Resolving climate impacts on fish stocks

Evidence is accumulating that the increase in CO2 is affecting the global climate, with far‐reaching implications for biological processes and ecosystem services. Recent studies suggest that there is evidence for a northward shift in the distributional range of fish species, but the mechanisms underlying these changes remain uncertain. Hence, it is largely unknown whether the observed distributional shifts are caused by a relocation of the spawning and feeding grounds, a change in the local survival of fish, or immigration into new habitats

Inter-annual and inter-specific differences in the drift of fish eggs and yolksac larvae in the North Sea: A biophysical modeling approach

We employed 3-D biophysical modeling and dispersion kernel analysis to explore inter-annual and inter-specific differences in the drift trajectories of eggs and yolksac larvae of plaice (Pleuronectes platessa), Atlantic cod (Gadus morhua), sprat (Sprattus sprattus) and horse mackerel (Trachurus trachurus) in the North Sea. In this region, these four species exhibit peak spawning during the boreal winter, late winter/early spring, late spring/early summer, and mid-summer respectively, but utilize the same spawning locations (our simulations included Dogger Bank, Southern Bight and the German Bight). Inter-annual differences in the temperature history, and an increase in the area of dispersion and final distribution at the end of the yolksac phase were more pronounced (and related to the North Atlantic Oscillation) for winter- and early spring-spawners compared to late spring/summer spawners. The progeny of the latter experienced the largest (up to 10-fold) inter-annual differences in drift distances, although absolute drift distances were modest (~2 to 30 km) when compared to those of the former (~ 20 to 130 km). Our results highlight the complex interplay that exists between the specific life history strategies of the different species and the impacts of the variability in (climate-driven) physical factors during the earliest life stages of marine fish. Resumen: Diferencias interanuales e interespecíficas en la deriva de huevos y larvas lecitotróficas en el mar Norte: Aproximación a través un modelo biofísico. – En este trabajo utilizamos un modelo 3-D físico-biológico y un análisis de dispersión del núcleo para investigar las diferencias interespecíficas e interanuales en las trayectorias de la deriva de huevos y larvas lecitotróficas de la solla (Pleuronectes platessa), el bacalao Atlántico (Gadus morhua), el espadín (Sprattus sprattus) y el jurel (Trachurus trachurus) en el Mar del Norte. En esta región, las especies estudiadas muestran distintos picos de distintos desoves en el tiempo: invierno boreal, invierno tardío/primavera temprana, primavera tardía/verano temprano y mitad del verano, respectivamente, aunque comparten las mismas zonas de desove. Las simulaciones efectuadas corresponden a tres de estas zonas: Dogger Bank, Southern Bight y German Bight. Los resultados mostraron diferencias interanuales en la temperatura experimentada por las larvas, en el área de dispersión y en el patrón de distribución al final del estadio lecitotrófico, que fueron más evidentes en el bacalao Atlántico, en comparacion con el espadín. Así mismo, estos factores estuvieron correlacionados con la Oscilación del Atlántico Norte. La progenie del espadín, además, mostró la mayor variación interanual en la distancia de dispersión, siendo hasta 10 veces mayor, aunque la distancia absoluta alcanzada fue relativamente modesta (~2-30 km) en comparación con la observada para el bacalao Atlántico (~20-130 km). Nuestros resultados subrayan la compleja interacción que existe, durante los estadios tempranos del desarrollo de peces marinos, entre las estrategias ecológica

Born small, die young: Intrinsic, size-selective mortality in marine larval fish

Mortality during the early stages is a major cause of the natural variations in the size and recruitment strength of marine fish populations. In this study, the relation between the size-at-hatch and early survival was assessed using laboratory experiments and on field-caught larvae of the European sardine (Sardina pilchardus). Larval size-at-hatch was not related to the egg size but was significantly, positively related to the diameter of the otolith-at-hatch. Otolith diameter-at-hatch was also significantly correlated with survival-at-age in fed and unfed larvae in the laboratory. For sardine larvae collected in the Bay of Biscay during the spring of 2008, otolith radius-at-hatch was also significantly related to viability. Larval mortality has frequently been related to adverse environmental conditions and intrinsic factors affecting feeding ability and vulnerability to predators. Our study offers evidence indicating that a significant portion of fish mortality occurs during the endogenous (yolk) and mixed (yolk /prey) feeding period in the absence of predators, revealing that marine fish with high fecundity, such as small pelagics, can spawn a relatively large amount of eggs resulting in small larvae with no chances to survive. Our findings help to better understand the mass mortalities occurring at early stages of marine fish.info:eu-repo/semantics/publishedVersio

Automated Landing Error Scoring System Performance and the Risk of Bone Stress Injury in Military Trainees

Context: Lower extremity bone stress injuries (BSIs) place a significant burden on the health and readiness of the US Armed Forces. Objective: To determine if preinjury baseline performance on an expanded and automated 22-item version of the Landing Error Scoring System (LESS-22) was associated with the incidence of BSIs in a military training population. Design: Prospective cohort study. Setting: US Military Academy at West Point, NY. Patients or Other Participants: A total of 2235 incoming cadets (510 females [22.8%]). Main Outcome Measure(s): Multivariable Poisson regression models were used to produce adjusted incidence rate ratios (IRRs) to quantify the association between preinjury LESS scores and BSI incidence rate during follow-up and were adjusted for pertinent risk factors. Risk factors were included as covariates in the final model if the 95% CI for the crude IRR did not contain 1.00. Results: A total of 54 BSIs occurred during the study period, resulting in an overall incidence rate of 0.07 BSI per 1000 person-days (95% CI = 0.05, 0.09). The mean number of exposure days was 345.4 6 61.12 (range = 3–368 days). The final model was adjusted for sex and body mass index and yielded an adjusted IRR for a LESS-22 score of 1.06 (95% CI = 1.002, 1.13; P = .04), indicating that each additional LESS error documented at baseline was associated with a 6.0% increase in the incidence rate of BSI during the follow-up period. In addition, 6 individual LESS-22 items, including 2 newly added items, were significantly associated with the BSI incidence. Conclusions: We provided evidence that performance on the expanded and automated version of the LESS was associated with the BSI incidence in a military training population. The automated LESS-22 may be a scalable solution for screening military training populations for BSI risk

Conservation physiology across scales: Insights from the marine realm

As the field of conservation physiology develops and becomes increasingly integrated with ecolog

Understanding the individual to implement the ecosystem approach to fisheries management

Ecosystem-based approaches to fisheries management (EAFMs) have emerged as requisite for sustainable use of fisheries resources. At the same time, however, there is a growing recognition of the degree of variation among individuals within a population, as well as the ecological consequences of this variation. Managing resources at an ecosystem level calls on practitioners to consider evolutionary processes, and ample evidence from the realm of fisheries science indicates that anthropogenic disturbance can drive changes in predominant character traits (e.g. size at maturity). Eco-evolutionary theory suggests that human-induced trait change and the modification of selective regimens might contribute to ecosystem dynamics at a similar magnitude to species extirpation, extinction and ecological dysfunction. Given the dynamic interaction between fisheries and target species via harvest and subsequent ecosystem consequences, we argue that individual diversity in genetic, physiological and behavioural traits are important considerations under EAFMs. Here, we examine the role of individual variation in a number of contexts relevant to fisheries management, including the potential ecological effects of rapid trait change. Using select examples, we highlight the extent of phenotypic diversity of individuals, as well as the ecological constraints on such diversity. We conclude that individual phenotypic diversity is a complex phenomenon that needs to be considered in EAFMs, with the ultimate realization that maintaining or increasing individual trait diversity may afford not only species, but also entire ecosystems, with enhanced resilience to environmental perturbations. Put simply, individuals are the foundation from which population- and ecosystem-level traits emerge and are therefore of central importance for the ecosystem-based approaches to fisheries management

Identification of women at risk for developing postmenopausal osteoporosis with vertebral fractures: role of history and single photon absorptiometry

Putative risk factors for the development of postmenopausal osteoporosis (PMO) with vertebral fractures were examined in a retrospective study of 663 postmenopausal white females aged 45-75 years (266 women with non-traumatic vertebral compression fractures (VF+), 134 non-fractured women from a general medicine clinic (controls) and 263 non-fractured women who were evaluated when they presented specifically for osteoporosis screening (VF-)). The VF+ women differed from control women in several respects. The VF+ group reported a higher prevalence of a positive family history of osteoporosis, and a higher prevalence of a history of medical or surgical conditions known to be independently associated with metabolic bone disease, had fewer children, were smaller (weight, height) and were slightly older. The two groups, VF+ and controls, did not differ with respect to cigarette smoking, alcohol consumption, exercise habits, menstrual or menopausal history, dietary intake of milk and cheese or in amount taking calcium supplements during pregnancy.The VF+ group also differed in certain respects from the VF- group. The VF+ group were smaller (weight, height) and were older. The VF+ group had lower cortical bone mass (measured by single photon absorptiometry of the non-dominant forearm) than either the control or VF- groups. The latter two groups did not differ from each other with respect to this measurement.These markers demonstrated limited sensitivity and specificity as estimated from a confirmatory data set, particularly for the historical and anthropometric variables. We conclude that an assessment of the risk of developing PMO with vertebral fractures cannot be based on the putative risk factors as measured in our study, but must be based on measurement of bone mass.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27770/1/0000164.pd

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd