Gillnet size selectivity of shark and ray species from Queensland, Australia

Gillnets are size-selective fishing gears commonly used by industrial and small-scale fishers, so understanding selectivity can aid fisheries management by identifying suitable mesh sizes to optimize catches of target species while reducing bycatch. Few size selectivity parameters have been estimated for sharks, with even fewer for rays. Size selection parameters were estimated for seven species of sharks and two species of rays from the Queensland East Coast Inshore Finfish Fishery (ECIFF). Size frequency data from a fishery observer program on ECIFF vessels was used to fit a standard size selection model. Mesh size independent parameters, θ1 and θ2, were estimated for each species to define selectivity curves for different mesh sizes for each species. Parameter values were compared with previous studies that used the same method. Estimates of θ1 were similar among species within the same genus, such as Carcharhinus, Rhizoprionodon, and Sphyrna. Anoxypristis cuspidata had the largest θ1 and θ2 values, likely because of its toothed rostrum that affected catchability in gillnets. Our findings can be used for the ECIFF and other gillnet fisheries to aid in mesh size recommendations and risk mitigation

Influence of controlled-release urea (polymer-coated ESN) on seed yield, soil nitrate-N, and nitrous oxide gas emissions in northeastern Saskatchewan

Non-Peer Reviewe

Where is nitrogen going in long-term cropping systems?

Non-Peer ReviewedFertilizer nitrogen use efficiency (NUE) is normally low, and has led to the idea that a large proportion of N applied as fertilizer is lost from the soil. However, N balances calculated for a long-term rotation study at Swift Current indicate that losses of fertilizer N from the soil are small, and comparison of cumulative N balances with actual soil organic matter measurements show that an overwhelming proportion of this N is cycled through the organic matter, through microbially mediated processes, enhancing the fertility of the soil

Effects of crop rotation and fertilization on soil carbon sequestration in the semiarid region

Non-Peer Reviewe

Relationship between soil texture and soil organic carbon at small field scale

Non-Peer ReviewedThe capacity of a soil to store organic carbon is related to its particle size distribution, or soil texture, mainly because the capacity of clay particles to stabilize organic materials. A study of the relationship of soil organic carbon (SOC) and particle size distribution at field level in two soils of Saskatchewan indicated that making broad assumptions about the relationship between soil texture and SOC in soils within a filed might lead to erroneous conclusions. At field scale dominant dynamic processes affecting the spatial distribution of soil texture, or other factors may create local conditions that override the fundamental texture SOC relationship of soils

Baling straw for ethanol production: the long-term implications on soil quality and productivity

Non-Peer Reviewe

Effect of fallow frequency, fertilizer, and available water on net N mineralization under wheat grown in the semi-arid Brown Soil Zone

Non-Peer Reviewe

Nitrate leaching after 17 years in no-tilled crop rotations in southwestern Saskatchewan

Non-Peer Reviewe

Effect of cropping frequency, crop type, and fertilization on nitrate leaching in a semi-arid environment

Non-Peer Reviewe

Quantitative changes in soil organic C over 37 years under conventional tillage - effect of crop rotations and fertilizers

Non-Peer Reviewe