Complex movement patterns by foraging loggerhead sea turtles outside the breeding season identified using Argos‐linked Fastloc‐Global Positioning System

We used Argos‐linked Fastloc‐Global Positioning System (Argos‐linked Fastloc‐GPS) satellite tags to investigate how loggerhead sea turtles use neritic foraging habitats at multiple scales. Out of 24 turtles, six individuals used more than one foraging site, with all sites being separated by >25 km. These six individuals used up to four sites, remaining at each site for a mean of 150 days and returning to the same site a minimum of 52 days later. The other 18 turtles remained in a single site. The area within sites was not used uniformly, with 15 out of 24 turtles exhibiting complex movement patterns within and amongst up to five focal patches, which were typically 0.1–5.0 km apart within a single site. Movements between sites and patches might sometimes have reflected overwintering behaviour; however, similar movement patterns occurred at multiple times of the year, suggesting other factors were also involved. Use of multiple sites and patches might be driven by differences in resource availability, such as food and/or night‐time refuges, competition, or exploratory movement to investigate or locate alternative patches. We confirmed competition via direct visual observations of aggressive interactions between individuals at one foraging patch. Our results illustrate the importance of standardizing data to the same number of locations per day and night to accurately delineate key areas used by turtles or for evidence‐based marine protected area planning.     

<Emphasis Type="Italic">GALEX</Emphasis> far-ultraviolet observations of metal-poor subdwarfs

Far-ultraviolet photometry derived from the GALEX satellite observatory has been compiled for a sample of metal-poor subdwarfs with \(\mathrm{[Fe/H]} < -1.0\). The FUV properties of these subdwarfs are compared with those of a set of Population I dwarfs that are known to have low levels of chromospheric activity. Comparisons are made via a number of photometric plots, including an absolute FUV magnitude versus \((V-K_{s})\) diagram, two-colour diagrams involving both \((m_{ \mathrm{FUV}}-B)\) and \((m_{\mathrm{FUV}}-V)\) versus \(B-V\), and a two-colour diagram composed of \((m_{\mathrm{FUV}}-V)\) versus \((V-K_{s})\). The warmest subdwarfs with \((V-K_{s}) \sim1.2\mbox{--}1.4\) show FUV excesses ranging from \(\sim2\mbox{--}3~\mbox{mag}\) relative to the Population I dwarfs, with the amount of FUV enhancement decreasing among subdwarfs of decreasing effective temperature. The coolest dwarfs that are compared have \((V-K_{s}) \sim1.8\), and among these stars the subdwarfs with \(-2.0 \leq{\mathrm{[Fe/H]}} \leq-1.0\) approach the locus of low activity Population I dwarfs in the \((m_{\mathrm{FUV}}-V, V-K_{s})\) diagram. In the \((m_{\mathrm{FUV}}-B, B-V)\) diagram the subdwarfs in this metallicity range overlap the Population I dwarf sequence for \((B-V) > 0.6\). The behaviour of the subdwarfs is consistent with their FUV fluxes being determined by a combination of a photospheric FUV spectrum, the strength of which diminishes towards cooler effective temperatures, and a spectrum of emission lines arising from a chromosphere and/or transition region which are of comparable strength between the coolest dwarfs and subdwarfs.     

Unreported bycatch in the New Zealand West Coast South Island hoki fishery

There are recognised benefits to managing fisheries by individual transferable quotas (ITQs), but ITQs may increase incentives to discard fish.     

Can ecological and evolutionary arguments solve the riddle of the missing marine insects?

We critically appraise the recent literature on the paucity of marine insects and conclude that this near‐absence does demand explanation; but this explanation is unlikely to be found in the suggested problems of depth for insect respiratory systems. We tentatively suggest some areas where further consideration may yield fruitful answers to this long‐standing evolutionary riddle.     

Drought in the Southern United States over the 20th century: variability and its impacts on terrestrial ecosystem productivity and carbon storage

Drought is one of the most devastating natural hazards faced by the Southern United States (SUS). Drought events and their adverse impacts on the economy, society and environment have been extensively reported during 1895?C2007. Our aim is thus to characterize drought conditions in the SUS and explore the impacts on terrestrial ecosystem function (i.e., net primary productivity (NPP) and net carbon exchange (NCE)). Standard precipitation index (SPI) was used to characterize drought intensity and duration, and a process-based ecosystem model was used to explore the relationship between drought and ecosystem function. Combining overall information on growing-season SPI, drought area and duration, we concluded there was no significant change in drought conditions for the SUS during 1895?C2007. However, increased drought intensity was found for many areas in the east, resulting in significant decreases in NPP for these areas, with the largest decrease up to 40% during extreme droughts. Changes in precipitation patterns increased C emissions of 0.16 Pg (1 Pg?=?10¹⁵?g) in the SUS during 1895?C2007. The west (dry region) acted as a C sink due to increased precipitation, while the east (water-rich region) acted as a C source due to increased drought intensity. Both NPP and NCE significantly increased along a gradient of declining drought intensity. Changes in precipitation resulted in C sources in forest, wetland, and cropland ecosystems, while C sinks in shrubland and grassland ecosystems. Changes in air temperature could either enhance or reduce drought impacts on NPP and NCE across different vegetation types.     

The Hekla 1947 tephra in the north of Ireland: regional distribution,concentration and geochemistry

A cryptotephra layer from the eruption of Hekla in 1947 has recently been discovered in Irish peatlands. This tephra layer represents the most recent deposition of volcanic ash in the UK prior to the eruption of Eyjafjallajökull in 2010. Here we examine the concentration and geochemistry of the Hekla 1947 tephra in 14 peat profiles from across Northern Ireland. Electron probe microanalysis of individual tephra shards (n = 91) reveals that the tephra is of dacitic–andesitic geochemistry and is highly similar to the Hekla 1510 tephra, although spheroidal carbonaceous particle profiles can be used for successful discrimination of the two layers. The highest concentrations of Hekla 1947 are found in western sites, probably reflecting the pathway of the ash fall event due to the prevailing wind direction. Comparable tephra concentrations from two cores (1 km apart) from a single bog and from nearby sites may suggest that tephra shard concentrations in peat profiles reflect ash fallout densities across a specific region, rather than site‐specific factors associated with peatlands. This paper firmly establishes Hekla 1947 as a useful chronostratigraphic marker for the twentieth century, although within a restricted zone. Copyright © 2012 John Wiley & Sons, Ltd.     

Evidence for Systemic Changes in the Benthic Fauna of Tropical Estuaries as a Result of Urbanization

The effects of urban development cause substantial physical changes in coastal waterways through hardening and reclamation of river banks, alteration of water flow, and diffuse and point-source discharges of pollutants. The cumulative effects of urbanization on the fauna of estuaries are not well understood. This study examined the benthic infauna of two urban and three rural estuaries near Townsville, North Queensland. A range of univariate and multivariate statistics was used to relate variation in the benthic assemblages to concentrations of contaminants (heavy metals and hydrocarbons) within the sediments of each estuary. Sediments in the most developed estuary contained concentrations of heavy metals and petroleum hydrocarbons that were several orders of magnitude greater than those from non-urban waterways. The fauna at these sites was dominated by cirratulid and sternaspid polychaetes and lacked filter-feeding bivalves and other molluscs that were common in less developed estuaries. These differences were generally consistent throughout each estuary, indicating estuary-wide patterns of change, that were most strongly associated with spatial patterns in the distribution of Pb, Cu and hydrocarbons.     

Heat source for Tongonan Geothermal Field

Abstract The primary mineral and whole-rock chemistry of 46 core samples from the host rocks of the Tongonan Geothermal Field (the Philippines) have been used to infer the likely composition of the heat source for the system. The host rocks consist of andesite lavas (with intercalated fossiliferous early to mid–Miocene shales and limestone), and a plutonic rock basement ranging in composition from gabbro to granite. The whole rock TiO₂, Fe₂O₃ (total iron), MgO, P₂O₅ and V data for volcanic and plutonic rocks are colinear on conventional Harker diagrams. This, along with similar hornblende chemistry, age and close spatial relationship suggests that the basement and cover rocks are cogenetic and evolved by low-pressure crystal fractionation. Crystal fractionation models indicate that separation of 60% plagioclase and 30% hornblende from original magma controlled the chemistry of the host rocks. The original Miocene magma chambers beneath the Tongonan field crystallized inwards from the walls at approximately 750°C and 1 kb pressure (3–4 km depth) thus forming a series of plutons or a batholith at drilled depths. A supercritical hydrothermal fluid trapped in the crystallizing, hornblende-granite-pegmatite core of a crystallized Miocene diorite batholith was gradually being released to shallower levels through antithetic cross fractures during creep and uplift along the main branches of the Philippine Fault from the Pliocene. This ascending fluid is now thought to be responsible for the present thermal activity of the field.     

The effects of spiral arms on the multi-phase ISM

Statistical parameters of the ISM driven by thermal energy injectionsfrom supernova explosions have been obtained from 3D, nonlinear,magnetohydrodynamic, shearing-box simulations for spiral arm andinterarm regions. The density scale height obtained for the interarm regionsis 50% larger than within the spiral arms because of thehigher gas temperature. The filling factorof the hot gas is also significantly larger between the armsand depends sensitively on magnetic field strength.