Annual recruitment in fish is undoubtedly impacted by a vast number of biotic and abiotic factors. That is especially the case for fish species such as the black bass (species in the genus Micropterus), where there is extended parental care. Although much focus has been given in the past on determining the roles that many of these factors (e.g., temperatures, wind, flow rates, and habitat change) play in determining recruitment among the back basses, little attention has been given to assessing what role reproductive success plays in that determination. To address this question, we conducted a long-term study on two adjacent smallmouth bass (SMB) Micropterus dolomieu Lacepède, 1802 populations in eastern ON to assess the relationship between annual fry cohort size (FCS) (i.e., population-wide reproductive success) and annual recruitment. To measure population-wide annual FCS, we used snorkel surveys to conduct a complete census of nesting SMB males during the spawn from 1990 to 2015. During those surveys, we quantified mating success, determined which nests were successful or not, and calculated the number of independent fry produced each year by summing those numbers across all successful nests. Summer snorkel surveys from 1991 to 2016 assessed annual recruitment through visual counts of age 1+ juveniles. Results demonstrated a highly significant, positive, linear relationship between annual FCS and annual recruitment.

Correct species identification is critical for studies on biodiversity, ecology, and conservation. Determining Opuntia s.s. species is difficult because they have similar traits and are phenotypically plastic. Taxonomic keys are based on vegetative traits rather than reproductive ones such as flowers, because they are assumed to be too similar. We analyzed morphometric characteristics of flowers and cladodes over 6 years to determine which of these is most useful for differentiating Opuntia species from the Chihuahuan Desert. For each species (Opuntia robusta H.L. Wendl. ex Pfeiff., O. cantabrigiensis Lynch, O. tomentosa Salm-Dyck, and O. streptacantha Lem.), we tagged 20 hermaphroditic and 40 dioecious plants (totaling 100) from 2014 to 2020 to complete the sample size of flowers and cladodes. Seventeen morphometric characters were measured for new cladodes and 15 for flowers, and discriminant analysis was applied to determine which traits enabled species delimitation. Six of the 17 cladode characteristics combined explained 89% of the variation, while 9 floral characteristics combined explained 94% of the variation. Floral morphometrics proved to be very useful to accurately differentiate species and should be included, in addition to cladodes, in future taxonomic studies. Here, we provide the first taxonomic key that includes floral traits to identify Opuntia and a new description of each studied species.

Random utility models have been widely used to model spatial choice within fisheries, but less attention has been paid to modeling participation and movement between fisheries. Fishers may switch fisheries in response to time closures or changes in profitability potentially creating management implications for those fisheries, as well as the fishery with the closure. We used a random utility maximization framework to model participation, fishery choice, and location choice for a large fleet of West Coast salmon trollers, many of which also participate in other fisheries. We used the model to demonstrate substitution effects across fisheries due to spatial policies implemented in the salmon fishery. Our work suggests that spatial management of a single fishery needs to take into consideration fishers’ full choice set to predict behavioral responses to spatial policies. Our analysis also provides insights into how fishers construct multifishery harvest strategies that enable them to more fully use capital or adjust to closures or changes in relative profitability.

Using multi-scale trembling aspen tree-ring width data from Alberta, we show that scaling has a profound influence on dendroecological inferencing. At all scales of sampling, there is a significant climatological signal whose strength is nevertheless superseded by the pervasive effect of insect herbivory. At the smallest spatial scale, 20 km × 20 km, we demonstrate a quasi-periodic pattern of sharp growth reductions and the existence of negative spatial correlations among successive outbreaks. At the intermediate spatial scale of 20 km × 80 km, we show that the period 1930–1963 was marked by extremely low correlations in aspen ring widths, with much higher correlations occurring both before and after, despite high variance in precipitation that might have caused ring widths to correlate under moisture limitation. At the largest spatial scale of the entire province, aspen ring widths in the boreal forest became decorrelated abruptly in 1916, after cycling synchronously for the previous 80 years. This occurred despite a warming climate that heightened moisture limitation. Something in the environment prevents some outbreak cycles from rising to maximum intensity and from spreading to maximum extent. This appears to be the key to better predictability and management of forest insects and forests at short and long time-scales.

Biofilms are widely recognized as a prominent mode of microbial growth and strategy of antimicrobial tolerance in many environments. Characteristics that are often overlooked in biofilm investigations include the examination of metabolic pathways as the assumption might be that interference with central pathways such as glycolysis would only reduce growth and thus not be meaningful. Using the Keio collection of Escherichia coli mutants, we investigated the influence of biofilm formation and planktonic growth in full-strength and diluted Luria–Bertani (LB) broths using strains with a disruption of glycolysis (Δpgi), the Entner–Doudoroff pathway (Δedd), or the pentose phosphate pathway (Δgnd). Unexpectedly, in contrast to the E. coli Keio parent strain (BW25113), planktonic growth was enhanced in full strength and diluted LB broths in the metabolic mutants. Using a microtiter biofilm assay, the E. coli parent strain showed the highest crystal violet staining. However, when analyzed by culture assays, there was an increase in biofilm populations in the mutants in comparison to the parent strain. Fluorescence microscopy showed differences in colonization patterns in the strains. Given the availability of mutant collections in many model organisms, similar metabolic studies are warranted for biofilms, given their importance in nature.