The recovery of depleted species depends on their population dynamics at low abundance. Classical growth models, applied widely in fisheries science, assume that per capita offspring production increases as abundance declines (compensation). However, slow or absent by many fishes might reflect unexpectedly weak compensation the presence Allee effects (depensation). Using meta-analytical techniques to describe reproductive dynamics, we find considerable variability among 207 exploited marine...

Abstract Recovery of depleted populations is fundamentally important for conservation biology and sustainable resource harvesting. At low abundance, population growth rate, a primary determinant recovery, generally assumed to be relatively fast because competition (i.e., negative density dependence). But can limited in small by an Allee effect. This particularly relevant collapsed or species that have not recovered despite large reductions in, elimination of, threats. We investigated how...

Population trends play a large role in species risk assessments and conservation planning, are often considered threatened if their recent rate of decline meets certain thresholds, regardless how the population is. But reliable an indicator extinction is single estimate trend? Given integral this decline-based approach has played setting priorities, it surprising that undergone little empirical scrutiny. We compile extensive global dataset time series abundance data for over 1300 vertebrate...

In fisheries management, there has been a great deal of effort focused on uncertainty quantification, especially for biomass indices used in stock assessments. Notwithstanding, many models still treat total an observed tow as single observation ignoring the impact preliminary analyses and/or modelling required to estimate it. Our work aims assess propagating uncertainties these data through index by way transformation variables and non-parametric bootstrapping. We our proposed approaches with...

Abstract Captive‐breeding programs can be implemented to preserve the genetic diversity of endangered populations such that controlled release captive‐bred individuals into wild may promote recovery. A common difficulty, however, is are founded with limited broodstock, and inbreeding become increasingly difficult avoid successive generations in captivity. Program managers must choose between maintaining purity populations, at risk depression, or interbreeding outbreeding depression. We...

Abstract Exploited fish populations frequently exhibit truncated age-structure. To address a basic question in fisheries science and conservation biology—how does age truncation affect population dynamics productivity?—we explored the effect of age-structure on recruitment ten stocks Atlantic cod (Gadus morhua). Based six alternative stock–recruitment relationships, we compared models that included excluded maternal effects recruitment. In all stocks, model age-dependent was preferred over...

Karst forests are often located in mountainous regions, and because of various geological factors both soil water loss major conservation concerns. We investigated the water-holding characteristics 3 typical karst forest types through field sampling laboratory experiments. The results showed that (1) total litter mass coniferous was significantly higher than either mixed or broadleaved forest; (2) semidecomposed undecomposed litter; (3) layers had similar maximum capacity, whereas capacity...

Abstract The partially decomposed organic layer (duff: F and H layers) of the forest floor is an important boundary between soil atmospheric processes. Here we use both empirical data a three‐dimensional coupled heat water budget model to explain duff hydrological hillslope shift very brief wet periods when lateral flow in infiltration into mineral occur dry evaporative dominates are not important. moisture transitions from were result low which moves liquid vapour only centimetres metres,...

Understanding the process of recruitment is fundamental to fisheries biology and management. However, in natural populations highly variable rarely well described by classical stock–recruitment relationships (SRRs). Recent analyses suggest that age composition spawning biomass may play an important role mismatch between SRRs data. Here we develop a generalization Ricker SRR incorporates structure allowing mortality fecundity rates depend on maternal age. We provide flexible with biologically...

Abstract Independent of the effects spawning-stock biomass (SSB), environmental variability in juvenile production, driven by factors such as temperature and food supply, have considerable potential to influence population resilience fishing depletion. Here, we analyse 18 time-series Atlantic cod (Gadus morhua) stocks empirically estimate this “environmental variability” recruit-per-spawner (RPS) ratios. We then investigate role recruitment on ability recover following To end, dynamics are...

The forest floor in many ecosystems consists of a partially decomposed organic layer (duff), which together with the litter comprises boundary between atmosphere and mineral soil. Processes controlling duff water budget during dry periods (which occur most summer) were investigated using field monitoring, flow exclusion manipulations, coupled, multiphasic heat modeling. objective this paper is to model significant processes that govern dynamics drying. During moisture content duff's F cycles...

Abstract Size-selective harvesting is expected to reduce the average age and weight of commercially exploited fishes. The loss larger, older fish has been hypothesized negatively affect metrics population viability, such as spawning behaviour, recruitment, adult survival. Most studies date have focussed on individual stocks. Here, we examine trends in at broad taxonomic temporal scales, using subsets data compiled 95 marine Following moderate declines between 1960 1990, find that generally...

Fuel moisture plays an important role in predicting wildfire spread rates, fuel consumption, and heat output. The purpose of this study was to find how much we can simplify F H layer model by comparing empirical-phenomenalistic drying with a mechanistic waterbudget that included all the major water fluxes. Traditionally, has been calculated using phenomenalistic exponential rate models, which use standard meteorological station variables (temperature, precipitation, relative humidity, day...

The United Nations Convention on Biological Diversity was established in 1993. Canada is a signatory nation that has adopted, and exceeded, the UN Aichi biodiversity target to protect 10% of coastal marine areas through protected or “other effective area-based conservation measures” (OECMs) by 2020. However, science OECMs as contributors relatively young their definition efficacy testing continue evolve. Here, we examine whether closed fishing Scotian Shelf Atlantic Canada, where groundfish...

Abstract Numerous spatiotemporal species distribution modeling frameworks are now available to the ecological practitioner. This study compared three such accessible in R programming language: generalized additive models with smooths as implemented by mgcv, linear mixed based on nearest neighbor Gaussian processes starve, and stochastic partial differential equations approach sdmTMB. The primary focus was compare inferences obtained from applying these case of orange‐footed sea cucumber,...

Evidence of large‐scale biodiversity degradation in marine ecosystems has been reported worldwide, yet most research focused on few species interest or limited spatiotemporal scales. Here we assessed the spatial and temporal changes taxonomic functional composition fish communities European seas over last 25 years (1994–2019). We then explored how these community were linked to environmental gradients fishing pressure. show that variation is more than two times higher variation, with a...

The continuous, synoptical and high spatio-temporal resolution of thermal visible satellite observations constitute an asset when characterizing monitoring biogeochemical cycles in the oceans. In particular, they provide a unique insight into hydrodynamics surface ocean phytoplankton phenology. This information can be combined with in-situ higher trophic levels to understand functioning marine ecosystem, potential use for fisheries aquaculture. Gulf Maine, off eastern seaboard North America,...

Abstract The sustainable management of fisheries has largely relied on stock assessment models that assume stocks are homogeneous throughout their domain. However, ignoring complex underlying spatial patterns can lead to increased risk failures in management. Utilizing geostatistical approaches conjunction with a traditional fishery biomass dynamics model, we develop spatially-explicit modelling framework treats the population as processes. Simulation experiments demonstrate this approach...

Length–weight relationships (LWRs) are an essential component of fishery stock assessments. They used to develop indices condition and convert length data into estimates biomass. Attempts capture variability in underlying ecological processes within statistical modeling frameworks for LWRs have typically relied on the inclusion environmental variables. Here, using a case study sea scallop ( Placopecten magellanicus), we demonstrate that introducing spatiotemporal random effects generalized...

Globally, economies and marine ecosystems are increasingly dependent on sustainable fisheries management (SFM) to balance social, economic, conservation needs. The overarching objectives of SFM maximize both socio-economic benefits, while minimizing short-term costs. A number tools have been developed achieve objectives, ranging from fishery specific ecosystem-based strategies. Closures a common tool used the trade-off between considerations; they vary in scope small-scale temporary closures...

Previous research confirms that first-semester grade-point average (GPA) is related to college student persistence, retention, and graduation. Thus, it important identify factors enhancing GPA. In this study, researchers asked faculty students in the disciplines of journalism, strategic communication or public relations, mass media production design, motion picture film, general, rate themselves on success-related lifestyle habits. Students were grouped according five GPA categories, each...