Take the money and run: Economic segregation in U.S. metropolitan areas

Compared to racial segregation, economic segregation has received little attention in recent empirical literature. Yet a heated debate has arisen concerning Wilson's hypothesis (1987) that increasing economic segregation plays a role in the formation of urban ghettos. This paper presents a methodological critique of the measure of economic segregation used by Massey and Eggers (1990) and finds that it confounds changes in the income distribution with spatial changes. I develop a "pure" measure of economic segregation and present findings on all U.S. metropolitan areas from 1970 to 1990. There have been steady increases in economic segregation for whites, blacks, and Hispanics in both the 1970s and 1980s, but the increases have been particularly large and widespread for blacks and Hispanics in the 1980s. The causes of these changes are explored in a reduced form, fixed-effects model. Social distance theory and structural economic transformations do affect economic segregation, but the large increases in economic segregation among minorities in the 1980s cannot be fully explained within the model. These rapid increases in economic segregation, especially in the context of recent, albeit small, declines in racial segregation, have important implications for urban policy, poverty policy, and the stability of urban communities.

Life History Patterns and the Spatial and Trophic Ecology of Batoids in a Northern Gulf of Mexico Estuary

Mobile Bay is a dynamic estuary home to a diverse faunal assemblage, which includes several species of batoid fishes (Chondrichthyes: Batoidea). To better understand the dynamics of this batoid assemblage, batoids were opportunistically sampled from 440 trawls performed in and around Mobile Bay from 2016 to 2017. The species Hypanus sabinus and Gymnura lessae were the most common batoids collected (86% of catch). PERMANOVA analysis found the variables day length, location, year, and water temperature best described catch variability. Furthermore, stomach contents from Gymnura lessae were sampled to investigate its diet. Most prey were heavily degraded, thus DNA metabarcoding was used to enhance prey identification. Most prey (88.3%) were from the families Sciaenidae and Engraulidae, and the variables season and sex best explained the dietary variability. These data will be necessary for modeling potential habitat and dietary shifts of Mobile Bay’s batoids as climate change and anthropogenic disturbances alter estuaries

Suburban Poverty and Racial Segregation

Over the past thirty years, increasing numbers of low-income people live in suburbs in the United States, with an increased proportion of racial and ethnic minorities among them (Covington, Freeman, & Stoll, 2011; Frey, 2011; Howell & Timberlake, 2014; Puentes & Warren, 2006). In urban areas, increases in poverty rates have been marked by increases in racial and ethnic segregation among people living in poverty (Logan & Stults, 2010; Massey, 1990; Orfield & Luce, 2012). What is less clear from the research on suburban poverty is how much racial segregation exists. For example, some research indicates that there is more segregation among black people in the suburbs than in urban areas (Darden & Kamel, 2002) whereas other research finds that black people in the suburbs are less likely to live in segregated communities than black people in urban areas (Alba, Logan, & Stults, 2000). This paper presents findings from a new set analyses, using data from the U.S. Census Bureau’s American Community Survey, to first examine the distribution of poverty across different kinds of suburban communities and then the degree of racial and ethnic segregation within and across different kinds of suburban communities. The goal of the analyses is to better understand how policy solutions might best address racial and economic inequality in the suburbs

Co-Producing a Shared Characterization of Depredation in the Gulf of Mexico Reef Fish Fishery: Comprehensive Report

Depredation, defined as the partial or complete removal of a hooked fish by a non-target species, is a cryptic form of mortality that can affect the accuracy of stock assessments and species management efforts. Accounting for depredation is crucial to minimize uncertainty in stock assessment models and to obtain accurate and reliable fisheries catch data. If these interactions are frequent, failure to properly quantify this form of mortality can lead to the underestimation of reef fish population removals, inappropriate harvest recommendations, and stakeholder unrest. In recent years, depredation has escalated in the Gulf of Mexico (GoM) reef fish fishery. Although GoM reef fish fishery stakeholders (fishermen) have actively pushed for resource managers to implement solutions to address these increasingly pervasive interactions, a comprehensive characterization of this issue is lacking, and trends surrounding GoM reef fish depredation – as well as factors that impact depredation – have not been adequately described or evaluated. Therefore, the objective of this project was to co-produce a shared characterization of the impacts of depredation in the GoM reef fish fishery. To accomplish this, we employed a three-phased approach consisting of synthesis (phase 1), survey (phase 2), and feedback (phase 3). During phase 1, we synthesized data from the NOAA Fisheries Southeast Fisheries Science Center (SEFSC) GoM Reef Fish Observer Program, the largest and longest depredation-related dataset available. Marked increases in depredation were shown starting in 2017 for both bottom longline and vertical longline, particularly in the Eastern GoM. To complement the analysis of the commercial sector from phase 1, we designed and implemented an electronic survey of private recreational anglers in phase 2. Survey results demonstrate that anglers across the GoM routinely experience depredation and have identified a variety of influential factors such as geographic location and depth. Surprisingly, depredation has not affected fishing behavior for the majority of those surveyed. Findings from the commercial fishery (phase 1) and private recreational fishery (phase 2) were then presented to a representative group of (predominantly) charter-for-hire fishermen during an in-person, collaborative participatory modeling workshop (phase 3). These stakeholders provided unique insights, suggesting that factors like the length of the red snapper fishing season, recreational angler high-grading, and a diminished GoM shrimp trawl fleet, have led to increases in depredation. Perhaps more importantly, these stakeholders noted a growing disconnect between their on-the-water observations (i.e., increased depredation), and what they perceived as an increasing desire from NOAA Fisheries and the general public to protect all sharks. Notably, these sentiments resulted in a lack of trust with respect to shark science, stock assessments, and resource management. Ultimately, this planning project led to a deeper understanding of shark depredation in the GoM commercial, private recreational, and charter-for-hire fisheries. Project findings formed the basis of a comprehensive Research and Development Plan and an Application Plan. In addition, data and insights from this planning project contributed to a peer-reviewed depredation review (Mitchell et al. 2022), a stock assessment report (Drymon et al. 2022), a manuscript in prep (Duffin et al.), five conference presentations, and three outreach products.

Age, Growth, and Mortality of Atlantic Tripletail in the North-Central Gulf of Mexico

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, Atlantic Tripletail (N = 230, including a near-record-size specimen) were collected from the north-central GOM via hook and line and were aged using otoliths and first dorsal spines. Total length ranged from 212 to 940 mm, and age ranged from 0.07 to 5.27 years. Otoliths produced higher percent agreement (95.0%) and lower average percent error (3.0%) between readers compared to spines (82.9% and 6.5%, respectively). The von Bertalanffy growth parameters differed slightly between the otolith-based data (mean asymptotic length [L∞] = 762.42 mm, Brody growth rate coefficient [k] = 0.69 year−1, and hypothetical age at which length equals zero [t0] = −0.58 year) and spine-based data (L∞ = 718.83 mm, k = 0.79 year−1, and t0 = −0.56 year). For both otolith- and spine-based sex-specific data, the best-fitting version of the von Bertalanffy growth function permitted L∞ to vary by sex. Chapman– Robson estimates of instantaneous total mortality rate and total annual mortality rate were 1.15 and 68.66%, respectively. Based on empirical, life history-based methods, the instantaneous natural mortality rate was estimated at 0.75–0.97 and the instantaneous fishing mortality rate was estimated at 0.18–0.45, suggesting low levels of exploitation. These growth parameters and mortality estimates will provide information for future stock assessments, thereby ensuring sustainability of the GOM stock of Atlantic Tripletail

Population Dynamics, Relative Abundance, and Habitat Suitability of Adult Red Drum (Sciaenops ocellatus) in Nearshore Waters of the North-Central Gulf of Mexico

In the Gulf of Mexico, the red drum (Sciaenops ocellatus) is an immensely popular sportfish, yet the Gulf of Mexico stock is currently managed as data-limited in federal waters. The results of the federal stock assessment conducted in 2016 for Gulf of Mexico red drum were not recommended for providing management advice. Consequently, we sought to address data gaps highlighted in the assessment by producing up-to- date overall and sex-specific growth models, standardized indices of relative abundance, and predictions of habitat suitability and by updating estimates of natural mortality. Using a time series for the period of 2006–2018, we assigned ages of 0–36 years to 1178 red drum. A negative binomial generalized linear model including variables for year, depth, surface temperature, dissolved oxygen, and bottom salinity was used to standardize an index of relative abundance. Examination of catch per unit of effort revealed that adult red drum were significantly more abundant in state waters than in federal waters. These findings were explained by habitat suitability models, which were used to identify surface current velocity, surface temperature, and depth as the strongest predictors of relative abundance. The results of our investigation reveal that the adult spawning stock of red drum in the Gulf of Mexico is not fully protected by the catch moratorium in federal waters

Documentation of Atlantic Tarpon (Megalops atlanticus) Space Use and Move Persistence in the Northern Gulf of Mexico Facilitated by Angler Advocates

Atlantic tarpon (Megalops atlanticus, hereafter tarpon) are facing a multitude of stressors and are considered Vulnerable by the IUCN; however, significant gaps remain in our understanding of tarpon space use and movement. From 2018 to 2019, citizen scientists facilitated tagging of 23 tarpon with SPOT tags to examine space use and movement across the northern Gulf of Mexico. Movement-based kernel densities were used to estimate simplified biased random bridge-based utilization distributions and a joint move persistence model was used to estimate a behavioral index for each fish. Tarpon showed consistent east–west movement from the Alabama/Florida border to Louisiana, and utilization distributions were highest in the Mississippi River Delta. Move persistence was highest in Alabama and Mississippi and lowest in Louisiana. Our examination of tarpon space use and movement indicates that Louisiana is a critical, yet understudied, part of their range