Impulsive noise pollution in the Northeast Atlantic: Reported activity during 2015-2017

Underwater noise pollution from impulsive sources (e.g. explosions, seismic airguns, percussive pile driving) can affect marine fauna through mortality, physical injury, auditory damage, physiological stress, acoustic masking, and behavioural responses. Given the potential for large-scale impact on marine ecosystems, some countries are now monitoring impulsive noise activity, coordinated internationally through Regional Seas Conventions. Here, we assess impulsive noise activity in the Northeast Atlantic reported during 2015-2017 to the first international impulsive noise register (INR), established in 2016 under the OSPAR Convention. Seismic airgun surveys were the dominant noise source (67%-83% of annual activity) and declined by 38% during 2015-2017. Reported pile driving activity increased 46%. Explosions and sonar/acoustic deterrent devices both had overall increases in reported activity. Some increases were attributable to more comprehensive reporting in later years. We discuss utilising the INR for risk assessment, target setting, and forward planning, and the implementation of similar systems in other regions

A European competency level applied to the use of the closed circuit rebreather in scientific diving at work. First step. Highlighting the best practice

International audienceThe use of the closed circuit rebreather (CCR) for scientific diving activities is growing. During the last 10 years more and more scientists and scientific projects did take advantage of the furtive behaviour CCR offers together with the very efficient gas management, optimized decompression and enhanced diving safety. Many applications exists, among others, the exploration of the mesophotic zone or the fishes sensing, sampling, study of their vocal communication. The use of rebreather in sciences exploration constitutes a new technological paradigm.The American Academy of Underwater Science (AAUS) in the USA established a standard for the use of rebreathers in scientific diving some 10 years ago and such document is lacking in Europe. Today in Europe the use of rebreather is generally not permitted by existing national legislation. If accepted in Belgium, France is currently undergoing changes to its laws and should allow the use of closed circuit rebreather early 2017. These national legislations need to evolve and adapt to the new technique used for scientific diving but that takes time. So it is time to establish at European level a competency level for the use of CCR at work. Taking advantage of the existing European norm for that respiratory equipment will permit to put more emphasis on the best practice rules aiming at inferring adapted and unified training around Europe using a common reference frame. This paper is a first step on that process and will highlight all the points that will need to be addressed in this future new competency level

Long term volumetric evolution of an exploited sandbank. Case study on the coastal Belgian North Sea Kwintebank

Exploitation of aggregates from sandbanks off the Belgian coast has been growing over the two last decades. The authorities are now clearly facing the question of the sustainability of that activity. Ten to fifteen years of bathymetric measurements along reference tracks are available today. From those data, time series of volumes above a given reference level are computed and submitted to trend analysis techniques. The analysis indicates that the volume is decreasing (with a high level of confidence) almost everywhere. Estimated volume decrease is then compared to available exploitation data. Despite all the shortcomings of the procedure, the two quantities appear to be close to each others. Exploitation seems however not being the single component of the observed decrease

Biogeochemical box modelling at small scale. Application to the inorganic carbon cycle in the bay of Calvi

This paper describes a processes 0D biogeochemical model valid at small scale (1 km, 1 hour). It is used to study the inorganic carbon cycle in the Bay of Calvi (Corsica), a near-shore coastal area characterised by properties that simplify the modelling approach: no river input, no tide, a constant circulation pattern and two quite well-studied ecosystems (the Spring phytoplankton bloom and a Posidonia seagrass bed). The model has been developed from available field data and then calibrated using an independent data set. Results show that the obtained steady-state is close to the one observed in the Bay of Calvi, and calculated fluxes are in good agreement with the measured ones. Numerical integrations have been carried out using two market softwares (SENECA 1.5 and STELLA II) and no significant differences are found

Specific initial training standards are needed to dive for science in Europe, Occupational vs. Citizen Science Diving

International audienceToday, collaboration between scientific research and civil society is growing significantly. The general public’s curiosity drives it to engage with the scientific process and culture and in the search for solutions to complex issues (economic, social, health, environmental, cultural, educational, or ethical). Clarification is needed to differentiate between occupational scientific activity and citizen-based science. They do not require the same scientific and technical skills despite using similar equipment and their legal and administrative frameworks being totally different. The confusion created by the indiscriminate use of the same term “scientific diving” to refer to different training courses and activities compromises the quality of existing occupational standards and, ultimately, has a negative impact on the safety of the activity at work. A clear definition of Citizen Scientific Diving and Occupational Scientific Diving makes it possible to differentiate between the objectives and target groups of these two activities and their legal framework. There is a need to establish an accepted and shared standard in the occupational field and to ensure the mobility of scientists. A long process undertaken by a motivated scientific community (late 1980s-2000s) led to the establishment of European initial training standards for Occupational Scientific Diving through the ESDP-European Scientific Diving Panel (firstly under the aegis of the European Marine Board, now of the MARS-European marine stations network). The quality and general acceptance of these standards by a large part of the European scientific community have already adopted them in the occupational health and safety legislation of seven European countries (Belgium, Finland, France, Germany, Norway, Sweden, and the UK in 2023). Adopting them in other countries’ health and safety legislation is still desirable. This will increase their recognition, acceptance and use for the benefit of scientific work. Building bridges between academic science and non-academic citizen science is possible and this is done by developing coherent projects that produce results that benefit both science and society. While distinguishing between the two, as an added value, this approach could better guide the recreational diving training sector in developing a new market

European standards for initial training in occupational scientific diving, a necessity, and a guarantee for the mobility of scientists and effective research in the coastal environment

International audienceGetting diving recognised as a scientific technique has long been a challenge in most European countries because of the ”recreational” image associated with its practice. Another important difficulty for its administrative acceptance has been its supposed danger and the chain of responsibilities that an accident could initiate. As early as the 1980s, it was understood that an essential aspect of making underwater interventions possible in the various scientific disciplines that needed them was the definition and implementation of an initial training that would guarantee maximum safety. A framework at least at European level was necessary to allow scientists from several countries to collaborate and therefore to allow their mobility. The scientific community was mobilised. The most difficult and important task was to set up a representative committee and to define harmonised standards, acceptable and recognised by the Member States. A long process (late 1980’s - 2000’s) led to the proposal to establish European standards for scientific diving and to make visible a ”European Scientific Diving Panel” through the ESF Marine Board between 2008 and 2017. This panel is currently receiving organisational support from the European Network of Marine Institutes and Stations (MARS). This effort finally led to the acceptance and development of two European standards for scientific diving: the European Scientific Diver standard (ESD) and the Advanced European Scientific Diver standard (AESD). Currently, 17 countries recognise and apply these standards (or equivalent). The quality and general acceptance of these standards by a large part of the European scientific community has led to their adoption in the health and safety legislation of 7 European countries (BE, DE, FI, FR, NO, SE, UK). A similar legal process is underway in several other countries. These standards have been defined in the context of the occupational practice of professional scientists. However, the use of the term ”scientific diving” in the world of recreational diving, which does not follow the same rules of professional training and is aimed at volunteers, is currently blurring the original concept of scientific diving. An urgent clarification is needed to differentiate between scientific activity and citizen science, which does not require the same scientific and technical skills, despite the use of similar equipment. The (semantic) confusion created by the indiscriminate use of the same terms to refer to different training and activities risks compromising these years of effort and diminishing the quality of ESD and AESD standards, which are often considered too high and restrictive by the recreational diving sector willing to develop with ISO their own standards, keeping the same wording ”scientific diving” but with a ”citizen science diver” content. Be warned

A 3-dimensional Model of the Water Circulation Around An Island in Shallow-water

A three-dimensional model is applied to the study of the tidal flow in the shallow waters around Rattray Island, Great Barrier Reef, Australia. The model uses the sigma-coordinate system and the numerical procedure is based on the finite volume approach. Two counter-rotating eddies develop in the wake of the island. The shearing and veering of the horizontal velocity is predicted to be small, hence the vertical motions are negligible almost everywhere, with the exception of some small regions. In the center of the eddies important upwelling is found, which is in qualitative agreement with theory and observations. The model exhibits strong downwelling along the upstream side of the island. Overall, the magnitude of the computed vertical motions may be too small and it is hypothesized that this may be due to a lack of resolution of the model. Further improvements to the model are outlined

Different modelling tools of aquatic ecosystems: A proposal for a unified approach

Over the last few decades, several modelling tools have been developed for the simulation of hydrodynamic and biogeochemical processes in aquatic ecosystems. Until late 70's, coupling hydrodynamic models to biogeochemical models was not common and today, problems linked to the different scales of interest remain. The time scale of hydrodynamic phenomena in coastal zone (minutes to hours) is much lower than that of biogeochemistry (few days). Over the last years, there has been an increasing tendency to couple hydrodynamic and biogeochemical models in a clear recognition of the importance of incorporating in one model the feedbacks between physical, chemical and biological processes. However, different modelling teams tend to adopt different modelling tools, with the result that benchmarking exercises are sometimes difficult to achieve in projects involving several institutions. Therefore, the objectives of this paper are to provide a quick overview of available modelling approaches for hydrodynamic and biogeochemical modelling, to help people choose among the diversity of available models, as a function of their particular needs, and to propose a unified approach to allow modellers to share software code, based on the object oriented programming potentiality. This approach is based on having object dynamic link libraries that may be linked to different model shells. Each object represents different processes and respective variables, e.g. hydrodynamic, phytoplankton and zooplankton objects. Some simple rules are proposed to link available objects to programs written in different source codes. (c) 2006 Elsevier B.V. All rights reserved

A bi-dimensional approach to assessing the volumetric evolution of an exploited sandbank

We analyse the multi-annual evolution of bathymetry along several cross-sections of the Kwintebank (one of the Flemish Banks). An important issue in the area is the intensive exploitation under regulations imposed by the Belgian authorities that aim to guarantee sustainability of extractions. All bathymetric data collected during the period 1987-2000 at a frequency of approximately four surveys per year are analysed, to identify volumetric temporal trends. The errors inherent in the measurements taken with a single-beam instrument are examined. The lack of indisputable quality criteria led to the choice of robust statistical methods. A statistically significant annual decline of approximately 1.5% in bank volume is shown. Another practical conclusion is that a big increase in sampling frequency is necessary if the authorities set a criterion regarding the long-term sustainability of the bank and wish to have a swift guarantee that this criterion is being observed. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved