scholarly journals Use of Underwater Acoustics in Marine Conservation and Policy: Previous Advances, Current Status, and Future Needs

2021 ◽  
Vol 9 (2) ◽  
pp. 173
Author(s):  
Shane Guan ◽  
Tiffini Brookens ◽  
Joseph Vignola

The interdisciplinary field of assessing the impacts of sound on marine life has benefited largely from the advancement of underwater acoustics that occurred after World War II. Acoustic parameters widely used in underwater acoustics were redefined to quantify sound levels relevant to animal audiometric variables, both at the source and receiver. The fundamental approach for assessing the impacts of sound uses a source-pathway-receiver model based on the one-way sonar equation, and most numerical sound propagation models can be used to predict received levels at marine animals that are potentially exposed. However, significant information gaps still exist in terms of sound source characterization and propagation that are strongly coupled with the type and layering of the underlying substrate(s). Additional challenges include the lack of easy-to-use propagation models and animal-specific statistical detection models, as well as a lack of adequate training of regulatory entities in underwater acoustics.

2021 ◽  
Vol 9 (9) ◽  
pp. 934
Author(s):  
Alena Zakharenko ◽  
Mikhail Trofimov ◽  
Pavel Petrov

Numerous sound propagation models in underwater acoustics are based on the representation of a sound field in the form of a decomposition over normal modes. In the framework of such models, the calculation of the field in a range-dependent waveguide (as well as in the case of 3D problems) requires the computation of normal modes for every point within the area of interest (that is, for each pair of horizontal coordinates x,y). This procedure is often responsible for the lion’s share of total computational cost of the field simulation. In this study, we present formulae for perturbation of eigenvalues and eigenfunctions of normal modes under the water depth variations in a shallow-water waveguide. These formulae can reduce the total number of mode computation instances required for a field calculation by a factor of 5–10. We also discuss how these formulae can be used in a combination with a wide-angle mode parabolic equation. The accuracy of such combined model is validated in a series of numerical examples.


2021 ◽  
Author(s):  
Hollie Booth ◽  
M Said Ramdlan ◽  
Ayesha Hafizh ◽  
Karto Wongsopatty ◽  
Susana Mourato ◽  
...  

Large, long-lived marine animals (‘marine megafauna’) play critical roles in ocean ecosystems, however, they are threatened by overfishing. Technologies and practices that reduce fisheries’ impacts on marine megafauna are well documented, yet less is known about how to encourage their adoption. This is particularly challenging in small-scale fisheries (SSFs), where endangered species can have important consumptive use values. We used a novel combination of methods – scenario interviews with contingent valuation (CV) – to investigate how incentive-based interventions might influence fisher behaviour and reduce mortality of Critically Endangered taxa (hammerhead sharks (Sphyrna spp.) and wedgefish (Rhynchobatus spp.)) in two case study SSFs in Indonesia. Scenario interviews revealed that positive performance-based incentives were almost unanimously supported (98% and 96% of fishers would stop landing hammerheads and wedgefish, respectively). This is in contrast to 1% and 6% under a business as usual control scenario, and 52% and 46% in response to a regulation with a fine. Using CV, we estimated that an incentive-based scheme for catch mitigation of all hammerheads and wedgefish across both sites could cost US$71,620-298,820 annually, and save up to 18,500 hammerheads and 2,140 wedgefish relative to current catch baselines. This study provides empirical evidence that performance-based payments could offer a cost-effective, legitimate and socially-just approach for marine conservation in SSFs, and support “a sustainable and equitable blue economy” and “living in harmony with nature”. This is particularly important with the growing adoption of net-outcome goals for biodiversity, with studies such as this providing the basis for locally-appropriate investment ready schemes for bycatch-neutral seafood supply chains.


2015 ◽  
pp. 308-319
Author(s):  
Oğuzhan Karadeniz ◽  
Beytullah Kaya

In this chapter, the phenomenon of peace in the social studies curriculum is examined in the context of Turkey and Greece. The formation of the social studies curriculum and conceptual changes in programs in Turkey related with Greece is investigated. The studies that have been initiated after World Wars to prevail the perception of peace in Social Studies and History lessons are reviewed. The current status of the curriculum shows an attempt put forward by examining historically the studies initiated by UNESCO after World War II in order to eliminate the phenomenon of hostility in the textbooks which also include Turkey and Greece. Due to the nature of the study described in this chapter, the method of scanning was used. As a result of the study, it has been observed that the phenomenon of peace hasn't been given enough space, but there have been obvious positive regulations than those in the past. In this context, a continuation of the studies related with the phenomenon of peace which are included in the curriculum is suggested.


Author(s):  
Oğuzhan Karadeniz ◽  
Beytullah Kaya

In this chapter, the phenomenon of peace in the social studies curriculum is examined in the context of Turkey and Greece. The formation of the social studies curriculum and conceptual changes in programs in Turkey related with Greece is investigated. The studies that have been initiated after World Wars to prevail the perception of peace in Social Studies and History lessons are reviewed. The current status of the curriculum shows an attempt put forward by examining historically the studies initiated by UNESCO after World War II in order to eliminate the phenomenon of hostility in the textbooks which also include Turkey and Greece. Due to the nature of the study described in this chapter, the method of scanning was used. As a result of the study, it has been observed that the phenomenon of peace hasn't been given enough space, but there have been obvious positive regulations than those in the past. In this context, a continuation of the studies related with the phenomenon of peace which are included in the curriculum is suggested.


2019 ◽  
Vol 11 (7) ◽  
pp. 1972 ◽  
Author(s):  
Ioannis Liritzis ◽  
Elena Korka

The interdisciplinary field of archaeometry covers a wide range of subject categories and disciplines in relation to science and humanities. It is a well-established academic field of study and accredited part of higher education. Since its inception, the nomenclature designation of archaeometry signifies the appropriate methodology applied to archaeological materials and questions emerging from this field, regarding monuments, artifacts, and the reconstruction and management of landscape bearing cultural assets. The measurements of tangible culture denote significant information, such as chronology, authenticity, technology, characterization, provenance, discovering buried antiquities, ancient-day life activities, and three-dimensional (3D) reconstructions and modelling; furthermore, proxy data collected from environmental dynamic non-liner perturbations, which link local ecosystems with dwellings, are gathered by academia to study the past. The traditional rooting signifies the cultural legacies of people, which define the human desire and the confidence of memory and future trends. Beyond the mere study of the past, archaeometry’s role increasingly proves affinity to prosperity, if properly managed. The major archaeometrical contributions in cultural heritage and archaeology in general are reviewed herein, and we present the policies that could develop archaeometrical data into a sustainable stage of local, regional, and national economic development. Τhe United Nations Educational, Scientific, and Cultural Organization (UNESCO) conventions for the documentation and protection of cultural heritage via new technologies and archaeometry are reviewed and connected to development strategies and sustainable development goals.


2011 ◽  
Vol 51 (1) ◽  
pp. 467
Author(s):  
Dick Petersen ◽  
Antoine David ◽  
Darren Jurevicius

The oil and gas industry uses some exploration and production technologies that produce high levels of underwater sound, such as seismic surveys, underwater blasting for demolition and construction, and offshore piling. These underwater noise sources have the potential to impact marine species, which are usually reliant on sound instead of light as their primary sense for communication and sensing their environment. Regulatory interest in minimising the impacts of underwater noise on marine fauna is increasing. This paper presents a methodology for assessing these environmental impacts, with particular focus on cetaceans (whales and dolphins) and pinnipeds (seals and sea lions), although it can easily be adapted to other marine mammal species and fishes. It requires input from a variety of fields, such as: underwater acoustics for sound propagation modelling and source noise characterisation; marine bio-acoustics for determining the effects of sound on marine species’ hearing and communication; and marine ecology for identifying the marine species that may be affected and assessing the biological importance of noise-affected marine areas. These inputs are used in a risk assessment to assess the likely impacts of underwater noise on marine species, which is a collaborative effort by specialists in the fields of underwater acoustics, marine bio-acoustics and marine ecology.


2020 ◽  
Vol 375 (1814) ◽  
pp. 20190445 ◽  
Author(s):  
Thomas J. Webb ◽  
Bart Vanhoorne

Recent decades have seen an explosion in the amount of data available on all aspects of biodiversity, which has led to data-driven approaches to understand how and why diversity varies in time and space. Global repositories facilitate access to various classes of species-level data including biogeography, genetics and conservation status, which are in turn required to study different dimensions of diversity. Ensuring that these different data sources are interoperable is a challenge as we aim to create synthetic data products to monitor the state of the world's biodiversity. One way to approach this is to link data of different classes, and to inventory the availability of data across multiple sources. Here, we use a comprehensive list of more than 200 000 marine animal species, and quantify the availability of data on geographical occurrences, genetic sequences, conservation assessments and DNA barcodes across all phyla and broad functional groups. This reveals a very uneven picture: 44% of species are represented by no record other than their taxonomy, but some species are rich in data. Although these data-rich species are concentrated into a few taxonomic and functional groups, especially vertebrates, data are spread widely across marine animals, with members of all 32 phyla represented in at least one database. By highlighting gaps in current knowledge, our census of marine diversity data helps to prioritize future data collection activities, as well as emphasizing the importance of ongoing sustained observations and archiving of existing data into global repositories. This article is part of the theme issue ‘Integrative research perspectives on marine conservation’.


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