Evaluating the Effects of a Deep-Water Marine Protected Area a Decade After Closure: A Multifaceted Approach Reveals Equivocal Benefits to Reef Fish Populations

Marine protected areas (MPAs) are increasingly used to rebuild fish populations. In 2009, eight MPAs were designated off the southeast United States with the goal of rebuilding populations of long-lived deep-water reef fishes. We tested whether reef fish within the largest of these MPAs, the Snowy Wreck Marine Protected Area (SWMPA), have increased in size and abundance relative to a nearby control area and compared to pre-closure. Hurdle models fitted through Bayesian inference on echosounder data collected in 2007–2009 and 2018–2020 yielded no evidence of an MPA effect. Comparisons of catch-per-unit-effort (CPUE) of all reef fishes yielded similar null results. However, CPUE of reef species with formal stock assessments increased 47% in the SWMPA and decreased 50% in the control area. We found significant increases in mean length of red porgy (Pagrus pagrus) inside the SWMPA but not in the control area. We also found community composition changes, including shifts away from groupers (Serranidae; Epinephelinae) and toward snappers (Lutjanidae) and tilefish (Malacanthidae) in both areas, though we did not detect an MPA effect with this analysis. Our equivocal results indicate that more time and stricter enforcement may be necessary before more biological effects of the SWMPA can be detected.

Unified landslide hazard assessment using hurdle models: a case study in the Island of Dominica

Climatically-induced natural hazards are a threat to communities. They can cause life losses and heavy damage to infrastructure, and due to climate change, they have become increasingly frequent. This is especially in tropical regions, where major hurricanes have consistently appeared in recent history. Such events induce damage due to the high wind speed they carry, and the high intensity/duration rainfall they discharge can further induce a chain of hydro-morphological hazards in the form of widespread debris slides/flows. The way the scientific community has developed preparatory steps to mitigate the potential damage of these hydro-morphological threats includes assessing where they are likely to manifest across a given landscape. This concept is referred to as susceptibility, and it is commonly achieved by implementing binary classifiers to estimate probabilities of landslide occurrences. However, predicting where landslides can occur may not be sufficient information, for it fails to convey how large landslides may be. This work proposes using a flexible Bernoulli-log-Gaussian hurdle model to simultaneously model landslide occurrence and size per areal unit. Covariate and spatial information are introduced using a generalised additive modelling framework. To cope with the high spatial resolution of the data, our model uses a Markovian representation of the Matérn covariance function based on the stochastic partial differential equation (SPDE) approach. Assuming Gaussian priors, our model can be integrated into the class of latent Gaussian models, for which inference is conveniently performed based on the integrated nested Laplace approximation method. We use our modelling approach in Dominica, where Hurricane Maria (September 2017) induced thousands of shallow flow-like landslides passing over the island. Our results show that we can not only estimate where landslides may occur and how large they may be, but we can also combine this information in a unified landslide hazard model, which is the first of its kind.

Reactivity to Daily Self-Monitoring of Cannabis Use in Biological Females

Assessment reactivity involves changes to behaviours from self-monitoring those behaviours (Nelson & Hayes, 1981). In the substance use field, reactivity has been identified both as a potential confound in daily diary research (Cohn et al., 2015) and as a possible intervention tool in clinical practice (Cohn et al., 2018). Reactivity to daily self-monitoring of alcohol and tobacco use has been inconsistent in prior research. Reactivity to daily self-monitoring of cannabis use quantity has received far less study. This study involved secondary analyses of data from N = 88 females who self-monitored their cannabis use for 32 days. We examined objective reactivity of cannabis use to daily self-monitoring by assessing changes in daily cannabis use over 32 days. We also explored participants’ perceptions of the impact daily self monitoring had on their cannabis use at study completion (i.e., subjective reactivity). In hurdle models testing objective reactivity, neither probability of cannabis use, nor quantity of cannabis use, changed significantly over the study period. Many respondents (45%) reported no subjective reactivity, though a slight majority (55%) reported some subjective reactivity. Subjective reactivity did not moderate objective reactivity over time; however, higher subjective reactivity was significantly associated with increased variability (interquartile range [IQR]) in cannabis use across the self-monitoring period. Overall, reactivity appears unlikely to confound research utilizing daily diary cannabis measures, and daily self-monitoring of cannabis use may be unlikely to serve as a useful stand-alone intervention for reducing cannabis use in non-treatment-seeking individuals. Potential clinical implications of the novel finding of a link between subjective reactivity and objective cannabis use variability are discussed.

Effects of Precipitation, Temperature and Wind in Alpine Areas on Backcountry Avalanche Accidents Reported in the Western Part of Austria within 1987-2009

In this article, we are going to investigate the effects of snow, rain, temperature and wind on the number of backcountry and off-piste avalanche accidents. The data base of our survey is restricted on the western part of Austria (federal states Tyrol and Vorarlberg) within the winter periods 1987/88--2008/09. We are able to stratify the daily data for municipalities in Tyrol and Vorarlberg. Employing spatial kriging and hurdle models, we found a positive significant effect of the snow water equivalent measurement on avalanche accident counts (if we consider the running average over the past 3 days). The variables rain and temperature 1800 meter above sea level showed negative effects on the number of accident counts. In the case of the variable wind - ERA5 global reanalysis data turned out not to be reliable -- we had a focus on the 3 avalanche accident hot spots of Austria St. Anton am Arlberg, Lech and Sölden observing wind data of the weather stations Galzig, Warth and Obergurgl. At least in the case of St. Anton and Lech, we found significant positive effects (daily velocity totals and west wind component) on the number of avalanche counts. Calculating the daily mean wind load showed a positive effect only in the case of St. Anton am Arlberg.Finally, we tried to find conclusions in connection with `avalanche problems' such as used by several avalanche information services only finding (beside `new snow') some evidence for a `spring scenario'.

Households’ Willingness to Pay For The Rehabilitation of Wetlands: Evidence From Gudera Wetland, Northwest Ethiopia

Although Gudera wetland is known for its multi-functionality, it is at the edge of collapse at this time. The study was initiated to estimate households’ mean willingness to pay (WTP) for the rehabilitation of the wetland and its welfare gains from the intervention. It was also aimed to identify major determinants for the wetland rehabilitation intervention. To meet these objectives, data from 237 rural households were collected using two stage random sampling procedures. Econometric models such as, seemingly unrelated bivariate probit and double hurdle models were used to estimate mean WTP and determinants of WTP, respectively. The result shows that the mean WTP values from double bounded dichotomous choice ranges from 70.44 to 80.64 Ethiopian Birr per year per household. Therefore, the aggregated welfare gain expected from the rehabilitation intervention ranges from 2,033,180 to 2,327,593 Ethiopian Birr per year. Factors such as farm income, participation in natural resource conservation, frequency of extension contact and trust on budget allocation have a positive and significant effect on the households’ WTP. While, factors such as land size around the wetland, distance to the wetland and credit have a negative influence on households’ WTP. Thus, critical consideration of such factors is pertinent to increase the level of public support towards the rehabilitation intervention.

A comparison of zero-inflated and hurdle models for modeling zero-inflated count data

Counts data with excessive zeros are frequently encountered in practice. For example, the number of health services visits often includes many zeros representing the patients with no utilization during a follow-up time. A common feature of this type of data is that the count measure tends to have excessive zero beyond a common count distribution can accommodate, such as Poisson or negative binomial. Zero-inflated or hurdle models are often used to fit such data. Despite the increasing popularity of ZI and hurdle models, there is still a lack of investigation of the fundamental differences between these two types of models. In this article, we reviewed the zero-inflated and hurdle models and highlighted their differences in terms of their data generating processes. We also conducted simulation studies to evaluate the performances of both types of models. The final choice of regression model should be made after a careful assessment of goodness of fit and should be tailored to a particular data in question.

An empirically based simulation model to inform flow management for endangered species conservation

Increasing water demand, water development, and on-going climate change have driven extensive changes to the hydrology, geomorphology and biology of arid-land rivers globally, driving an increasing need to understand how annual hydrologic conditions affect the distribution and abundance of imperiled desert fish populations. We analyzed the relationship between annual hydrologic conditions and the endangered Rio Grande silvery minnow in the Middle Rio Grande, New Mexico, USA, using hurdle models to predict both presence and density as a function of integrated annual hydrologic metrics. Both presence and density were positively related to spring high flow magnitude and duration and negatively related to summer drying, as indicated by an integrated flow metric. Simulations suggest hydrologic conditions near the wettest observed in the data set would be required to meet recovery goals in a single year in all reaches. We demonstrate how the models developed herein can be used to examine alternative water management strategies, including strategies that may currently be socially and logistically infeasible to implement, to identify strategies minimizing trade-offs between conservation and other management goals.

Asymmetric information and opportunism in insider share-pledging

PurposeAmid growing attention from investors, regulators and advisory firms in recent years, this study assesses whether managers exploit private information to time share-pledge transactions and extract personal benefits while avoiding unintended market scrutiny.Design/methodology/approachWe use hand-collected pledging data for a random sample of S&P 1500 firms to examine whether private information influences insider share-pledging activity using Heckman selection and two-part hurdle models of the pledge decision. We also conduct an event study analysis of announcement returns to measure market reactions to pledging news and determine whether share-pledge disclosures affect investor risk assessments.FindingsConsistent with insiders timing pledges prior to anticipated performance declines, both the likelihood and level of pledging increase significantly with negative earnings surprises. New share-pledges precede significant decreases in abnormal returns, and public announcement of new pledging corresponds with significant negative cumulative abnormal returns. The evidence suggests that insiders exploit private information to time pledges, and that investors update risk assessments and value estimates based on information conveyed by these transactions.Practical implicationsOur findings hold important implications for governance and regulation of pledged shares, indicating that permissive reporting requirements in the US facilitate informed pledging and may undermine incentive alignment between managers and shareholders. The analysis promotes transaction-specific disclosures and transparent corporate policies for insider share-pledging.Originality/valueOurs is among the first empirical analyses of share-pledging in US firms and the first to examine the role of private information in pledging decisions. We offer novel evidence on the opportunistic use of pledged shares and provide insight to predictors of share-pledging behavior.