It often howls more than it chugs: Wind versus ship noise under water in Australia’s maritime regions

Marine soundscapes consist of cumulative contributions by diverse sources of sound grouped into: physical (e.g., wind), biological (e.g., fish), and anthropogenic (e.g., shipping)—each with unique spatial, temporal, and frequency characteristics. In terms of anthropophony, shipping has been found to be the greatest (ubiquitous and continuous) contributor of low-frequency underwater noise in several northern hemisphere soundscapes. Our aim was to develop a model for ship noise in Australian waters, which could be used by industry and government to manage marine zones, their usage, stressors, and potential impacts. We also modelled wind noise under water to provide context to the contribution of ship noise. The models were validated with underwater recordings from 25 sites. As expected, there was good congruence when shipping or wind were the dominant sources. However, there was less agreement when other anthropogenic or biological sources were present (i.e., primarily marine seismic surveying and whales). Off Australia, pristine marine soundscapes (based on the dominance of natural, biological and physical sound) remain, in particular, near offshore reefs and islands. Strong wind noise dominates along the southern Australian coast. Underwater shipping noise dominates only in certain areas, along the eastern seaboard and on the northwest shelf, close to shipping lanes

Endoscopic papillectomy: a retrospective international multicenter cohort study with long-term follow-up

Background Endoscopic papillectomy (EP) is considered a relatively safe and minimally invasive treatment for papillary adenomas. In the literature a significant risk for local recurrence is described. The aim of this study was to evaluate long-term recurrence rates and time-to-recurrence. Additionally, risk factors for recurrence, malignancy and adverse events were studied. Methods This is a retrospective study in consecutive patients with papillary adenomas who underwent EP in two tertiary referral hospitals between 2001 and 2018. Primary outcome was recurrence in patients with at least 1-year endoscopic follow-up. Secondary outcomes were surgery free survival, adverse events, and mortality within 30 days after the index procedure. Results A total of 259 patients were found eligible [median age 66 years, 130 male (50.2%)]. Forty-three patients were known with familial adenomatous polyposis (FAP) (16.6%). At least 1-year endoscopic follow-up was available in 154 patients with a total follow-up of 586 person-years and median of 40 months [interquartile range (IQR) 25-75]. Recurrence occurred in 24 cases (15.6%) of which 8 were known with FAP, leading to a recurrence incidence rate of 4.1 per 100 person-years with a median time-to-recurrence of 29 months (IQR 14.75-59.5). Fifty-three patients underwent at least 5-year follow-up, in 6 (11.3%) of them recurrence was encountered after 5 years of which four were known with FAP. No risk factors for recurrence could be identified. Adverse events occurred in 50/259 patients (19.3%). One patient died within 30 days after the procedure. Papillary stenosis occurred in 19/259 (7.3%) of the patients. There were no cases of malignant degeneration during follow-up. Conclusions Recurrence after EP occurs in a significant proportion of patients and occurs even 5 years after EP. This emphasizes the need for long-term follow-up. We advise to consider at least 5-year follow-up in case of a sporadic adenoma, unless comorbidity makes follow-up clinically irrelevant

Marine acoustic zones of Australia

Underwater sound is modelled and mapped for purposes ranging from localised environmental impact assessments of individual offshore developments to large-scale marine spatial planning. As the area to be modelled increases, so does the computational effort. The effort is more easily handled if broken down into smaller regions that could be modelled separately and their results merged. The goal of our study was to split the Australian maritime Exclusive Economic Zone (EEZ) into a set of smaller acoustic zones, whereby each zone is characterised by a set of environmental parameters that vary more across than within zones. The environmental parameters chosen reflect the hydroacoustic (e.g., water column sound speed profile), geoacoustic (e.g., sound speeds and absorption coefficients for compressional and shear waves), and bathymetric (i.e., seafloor depth and slope) parameters that directly affect the way in which sound propagates. We present a multivariate Gaussian mixture model, modified to handle input vectors (sound speed profiles) of variable length, and fitted by an expectation-maximization algorithm, that clustered the environmental parameters into 20 maritime acoustic zones corresponding to 28 geographically separated locations. Mean zone parameters and shape files are available for download. The zones may be used to map, for example, underwater sound from commercial shipping within the entire Australian EEZ