The effect of two 12 kHz multibeam mapping surveys on the foraging behavior of Cuvier's beaked whales off of southern California.

The impact of multibeam echosounder (MBES) operations on marine mammals has been less studied compared to military sonars. To contribute to the growing body of MBES knowledge, echolocation clicks of foraging Cuvier's beaked whales were detected on the Southern California Antisubmarine Warfare Range (SOAR) hydrophones during two MBES surveys and assembled into foraging events called group vocal periods (GVPs). Four GVP characteristics were analyzed Before, During, and After 12 kHz MBES surveys at the SOAR in 2017 and 2019 to assess differences in foraging behavior with respect to the mapping activity. The number of GVP per hour increased During and After MBES surveys compared with Before. There were no other differences between non-MBES and MBES periods for the three other characteristics: the number of clicks per GVP, GVP duration, and click rate. These results indicate that there was not a consistent change in foraging behavior during the MBES surveys that would suggest a clear response. The animals did not leave the range nor stop foraging during MBES activity. These results are in stark contrast to those of analogous studies assessing the effect of Naval mid-frequency active sonar on beaked whale foraging, where beaked whales stopped echolocating and left the area.

A socio-environmental monitoring system for a UNESCO biosphere reserve.

To identify potentially critical changes in an area's ongoing ability to produce multiple ecosystem services, a monitoring system was designed and implemented for the Mornington Peninsula and Westernport Biosphere Reserve in southeast Australia. The system is underpinned by an "environmental vital signs" (EVS) approach that was adopted to provide early warning of critical changes in human and natural characteristics of the area. The six themes monitored are non-coastal water, land including vegetation, biodiversity, natural heritage, built environment (including human population and economic activity), and coasts. These are monitored for the entire area, and each of its five constituent town council areas. After a critical change in any of these is identified, further investigation is required to identify causal factors and, if required, determine an appropriate response. The system relies on data available from external (third-party) organisations to monitor the natural and human characteristics of the area that were important in its designation as a UNESCO biosphere reserve. Strengths and weaknesses associated with the use of third-party data are discussed. These include adoption of baseline years and data reporting periods for different factors, costs, and data quality.

Addressing Once More the (Im)possibility of Color Reconstruction in Underwater Images.

Color is an important cue in object recognition and classification problems. In underwater imagery, colors undergo strong distortion due to light propagation through an absorbing and scattering medium. Distortions depend on a number of complex phenomena, the most important being wavelength-dependent absorption and the sensitivity of sensors in trichromatic cameras. It has been shown previously that unique reconstruction in this case is not possible-at least for a simplified image formation model. In this paper, the authors use numerical simulations to demonstrate that this statement also holds for the underwater image formation model that is currently the most sophisticated.

Minimal COVID-19 quieting measured in the deep offshore waters of the U.S. Outer Continental Shelf.

Using a 2-year time series (2019-2020) of 1-min sound pressure level averages from seven sites, the extension of COVID-related quieting documented in coastal soundscapes to deep (approximately 200-900 m) waters off the southeastern United States was assessed. Sites ranged in distance to the continental shelf break and shipping lanes. Sound level decreases in 2020 were observed at sites closest to the shelf break and shipping lanes but were inconsistent with the timing of shipping changes related to a COVID-19 slowdown. These observations are consistent with increased numbers of vessel tracks in 2020 compared to 2019 at a majority of sites.

Detecting and Quantifying Forest Change: The Potential of Existing C- and X-Band Radar Datasets.

This paper evaluates the opportunity provided by global interferometric radar datasets for monitoring deforestation, degradation and forest regrowth in tropical and semi-arid environments. The paper describes an easy to implement method for detecting forest spatial changes and estimating their magnitude. The datasets were acquired within space-borne high spatial resolutions radar missions at near-global scales thus being significant for monitoring systems developed under the United Framework Convention on Climate Change (UNFCCC). The approach presented in this paper was tested in two areas located in Indonesia and Australia. Forest change estimation was based on differences between a reference dataset acquired in February 2000 by the Shuttle Radar Topography Mission (SRTM) and TanDEM-X mission (TDM) datasets acquired in 2011 and 2013. The synergy between SRTM and TDM datasets allowed not only identifying changes in forest extent but also estimating their magnitude with respect to the reference through variations in forest height.