Different marine habitats are characterised by different soundscapes. How or which differences may be representative of the habitat characteristics and/or community structure remains however to be explored. A growing project in passive acoustics is to find a way to use soundscapes to have information on the habitat and on its changes. In this study we have successfully tested the potential of two acoustic indices, i.e. the average sound pressure level and the acoustic complexity index based on the frequency spectrum. Inside and outside marine protected areas of Moorea Island (French Polynesia), sound pressure level was positively correlated with the characteristics of the substratum and acoustic complexity was positively correlated with fish diversity. It clearly shows soundscape can be used to evaluate the acoustic features of marine protected areas, which presented a significantly higher ambient sound pressure level and were more acoustically complex than non-protected areas. This study further emphasizes the importance of acoustics as a tool in the monitoring of marine environments and in the elaboration and management of future conservation plans.

ArticleAcoustic landscapes, or soundscapes, can vary due to biological (‘biophony’), geophysical (‘geophony’) and anthropogenic (‘anthrophony’) components, and in some environments, such as many coral reefs, biophony dominates the soundscape. We compared 126 sound recordings from 3 different times of day (day, dusk and night) at 42 locations with concurrent fish and habitat surveys to investigate the relationships of acoustic parameters with biological and physical characteristics of coral reefs in the Gambier Archipelago, French Polynesia. Principal Component Analysis revealed that most of the variability in soundscapes could be described using only 4 factors: (1) full bandwidth root mean squared sound pressure level (SPL; 0.01 to 22.5 kHz in dB re 1 µPa); SPL of frequencies (2) >0.63 kHz and (3) between 0.16 and 2.5 kHz; and (4) the number of snaps made by snapping shrimp. Number of snaps in a recording and SPL above 0.63 kHz were negatively related to live coral cover, and the density and diversity of adult and juvenile fish, but positively related to dead coral cover and time of day (as the day progressed from day to dusk to night). Full bandwidth SPL and midrange SPL were positively related to sea state, depth, Porites coral, the coral forms ‘branched’ and ‘massive’ and whether the bottom was coverd by coral (live or dead). Soundscape recordings can contribute to a more complete assessment of ecological landscapes and, in cases where logistical constraints preclude traditional survey methods, passive acoustic monitoring may give valuable information on whether habitats are changing over time

Mitochondrial membrane permeabilization (MMP) is a rate-limiting step of apoptosis, including in anticancer chemotherapy. Adenine nucleotide translocase (ANT) mediates the exchange of ADP and ATP on the inner mitochondrial membrane in healthy cells. In addition, ANT can cooperate with Bax to form a lethal pore during apoptosis. Humans possess four distinct ANT isoforms, encoded by four genes, whose transcription depends on the cell type, developmental stage, cell proliferation, and hormone status. Here, we show that the ANT2 gene is up-regulated in several hormone-dependent cancers. Knockdown of ANT2 by RNA interference induced no major changes in the aspect of the mitochondrial network or cell cycle but provoked minor increase in mitochondrial transmembrane potential and reactive oxygen species level and reduced intracellular ATP concentration without affecting glycolysis. At expression and functional levels, ANT2 depletion was not compensated by other ANT isoforms. Most importantly, ANT2, but not ANT1, silencing facilitated MMP induction by lonidamine, a mitochondrion-targeted antitumor compound already used in clinical studies for breast, ovarian, glioma, and lung cancer as well as prostate adenoma. The combination of ANT2 knockdown with lonidamine induced apoptosis irrespective of the Bcl-2 status. These data identify ANT2 as an endogenous inhibitor of MMP and suggest that its selective inhibition could constitute a promising strategy of chemosensitization. (Cancer Res 2006; 66(18): 9143-52)

Coral disease outbreaks have increased over the last three decades, but their causal agents remain mostly unclear (e.g., bacteria, viruses, fungi, protists). This study details a 14‐month‐long survey of coral colonies in which observations of the development of disease was observed in nearly half of the sampled colonies. A bimonthly qPCR method was used to quantitatively and qualitatively evaluate Symbiodinium assemblages of tagged colonies, and to detect the presence of Vibrio spp. Firstly, our data showed that predisposition to disease development in general, and, more specifically, infection by Vibrio spp. in Acropora cytherea depended on which clades of Symbiodinium were harbored. In both cases, harboring clade D rather than A was beneficial to the coral host. Secondly, the detection of Vibrio spp. in only colonies that developed disease strongly suggests opportunistic traits of the bacteria. Finally, even if sporadic cases of switching and probably shuffling were observed, this long‐term survey does not suggest specific‐clade recruitment in response to stressors. Altogether, our results demonstrate that the fitness of the coral holobiont depends on its initial consortium of Symbiodinium, which is distinct among colonies, rather than a temporary adaptation achieved through acquiring different Symbiodinium clades.