Habitat use patterns of the invasive red lionfish Pterois volitans: a comparison between mangrove and reef systems in San Salvador,Bahamas

The Indo‐Pacific red lionfish Pterois volitans is widespread both in its native and its non‐native habitats. The rapid invasion of this top predator has had a marked negative effect on fish populations in the Western Atlantic and the Caribbean. It is now well documented that lionfish are invading many tropical and sub‐tropical habitats. However, there are fewer data available on the change in lionfish abundance over time and the variation of body size and diet across habitats. A recent study in San Salvador, Bahamas, found body size differences between individuals from mangrove and reef systems. That study further suggested that ontogenetic investigation of habitat use patterns could help clarify whether lionfish are using the mangrove areas of San Salvador as nurseries. The aim of the present study is to determine temporal trends in lionfish relative abundance in mangrove and reef systems in San Salvador, and to further assess whether there is evidence suggesting an ontogenetic shift from mangroves to reef areas. Accordingly, we collected lionfish from mangrove and reef habitats and calculated catch per unit effort (a proxy for relative abundance), compared body size distributions across these two systems, and employed a combination of stable isotope, stomach content, and genetic analyses of prey, to evaluate differences in lionfish trophic interactions and habitat use patterns. Our results show that populations may have increased in San Salvador during the last 4 years, and that there is a strong similarity in body size between habitats, stark differences in prey items, and no apparent overlap in the use of habitat and/or food resources. These results suggest that there is not evidence an for ontogenetic shift from mangroves to reefs, and support other studies that propose lionfish are opportunistic forages with little movement across habitats.     

Reducing carbon transaction costs in community-based forest management

Abstract

The article considers the potential for community-based forest management (of existing forests) in developing countries, as a future CDM strategy, to sequester and mitigate carbon and to claim credits in future commitment periods. This kind of forestry is cost-effective, and should bring many more benefits to local populations than do afforestation and reforestation, thus contributing more strongly to sustainable development. However, community forest management projects are small-scale, and the transaction costs associated with justifying them as climate projects are likely to be high. A research project being carried out in five developing countries is testing carbon measurement and monitoring methods which can be carried out by community members with very little formal education, which should greatly reduce these transaction costs. Using hand-held computers with GIS capability and attached GPS, villagers with 4 years of primary education are able to accurately map their forest resource and input biomass data from sample plots into a program which calculates carbon values.     

The 2010/2011 Canterbury earthquakes: context and cause of injury

The aim of this study was to investigate causes of injury during the 2010/2011 Canterbury earthquakes. Data on patients injured during the Darfield (4 September 2010) and Christchurch (22 February 2011) earthquakes were sourced from the New Zealand Accident Compensation Corporation. The total injury burden was analyzed for demography, context of injury, causes of injury, and injury type. Injury context was classified as direct (shaking of the primary earthquake or aftershocks causing unavoidable injuries), action (movement of person during the primary earthquake or aftershocks causing potentially avoidable injuries), and secondary (cause of injury after shaking ceased). Nine categories of injury cause were identified. Three times as many people were injured in the Christchurch earthquake as in the Darfield earthquake (7,171 vs. 2,256). The primary shaking caused approximately two-thirds of the injuries from both quakes. Actions during the primary shaking and aftershocks led to many injuries (51.3 % Darfield and 19.4 % Christchurch). Primary direct caused the highest proportion of injuries during the daytime Christchurch quake (43.6 %). Many people were injured after shaking stopped in both events: 499 (22.1 % Darfield) and 1,881 (26.2 % Christchurch). Most of these people were injured during clean-up (320 (14.2 %) Darfield; 622 (8.7 %) Christchurch). In both earthquakes, more females than males (1,453 vs. 803 Darfield; 4,646 vs. 2,525 Christchurch) were injured (except by masonry, damaged ground, and during clean-up); trip/fall (27.9 % Darfield; 26.1 % Christchurch) was the most common cause of injury; and soft tissue injuries (74.1 % Darfield; 70.4 % Christchurch) was the most common type of injury. This study demonstrated that where people were and their actions during and after earthquakes influenced their risk of injury.     

Interannual Variability Influences Brown Tide (<Emphasis Type="Italic">Aureococcus anophagefferens</Emphasis>) Blooms in CoastalEmbayments

Blooms of Aureococcus anophagefferens in Chincoteague Bay were observed during 5 of 6 years between 2002 and 2007. In order to understand factors controlling blooms, interannual differences in nitrogen and carbon uptake and concentrations of dissolved constituents were compared at two sites in Chincoteague Bay, MD and VA over the 6-year time period. Over that time, we observed that there was no single nitrogen compound that fueled blooms each year. Instead, A. anophagefferens took up a wide range of nitrogen compounds to meet its nutritional demands. Although photosynthetic carbon fixation was the dominant form of carbon acquisition during blooms, organic carbon uptake contributed up to 30 % of the total carbon uptake. In addition to interannual variability in nitrogen and carbon uptake, we observed that there was an increase in bloom intensity and duration over the 6-year study period during which dissolved organic carbon appeared to accumulate in the system.     

Metabolites in bile of fish from São Sebastião Channel, São Paulo, Brazil as biomarkers of exposure to petrogenic polycyclic aromatic compounds

This study reports the analysis of polycyclic aromatic compound (PAC) metabolites, as biomarkers of exposure to PACs in marine environment. PAC metabolites were measured in bile samples from 14 species of demersal fish caught in the São Sebastião Channel (SSC), SE Brazilian coastline. Naphthalene (NPH) equivalents, phenanthrene (PHN) equivalents, and benzo[a]pyrene (BaP) equivalents were quantified using a reverse-phase high-performance liquid chromatography coupled with fluorescence detection method. For all samples, the means (±standard deviation, n = 37) of concentrations obtained for NPH, PHN, and BaP equivalents were, respectively, 290,000 ± 200,000 ng/g, 18,000 ± 14,000 ng/g, and 970 ± 1900 ng/g. These results indicate recent exposure of these fish to PACs in their environment. In addition, two species (Cyclichthys spinosus and Prionotus nudigula) of fish were analyzed in order to investigate local sources of PAC contamination in the SSC and the influence of the petroleum terminal in fish caught in remote areas. The results showed that these fish species potentially migrate along the channel, especially P. nudigula. Correlations among groups of PAC metabolites indicate the same petrogenic source for NPH and PHN equivalents and a combustion source (e.g., automobile, ships) for BaP equivalents. The ratio BaP/PHN equivalents (0.05 ± 0.07, n = 37) confirms the predominance of petrogenic PACs for contamination by these chemicals in this region.     

Alkenone paleothermometry: Biological lessons from marine sediment records off western South America

An empirical global core-top calibration that relates the alkenone unsaturation index to mean annual SST (maSST) is statistically the same as that defined for a subarctic Pacific strain of Emiliania huxleyi (CCMP1742) grown exponentially in batch culture under isothermal conditions. Although both equations have been applied widely for paleoSST reconstruction, uncertainty still stems from two key ecological factors: variability in the details of biosynthesis among genetically distinct alkenone-producing strains, and impacts of non-thermal physiological growth factors on . New batch culture experiments with CCMP1742 here reveal that diverge systematically from the core-top calibration in response to nutrient depletion and light deprivation, two physiological stresses experienced by phytoplankton populations in the real ocean. Other aspects of alkenone/alkenoate composition also respond to these stresses and may serve as signatures of such effects, providing an opportunity to detect, understand, and potentially correct for such impacts on the geologic record. A test case documents that sediments from the Southeast Pacific display the alkenone/alkenoate compositional signature characteristic of cells physiologically stressed by light deprivation. Such an observation could be explained if marine snow provided a major vector of sedimentation for these biomarkers. Late Pleistocene records in the Southeast Pacific yield plausible paleotemperature histories of ice-age cooling, but ice-age alkenone/alkenoate signatures fall outside the range of modern calibration samples of similar . They better match core-top samples deposited beneath waters characterized by much cooler maSST, suggesting key features of ice-age ecology for alkenone-producing haptophytes were different from today, and that the index taken alone may misgauge the total range of ice-age cooling at these locations. Analysis of the full spectrum of alkenone/alkenoate compositions preserved in sediments opens up a new opportunity that may improve the accuracy of paleotemperature estimates based on simple analysis and help resolve longstanding disagreements between various paleotemperature reconstruction methods.     

Population Structure of Adult Blue Crabs, <Emphasis Type="Italic">Callinectes sapidus</Emphasis>, in Relation to Physical Characteristics in Barnegat Bay,New Jersey

Blue crabs (Callinectes sapidus) are an important species in coastal or lagoonal estuaries where adult population characteristics may differ as compared to drowned-river estuaries. Barnegat Bay, in southern New Jersey, is composed of two large embayments: one without and one with a salinity gradient. We tested the influence of physical characteristics on the abundance, sex ratio, and size of adult blue crabs and examined variation in measures of reproductive potential (e.g., sperm stores) in both sexes in Barnegat Bay from June to September, 2008–2009. Population structure was distinct between the embayments due to sex-specific responses to salinity: male abundance was negatively correlated with salinity whereas adult females were more abundant in high salinity because of proximity to Barnegat Inlet. This produced high sex ratios in low salinity areas and low sex ratios in high salinity areas. Summer was a growing season for adult males while in late summer-early fall, juvenile males recruited to the adult size class. The spawning season lasted from May to August and ovigerous females were concentrated near the inlets. Information on female sperm stores and ovarian development identified two cohorts of adult females: females that will spawn in the current summer and females that will not spawn until the following summer. Thus, not all adult females near the spawning grounds were members of the current spawning stock. This suggests that annual estimates of spawning stock size which overlook the proximity of females to spawning are overestimating the current spawning stock in Barnegat Bay and other estuaries.     

Extra-tropical atmospheric response to ENSO in the CMIP5 models

The seasonal mean extra-tropical atmospheric response to El Niño/Southern Oscillation (ENSO) is assessed in the historical and pre-industrial control CMIP5 simulations. This analysis considers two types of El Niño events, characterized by positive sea surface temperature (SST) anomalies in either the central equatorial Pacific (CP) or eastern equatorial Pacific (EP), as well as EP and CP La Niña events, characterized by negative SST anomalies in the same two regions. Seasonal mean geopotential height anomalies in key regions typify the magnitude and structure of the disruption of the Walker circulation cell in the tropical Pacific, upper tropospheric ENSO teleconnections and the polar stratospheric response. In the CMIP5 ensembles, the magnitude of the Walker cell disruption is correlated with the strength of the mid-latitude responses in the upper troposphere i.e., the North Pacific and South Pacific lows strengthen during El Niño events. The simulated responses to El Niño and La Niña have opposite sign. The seasonal mean extra-tropical, upper tropospheric responses to EP and CP events are indistinguishable. The ENSO responses in the MERRA reanalysis lie within the model scatter of the historical simulations. Similar responses are simulated in the pre-industrial and historical CMIP5 simulations. Overall, there is a weak correlation between the strength of the tropical response to ENSO and the strength of the polar stratospheric response. ENSO-related polar stratospheric variability is best simulated in the “high-top” subset of models with a well-resolved stratosphere.     

Estimate of Boundary-Layer Depth Over Beijing,China, Using Doppler Lidar Data During SURF-2015

Planetary boundary-layer (PBL) structure was investigated using observations from a Doppler lidar and the 325-m Institute of Atmospheric Physics (IAP) meteorological tower in the centre of Beijing during the summer 2015 Study of Urban-impacts on Rainfall and Fog/haze (SURF-2015) field campaign. Using six fair-weather days of lidar and tower data under clear to cloudy skies, we evaluate the ability of the Doppler lidar to probe the urban boundary-layer structure, and then propose a composite method for estimating the diurnal cycle of the PBL depth using the Doppler lidar. For the convective boundary layer (CBL), a threshold method using vertical velocity variance \((\sigma _w^2 >0.1\,\hbox {m}^{2}\hbox {s}^{-2})\) is used, since it provides more reliable CBL depths than a conventional maximum wind-shear method. The nocturnal boundary-layer (NBL) depth is defined as the height at which \(\sigma _w^2\) decreases to 10 % of its near-surface maximum minus a background variance. The PBL depths determined by combining these methods have average values ranging from \(\approx \)270 to \(\approx \)1500 m for the six days, with the greatest maximum depths associated with clear skies. Release of stored and anthropogenic heat contributes to the maintenance of turbulence until late evening, keeping the NBL near-neutral and deeper at night than would be expected over a natural surface. The NBL typically becomes more shallow with time, but grows in the presence of low-level nocturnal jets. While current results are promising, data over a broader range of conditions are needed to fully develop our PBL-depth algorithms.