Affordable, autonomous recording devices facilitate large scale acoustic monitoring and Rapid Acoustic Survey is emerging as a cost-effective approach to ecological monitoring; the success of the approach rests on the development of computational methods by which biodiversity metrics can be automatically derived from remotely collected audio data. Dozens of indices have been proposed to date, but systematic validation against classical, in situ diversity measures are lacking. This study conducted the most comprehensive comparative evaluation to date of the relationship between avian species diversity and a suite of acoustic indices. Acoustic surveys were carried out across habitat gradients in temperate and tropical biomes. Baseline avian species richness and subjective multi-taxa biophonic density estimates were established through aural counting by expert ornithologists. 26 acoustic indices were calculated and compared to observed variations in species diversity. Five acoustic diversity indices (Bioacoustic Index, Acoustic Diversity Index, Acoustic Evenness Index, Acoustic Entropy, and the Normalised Difference Sound Index) were assessed as well as three simple acoustic descriptors (Root-mean-square, Spectral centroid and Zero-crossing rate). Highly significant correlations, of up to 65%, between acoustic indices and avian species richness were observed across temperate habitats, supporting the use of automated acoustic indices in biodiversity monitoring where a single vocal taxon dominates. Significant, weaker correlations were observed in neotropical habitats which host multiple non-avian vocalizing species. Multivariate classification analyses demonstrated that each habitat has a very distinct soundscape and that AIs track observed differences in habitat-dependent community composition. Multivariate analyses of the relative predictive power of AIs show that compound indices are more powerful predictors of avian species richness than any single index and simple descriptors are significant contributors to avian diversity prediction in multi-taxa tropical environments. Our results support the use of community level acoustic indices as a proxy for species richness and point to the potential for tracking subtler habitat-dependent changes in community composition. Recommendations for the design of compound indices for multi-taxa community composition appraisal are put forward, with consideration for the requirements of next generation, low power remote monitoring networks.

Through their synergies, trade-offs, and contradictions, the sustainable development goals (SDGs) have the potential to lead to environmental justices and injustices. Yet, environmental justice (EJ), and social justice more broadly, are not currently embedded within the language and spirit of the SDGs. We part from the premise that "many 'environmental' problems are, by their very nature, problems of justice" (Lele, Wiley Interdiscip Rev Water 4:e1224, 2017). We review progress in EJ frameworks in recent years, arguing for the need to move beyond a focus on the four principles of mainstream EJ (distribution, procedure, recognition, and capabilities) towards a more intersectional decolonial approach to environmental justice that recognises the indispensability of both humans and non-humans. EJ frameworks, and the SDGs should recognise power dynamics, complex interactions among injustices, and listens to the different 'senses of justice' and desires of theorists, activists, and other stakeholder from the Global South. We analyze how EJ frameworks are, or fail to be, incorporated in the SDGs with a focus on the food-water-health nexus (SDG2, 3, 6); climate-energy (SDG7, 13), conservation (SDG14, 15); and poverty and inequality (SDG1, 10). We call attention to the 'elephant in the room'-the failure to go beyond GDP but instead include economic growth as a goal (SDG8). We argue that sustainable degrowth and intersectional decolonial environmental justices would create better conditions for the transformative changes needed to reach the broader aim of the SDGs: to leave no one behind.

The occurrence of intersex fish in a number of European rivers has been attributed to exposure to estrogenic chemicals present in sewage treatment work (STW) effluents. To further understand the environmental fate of these contaminants, the estrogenic activity of effluents, water, and sediments were investigated both upstream and downstream of the major STW discharge in two United Kingdom rivers. Estrogenic activity, determined using the yeast estrogen-receptor transcription screen, of the major STW effluents on both rivers was similar, ranging from 1.4 to 2.9 ng 17beta-estradiol equivalents (EEQ)/L. Estrogenic activities of surface waters 1 km upstream and downstream of both STW inputs were less than the limits of detection (0.04 ng/L); however, levels of estrogenic activity in sediments were between 21.3 and 29.9 ng EEQ/kg and were similar at both upstream and downstream sites. Effluent and sediment extracts were fractionated by reverse phase-high-performance liquid chromatography, and estrogenic active fractions were further analyzed by gas chromatography-mass spectrometry. The major active chemicals in the two effluents and in the sediments were estrone with lesser amounts of 17beta-estradiol; however, at one site, a number of other unidentified estrogenic fractions were detected in the sediments. These results suggest that riverine sediments are a major sink and a potential source of persistent estrogenic contaminants.

Passive acoustic monitoring is emerging as a promising non-invasive proxy for ecological complexity with potential as a tool for remote assessment and monitoring (Sueur & Farina, 2015). Rather than attempting to recognise species-specific calls, either manually or automatically, there is a growing interest in evaluating the global acoustic environment. Positioned within the conceptual framework of ecoacoustics, a growing number of indices have been proposed which aim to capture community-level dynamics by (e.g., Pieretti, Farina & Morri, 2011; Farina, 2014; Sueur et al., 2008b) by providing statistical summaries of the frequency or time domain signal. Although promising, the ecological relevance and efficacy as a monitoring tool of these indices is still unclear. In this paper we suggest that by virtue of operating in the time or frequency domain, existing indices are limited in their ability to access key structural information in the spectro-temporal domain. Alternative methods in which time-frequency dynamics are preserved are considered. Sparse-coding and source separation algorithms (specifically, shift-invariant probabilistic latent component analysis in 2D) are proposed as a means to access and summarise time-frequency dynamics which may be more ecologically-meaningful.

Brown-headed spider monkeys (Ateles fusciceps), endemic to the ChocoDarien forests and lower Andean forests of NW Ecuador, are considered critically endangered. Unfortunately, scientific data regarding the actual status of populations is lacking. We combined satellite image analysis, species-specific habitat assessment, and a field survey technique using playback to focus conservation efforts for this species. First, we identified remaining forest via a LANDSAT mosaic and then applied species-specific criteria to delineate remaining forest with potential to hold populations. By combining this with the historical distribution from ecological niche modeling and predicted hunting intensity we generated a species-specific landscape map. Within our study area, forest capable of sustaining Ateles fusciceps covers 5872 km 2 , of which 2172 km 2 (40%) is protected. Unprotected forest considered suitable for Ateles fusciceps extends to 3700 km 2 but within this only 989 km 2 (23%) is under low hunting pressure and likely to maintain healthy populations of Ateles fusciceps. To overcome problems of sampling at low primate density and in difficult mountain terrain we developed a field survey technique to determine Int presence and estimate abundance using acoustic sampling. For sites under low hunting pressure density of primates varied with altitude. Densities decreased from 7.49 individuals/km 2 at 332 masl to 0.9 individuals/km 2 at 1570 masl. Based on combining data sets in a gap analysis, we recommend conservation action focus on unprotected lowland forest to the south and west of the Cotacachi-Cayapas Ecological Reserve where hunting pressure is low and population densities of Ateles fusciceps are greatest.