Remote Antarctic feeding ground important for east Australian humpback whales

Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales.     

Spawning and development in <Emphasis Type="Italic">Osedax</Emphasis> boneworms (Siboglinidae,Annelida)

We report observations on spawning and early development in bone-eating worms of the genus Osedax. Individual females of Osedax rubiplumus were observed at 1820 m depth freely spawning hundreds of oocytes, and females of an undescribed species, Osedax “orange collar”, were observed spawning in laboratory aquaria. Cytological and molecular analysis of the spawned oocytes of two Osedax species revealed no evidence for the bacterial endosymbionts that the female worms require for their nutrition, suggesting that the bacteria must be acquired later from the environment, as they are in other siboglinids. Individual O. “orange collar” females released an average of 335 (±130) eggs per day, but the number of oocytes spawned per day varied greatly, suggesting that not all the females spawned daily. Fertilization rates of the spawned oocytes varied from 0 to 100%, though most females showed nearly 100% fertilization rates. Oocytes spawned in the laboratory at 4–6°C were negatively buoyant. If fertilized, these oocytes extruded polar bodies and then after at least four hours cleaved unequally. Subsequent cleavages occurred in a spiral pattern at roughly 2-h intervals, resulting in free-swimming trochophore larvae after 24 h. These lecithotrophic trochophores swam for 9–16 days before settling with several hooked chaetae, similar to those of dwarf Osedax males. The larval life span of the Osedax species studied in the laboratory appears to be shorter than in closely related Vestimentifera. Osedax rubiplumus, on the other hand, has much larger oocytes and so may have greater dispersal potential than these other Osedax species. The high fecundity and apparently continuous reproduction of Osedax boneworms permits the opportunistic exploitation of sunken vertebrate bones. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Photosynthetic resource-use efficiency and demographic variability in desert winter annual plants

We studied a guild of desert winter annual plants that differ in long-term variation in per capita reproductive success (lb, the product of per capita survival from germination to reproduction, l, times per capita reproduction of survivors, b) to relate individual function to population and community dynamics. We hypothesized that variation in lb should be related to species' positions along a trade-off between relative growth rate (RGR) and photosynthetic water-use efficiency (WUE) because lb is a species-specific function of growing-season precipitation. We found that demographically variable species have greater RGR and greater leaf carbon isotope discrimination (Delta, a proxy inversely related to WUE). We examined leaf nitrogen and photosynthetic characteristics and found that, in this system, variation in Delta is a function of photosynthetic demand rather than stomatal regulation of water loss. The physiological characteristics that result in low Delta in some species may confer greater photosynthetic performance during the reliably moist but low temperature periods that immediately follow winter rainfall in the Sonoran Desert or alternatively during cool periods of the day or early growing season. Conversely, while species with high Delta and high RGR exhibit low leaf N, they have high biomass allocation to canopy leaf area display. Such trait associations may allow for greater performance during the infrequent conditions where high soil moisture persists into warmer conditions, resulting in high demographic variance. Alternatively, high variance could arise from specialization to warm periods of the day or season. Population dynamic buffering via stress tolerance (low RGR and Delta) correlates negatively with buffering via seed banks, as predicted by bet-hedging theory. By merging analyses of population dynamics with functional trait relationships, we develop a deeper understanding of the physiological, ecological, and evolutionary mechanisms involved in population and community dynamics.     

Personality and teamwork behavior in context: The cross‐level moderating role of collective efficacy

This research examines whether the relationship between an individual's personality and their behavior within a team is contingent on the team's overall perception of its capability. Individuals were peer‐rated on the extent to which they displayed interpersonal and performance management teamwork behaviors over the course of an 8 week business simulation. The personality trait of agreeableness predicted interpersonal teamwork behavior, while the personality traits of conscientiousness and core self‐evaluation (CSE) predicted performance management behavior. Multilevel analysis showed that collective efficacy influenced the extent to which an individual engaged in both types of behavior, and was also a cross‐level moderator of the relationship between agreeableness and interpersonal behavior and the relationship between CSE and performance management behavior. At the team level, interpersonal behavior mediated between collective efficacy and team performance. The study's results show that in team settings the personality and individual behavior relationship may depend on group level confidence perceptions. Copyright © 2010 John Wiley & Sons, Ltd.     

Managing Excessive Methanogenesis During ERD/ISCR Remedial Action

Excessive production of methane has been observed at some remediation sites following the addition of organic hydrogen donors such as (emulsified) oils/lecithin, sugars, and conventional carbon + zero‐valent iron (ZVI) amendments. This is due to the fact that methanogens are commonly the most ubiquitous indigenous microbes in anoxic aquifer settings, and, under enriched environmental conditions, methanogens replicate every one to two hours (whereas Dehalococcoides spp., e.g., double in 24–48 hr). Hence, methanogens often bloom and dominate the microbial ecosystem following the addition of remedial amendments, thereby liberating large amounts of methane gas. There are at least three important consequences of this response:

1. By utilizing hydrogen, the methanogens compete with dechlorinating microbes, thus making inefficient use of the remedial amendment (just 20 ppm methane in groundwater represents an approximate 30 percent “waste” of added fermentable substrate (i.e., hydrogen donor)—this is a common and tangible detriment);
2. Methanogens can methylate heavy metals and their rapid growth consumes alkalinity, while generating acidity, thereby facilitating multiple potential mechanisms for creating secondary contaminant issues (i.e., arsenic plumes); and
3. Elevated methane concentrations can exceed current and pending regulations of <10 to <28 ppm methane in groundwater and/or 0.5 percent by volume methane in soil gas (e.g., 10 percent of the lower explosive limit) and/or indoor air (methane is flammable between 5 percent and 15 percent by volume) and this will induce migration of contaminant vapors potentially causing indoor air issues.

Considering the recent guidelines for indoor air published by the US Environmental Protection Agency, it is increasingly important to prevent excessive methanogenesis associated with remedial actions. From a regulatory perspective, public safety issues are paramount; from a property re‐use or real estate (brownfield) developers’ perspective, project delays are costly and can jeopardize an entire program. The use of antimethanogenic compounds as inhibitors of protein biosynthesis and the activity of enzyme systems unique to Archaea (i.e., methanogens) during in situ remedial action can improve contaminant removal while offering safer, more efficacious treatment, simply by impeding the methanogenic bacteria's ability to proliferate and out compete desired bacterial communities (e.g., Dehalococcoides spp.). ©2016 Wiley Periodicals, Inc.     

Using a systems approach to improve process and environmental performance

By providing companies with a set of analytical tools, the systems approach allows decision makers to achieve the elusive goal of continuous environmental improvement. © 2000 John Wiley & Sons, Inc.