Postdoctoral position in marine acoustics : mapping underwater noise in the English Channel

Context: The EBESCO project: effect of underwater noise on species of commercial interest is led by the regional fisheries committee of Normandy, IFREMER, and the Waves and Complex Media Lab at the University of Le Havre. It is funded for three years (01/2024 – 12/2026) by the European Maritime, Fisheries and Aquaculture Fund (EMFAF). The objective is to establish a mapping of underwater noise in the English Channel, specifically in the Seine Bay, and to study the impact of this noise on two priority species for fishing in Normandy: scallops and whelks.

The English Channel is one of the most anthropized areas in the world with the coexistence of multiple activities: maritime traffic, fishing, marine sediment extractions, port and coastal development and offshore wind farm installations, among others. All these activities generate underwater noise, either continuously or intermittently, at potentially very high acoustic levels. Currently, there is no comprehensive and precise quantitative assessment of underwater noise pollution in the English Channel, and there are no studies specific to the English Channel environment regarding the effects of underwater noise on fishing stocks. The EBESCO project aims to answer the following questions: which are the sources of underwater noise in the Seine Bay and what is their intensity? Are there cumulative effects between different sources? How do the geographical areas most exposed to noise relate to the areas where species are present? What is the impact of noise on the species, especially those of major economic interest for fishing?

More specifically, for the acoustic component of the project addressed by this post-doctoral research, the first step will be to map underwater noise in the eastern English Channel using existing information about sources (maritime traffic, marine aggregate extraction, construction works, etc.) and a noise propagation model taking into account the hydrographic characteristics of this area (bathymetry and nature of the seabed). Then, in collaboration with researchers from IFREMER, the noise maps will be compared to spatiotemporal distribution maps of economically important species to identify areas at risk of noise impact on fishery resources. These efforts will help to anticipate the impact of future noise-generating projects (e.g. wind farms) on the marine ecosystem and complement existing methodologies contributing to the protection of aquatic ecosystems.

Tasks

Activities:

• Compilation of quantitative and geolocalized information on underwater noise sources in the English Channel.
• Implementation of computation codes for acoustic propagation in a marine environment (modal method and/or parabolic equation), adapted to the Channel environment (local bathymetry, nature of the seabed).
• Creation of underwater noise maps for different sources based on acoustic propagation modeling.
• Processing of data from acoustic measurements at sea, comparison with the model for validation.
• Cross-referencing of noise maps with spatio-temporal distribution of species of interest (in collaboration with IFREMER).

Requirements

Desired skills:

• PhD in acoustics, preferably in relation with underwater acoustics.
• Scientific programming with Matlab or Python.
• Experience and/or interest in processing geospatial data would be appreciated.
• Ability to present work and results at scientific conferences and write scientific publications in English.

Benefits

Salary: Gross salary from 2400 to 2700€ depending on experience, plus a contribution to transport and mutual insurance costs.

Application:

We invite you to submit a CV, cover letter and contacts of two references. We look forward to receiving your application. The vacancy will remain open until 31st October 2024. The employment is a temporary position of 24 months with a starting date as agreed and as soon as possible.

Contacts:

Simon Bernard, Fernand Léon, Waves and Complex Media Laboratory – Laboratoire Ondes et Milieux Complexes, UMR CNRS 6294, University of Le Havre