A number of key knowledge gaps were identified through a review of recent literature and as outcomes of a specially convened workshop of international experts held in Brussels in April 2014. This report presents a high-level summary of the project findings. To this end, the European Commission (EC) supported the present Cefas-led project with the aim of developing a roadmap towards defining thresholds for Good Environmental Status (GES), and evaluating the use of sound maps for GES assessment.
Although scientific understanding of the effects of noise has advanced rapidly in recent years, further research is needed to develop the tools and knowledge necessary to inform effective management decisions. To address the risk of such impacts in European waters, a number of legislative instruments are being developed and implemented, including Descriptor 11 of the Marine Strategy Framework Directive (MSFD), which addresses underwater noise directly at the European level. Underwater noise from human activities may have significant negative impacts on marine ecosystems through a variety of direct and indirect effects on marine organisms.
We recommend as a priority the implementation of noise quieting technologies and the spatial and temporal exclusion of noise to minimize contact with marine life. As with other forms of pollution, reducing input at source is likely to be the most effective way of reducing impacts. New technologies are being developed for a number of activities which can substantially reduce noise inputs into the marine environment. Longer-term chronic impacts of noise including disturbance or masking of sounds critical for feeding and reproduction have received substantially less attention in management. Most current mitigation efforts are directed at reducing the risk of injury from exposure to intense noise, although the effectiveness of such mitigation measures in terms of risk reduction has rarely been quantified. The result has been efforts involving a variety of disciplines, and relevant legislation and associated guidance are now in place in many parts of the world. The issue has become a primary focus of marine mammal research, but is also of concern to the public and policy makers. If a transducer is lost or severely damaged, a replacement or repair fee is charged.Over the last two decades, marine noise pollution has become increasingly recognized as an issue of major significance. Normally, the loan fee provides for shipping costs, 30 meters of underwater electrical cable, a standard calibration (free-field voltage sensitivity and/or typical transmitting response), and minor repair or maintenance of a transducer.
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The full amount of the loan fee must be received prior to shipment of a transducer. USRD charges a loan fee for use of transducers in order to recover incurred costs. For general guidance, refer to the chart of transducer specifications below. Based on this information, the USRD staff can help select an appropriate transducer. The intended use, the measurement environment, and the frequency range of interest determine the type of transducer that is best suited to the application. Once authorized, loans to foreign governments are treated the same as loans to U.S. government and 55% of these customers are from commercial industry, universities, and state governments. Approximately 45% of the customers for these transducers are from various parts of the U.S. USRD transducer standards are used to verify specifications, to show conformance with contractual obligations, to show conformance with environmental laws, and to provide a reference base for advancing science and technology within the underwater acoustics community. with a wide variety of underwater transducer standards. Consistent with this role, USRD provides the U.S.
The Underwater Sound Reference Division (USRD) at the Naval Undersea Warfare Center (NUWC) in Newport, Rhode Island performs as the equivalent to NIST in underwater acoustics with traceability to NIST electrical voltage and current standards. The National Institute of Standards and Technology (NIST) performs the governmental function of providing standards in areas except underwater sound. The impetus for this effort is to ensure consistent and accurate measurements for research, development, inspection, acceptance and maintenance of ships, aircraft, and weapon systems. Navy's policy to maintain acoustic standards of measurement to certify performance of test and measuring equipment.
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