Contrasting ecological information content in whaling archives with modern cetacean surveys for conservation planning and identification of historical distribution changes

Many species are restricted to a marginal or suboptimal fraction of their historical range due to anthropogenic impacts, making it hard to interpret their ecological preferences from modern-day data alone. However, inferring past ecological states is limited by the availability of robust data and biases in historical archives, posing a challenge for policy makers . To highlight how historical records can be used to understand the ecological requirements of threatened species and inform conservation, we investigated sperm whale (Physeter macrocephalus) distribution in the Western Indian Ocean. We assessed differences in information content and habitat suitability predictions based on whale occurrence data from Yankee whaling logs (1792–1912) and from modern cetacean surveys (1995–2020). We built maximum entropy habitat suitability models containing static (bathymetry-derived) variables to compare models comprising historical-only and modern-only data. Using both historical and modern habitat suitability predictions  we assessed marine protected area (MPA) placement by contrasting suitability in- and outside MPAs. The historical model predicted high habitat suitability in shelf and coastal regions near continents and islands, whereas the modern model predicted a less coastal distribution with high habitat suitability more restricted to areas of steep topography. The proportion of high habitat suitability inside versus outside MPAs was higher when applying the historical predictions than the modern predictions, suggesting that different marine spatial planning optimums can be reached from either data sources. Moreover, differences in relative habitat suitability predictions between eras were consistent with the historical depletion of sperm whales from coastal regions, which were easily accessed and targeted by whalers, resulting in a modern distribution limited more to steep continental margins and remote oceanic ridges. The use of historical data can provide important new insights and, through cautious interpretation, inform conservation planning and policy, for example, by identifying refugee species and regions of anticipated population recovery.     

The effects of daylight saving time on vehicle crashes in Minnesota

Introduction: Daylight saving time (DST), implemented as an energy saving policy, impacts many other aspects of life; one is road safety. Based on vehicle crash data in Minnesota from 2001 to 2007, this paper evaluates long- and short-term effects of DST on daily vehicle crashes. Method: To provide evidence to explain the causes of more/fewer crashes in DST, we examine the impact of DST on crashes in four periods of a day: 3 a.m.-9 a.m., 9 a.m.-3 p.m., 3 p.m.-9 p.m., 9 p.m.-midnight. The effects of risk and exposure to traffic are also separated. Our statistical models not only include weather conditions and dummy variables for days in DST as independent variables, but also consider traffic volumes on major roads in different periods of a day. Our major finding is that the short-term effect of DST on crashes on the morning of the first DST is not statistically significant. Moreover, it is interesting to notice that while DST per se is associated with fewer crashes during dusk, this is in part offset because it is also associated with more traffic on roads (and hence more crashes). Our path analysis shows that overall DST reduces crashes. Impact on industry: Daylight saving time can lead to fewer crashes on roads by providing better visibility for drivers.     

Predicting Invasiveness of Plant Species Based on Biological Information

Abstract: Previous studies suggest that, within particular groups of plant species, biological attributes can be used to predict the potential invasiveness of species that are intentionally introduced for horticultural or agricultural purposes. We examined the broad question of whether commonly available biological information can predict the invasiveness of a wide range of intentionally and accidentally introduced species. We collected information from published floras on 165 pairs of plant species. In each pair, one species originated in Europe and successfully invaded New Brunswick, Canada, and the other was a congeneric species that has not invaded North America. Only three biological characters—lifeform, stem height, and flowering period—and European geographic range were known for all species. We conducted multiple logistic regression analyses using two-thirds (110) of the species pairs and tested the predictive ability of resulting models using the remaining 55 pairs. Although a significant logistic regression model was obtained using the biological attributes, the model could not predict invasiveness of the test species pairs. In contrast, a model using only European range successfully predicted invasiveness in 70% of the test species. The importance of geographic range suggests that prediction of invasiveness on a species-by-species basis is not likely to help stem the flow of accidentally introduced invasive species. Species that are inadvertently picked up and moved to a new location due to their wide distribution are the same species that are likely to succeed in a new environment due to their wide environmental tolerances.     

Population dynamics,reproduction and growth of the Indo-Pacific horned sea star, <Emphasis Type="Italic">Protoreaster nodosus</Emphasis> (Echinodermata; Asteroidea)

The horned sea star (Protoreaster nodosus) is relatively common in the Indo-Pacific region, but there is little information about its biology. This study of the population biology of P. nodosus was carried out in Davao Gulf, The Philippines (7°5′N, 125°45′E) between September 2006 and May 2008. Protoreaster nodosus was found in sand and seagrass dominated habitats at a mean density of 29 specimens per 100 m² and a mean biomass of 7.4 kg per 100 m², whereas a significantly lower density and biomass was found in coral and rock dominated habitats. Adult specimens (mean radius R = 10.0 cm) were found at depths of 0–37 m, whereas juveniles (R < 8 cm) were only found in shallow sandy habitats with abundant seagrass (water depth ≤2 m). Increased gonad weights were found from March to May (spawning period), which coincided with an increasing water temperature and a decreasing salinity. Density and biomass did not change significantly during reproduction, but sea stars avoided intertidal habitats. All specimens with R > 8 cm had well developed gonads and their sex ratio was 1:1. Protoreaster nodosus grew relatively slowly in an enclosure as described by the exponential function G = 7.433 e^{−0.257 × R} . Maturing specimens (R = 6–8 cm) were estimated to have an age of 2–3 years. Specimens with a radius of 10 cm (population mean) were calculated to have an age of 5–6 years, while the maximum age (R = 14 cm) was estimated as 17 years. Potential effects of ornamental collection on the sea star populations are discussed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Spatial selection and inheritance: applying evolutionary concepts to population dynamics in heterogeneous space

Organisms in highly suitable sites generally produce more offspring, and offspring can inherit this suitability by not dispersing far. This combination of spatial selection and spatial inheritance acts to bias the distribution of organisms toward suitable sites and thereby increase mean fitness (i.e., per capita population increase). Thus, population growth rates in heterogeneous space change over time by a process conceptually analogous to evolution by natural selection, opening avenues for theoretical cross-pollination between evolutionary biology and ecology. We operationally define spatial inheritance and spatial selective differential and then combine these two factors in a modification of the breeder's equation, derived from simple models of population growth in heterogeneous space. The modified breeder's equation yields a conservative criterion for persistence in hostile environments estimable from field measurements. We apply this framework for understanding gypsy moth population persistence amidst abundant predators and find that the predictions of the modified breeder's equation match initial changes in population growth rate in independent simulation output. The analogy between spatial dynamics and natural selection conceptually links ecology and evolution, provides a spatially implicit framework for modeling spatial population dynamics, and represents an important null model for studying habitat selection.     

Evaluating portable infrared spectrometers for measuring the silica content of coal dust

Miners face a variety of respiratory hazards while on the job, including exposure to silica dust which can lead to silicosis, a potentially fatal lung disease. Currently, field-collected filter samples of silica are sent for laboratory analysis and the results take weeks to be reported. Since the mining workplace is constantly moving into new and often different geological strata with changing silica levels, more timely data on silica levels in mining workplaces could help reduce exposures. Improvements in infrared (IR) spectroscopy open the prospect for end-of-shift silica measurements at mine sites. Two field-portable IR spectrometers were evaluated for their ability to quantify the mass of silica on filter samples loaded with known amounts of either silica or silica-bearing coal dust (silica content ranging from 10-200 μg/filter). Analyses included a scheme to correct for the presence of kaolin, which is a confounder for IR analysis of silica. IR measurements of the samples were compared to parallel measurements derived using the laboratory-based U.S. Mine Safety and Health Administration P7 analytical method. Linear correlations between Fourier transform infrared (FTIR) and P7 data yielded slopes in the range of 0.90-0.97 with minimal bias. Data from a variable filter array spectrometer did not correlate as well, mainly due to poor wavelength resolution compared to the FTIR instrument. This work has shown that FTIR spectrometry has the potential to reasonably estimate the silica exposure of miners if employed in an end-of-shift method.     

Managing biological invasions: charting courses to desirable futures in the Cape Floristic Region

Invasive species alter the functioning of natural ecosystems, creating “novel ecosystems” comprising species occurring in combinations with no analogs within a given biome. This poses major challenges for managers who cannot rely exclusively on previous experiences. Multiple factors that drive invasion and which interact in complex ways demand innovative management approaches. We show the utility of scenario planning in considering options for management in a region with substantial problems with invasive alien plants: South Africa’s Cape Floristic Region. The approach allows us to identify the driving forces that shape the status and trajectories of major woody invasive plants and to identify sensible strategies by considering a set of scenarios based on the main uncertainties that encapsulate the linkages between the various components of the management of biological invasions. Attitudes of landowners and management capacity are shown to be the crucial uncertainties influencing the spread of major invasive species; axes based on these factors define our scenarios. Mapping current management projects onto scenario axes highlighted key differences among areas. These insights can assist in directing particular management units toward more desirable futures. Our study highlights the need to link social, political and legal constraints with ecological processes to assure the effectiveness of management operations in controlling biological invasions.     

Degradative fate of 3-chlorocarbazole and 3,6-dichlorocarbazole in soil

Background, aim, and scope  

3-Chlorocarbazole and 3,6-dichlorocarbazole were isolated from Bavarian soils. The stereospecific formation of the isomers of these chlorinated carbazols can be explained by quantum mechanical calculations using the DFT method. It was shown that chlorination of carbazole and 3-chlorocarbazole respectively is preferred via the sigma-complexes 3-chlorocarbazole and 3,6-dichlorocarbazole as the most stable products. The dioxin-like toxicological potential of 3,6-dichlorocarbazole, determined by the Micro-EROD Test, is in the range of some picogram TCDD equivalents per milligram carbazole. The degradative fate of 3-chlorocarbazole and 3,6-dichlorocarbazole was analysed within a long-term study (57 days) in soil.     

Carbon content of common airborne fungal species and fungal contribution to aerosol organic carbon in a subtropical city

Interest in the role and contribution of fungi to atmospheric aerosols and processes grows in the past decade. Substantial data or information such as fungal mass or carbon loading to ambient aerosols is however still lacking. This study aimed to quantify the specific organic carbon content (OC per spore) of eleven fungal species commonly found airborne in the subtropics, and estimated their contribution to organic carbon in aerosols. The specific OC contents showed a size-dependent relationship (r = 0.64, p < 0.05) and ranged from 3.6 to 201.0 pg carbon per spore or yeast cell, giving an average of 6.0 pg carbon per spore (RSD 51%) for spore or cell size less than 10 μm. In accounting for natural variations in the composition and abundance of fungal population, weighted-average carbon content for field samples was adopted using the laboratory determined specific OC values. An average of 5.97 pg carbon per spore (RSD 3.8%) was enumerated from 28 field samples collected at the university campus. The mean fungal OC concentration was 3.7, 6.0 and 9.7 ng m^?3 in PM_2.5, PM_2.5–10 and PM₁₀, respectively. These corresponded to 0.1%, 1.2% and 0.2% of the total OC in PM_2.5, PM_2.5–10 and PM₁₀, respectively. In the study period, rain provided periods with low total OC but high fungal prevalence and fungi contributed 7–32% OC in PM_2.5–10 or 2.4–7.1% OC in PM₁₀. More extensive studies are deserved to better understand the spatial-, temporal- and episodic dependency on the fungal OC contribution to the atmospheric aerosols.