical ecosystems to determine if there were lessons to be learned from other parts of the world (Chapter 5). We also included a discussion of social and economic considerations germane to the public policy decision-making processes associated with marine reserves (Chapter 6). After reviewing all of these resources, we provided a summary of the ecological benefits that could be expected from existing reserves in Central California. The summary is presented in Part II of this report. (PDF contains 133 pages.)

A review of the ecological effectiveness of subtidal marine reserves in Central California, Part II: Summary of existing marine reserves in Central California and their potential benefits

In Central California, and elsewhere around the world, a great deal of discussion is occurring about the use of marine protected areas (MPAs) as a tool to help manage marine resources. This discussion is taking place because there is growing evidence that humans have depleted marine resources in many parts of the world, often despite strong regulatory efforts. Moreover, there is also mounting evidence that the degradation of marine resources began long ago, and we do not fully realize how much humans have altered “natural” environments. This uncertainty has led people to discuss the use of MPAs as a precautionary tool to prevent depletion or extinction of marine resources, and as a means of redressing past damages. The discussion about the use of marine reserves is increasing in intensity in California because several resource management agencies are considering reserves as they create or revise management plans. Often, the discussions surrounding this important public policy debate lead to questions about the biological or ecological value of existing marine protected areas. More than 100 MPAs exist along the coast of California. Many of these were established arbitrarily and lack specific purposes. Some California marine protected areas also have co-occurring or overlapping boundaries, have conflicting designations for use, and have conflicting rules and regulations. Because few of the existing marine protected areas have clearly articulated goals or objectives, however, it is difficult or impossible to evaluate their ecological effectiveness. (PDF contains 18 pages.)

Cost effectiveness of a combination of instruments for global warming: a quantitative approach for Spain

Climate change is an important environmental problem and one whose economic implications are many and varied. This paper starts with the presumption that mitigation of greenhouse gases is a necessary policy that has to be designed in a cost effective way. It is well known that market instruments are the best option for cost effectiveness. But the discussion regarding which of the various market instruments should be used, how they may interact and what combinations of policies should be implemented is still open and very lively. In this paper we propose a combination of instruments: the marketable emission permits already in place in Europe for major economic sectors and a CO(2) tax for economic sectors not included in the emissions permit scheme. The study uses an applied general equilibrium model for the Spanish economy to compute the results obtained with the new mix of instruments proposed. As the combination of the market for emission permits and the CO(2) tax admits different possibilities that depend on how the mitigation is distributed among the economic sectors, we concentrate on four possibilities: cost-effective, equalitarian, proportional to emissions, and proportional to output distributions. Other alternatives to the CO(2) tax are also analysed (tax on energy, on oil and on electricity). Our findings suggest that careful, well designed policies are needed as any deviation imposes significant additional costs that increase more than proportionally to the level of emissions reduction targeted by the EU.

A comparative study of Young's modulus of single-walled carbon nanotube by CPMD, MD, and first principle simulations

Carbon nanotubes (CNTs), due to their exceptional magnetic, electrical and mechanical properties, are promising candidates for several technical applications ranging from nanoelectronic devices to composites. Young's modulus holds the special status in material properties and micro/nano-electromechanical systems (MEMS/NEMS) design. The excellently regular structures of CNTs facilitate accurate simulation of CNTs' behavior by applying a variety of theoretical methods. Here, three representative numerical methods, i.e., Car-Parrinello molecular dynamics (CPMD), density functional theory (DFT) and molecular dynamics (MD), were applied to calculate Young's modulus of single-walled carbon nanotube (SWCNT) with chirality (3,3). The comparative studies showed that the most accurate result is offered by time consuming DFT simulation. MID simulation produced a less accurate result due to neglecting electronic motions. Compared to the two preceding methods the best performance, with a balance between efficiency and precision, was deduced by CPMD.

A comparative assessment of the methods of control of water hyacinth infestation with regards to fish production

Water hyacinth (Eichhornia crassipes) has been subject of three control methods since its arrival into the Nigerian freshwater lagoon system in 1984 - mechanical, chemical and biological. An assessment of these three methods seems to suggest that mechanical and chemical control methods, both of which being costly, must be applied either solely or integrated to combat the present level of considerable infestation in Nigeria. The biological control methods are advisable for slow, sustained control and can only cope with low levels of infestation. It is thus concluded that the preliminary control method should be mechanical or chemical to effectively abate the nuisance plant, followed by biological control once infestation levels have been sufficiently reduced

Comparative growth and survival of fry of Clarias gariepinus (B), Clarias anguillaris (L), Heterobranchus bidorsalis (G), Heteroclarias, Clariabranchus and Clarias hybrids under outdoor nursery management system

Hybrids of Clariid catfishes; C. gariepinus (Netherlands), C. anguillaris, H. bidorsalis and their parental species were monitored for 8 weeks in 2 x 2 x 1m outdoor concrete tanks. The fry were fed NIFFR diet (40% crude protein) twice daily, 7 days of the week. Growth and survival records were taken weekly. The male HEB X female CLG hybrid showed an overall highest performance in growth rate while the lowest was recorded in male CLA X female CLG hybrid. The male HEB X female CLG hybrid grew at a faster rate than its reciprocal hybrid. In view or their growth rate, it is possible that the growth and survival rates or H. bidorsalis especially at the fry to fingerling stage could be improved through hybridization. The hybrid have potential as commercial food fish

Managing and resisting ‘degeneration’ in employee-owned businesses: a comparative study of two large retailers in Spain and the UK

Employee-owned businesses have recently enjoyed a resurgence of interest as possible ‘alternatives’ to the somewhat tarnished image of conventional investor-owned capitalist firms. Within the context of global economic crisis, such alternatives seem newly attractive. This is somewhat ironic because, for more than a century, academic literature on employee-owned businesses has been dominated by the ‘degeneration thesis’. This suggested that these businesses tend towards failure – they either fail commercially, or they relinquish their democratic characters. Bucking this trend and offering a beacon - especially in the UK - has been the commercially successful, co-owned enterprise of the John Lewis Partnership (JLP) whose virtues have seemingly been rewarded with favourable and sustainable outcomes. This paper makes comparisons between JLP and its Spanish equivalent Eroski – the supermarket group which is part of the Mondragon cooperatives. The contribution of this paper is to examine in a comparative way how the managers in JLP and Eroski have constructed and accomplished their alternative scenarios. Using longitudinal data and detailed interviews with senior managers in both enterprises it explores the ways in which two large, employee-owned, enterprises reconcile apparently conflicting principles and objectives. The paper thus puts some new flesh on the ‘regeneration thesis’.

The marine protected area planning process in Washington state: Recommendations for increased effectiveness

In Washington State, the Department of Natural Resources (WA DNR) is responsible for managing state-owned aquatic lands. Aquatic reserves are one of many Marine Protected Area (MPA) designations in WA State that aim to protect sensitive aquatic and ecological habitat. We analyzed the designation and early planning processes of WA State aquatic reserves, identified gaps in the processes, and recommend action to improve the WA State aquatic reserve early planning approach. (PDF contains 4 pages)