The contribution of carbon-based payments to wetland conservation compensation on agricultural landscapes

This paper evaluates the potential of payments for carbon sequestered through wetland and riparian conservation, to offset the costs of publicly funded wetland conservation programs. In particular, the research focuses on quantifying the value of carbon sequestered in wetland and riparian zones of the Prairie Pothole Region in the province of Saskatchewan. The analysis examines a number of different program design, targeting alternatives and carbon prices and finds that payments for carbon contribute up to 3% (at $5 t⁻¹ CO₂e) and up to 9% (at $15 t⁻¹ CO₂e) of the monetary costs to compensate farmers for adopting wetland and riparian conservation management.     

Growth and yield responses of cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis>) to inorganic and organic fertilizers in southern Malawi

Fertilizer trees, the nitrogen-fixing legumes, such as gliricidia (Gliricidia sepium) and tephrosia (Tephrosia spp.) have been used to improve soil fertility for higher crop yields in nitrogen deficient soils. Many studies have focused on how these fertilizer trees improve maize yield, but there has been a dearth of information on the effect of fertilizer tree species on cotton growth and yield. A study was undertaken for two cropping seasons (2012/13 and 2013/14) with the objective of assessing IRM 81 cotton growth and yield responses to tephrosia and/or gliricidia biomass with or without inorganic fertilizer application. Boll opening significantly varied (P < 0.0001) with treatments and early boll opening was observed in plots where only inorganic fertilizer was applied. Higher lint yield (mean of 1397 kg/ha) was obtained in the second cropping season than in the first cropping season (480 kg/ha) and the application of gliricidia biomass with fertilizer gave the highest lint yield (2121 kg/ha). The lowest lint and seed yields were obtained from plots where tephrosia biomass only was applied. It is concluded that the use of gliricidia biomass with inorganic fertilizer improved cotton yields. The high amount of gliricidia biomass (due to prolific coppicing) applied contributed to higher cotton lint yields with reduced rates of inorganic fertilizer application, making gliricidia-cotton intercropping a cost-effective option to smallholder farmers.     

Potential Reservoirs and Risk Factors for VHSV IVb in an Enzootic System: Budd Lake,Michigan

Abstract

Viral hemorrhagic septicemia virus genotype IVb (VHSV IVb) has caused major, sporadic fish die-offs in the Laurentian Great Lakes region of North America since 2005. Presently, factors affecting VHSV IVb persistence in enzootic systems are not well understood. Even with annual surveillance, the virus can go undetected for several years after an outbreak before again re-emerging, which suggests that the virus is maintained in the system either below detectable levels or in untested reservoirs. The aim of this study was to identify potential reservoirs of VHSV IVb in Budd Lake, Michigan; VHSV IVb was first detected in Budd Lake in 2007 but remained undetected until 2011. Additionally, we explored the susceptibility of naive fish introduced into a water body enzootic for VHSV IVb by stocking age-0 Largemouth Bass Micropterus salmoides at varying densities into enclosures in the lake. The virus was not detected among samples of the fishes Notropis spp. and Lepomis spp., cylindrical papershell mussels Anodontoides ferussacianus, leeches (subclass Hirudinea), sediment, or water. However, the virus was successfully isolated from amphipods (family Hyalellidae) and Largemouth Bass held in the enclosures. Our finding of VHSV IVb in Hyalellidae amphipods in combination with other research that has detected the virus in Diporeia spp., a large benthic amphipod important as a food resource to Great Lake fishes, suggests that benthic macroinvertebrates are a reservoir for VHSV IVb in infected systems. If there are environmental reservoirs for VHSV IVb in infected systems, they are likely unevenly distributed. Findings of this study add to our understanding of the seemingly complex ecology of this deadly and economically detrimental virus.

Received February 22, 2016; accepted October 16, 2016 Published online February 6, 2017     

Ocular myxoid leiomyosarcoma in a cat

A case of myxoid leiomyosarcoma likely of iris dilator muscle origin in the enucleated eye of a 6-year-old domestic short haired cat is reported. The poorly demarcated mass expanded the iris, partially filled the globe and extended into the optic nerve. The mass was composed of spindle cells separated by abundant matrix positive for mucopolysaccharides with alcian blue. The neoplastic cells were immunoreactive for smooth muscle actin (SMA), S100 and vimentin, and negative for cytokeratin, Melan-A, glial fibrillary protein (GFAP) and desmin. There was no evidence of recurrence or metastasis 6 months after enucleation.     

Selective breeding for the hybrid striped bass (Morone chrysops, Rafinesque ×M. saxatilis, Walbaum) industry: status and perspectives

The hybrid striped bass (HSB) farming industry has considerable potential for growth into domestic retail markets, but expansion of this industry is limited by high production costs that dictate high prices for HSB. It is widely recognized within the industry that selective breeding of an improved HSB will be required to increase production efficiency and reduce market prices. A National Program of Genetic Improvement and Selective Breeding for the HSB Industry has been initiated and some progress has been made toward domestication of the parent species of the hybrid. However, uncertainty remains as to which breeding procedures will most rapidly yield sustainable genetic gains in key production traits. This paper consolidates and reviews general information on the biology of temperate basses (genus Morone) relevant to selective breeding of improved HSB. The topics covered include control of reproduction, geographic distribution of stocks and population genetic variation. This is followed by a brief review of the current application of selective breeding techniques, including those based on molecular markers. Finally, we discuss potential avenues for genetic improvement of HSB in a selective breeding program.     

Comparing the roles of Pacific halibut and arrowtooth flounder within the Gulf of Alaska ecosystem and fishing economy

The fishing industry of the western and central regions of the coastal Gulf of Alaska (CGoA) directly employs over 17,000 people and processes fish with a wholesale value of US$618 million annually. Pacific halibut (Hippoglossus stenolepis) are a valued groundfish species because of the high quality of their flesh. In contrast, arrowtooth flounder (Atheresthes stomias) are much more abundant but of low value because their flesh degrades upon heating. Both are high trophic level predators but play different roles in the ecosystem because of differences in abundance and diet. Using an end‐to‐end ecosystem model, we evaluate the impact of alternate levels of fishing effort and large‐scale changes in oceanographic conditions upon both species, the ecosystem, and the fishing economy. Reduction of longline efforts to reduce Pacific halibut mortality led to reduction in total value of all CGoA landings but increase in value landed by sport fisheries, trawl fleets, and fish pot vessels as they exploit a greater share of available halibut, sablefish, and Pacific cod. Increased trawl effort to raise arrowtooth flounder mortality led to increase in total value of all landings but large reductions in value landed by longline, jig, fish pot, and sport fleets with greater competition for available Pacific cod, halibut, and sablefish. Oceanographic conditions that enhance pelagic food chains at the expense of benthic food chains negatively impact groundfish in general, though Pacific halibut and arrowtooth flounder are resilient to these effects because of the high importance of pelagic fish in their diets.     

Efficacy of leaf litter mulch to mitigate runoff and sediment yield following mechanized operations in the Hyrcanian mixed forests

Journal of Soils and Sediments - Following ground-based skidding operations, understory vegetation and litter layer are commonly damaged or displaced by the movement of machines and timber on the...