Publications by authors named "Hannes Baumann"

19 Publications

  • Page 1 of 1

App-Tailoring Requirements to Increase Stress Management Competencies Within Families: Cross-sectional Survey Study.

J Med Internet Res 2021 Jul 30;23(7):e26376. Epub 2021 Jul 30.

Department of Movement Science, Faculty of Psychology and Human Movement, University of Hamburg, Hamburg, Germany.

Background: Families experiencing high levels of psychological distress are considered a particularly vulnerable population for adverse effects on mental and physical health. Moreover, highly stressed individuals engage less in mental health promoting activities and show low stress management competencies. App-based stress interventions seem promising for the treatment and prevention of stress outcomes and might be a low-threshold solution.

Objective: The aim of this study was to identify the requirements for a tailored app to reduce stress in a cohort of highly stressed families that have low stress management skills.

Methods: Parents (n=1008; age: mean 47.7 years, SD 6.1; female: 599/1008, 59.7%) completed an extensive web-based survey and were subdivided into a target (stressed individuals with low stress competency) and nontarget group according to their reported stress level and stress management competencies. Group differences were analyzed using analysis of variance. In principal component analysis with Kaiser varimax rotation, personally defined stress management goals were grouped into components. Linear regression models were also calculated.

Results: A 3-factor solution cumulatively explained 56% of the variance in personally defined goals of interest for stress management with (1) active strategies (25.61% explained variance), (2) general competency (17.95% explained variance) and (3) passive strategies (12.45% explained variance). The groups differed in age (F=27.67, P<.001), health index (F=246.14, P<.001), personally defined general-competency goal (F=94.16 P<.001), as well as "information acquisition" (F=14.75, P<.001) and "need for stimulation" (F=54.49, P<.001) personality traits. A regression model showed that for the active strategies goals of interest, only app feature information or instructional videos had a significant effect (P=.02). The general competency factor showed none, and the passive strategies factor showed significant effects for 2 app features-suggestions for planning possible activities with the family (P=.01) and diaries for documentation and development of strategies (P=.03).

Conclusions: The results of this survey study highlight the need to develop an app to increase stress management competencies that takes into consideration perceived stress level, stress management skills, personality, and personally defined goals of the user. The content of the app should be tailored to previously detected personality traits, especially selective information acquisition and low need for stimulation. Furthermore, personally defined stress management goals seem to affect interest in some features.
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http://dx.doi.org/10.2196/26376DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8367136PMC
July 2021

Natal origin and age-specific egress of Pacific bluefin tuna from coastal nurseries revealed with geochemical markers.

Sci Rep 2021 Jul 9;11(1):14216. Epub 2021 Jul 9.

Institute of Oceanography, National Taiwan University, Taipei, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan.

Geochemical chronologies were constructed from otoliths of adult Pacific bluefin tuna (PBT) to investigate the timing of age-specific egress of juveniles from coastal nurseries in the East China Sea or Sea of Japan to offshore waters of the Pacific Ocean. Element:Ca chronologies were developed for otolith Li, Mg, Mn, Zn, Sr, and Ba, and our assessment focused on the section of the otolith corresponding to the age-0 to age-1 + interval. Next, we applied a common time-series approach to geochemical profiles to identify divergences presumably linked to inshore-offshore migrations. Conspicuous geochemical shifts were detected during the juvenile interval for Mg:Ca, Mn:Ca, and Sr:Ca that were indicative of coastal-offshore transitions or egress generally occurring for individuals approximately 4-6 mo. old, with later departures (6 mo. or older) linked to overwintering being more limited. Changepoints in otolith Ba:Ca profiles were most common in the early age-1 period (ca. 12-16 mo.) and appear associated with entry into upwelling areas such as the California Current Large Marine Ecosystem following trans-Pacific migrations. Natal origin of PBT was also predicted using the early life portion of geochemical profile in relation to a baseline sample comprised of age-0 PBT from the two primary spawning areas in the East China Sea and Sea of Japan. Mixed-stock analysis indicated that the majority (66%) of adult PBT in our sample originated from the East China Sea, but individuals of Sea of Japan origin were also detected in the Ryukyu Archipelago.
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http://dx.doi.org/10.1038/s41598-021-93298-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270904PMC
July 2021

A comprehensive non-redundant reference transcriptome for the Atlantic silverside Menidia menidia.

Mar Genomics 2020 Oct 25;53:100738. Epub 2020 Jan 25.

Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, CT-06340 Groton, USA.

The Atlantic silverside (Menidia menidia) has been the focus of extensive research efforts in ecology, evolutionary biology, and physiology over the past three decades, but lack of genomic resources has so far hindered examination of the molecular basis underlying the remarkable patterns of phenotypic variation described in this species. We here present the first reference transcriptome for M. menidia. We sought to capture a single representative sequence from as many genes as possible by first using a combination of Trinity and the CLC Genomics Workbench to de novo assemble contigs based on RNA-seq data from multiple individuals, tissue types, and life stages. To reduce redundancy, we passed the combined raw assemblies through a stringent filtering pipeline based both on sequence similarity to related species and computational predictions of transcript quality, condensing an initial set of >480,000 contigs to a final set of 20,998 representative contigs, amounting to a total length of 53.3 Mb. In this final assembly, 91% of the contigs were functionally annotated with putative gene function and gene ontology (GO) terms and/or InterProScan identifiers. The assembly contains complete or nearly complete copies of >95% of 248 highly conserved core genes present in low copy number across higher eukaryotes, and partial copies of another 3.8%, suggesting that our assembly provides relatively comprehensive coverage of the M. menidia transcriptome. The assembly provided here will be an important resource for future research.
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http://dx.doi.org/10.1016/j.margen.2019.100738DOI Listing
October 2020

Are long-term growth responses to elevated pCO2 sex-specific in fish?

PLoS One 2020 17;15(7):e0235817. Epub 2020 Jul 17.

Department of Marine Sciences, University of Connecticut, Groton, CT, United States of America.

Whether marine fish will grow differently in future high pCO2 environments remains surprisingly uncertain. Long-term and whole-life cycle effects are particularly unknown, because such experiments are logistically challenging, space demanding, exclude long-lived species, and require controlled, restricted feeding regimes-otherwise increased consumption could mask potential growth effects. Here, we report on repeated, long-term, food-controlled experiments to rear large populations (>4,000 individuals total) of the experimental model and ecologically important forage fish Menidia menidia (Atlantic silverside) under contrasting temperature (17°, 24°, and 28°C) and pCO2 conditions (450 vs. ~2,200 μatm) from fertilization to ~ a third of this annual species' life span. Quantile analyses of trait distributions showed mostly negative effects of high pCO2 on long-term growth. At 17°C and 28°C, but not at 24°C, high pCO2 fish were significantly shorter [17°C: -5 to -9%; 28°C: -3%] and weighed less [17°C: -6 to -18%; 28°C: -8%] compared to ambient pCO2 fish. Reductions in fish weight were smaller than in length, which is why high pCO2 fish at 17°C consistently exhibited a higher Fulton's k (weight/length ratio). Notably, it took more than 100 days of rearing for statistically significant length differences to emerge between treatment populations, showing that cumulative, long-term CO2 effects could exist elsewhere but are easily missed by short experiments. Long-term rearing had another benefit: it allowed sexing the surviving fish, thereby enabling rare sex-specific analyses of trait distributions under contrasting CO2 environments. We found that female silversides grew faster than males, but there was no interaction between CO2 and sex, indicating that males and females were similarly affected by high pCO2. Because Atlantic silversides are known to exhibit temperature-dependent sex determination, we also analyzed sex ratios, revealing no evidence for CO2-dependent sex determination in this species.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235817PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7367484PMC
September 2020

Diel and tidal pCO × O fluctuations provide physiological refuge to early life stages of a coastal forage fish.

Sci Rep 2019 12 3;9(1):18146. Epub 2019 Dec 3.

University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, 06340, Groton, CT, USA.

Coastal ecosystems experience substantial natural fluctuations in pCO and dissolved oxygen (DO) conditions on diel, tidal, seasonal and interannual timescales. Rising carbon dioxide emissions and anthropogenic nutrient input are expected to increase these pCO and DO cycles in severity and duration of acidification and hypoxia. How coastal marine organisms respond to natural pCO × DO variability and future climate change remains largely unknown. Here, we assess the impact of static and cycling pCO × DO conditions of various magnitudes and frequencies on early life survival and growth of an important coastal forage fish, Menidia menidia. Static low DO conditions severely decreased embryo survival, larval survival, time to 50% hatch, size at hatch and post-larval growth rates. Static elevated pCO did not affect most response traits, however, a synergistic negative effect did occur on embryo survival under hypoxic conditions (3.0 mg L). Cycling pCO × DO, however, reduced these negative effects of static conditions on all response traits with the magnitude of fluctuations influencing the extent of this reduction. This indicates that fluctuations in pCO and DO may benefit coastal organisms by providing periodic physiological refuge from stressful conditions, which could promote species adaptability to climate change.
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http://dx.doi.org/10.1038/s41598-019-53930-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6890771PMC
December 2019

High sensitivity of a keystone forage fish to elevated CO and temperature.

Conserv Physiol 2019 21;7(1):coz084. Epub 2019 Nov 21.

Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Avery Point, CT 06340, USA.

Sand lances of the genus are keystone forage fish in coastal ecosystems across the northern hemisphere. Because they directly support populations of higher trophic organisms such as whales, seabirds or tuna, the current lack of empirical data and, therefore, understanding about the climate sensitivity of sand lances represent a serious knowledge gap. Sand lances could be particularly susceptible to ocean warming and acidification because, in contrast to other tested fish species, they reproduce during boreal winter months, and their offspring develop slowly under relatively low and stable CO conditions. Over the course of 2 years, we conducted factorial CO × temperature exposure experiments on offspring of the northern sand lance , a key forage species on the northwest Atlantic shelf. Wild, spawning-ripe adults were collected from Stellwagen Bank National Marine Sanctuary (Cape Cod, USA), and fertilized embryos were reared at three CO conditions (400, 1000 and 2100 μatm) crossed with three temperatures (5, 7 and 10 ˚C). Exposure to future CO conditions consistently resulted in severely reduced embryo survival. Sensitivity to elevated CO was highest at 10 ˚C, resulting in up to an 89% reduction in hatching success between control and predicted end-of-century CO conditions. Moreover, elevated CO conditions delayed hatching, reduced remaining endogenous energy reserves at hatch and reduced embryonic growth. Our results suggest that the northern sand lance is exceptionally CO-sensitive compared to other fish species. Whether other sand lance species with similar life history characteristics are equally CO-sensitive is currently unknown. But the possibility is a conservation concern, because many boreal shelf ecosystems rely on sand lances and might therefore be more vulnerable to climate change than currently recognized. Our findings indicate that life history, spawning habitat, phenology and developmental rates mediate the divergent early life CO sensitivities among fish species.
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http://dx.doi.org/10.1093/conphys/coz084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6868386PMC
November 2019

Contrasting genomic shifts underlie parallel phenotypic evolution in response to fishing.

Science 2019 08;365(6452):487-490

Department of Biology, Stanford University and Hopkins Marine Station, Pacific Grove, CA, USA.

Humans cause widespread evolutionary change in nature, but we still know little about the genomic basis of rapid adaptation in the Anthropocene. We tracked genomic changes across all protein-coding genes in experimental fish populations that evolved pronounced shifts in growth rates due to size-selective harvest over only four generations. Comparisons of replicate lines show parallel allele frequency shifts that recapitulate responses to size-selection gradients in the wild across hundreds of unlinked variants concentrated in growth-related genes. However, a supercluster of genes also rose rapidly in frequency and dominated the evolutionary dynamic in one replicate line but not in others. Parallel phenotypic changes thus masked highly divergent genomic responses to selection, illustrating how contingent rapid adaptation can be in the face of strong human-induced selection.
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http://dx.doi.org/10.1126/science.aaw7271DOI Listing
August 2019

Citizen science observations reveal rapid, multi-decadal ecosystem changes in eastern Long Island Sound.

Mar Environ Res 2019 Apr 21;146:80-88. Epub 2019 Mar 21.

University of Connecticut, Department of Marine Sciences, 1080 Shennecossett Road, 06340, Groton, CT, USA. Electronic address:

Long-term environmental records are among the most valuable assets for understanding the trajectory and consequences of climate change. Here we report on a newly recovered time-series from Project Oceanology, a non-profit ocean science organization serving New England schools (USA) since 1972. As part of its educational mission, Project Oceanology has routinely and consistently recorded water temperature, pH, and oxygen as well as invertebrate and fish abundance in nearshore waters of the Thames River estuary in eastern Long Island Sound (LIS). We digitized these long-term records to test for decadal trends in abiotic and biotic variables including shifts in species abundance, richness, and diversity. Consistent with previous studies, the data revealed an above-average warming rate of eastern LIS waters over the past four decades (+0.45 °C decade), a non-linear acidification trend twice the global average (-0.04 pH units decade), and a notable decline in whole water-column dissolved oxygen concentrations (-0.29 mg L decade). Trawl catches between 1997 and 2016 suggested a significant decrease in overall species diversity and richness, declines in cold-water adapted species such as American lobster (Homarus americanus), rock crab (Cancer irroratus), and winter flounder (Pseudopleuronectes americanus), but concurrent increases in the warm-water decapod Libinia emarginata (spider crab). Our study confirmed that Long Island Sound is a rapidly changing urban estuary, while demonstrating the value of long-term observations made by citizen-scientists, educators, and other stakeholders.
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http://dx.doi.org/10.1016/j.marenvres.2019.03.007DOI Listing
April 2019

Robust quantification of fish early life CO sensitivities via serial experimentation.

Biol Lett 2018 11 28;14(11). Epub 2018 Nov 28.

Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, 06340 Groton, CT,, USA.

Despite the remarkable expansion of laboratory studies, robust estimates of single species CO sensitivities remain largely elusive. We conducted a meta-analysis of 20 CO exposure experiments conducted over 6 years on offspring of wild Atlantic silversides () to robustly constrain CO effects on early life survival and growth. We conclude that early stages of this species are generally tolerant to CO levels of approximately 2000 µatm, likely because they already experience these conditions on diel to seasonal timescales. Still, high CO conditions measurably reduced fitness in this species by significantly decreasing average embryo survival (-9%) and embryo+larval survival (-13%). Survival traits had much larger coefficients of variation (greater than 30%) than larval length or growth (3-11%). CO sensitivities varied seasonally and were highest at the beginning and end of the species' spawning season (April-July), likely due to the combined effects of transgenerational plasticity and maternal provisioning. Our analyses suggest that serial experimentation is a powerful, yet underused tool for robustly estimating small but true CO effects in fish early life stages.
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http://dx.doi.org/10.1098/rsbl.2018.0408DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283935PMC
November 2018

Mercury Stable Isotopes Reveal Influence of Foraging Depth on Mercury Concentrations and Growth in Pacific Bluefin Tuna.

Environ Sci Technol 2018 06 24;52(11):6256-6264. Epub 2018 May 24.

Harvard John A. Paulson School of Engineering and Applied Science , Harvard University , Cambridge , Massachusetts 02138 , United States.

Pelagic ecosystems are changing due to environmental and anthropogenic forces, with uncertain consequences for the ocean's top predators. Epipelagic and mesopelagic prey resources differ in quality and quantity, but their relative contribution to predator diets has been difficult to track. We measured mercury (Hg) stable isotopes in young (<2 years old) Pacific bluefin tuna (PBFT) and their prey species to explore the influence of foraging depth on growth and methylmercury (MeHg) exposure. PBFT total Hg (THg) in muscle ranged from 0.61 to 1.93 μg g dw (1.31 μg g dw ±0.37 SD; 99% ± 6% MeHg) and prey ranged from 0.01 to 1.76 μg g dw (0.13 μg g dw ±0.19 SD; 85% ± 18% MeHg). A systematic decrease in prey δHg and ΔHg with increasing depth of occurrence and discrete isotopic signatures of epipelagic prey (δHg: 0.74 to 1.49‰; ΔHg: 1.76-2.96‰) and mesopelagic prey (δHg: 0.09 to 0.90‰; ΔHg: 0.62-1.95‰) allowed the use of Hg isotopes to track PBFT foraging depth. An isotopic mixing model was used to estimate the dietary proportion of mesopelagic prey in PBFT, which ranged from 17% to 55%. Increased mesopelagic foraging was significantly correlated with slower growth and higher MeHg concentrations in PBFT. The slower observed growth rates suggest that prey availability and quality could reduce the production of PBFT biomass.
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http://dx.doi.org/10.1021/acs.est.7b06429DOI Listing
June 2018

Mercury bioaccumulation increases with latitude in a coastal marine fish (Atlantic silverside, Menidia menidia).

Can J Fish Aquat Sci 2017 Jul 30;74(7):1009-1015. Epub 2016 Nov 30.

Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton CT, 06340.

Human exposure to the neurotoxic methylmercury (MeHg) occurs primarily via the consumption of marine fish, but the processes underlying large-scale spatial variations in fish MeHg concentrations [MeHg], which influence human exposure, are not sufficiently understood. We used the Atlantic silverside (), an extensively studied model species and important forage fish, to examine latitudinal patterns in total Hg [Hg] and [MeHg]. Both [Hg] and [MeHg] significantly increased with latitude (0.014 and 0.048 μg MeHg g dw per degree of latitude in juveniles and adults, respectively). Four known latitudinal trends in silverside traits help explain these patterns: latitudinal increase in MeHg assimilation efficiency, latitudinal decrease in MeHg efflux, latitudinal increase in weight loss due to longer and more severe winters, and latitudinal increase in food consumption as an adaptation to decreasing length of the growing season. Given the absence of a latitudinal pattern in particulate MeHg, a diet proxy for zooplanktivorous fish, we conclude that large-scale spatial variation in growth is the primary control of Hg bioaccumulation in this and potentially other fish species.
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http://dx.doi.org/10.1139/cjfas-2016-0396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5502350PMC
July 2017

Hypoxia and acidification in ocean ecosystems: coupled dynamics and effects on marine life.

Biol Lett 2016 05;12(5)

Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.

There is increasing recognition that low dissolved oxygen (DO) and low pH conditions co-occur in many coastal and open ocean environments. Within temperate ecosystems, these conditions not only develop seasonally as temperatures rise and metabolic rates accelerate, but can also display strong diurnal variability, especially in shallow systems where photosynthetic rates ameliorate hypoxia and acidification by day. Despite the widespread, global co-occurrence of low pH and low DO and the likelihood that these conditions may negatively impact marine life, very few studies have actually assessed the extent to which the combination of both stressors elicits additive, synergistic or antagonistic effects in marine organisms. We review the evidence from published factorial experiments that used static and/or fluctuating pH and DO levels to examine different traits (e.g. survival, growth, metabolism), life stages and species across a broad taxonomic spectrum. Additive negative effects of combined low pH and low DO appear to be most common; however, synergistic negative effects have also been observed. Neither the occurrence nor the strength of these synergistic impacts is currently predictable, and therefore, the true threat of concurrent acidification and hypoxia to marine food webs and fisheries is still not fully understood. Addressing this knowledge gap will require an expansion of multi-stressor approaches in experimental and field studies, and the development of a predictive framework. In consideration of marine policy, we note that DO criteria in coastal waters have been developed without consideration of concurrent pH levels. Given the persistence of concurrent low pH-low DO conditions in estuaries and the increased mortality experienced by fish and bivalves under concurrent acidification and hypoxia compared with hypoxia alone, we conclude that such DO criteria may leave coastal fisheries more vulnerable to population reductions than previously anticipated.
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http://dx.doi.org/10.1098/rsbl.2015.0976DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4892234PMC
May 2016

A quantitative genetic approach to assess the evolutionary potential of a coastal marine fish to ocean acidification.

Evol Appl 2015 Apr 13;8(4):352-62. Epub 2015 Feb 13.

Department of Marine Sciences, University of Connecticut Groton, CT, USA.

Assessing the potential of marine organisms to adapt genetically to increasing oceanic CO2 levels requires proxies such as heritability of fitness-related traits under ocean acidification (OA). We applied a quantitative genetic method to derive the first heritability estimate of survival under elevated CO2 conditions in a metazoan. Specifically, we reared offspring, selected from a wild coastal fish population (Atlantic silverside, Menidia menidia), at high CO2 conditions (∼2300 μatm) from fertilization to 15 days posthatch, which significantly reduced survival compared to controls. Perished and surviving offspring were quantitatively sampled and genotyped along with their parents, using eight polymorphic microsatellite loci, to reconstruct a parent-offspring pedigree and estimate variance components. Genetically related individuals were phenotypically more similar (i.e., survived similarly long at elevated CO2 conditions) than unrelated individuals, which translated into a significantly nonzero heritability (0.20 ± 0.07). The contribution of maternal effects was surprisingly small (0.05 ± 0.04) and nonsignificant. Survival among replicates was positively correlated with genetic diversity, particularly with observed heterozygosity. We conclude that early life survival of M. menidia under high CO2 levels has a significant additive genetic component that could elicit an evolutionary response to OA, depending on the strength and direction of future selection.
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http://dx.doi.org/10.1111/eva.12248DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408146PMC
April 2015

Detecting the unexpected: a research framework for ocean acidification.

Environ Sci Technol 2014 Sep 14;48(17):9982-94. Epub 2014 Aug 14.

Department of Ecology and Evolution, University of Chicago , Chicago, Illinois 60637, United States.

The threat that ocean acidification (OA) poses to marine ecosystems is now recognized and U.S. funding agencies have designated specific funding for the study of OA. We present a research framework for studying OA that describes it as a biogeochemical event that impacts individual species and ecosystems in potentially unexpected ways. We draw upon specific lessons learned about ecosystem responses from research on acid rain, carbon dioxide enrichment in terrestrial plant communities, and nitrogen deposition. We further characterize the links between carbon chemistry changes and effects on individuals and ecosystems, and enumerate key hypotheses for testing. Finally, we quantify how U.S. research funding has been distributed among these linkages, concluding that there is an urgent need for research programs designed to anticipate how the effects of OA will reverberate throughout assemblages of species.
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http://dx.doi.org/10.1021/es501936pDOI Listing
September 2014

Hypoxia and acidification have additive and synergistic negative effects on the growth, survival, and metamorphosis of early life stage bivalves.

PLoS One 2014 8;9(1):e83648. Epub 2014 Jan 8.

School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, New York, United States of America.

Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming. There is growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2. Presently, however, the concurrent effects of low oxygen and acidification on marine organisms are largely unknown, as most prior studies of marine hypoxia have not considered pH levels. We experimentally assessed the consequences of hypoxic and acidified water for early life stage bivalves (bay scallops, Argopecten irradians, and hard clams, Mercenaria mercenaria), marine organisms of significant economic and ecological value and sensitive to climate change. In larval scallops, experimental and naturally-occurring acidification (pH, total scale  = 7.4-7.6) reduced survivorship (by >50%), low oxygen (30-50 µM) inhibited growth and metamorphosis (by >50%), and the two stressors combined produced additively negative outcomes. In early life stage clams, however, hypoxic waters led to 30% higher mortality, while acidified waters significantly reduced growth (by 60%). Later stage clams were resistant to hypoxia or acidification separately but experienced significantly (40%) reduced growth rates when exposed to both conditions simultaneously. Collectively, these findings demonstrate that the consequences of low oxygen and acidification for early life stage bivalves, and likely other marine organisms, are more severe than would be predicted by either individual stressor and thus must be considered together when assessing how ocean animals respond to these conditions both today and under future climate change scenarios.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0083648PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3885513PMC
September 2014

Decadal Changes in the World's Coastal Latitudinal Temperature Gradients.

PLoS One 2013 18;8(6):e67596. Epub 2013 Jun 18.

School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, United States of America.

Most of the world's living marine resources inhabit coastal environments, where average thermal conditions change predictably with latitude. These coastal latitudinal temperature gradients (CLTG) coincide with important ecological clines,e.g., in marine species diversity or adaptive genetic variations, but how tightly thermal and ecological gradients are linked remains unclear. A first step is to consistently characterize the world's CLTGs. We extracted coastal cells from a global 1°×1° dataset of weekly sea surface temperatures (SST, 1982-2012) to quantify spatial and temporal variability of the world's 11 major CLTGs. Gradient strength, i.e., the slope of the linear mean-SST/latitude relationship, varied 3-fold between the steepest (North-American Atlantic and Asian Pacific gradients: -0.91°C and -0.68°C lat(-1), respectively) and weakest CLTGs (African Indian Ocean and the South- and North-American Pacific gradients: -0.28, -0.29, -0.32°C lat(-1), respectively). Analyzing CLTG strength by year revealed that seven gradients have weakened by 3-10% over the past three decades due to increased warming at high compared to low latitudes. Almost the entire South-American Pacific gradient (6-47°S), however, has considerably cooled over the study period (-0.3 to -1.7°C, 31 years), and the substantial weakening of the North-American Atlantic gradient (-10%) was due to warming at high latitudes (42-60°N, +0.8 to +1.6°C,31 years) and significant mid-latitude cooling (Florida to Cape Hatteras 26-35°N, -0.5 to -2.2°C, 31 years). Average SST trends rarely resulted from uniform shifts throughout the year; instead individual seasonal warming or cooling patterns elicited the observed changes in annual means. This is consistent with our finding of increased seasonality (i.e., summer-winter SST amplitude) in three quarters of all coastal cells (331 of 433). Our study highlights the regionally variable footprint of global climate change, while emphasizing ecological implications of changing CLTGs, which are likely driving observed spatial and temporal clines in coastal marine life.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0067596PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689001PMC
October 2017

Fukushima-derived radionuclides in the ocean and biota off Japan.

Proc Natl Acad Sci U S A 2012 Apr 2;109(16):5984-8. Epub 2012 Apr 2.

Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.

The Tōhoku earthquake and tsunami of March 11, 2011, resulted in unprecedented radioactivity releases from the Fukushima Dai-ichi nuclear power plants to the Northwest Pacific Ocean. Results are presented here from an international study of radionuclide contaminants in surface and subsurface waters, as well as in zooplankton and fish, off Japan in June 2011. A major finding is detection of Fukushima-derived (134)Cs and (137)Cs throughout waters 30-600 km offshore, with the highest activities associated with near-shore eddies and the Kuroshio Current acting as a southern boundary for transport. Fukushima-derived Cs isotopes were also detected in zooplankton and mesopelagic fish, and unique to this study we also find (110 m)Ag in zooplankton. Vertical profiles are used to calculate a total inventory of ~2 PBq (137)Cs in an ocean area of 150,000 km(2). Our results can only be understood in the context of our drifter data and an oceanographic model that shows rapid advection of contaminants further out in the Pacific. Importantly, our data are consistent with higher estimates of the magnitude of Fukushima fallout and direct releases [Stohl et al. (2011) Atmos Chem Phys Discuss 11:28319-28394; Bailly du Bois et al. (2011) J Environ Radioact, 10.1016/j.jenvrad.2011.11.015]. We address risks to public health and marine biota by showing that though Cs isotopes are elevated 10-1,000× over prior levels in waters off Japan, radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides.
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http://dx.doi.org/10.1073/pnas.1120794109DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3341070PMC
April 2012

Adaptation to climate change: contrasting patterns of thermal-reaction-norm evolution in Pacific versus Atlantic silversides.

Proc Biol Sci 2011 Aug 5;278(1716):2265-73. Epub 2011 Jan 5.

School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA.

How organisms may adapt to rising global temperatures is uncertain, but concepts can emerge from studying adaptive physiological trait variations across existing spatial climate gradients. Many ectotherms, particularly fish, have evolved increasing genetic growth capacities with latitude (i.e. countergradient variation (CnGV) in growth), which are thought to be an adaptation primarily to strong gradients in seasonality. In contrast, evolutionary responses to gradients in mean temperature are often assumed to involve an alternative mode, 'thermal adaptation'. We measured thermal growth reaction norms in Pacific silverside populations (Atherinops affinis) occurring across a weak latitudinal temperature gradient with invariant seasonality along the North American Pacific coast. Instead of thermal adaptation, we found novel evidence for CnGV in growth, suggesting that CnGV is a ubiquitous mode of reaction-norm evolution in ectotherms even in response to weak spatial and, by inference, temporal climate gradients. A novel, large-scale comparison between ecologically equivalent Pacific versus Atlantic silversides (Menidia menidia) revealed how closely growth CnGV patterns reflect their respective climate gradients. While steep growth reaction norms and increasing growth plasticity with latitude in M. menidia mimicked the strong, highly seasonal Atlantic coastal gradient, shallow reaction norms and much smaller, latitude-independent growth plasticity in A. affinis resembled the weak Pacific latitudinal temperature gradient.
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http://dx.doi.org/10.1098/rspb.2010.2479DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119017PMC
August 2011

The role of experiments in understanding fishery-induced evolution.

Evol Appl 2009 Aug;2(3):276-90

School of Marine and Atmospheric Sciences, Stony Brook University Stony Brook, NY, USA.

Evidence of fishery-induced evolution has been accumulating rapidly from various avenues of investigation. Here we review the knowledge gained from experimental approaches. The strength of experiments is in their ability to disentangle genetic from environmental differences. Common garden experiments have provided direct evidence of adaptive divergence in the wild and therefore the evolvability of various traits that influence production in numerous species. Most of these cases involve countergradient variation in physiological, life history, and behavioral traits. Selection experiments have provided examples of rapid life history evolution and, more importantly, that fishery-induced selection pressures cause simultaneous divergence of not one but a cluster of genetically and phenotypically correlated traits that include physiology, behavior, reproduction, and other life history characters. The drawbacks of experiments are uncertainties in the scale-up from small, simple environments to larger and more complex systems; the concern that taxons with short life cycles used for experimental research are atypical of those of harvested species; and the difficulty of adequately simulating selection due to fishing. Despite these limitations, experiments have contributed greatly to our understanding of fishery-induced evolution on both empirical and theoretical levels. Future advances will depend on integrating knowledge from experiments with those from modeling, field studies, and molecular genetic approaches.
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http://dx.doi.org/10.1111/j.1752-4571.2009.00079.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352492PMC
August 2009
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