Resident Stocks Research Articles

The peer effects of resident stock market participation: Evidence from 2019 CHFS.

Limited resident's participation in the stock market has become a key constraint to the capital market development. Utilizing the 2019 China Household Financial Survey (CHFS) data, our paper designs probit models to examine the peer effects of residents' stock market participation and explore the intermediary mechanisms with a multiple intermediary model. We find that: (1) Resident involvement in stock market decision-making exhibits significant peer effects. (2) Heterogeneity analysis reveals that males and rural residents display more pronounced peer effects than females and urban residents. Additionally, middle-aged residents demonstrate more potent peer effects than their younger and older counterparts, with the intensity of peer effects correlating with education levels. (3)We observe that the peer effects of market participation operate by altering economic expectations and enhancing residents' financial literacy. (4) Further investigation establishes that individuals engaging in stock market investments manifest peer effects when deciding whether to diversify their stock portfolio. This study holds reference value for analyzing the impact of social interaction on financial behaviors and regulating individuals' financial conduct.

Polychlorinated biphenyl and polybrominated diphenyl ether profiles vary with feeding ecology and marine rearing distribution among 10 Chinook salmon (Oncorhynchus tshawytscha) stocks in the North Pacific Ocean

Chinook salmon (Oncorhynchus tshawytscha) along the west coast of North America have experienced significant declines in abundance and body size over recent decades due to several anthropogenic stressors. Understanding the reasons underlying the relatively high levels of persistent organic pollutants (POPs) in Chinook stocks is an important need, as it informs recovery planning for this foundation species, as well for the Chinook-dependent Resident killer whales (Orcinus orca, RKW) of British Columbia (Canada) and Washington State (USA). We evaluated the influence of stock-related differences in feeding ecology, using stable isotopes, and marine rearing ground on the concentrations and patterns of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Chinook salmon. A principal components analysis (PCA) revealed a clear divergence of PCB and PBDE congener patterns between Chinook with a nearshore rearing distribution (‘shelf resident’) versus a more offshore distribution. Shelf resident Chinook had 12-fold higher PCB concentrations and 46-fold higher PBDE concentrations relative to offshore stocks. Shelf resident Chinook had PCB and PBDE profiles that were heavier and dominated by more bioaccumulative congeners, respectively. The higher δ13C and δ15N in shelf resident Chinook compared to the offshore rearing stocks, and their different marine distributions explain the large divergence in contaminant levels and profiles, with shelf resident stocks being heavily influenced by land-based sources of industrial contamination. Results provide compelling new insight into the drivers of contaminant accumulation in Chinook salmon, raise important questions about the consequences for their health, and explain a major pathway to the heavily POP-contaminated Resident killer whales that consume them.

Mark-recapture estimates of seasonal abundance and survivorship for bottlenose dolphins (Tursiops truncatus) near Charleston, South Carolina, USA

The stock structure of western North Atlantic bottlenose dolphins (Tursiops truncatus) is complex, with seasonally migratory stocks often overlapping with year-round resident stocks. High rates of exchange between northernmost sites have been documented but movement and seasonal fluctuation in abundance among sites along the southern portion of the US Atlantic coast is not well understood. To better understand seasonal abundance, a three-year mark-recapture study of bottlenose dolphins in coastal and estuarine waters near Charleston, South Carolina, USA was conducted. A robust design was employed in order to minimise bias and more precisely determine seasonal estimates of abundance and concurrently examine temporary immigration/emigration and survivorship. Systematic boat-based surveys were carried out (n = 192) from January 2004 to December 2006. The entire study area was surveyed one week per month; an additional survey was conducted in the months in which seasonal abundance was estimated: January (winter), April (spring), July (summer) and October (autumn). Standard photo-identification techniques were used to accumulate sightings of 521 distinctively marked dolphins, 65% of which were sighted more than once. Pollock’s robust design was applied using MARK and the ensuing abundance estimates were adjusted for the seasonal proportion of unmarked dolphins (ranging from 0.27 to 0.40) in the population. Estimates ranged from 364 (95% CI = 305–442) in January 2004 to 910 (95% CI = 819–1018) in October 2006. Summer abundance estimates were consistently greater than those from winter months, although estimates varied considerably among years. The same model was used to calculate an annual survival rate estimate of 0.951 (95% CI = 0.882–1.00) for marked individuals within the population. A high degree of transience, demonstrated by seasonal influxes of single-sighted individuals, made it difficult to differentiate between mortality and permanent emigration. The results support the occurrence of three distinct dolphin groups found in Charleston waters: year-round residents; seasonal residents; and transients. Reporting abundance and survivorship estimates together is useful in explaining and validating results for populations in which transient individuals occur. These results provide important information for stock and viability assessment of coastal bottlenose dolphins in the western North Atlantic.

Combined effects of exploitation and environmental change on life history: a comparative analysis on Atlantic herring

Abstract The consequences of fisheries-induced evolution on stock productivity and yield depend, to a large extent, on the general prospects for growth and survival. Here, we compare the selection pressures imposed by two distinct patterns of exploitation—principally targeting spawning or non-spawning aggregations—on age at maturity among 15 Canadian stocks of Atlantic herring (Clupea harengus) that have exhibited a consistent pattern of length-at-age responses to common large-scale environmental drivers since the 1960s. In accordance with expectations for maturity-dependent harvesting, the establishment of a spawner-targeted fishery in the southern Gulf of St. Lawrence coincided with a shift towards delayed maturity in both resident stocks, whereas stocks elsewhere subject to fisheries that also exploited juveniles more commonly exhibited trends towards earlier maturity. Despite these differences, we find that environmentally driven changes in length at maturation, combined with total mortality, may overwhelmingly determine lifetime reproductive success and possibly fitness. By linking phenotypic changes experienced in the juvenile period to simple correlates of egg production in mature age classes, our study highlights the importance of managing fisheries in the context of ubiquitous but contrasting environmental constraints on life histories.

Some aspects of biology and fishery of walleye pollock <i>Theragra chalcogramma</i> in the southwestern Chukchi Sea relative to the size and age structure

Catch distribution and size-age structure of walleye pollock in the Chukchi Sea are considered on the data obtained in surveys conducted by TINRO in 2018–2020. The age of pollock was determined by otoliths. Two age groups were presented in the catches: the first group of juveniles and 1-year old fish and the second group of 7–22-year old fish, mostly 8–15 years old (90 %). The fish of 3–6 year old were absent in the catches. This age structure suggests that the stock is formed by the fish migrated from the northern Bering Sea. However, the backward migration is doubtful; the pollock, once migrated to the Chukchi Sea, remain in this new habitat, as could be seen from the age-length dependence for a part of the stock distinguished by lower growth rate because of dwelling in severe conditions of this area. Aggregations of the fast-growing (just migrated from the Bering Sea) and slow-growing (local residents) pollock had different distribution patterns in the surveyed area in the southwestern Chukchi Sea. The fast-growing allochthonous pollock distributed widely, including the seaward waters, whereas the resident pollock preferred the coastal waters. The walleye pollock fishery has started in the southern coastal area of the Chukchi Sea in 2021, so the resident stock is exploited mainly.

Genotyping-in-Thousands by sequencing panel development and application for high-resolution monitoring of introgressive hybridization within sockeye salmon

Stocking programs have been widely implemented to re-establish extirpated fish species to their historical ranges; when employed in species with complex life histories, such management activities should include careful consideration of resulting hybridization dynamics with resident stocks and corresponding outcomes on recovery initiatives. Genetic monitoring can be instrumental for quantifying the extent of introgression over time, however conventional markers typically have limited power for the identification of advanced hybrid classes, especially at the intra-specific level. Here, we demonstrate a workflow for developing, evaluating and deploying a Genotyping-in-Thousands by Sequencing (GT-seq) SNP panel with the power to detect advanced hybrid classes to assess the extent and trajectory of intra-specific hybridization, using the sockeye salmon (Oncorhynchus nerka) stocking program in Skaha Lake, British Columbia as a case study. Previous analyses detected significant levels of hybridization between the anadromous (sockeye) and freshwater resident (kokanee) forms of O. nerka, but were restricted to assigning individuals to pure-stock or “hybrid”. Simulation analyses indicated our GT-seq panel had high accuracy, efficiency and power (> 94.5%) of assignment to pure-stock sockeye salmon/kokanee, F1, F2, and B2 backcross-sockeye/kokanee. Re-analysis of 2016/2017 spawners previously analyzed using TaqMan® assays and otolith microchemistry revealed shifts in assignment of some hybrids to adjacent pure-stock or B2 backcross classes, while new assignment of 2019 spawners revealed hybrids comprised 31% of the population, ~ 74% of which were B2 backcross or F2. Overall, the GT-seq panel development workflow presented here could be applied to virtually any system where genetic stock identification and intra-specific hybridization are important management parameters.

Foreign-Born Resident Networks and Stock Comovement: When Local Bias Meets Home (Country) Bias

AbstractForeign migration flows have important stock market consequences. Foreign-born resident networks within U.S. Metropolitan Statistical Areas (MSAs) are associated with excess return comovement between locally headquartered stocks and American Depositary Receipts (ADRs) from countries with ties to the MSA through the network of foreign-born residents. This comovement is hardly due to correlated fundamentals and at least partially driven by correlated trading within members of a common investor base consisting of foreign-born residents. Our evidence has implications for both investors and foreign multinational corporations (MNCs) seeking to reap benefits from cross-listings and is consistent with the notion that foreign-born residents exhibit both local bias and home (country) bias.

A spatial simulation approach to hydroacoustic survey design: A case study for Atlantic menhaden

Patchily distributed pelagic fish species present a challenge to classical approaches to hydroacoustic survey designs. We propose a spatial simulation approach to designing acoustic surveys and provide a case study in the northern resident stock of Atlantic menhaden Brevoortia tyrannus during winter. The structure and abundance of this stock is poorly characterized due to a paucity of fishery-independent surveys and the geographically limited range of the reduction fishery. In order to develop new fishery-independent information for this stock, we conducted a simulation study to estimate the accuracy and precision of an offshore hydroacoustic survey. We simulated a spatial super-population based on fishery-dependent data, and randomly re-sampled the population with various types of hydroacoustic survey equipment. Our results suggest that a combination of down-viewing echosounder and omni-directional sonar can generate biomass estimates with a coefficient of variation around 25%. The use of down-viewing echosounder alone, however, generated biomass estimates with poor precision. Our approach accounts for the patchy spatial distributions of the survey populations, which leads to more realistic estimates of precision than classical approaches implicitly assuming independence. The approach also evaluates several types of hydro-acoustic survey equipment in deriving absolute biomass estimates, and the survey, once implemented, may contribute to improved spatially explicit management of the stock.

Annual scheduling for anesthesiology medicine residents in task-related programs with a focus on continuity of care

This article presents a new model for constructing annual schedules for medical residents based on the regulations of a German teaching hospital as well as the program restrictions of the German Medical Association. Since resident programs of physicians do not only vary between disciplines but also between countries, it is essential to evaluate the main characteristics of the program. The main difference between the already well-studied resident programs in the US and the one of this article is the task-related structure. Residents need to perform different interventions several times to become specialists. This study will focus on Germany since there was a judgement in 2015 that hospital management needs training schedules guaranteeing the success of the resident program in time. Therefore, a new formulation of a tactical resident scheduling problem is presented. The problem is formulated in two stages considering the total number of interventions, equal progress in training as well as continuity of care. As the second stage of our formulation is a quadratic program and even by linearization standard solvers are not able to generate high-quality solutions within 24 h, a genetic algorithm using standard crossovers is developed for the second stage constructing annual schedules for an existing stock of residents. We evaluate our algorithm by comparing the solutions of the genetic algorithm and standard software with a real-world situation of a German training hospital from 2016.

Determinants of international tourism demand: Evidence from Australian states and territories

This article explores whether the determinants of international tourism demand differ by states and territories in Australia. This is the first attempt at econometric modelling of international tourism demand in the states and territories of Australia. A demand model is specified where international visits to states and territories is a function of world income, state-level transportation costs, stock of foreign-born residents, the Australian real exchange rate and the price levels of international and domestic substitutes. Panel and time series econometric techniques are employed to test the model variables for stationarity, cointegration and direction of causality. Panel and time series cointegration tests show that the model is cointegrated. The causality analysis indicates that all explanatory variables Granger cause international visits to the Australian states and territories. Further, we show that the impacts of the determinants of international tourism vary by states and territories. The results underscore the importance of targeted policymaking that takes into account the economic and social structure of each state and territory instead of designing tourism policies on the basis of one-size-fits-all approach.

Population Structure of Alligator Gar in a Gulf Coast River: Insights from Otolith Microchemistry and Genetic Analyses

AbstractGrowing interest in the Alligator Gar Atractosteus spatula among anglers and fishery managers has inspired efforts to better manage populations. Successful management requires identifying population structure and understanding the distribution of stocks and associated differences in life history. This is particularly important in river systems along the coast of the Gulf of Mexico, where transitions from freshwater rivers to saltwater bays provide the potential for life history diversification. We used otolith microchemistry and genetics to assess population structure of Alligator Gars in the Guadalupe River–San Antonio Bay system, Texas. Lifetime Sr:Ca revealed three, distinct life histories that differed in prevalence across the system. River‐resident fish (i.e., fish exclusive to freshwater) were present throughout the river but were most common in the uppermost river reach (74% of upper river fish). Transient fish that used both river and bay habitats were also found throughout the river but were most prevalent in the lowermost river reach (66% of lower river fish) and bay (91% of bay fish). Bay residents (i.e., fish exclusive to salt water) were detected but comprised only 9% of bay fish. Haplotype diversity based on mitochondrial DNA was lowest in the upper river, indicating limited gene flow compared with the lower river and bay. Similarly, nuclear DNA analyses indicated nonrandom mating between fish from the upper river, lower river, and bay. The differences in Alligator Gar movement and genetics along the river–bay continuum suggest the presence of a river resident stock that predominates the upper river, and a transient stock that predominates the lower river and bay. Therefore, a local‐scale management approach, consistent with the spatial partitioning between stocks, would conserve life history and genetic diversity within the system and provide opportunities to meet the needs of a diverse angling constituency. Understanding how population dynamics differ between stocks is needed to develop appropriate fishery management objectives and corresponding regulations for Alligator Gar.Received May 20, 2016; accepted December 2, 2016 Published online February 27, 2017

Sockeye salmon repatriation leads to population re-establishment and rapid introgression with native kokanee.

Re‐establishing salmonid populations to areas historically occupied has the substantial potential for conservation gains; however, such interventions also risk negatively impacting native resident stocks. Here, we assessed the success of the hatchery‐assisted reintroduction of anadromous sockeye salmon (Oncorhynchus nerka) into Skaha Lake, British Columbia, Canada, and evaluated the genetic consequences for native kokanee, a freshwater‐obligate ecotype, using single nucleotide polymorphism genotypic data collected from the reference samples of spawning Okanagan River sockeye and Skaha Lake kokanee presockeye reintroduction, along with annual trawl survey and angler‐caught samples obtained over an eight‐year period. Significant differentiation was detected between sockeye and kokanee reference samples, with >99% stock assignment. Low proportions of sockeye and hybrids were detected within 2008 and 2010 age‐0 trawl samples; however, by 2012, 28% were sockeye, rising to 41% in 2014. The number of hybrids detected rose proportionally with the increase in sockeye and exhibited an intermediate phenotype. Our results indicate that the reintroduction of anadromous sockeye to Skaha Lake is succeeding, with large numbers returning to spawn. However, hybridization with native kokanee is of concern due to the potential for demographic or genetic swamping, with ongoing genetic monitoring necessary to assess the long‐term effects of introgression and to support interactive fisheries management.

Return migration and Hong Kong's diverse circuits of mobility

The objective of this research is to extend a geographic understanding of the diversity of contemporary migration through a case-study of return migration to Hong Kong. We explore how political economic and socio-cultural factors associated with globalization and transnationalization have place-specific implications for return migration. To better understand such interdependencies, we shift attention away from return migration as an isolated individual-level event and argue for a consideration of circuits of mobility and how migrants manage the lengths of these circuits. Such a longitudinal approach hypothesizes that there is systematic variation in the length of each circuits or spells of time spent living outside Hong Kong, and that discernible factors can be associated with such variation. We surveyed 1011 adult Hong Kong permanent residents to derive an estimate of the stock of residents who have returned to Hong Kong having been out of the SAR and to explore the diversity of mobility circuits. We found that 11.8% of our respondents had lived outside Hong Kong and that they left and returned to the SAR for diverse but inter-connected political economic and socio-cultural reasons. The results suggest that mobility circuits unfold in strategic ways over borders, as individuals and families negotiate contrasting national and local regimes of migration. We conclude by raising implications for theory and policy and call for the development of a mobility information system for Hong Kong.

Harbour Porpoises Phocoena phocoena in the Eastern Scheldt: A Resident Stock or Trapped by a Storm Surge Barrier?

Coastal protection measures are planned and executed worldwide to combat the effects of global warming and climate change, in particular the acceleration of sea level rise, higher storm surge flooding and extensive coastal inundation. The extent to which these defensive measures may impact coastal and estuarine ecosystems is still poorly understood. Since the building of a storm surge barrier, movement of harbour porpoises Phocoena phocoena in and out of the Eastern Scheldt tidal bay (SW-Netherlands) may be limited. To measure residency, porpoises stranded along the Dutch North Sea coast between 2006 and 2008 were sampled for muscle (n = 102) and bone tissue (n = 118), of which 9 muscle (8.8%) and 12 bone samples (10.2%) were collected from animals stranded within the Eastern Scheldt. Stable carbon (δ13C) was analysed to get insight into the habitat use and residency of porpoises in the Eastern Scheldt. Our data showed significantly higher δ13C values in the muscle of porpoises stranded within the Eastern Scheldt (µ = −17.7‰, SD = 0.4‰) compared to animals stranded along the Dutch coast (µ = −18.3‰, SD = 0.5‰). This suggests that most porpoises stranded in the Eastern Scheldt foraged there for a longer period. The distinct δ13C signature of animals from the Eastern Scheldt was not observed in bone tissue, suggesting a relatively recent shift in habitat use rather than life-long residency of porpoises within the Eastern Scheldt. The high number of strandings within the Eastern Scheldt suggests a higher mortality rate compared to the Dutch coastal zone. Our study indicates that along with other changes in the physical environment, the storm surge barrier may play an important role in determining the residency of porpoises in the Eastern Scheldt, and that the area might act as an ecological trap for porpoises entering it.

Morphometric characteristics of Prochilodus lineatus (Valenciennes 1847), of the migratory and resident stocks of the river Mogí-Guaçu, São Paulo State, Brazil

The species Prochilodus lineatus, with great commercial relevance in the rivers Grande, Pardo and Mogi-Guacu, is characterized by the formation of great shoals which are capable of developing wide migratory displacements. Current assay evaluates, by means of the morphometric characteristics and age, whether the curimbatas (P. lineatus) of different migratory and resident stocks form a single population, with interactivities among the sub-populations during the 'piracema' period (reproduction migration). A completely randomized plot with a 4 x 2 factorial scheme, with four stocks (one resident and three migratory) as factors and two genders (male and female), with thirty replicates, was employed, with each fish taken as an experimental unit. An 80.19% variation for the first principal component and an 8.09% variation for the second principal component were reported as provided by the ten morphometric variables of resident and migratory stocks. The resident stock had the highest rate for the whole morphometric variables. There was superposition of individual scores of the same characteristics among the migratory stocks. Significant predominance of males was observed among resident stocks and migratory stocks I and II. Morphometric similarity verified among the migratory stocks showed a single population, with small inter-population variations.

An alternative method for estimating the status of resident reef fish stocks, based on differential fishing effort across a marine reserve boundary

The stock status of roman Chrysoblephus laticeps was estimated in the Goukamma, a temperate South African marine protected area (MPA). Standardised catch per unit effort (CPUE) from a controlled angling survey on both sides of the MPA border was employed to extrapolate the CPUE at zero fishing mortality. Converted into biomass, the estimate (61% of unexploited biomass) lay midway between those of two biomass-per-recruit (B/R) models for the same population based on angling and diving surveys (i.e. 52% and 69% of unexploited biomass respectively). The extrapolated CPUE at zero fishing mortality (4.4 fish angler-hour−1) in this study compared well with the mean CPUE of 4.6 fish angler-hour−1 determined during a concomitant survey in the core area of the nearby Tsitsikamma MPA – the oldest, and one of the largest, MPAs in Africa. Extrapolations of CPUE have the potential to deliver reliable and consistent estimates of stock status and could offer a practical alternative to conventional B/R models.

Stock delineation of migratory and resident Pacific hake in Canadian waters

Within Canadian waters there are two distinct stocks of Pacific hake ( Merluccius productus); an inshore resident stock and an offshore, migratory stock. From 2006 to 2008, a change in the migratory behavior of the offshore stock resulted in a shift of the entire fishery from the typical grounds off the west coast of Vancouver Island to the more northerly region of Queen Charlotte Sound. Management concerns regarding the unknown exploitation of any resident stocks prompted a re-examination of Pacific hake stock structure in Canadian waters. Population genetic techniques determined a connectivity of Pacific hake found in Queen Charlotte Sound in the summer to (1) the offshore migratory population; (2) the inshore resident population and (3) the populations in adjacent deepwater inlets. We provide evidence that supports the delineation of the resident and migratory stocks; and evidence of two other genetically differentiated resident groups. These results were supported by differences in biological parameters and parasite infection levels. Of note is the first record of the occurrence of the parasite Kudoa paniformis in the resident population.

제주 연안에 출현하는 큰돌고래(Bottlenose dolphins) 연안 정착성 개체군

Recently, bottlenose dolphins have frequently appeared in coastal waters of the Jeju Islands. To determine whether these individuals belong to one or more pods, the Cetacean Research Institute (CRI) established visual and photo-identification surveys in the Jeju Islands from November 2007 to July 2009. During visual surveys, pods composed of 10 to 80 individuals were sighted mainly in the northeastern and northwestern of Jeju Islands. Eighty-nine individuals were identified and cataloged by photo-identification using natural nicks and notches on their dorsal fins. Thirty-six individuals were identified three times or more, and nine individuals were identified five times during seven surveys. One individual appeared in November 2007, August 2008, October 2008, April 2009, and July 2009. The results of our study confirm that these dolphins represent a coastal resident stock. Futhermore, we will establish dolphin abundance, management, and usage studies using continuous visual and photo-identification surveys.

Temporal trends in stock origin and abundance of juvenile herring (Clupea harengus) in the Irish Sea

Abstract Burke, N., Brophy, D., Schön, P-J., and King, P. A. 2009. Temporal trends in stock origin and abundance of juvenile herring (Clupea harengus) in the Irish Sea. – ICES Journal of Marine Science, 66: 1749–1753. Celtic Sea herring (Clupea harengus) larvae partly disperse into the Irish Sea, where they mix with the resident stock during their first year of life. This affects the reliability of the use of acoustic estimates of juvenile abundance on the Irish Sea nursery grounds as a recruitment index for use in stock predictions. Otolith microstructure analysis can be used to distinguish between autumn-spawned and winter-spawned individuals. Because winter spawners do not occur in the Irish Sea, this component can be assigned to Celtic Sea immigrants. We used this method to estimate the proportion of winter-spawned individuals in samples of age-1 herring from the western Irish Sea over a 10-year period (1993–2003), and subtracted a corresponding proportion from the acoustic age-1 abundance estimates. The adjusted index for autumn-spawned (supposedly Irish Sea) juveniles was significantly correlated with the abundance of age-3 fish from the same year class in commercial catches and in the acoustic surveys (p < 0.05 and <0.01, respectively), whereas the correlations for unadjusted indices were not significant. These findings are discussed in relation to the monitoring and assessment of herring in the two areas.

Are growth and recapture of hatchery‐reared and resident brown trout (Salmo truttaL.) density dependent after stocking?

Abstract – The population density of brown trout (Salmo trutta) in a small natural system was manipulated in six equal‐length stream sections by stocking hatchery‐reared 1+ brown trout (unstocked, tripled and quintupled) over two consecutive years. The results showed that hatchery‐reared trout grew more slowly and were more mobile than resident trout, and that their growth was inversely density dependent. In contrast, growth of the resident trout was density independent. The recapture of 1+ resident and hatchery‐reared trout was inversely density dependent. This is most likely a consequence of increased competition. However, after a single winter the population density returned to its base level prior stocking and older resident trout showed no density‐dependent recapture. Thus, the advantage of stocking, here higher biomass, may have the detrimental effect of decreasing resident stocks of the same size class during summer.