One of the most important challenges researchers and managers confront in conservation ecology is predicting a population's response to sub-lethal stressors. Such predictions have been particularly ...elusive when assessing responses of large marine mammals to past anthropogenic pressures. Recently developed techniques involving baleen whale earplugs combine age estimates with cortisol measurements to assess spatial and temporal stress/stressor relationships. Here we show a relationship between baseline-corrected cortisol levels and corresponding whaling counts of fin, humpback, and blue whales in the Northern Hemisphere spanning the 20th century. We also model the impact of alternative demographic and environmental factors and determine that increased anomalies of sea surface temperature over a 46-year mean (1970-2016) were positively associated with cortisol levels. While industrial whaling can deplete populations by direct harvest, our data underscore a widespread stress response in baleen whales that is peripheral to whaling activities or associated with other anthropogenic change.
Many advanced vehicle technologies, including electric vehicles (EVs), hybrid electric vehicles (HEVs), and fuel cell vehicles (FCVs), are gaining attention throughout the World due to their ...capability to improve fuel efficiencies and emissions. When evaluating the operational successes of these new fuel-efficient vehicles, it is essential to consider energy usage and greenhouse gas (GHG) emissions throughout the entire lifetimes of the vehicles, which are comprised of two independent cycles: a fuel cycle and a vehicle cycle. This paper intends to contribute to the assessment of the environmental impacts from the alternative technologies throughout the lifetimes of various advanced vehicles through objective comparisons. The methodology was applied to six commercial vehicles that are available in the U.S. and that have similar dimensions and performances. We also investigated the shifts in energy consumption and emissions through the use of electricity and drivers’ behavior regarding the frequencies of battery recharging for EVs and plug-in hybrid electric vehicles (PHEVs). This study thus gives insight into the impacts of the electricity grid on the total energy cycle of a vehicle lifetime. In addition, the total ownership costs of the selected vehicles were examined, including considerations of the fluctuating gasoline prices. The cost analysis provides a resource for drivers to identify optimal choices for their driving circumstances.
The industrialized portion of the Houston Ship Channel (HSC) is heavily contaminated with anthropogenic contaminants, most prominent of which are the polychlorinated biphenyls (PCBs). This ...contamination has driven adaptive evolution in a keystone species for Galveston Bay, the Gulf killifish (Fundulus grandis). We investigated the geographical extent of PCB impacts by sampling 12 sites, ranging from the heavily industrialized upper portion of the HSC to Galveston Island. At each site, PCB concentrations and profiles were determined in three environmental compartments: sediment, water (polyethylene passive samplers), and fish tissue (resident Gulf killifish). We observed a steep gradient of PCB contamination, ranging from 4.00 to 100,000 ng/g organic carbon in sediment, 290–110,000 ng/g lipid in fish, and 4.5–2300 ng/g polyethylene in passive samplers. The PCB congener profiles in Gulf killifish at the most heavily contaminated sites were shifted toward the higher chlorinated PCBs and were highly similar to the sediment contamination profiles. In addition, while magnitude of total PCB concentrations in sediment and total fish contamination levels were highly correlated between sites, the relative PCB congener profiles in fish and passive samplers were more alike. This strong correlation, along with a lack of dependency of biota-sediment accumulation factors with total contamination rates, confirm the likely non-migratory nature of Gulf killifish and suggest their contamination levels are a good site-specific indicator of contamination in the Galveston Bay area. The spatial gradient of PCB contamination in Galveston Bay was evident in all three matrices studied and was observed effectively using Gulf killifish contamination as an environmentally relevant bioindicator of localized contamination in this environment.
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•Gradient of PCB contamination in Galveston Bay with Houston Ship Channel as source.•PCB congener profiles differ between disparately contaminated portions.•Fish and passive sampler contamination profiles were highly congruent.•Gulf killifish appear as a prime model for exploring trends of localized contamination.
We find a strong gradient in chemical contamination in Galveston Bay stemming from the Houston Ship Channel and present Gulf killifish as a model for studying localized contamination.
Despite decades of effort, significant knowledge gaps still exist regarding the global transport and distribution of persistent organic pollutants (POPs) in marine ecosystems, especially for periods ...prior to the 1970s. Furthermore, for long-lived marine mammals such as baleen whales, POPs impacts on early developmental (first years of life), as well as lifetime exposure profiles for periods of use and phase-out, are not well characterized. Recently, analytical techniques capable of reconstructing lifetime (i.e., birth to death; ~6 mos. resolution) chemical exposure profiles in baleen whale earplugs have been developed. Earplugs represent a unique opportunity to examine the spatiotemporal trends of POPs in the marine ecosystem. Baleen whale earplugs were collected from six whales (one blue whale (Balaenoptera musculus) and five fin whales (Balaenoptera physalus)), including four from archived collections and two from recent strandings. Lifespans for some of these individuals date back to the 1930s and provide insight into early periods of POP use. POP concentrations (reported in ng g–1 dry wt.) were determined in laminae (n = 35) and were combined with age estimates and calendar year to reconstruct lifetime POP exposure profiles and lifetime bioaccumulation rates. Dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) were found to be the most dominant POPs (spanning the past 80 y), were detected as early as the 1930s and were ubiquitous in the North Pacific and Atlantic Oceans. Lifetime bioaccumulation rates determined using baleen whale earplugs were 56 times higher in the North Pacific as compared to the North Atlantic. This suggest baleen whales from the North Pacific may be to be exposed to increased levels of POPs.
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•Reconstructed life-history of POP exposure using baleen whale earplugs.•POPs measured in marine mammals dating back to the 1930s.•Data suggest POP bioaccumulation rates higher in the North Pacific than Atlantic.•Exposure profiles were dominated by DDT, and its metabolites, and PCBs.
Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral ...part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale earplugs from three different species (N = 6 earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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•Reconstructed life-history δ13C and δ15N profiles in baleen whale•Evidence of the Suess effect in whale earplugs dating back to the 1930s•Life history behavior changes were observed in δ13C and δ15N profiles.•Long-term ecological change was identified using δ13C lifetime profiles.
B-cell lymphoma, a common morphologic variant of non-Hodgkin lymphoma, has been associated with persistent pollutants in humans, but this association is not well-characterized in top-level predators ...sharing marine resources with humans. We characterized and compared blubber contaminants and hormones of a pregnant harbor porpoise (
Phocoena phocoena
) with B-cell lymphoma, with those in two presumed healthy fishery by-caught porpoises with no lymphoma: a pregnant adult and female juvenile. Common historic use compounds, including polychlorinated biphenyls, polybrominated diphenyl ethers, and pesticides, were evaluated in blubber samples from three porpoises. In addition, blubber cortisol and progesterone levels (ng/g) were determined in all three animals. Total pollutant concentrations were highest in the juvenile porpoise, followed by the lymphoma porpoise and the nonlymphoma adult. Blubber cortisol concentrations were 191% greater in the pregnant with lymphoma porpoise compared with the pregnant no lymphoma porpoise, and 89% greater in the juvenile female compared with the pregnant no lymphoma porpoise. Although both adults were pregnant, progesterone levels were substantially greater (90%) in the healthy compared with the lymphoma adult. Health monitoring of top-level marine predators, such as porpoise, provides a sentinel measure of contaminants that serve as indicators of potential environmental exposure to humans.
In 2017, The National Academy of Sciences reported on the approaches to understanding the cumulative effects of stressors on marine mammals and suggested the use of baleen whale earplugs to evaluate ...both stress and stressors. The objective of this dissertation is to investigate historic and current organic and inorganic contaminants within the marine ecosystem to better understand the cumulative effects of stressors on marine mammals. Simultaneously, this dissertation also demonstrate links between.The long-term health impact of organic contaminants was assessed in harbor porpoises off the coast of Washington State. This study focused on the POP burden within the blubber of three females (two adults and one juvenile), one of which had a B-cell lymphoma. POP blubber concentrations from different life stages were used to assess the lifetime POPs burden. The juvenile porpoise had the highest contaminant burden followed by the adult female with lymphoma and the nonlymphoma adult.POP life history exposure profiles were reconstructed using baleen whale earplugs. This earplug study expands upon previous earplug studies of both spatial and temporal trends. POPs analysis using earplugs provided contaminant data 30 years prior to the first reports in marine species. Chemical exposure profiles and bioaccumulation rates were reconstructed for a total of six earplugs from the North Pacific and Atlantic Ocean basins. Bioaccumulation rates were found to be 56 times higher in the North Pacific compared to the North Atlantic, suggesting a higher risk of exposure in the North Pacific.Lastly, a single earplug was used to investigate temporal profiles of inorganic elements. The final study used a single fin whale earplug to produce more than 1,600 data points, which were used to reconstruct 48 distinct profiles of toxic, essential, nonessential, rare earth, and other non-biologically relevant elements. This research, in conjunction with concurrent studies, aimed to examine stress profiles and other stressors (e.g., reproduction and whaling; see appendix). Earplug data from this study provides insight into biological and biogeochemical processes as well as preliminary data for further elemental analysis of more earplugs.
Here we highlight some of the opportunities associated with combining advanced sample preparation techniques with stateof-the-art chemical analysis techniques. This article considers the unique ...combination of selective pressurized liquid extraction (SPLE) with gas chromatography (GC) coupled with mass spectrometry (MS) and ultrahigh-pressure liquid chromatography coupled with tandem MS (UHPLC-MS-MS). We use this powerful combination to develop a novel analytical technique capable of measuring hormones and organic contaminants in whale earwax plugs. We explore the analytical challenges with such combinations and the advantages of focusing both on sample preparation as well as chemical analysis.
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