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The Commission for the Conservation of Antarctic Marine Living Resources is responsible for management of the Antarctic marine ecosystem, including its living resources. The Commission has yet to implement precautionary measures that protect predators dependent upon Antarctic krill from potential food competition with fisheries where these now increasingly spatially aggregate. Here, we describe voluntary buffer zones (VBZ) implemented in 2018 by the Association of Responsible Krill harvesting companies (ARK) following negotiations with environmental NGOs. The VBZ now prohibit krill fishing during the penguin-breeding season around important penguin colonies along the Antarctic Peninsula. We describe the background of the VBZ and further actions that would ensure ongoing ecological benefits. Lack of data and delays in the implementation of the Commission's revised krill fishery management framework continue to concern NGOs and other stakeholders, especially as part of the management framework will expire in November 2022. Without action by CCAMLR, the ARK VBZ will be the only regulation providing precautionary protection at relevant spatial and temporal scales. The VBZ are an example of how responsible industry can help to protect marine ecosystems when regional management is unable to act given lack of data, and/or associated legal and political constraints.

Attenuation from fish can reduce the intensity of acoustic signals and significantly decrease detection range for long-range passive sensing of manmade vehicles, geophysical phenomena, and vocalizing marine life. The effect of attenuation from herring shoals on the Passive Ocean Acoustic Waveguide Remote Sensing (POAWRS) of surface vessels is investigated here, where concurrent wide-area active Ocean Acoustic Waveguide Remote Sensing (OAWRS) is used to confirm that herring shoals occluding the propagation path are responsible for measured reductions in ship radiated sound and corresponding detection losses. Reductions in the intensity of ship-radiated sound are predicted using a formulation for acoustic attenuation through inhomogeneities in an ocean waveguide that has been previously shown to be consistent with experimental measurements of attenuation from fish in active OAWRS transmissions. The predictions of the waveguide attenuation formulation are in agreement with measured reductions from attenuation, where the position, size, and population density of the fish groups are characterized using OAWRS imagery as well as in situ echosounder measurements of the specific shoals occluding the propagation path. Experimental measurements of attenuation presented here confirm previous theoretical predictions that common heuristic formulations employing free space scattering assumptions can be in significant error. Waveguide scattering and propagation theory is found to be necessary for accurate predictions.

Attenuation from fish can reduce the intensity of acoustic signals and significantly decrease detection range for long-range passive sensing of manmade vehicles, geophysical phenomena, and vocalizing marine life. The effect of attenuation from herring shoals on the Passive Ocean Acoustic Waveguide Remote Sensing (POAWRS) of surface vessels is investigated here, where concurrent wide-area active Ocean Acoustic Waveguide Remote Sensing (OAWRS) is used to confirm that herring shoals occluding the propagation path are responsible for measured reductions in ship radiated sound and corresponding detection losses. Reductions in the intensity of ship-radiated sound are predicted using a formulation for acoustic attenuation through inhomogeneities in an ocean waveguide that has been previously shown to be consistent with experimental measurements of attenuation from fish in active OAWRS transmissions. The predictions of the waveguide attenuation formulation are in agreement with measured reductions from attenuation, where the position, size, and population density of the fish groups are characterized using OAWRS imagery as well as in situ echosounder measurements of the specific shoals occluding the propagation path. Experimental measurements of attenuation presented here confirm previous theoretical predictions that common heuristic formulations employing free space scattering assumptions can be in significant error. Waveguide scattering and propagation theory is found to be necessary for accurate predictions.

This paper presents the technological developments and the policy contexts for the project “Autonomous Robotic Sea-Floor Infrastructure for Bentho-Pelagic Monitoring” (ARIM). The development is based on the national experience with robotic component technologies that are combined and merged into a new product for autonomous and integrated ecological deep-sea monitoring. Traditional monitoring is often vessel-based and thus resource demanding. It is economically unviable to fulfill the current policy for ecosystem monitoring with traditional approaches. Thus, this project developed platforms for bentho-pelagic monitoring using an arrangement of crawler and stationary platforms at the Lofoten-Vesterålen (LoVe) observatory network (Norway). Visual and acoustic imaging along with standard oceanographic sensors have been combined to support advanced and continuous spatial-temporal monitoring near cold water coral mounds. Just as important is the automatic processing techniques under development that have been implemented to allow species (or categories of species) quantification (i.e., tracking and classification). At the same time, real-time outboard processed three-dimensional (3D) laser scanning has been implemented to increase mission autonomy capability, delivering quantifiable information on habitat features (i.e., for seascape approaches). The first version of platform autonomy has already been tested under controlled conditions with a tethered crawler exploring the vicinity of a cabled stationary instrumented garage. Our vision is that elimination of the tether in combination with inductive battery recharge trough fuel cell technology will facilitate self-sustained long-term autonomous operations over large areas, serving not only the needs of science, but also sub-sea industries like subsea oil and gas, and mining.

This paper presents the technological developments and the policy contexts for the project “Autonomous Robotic Sea-Floor Infrastructure for Bentho-Pelagic Monitoring” (ARIM). The development is based on the national experience with robotic component technologies that are combined and merged into a new product for autonomous and integrated ecological deep-sea monitoring. Traditional monitoring is often vessel-based and thus resource demanding. It is economically unviable to fulfill the current policy for ecosystem monitoring with traditional approaches. Thus, this project developed platforms for bentho-pelagic monitoring using an arrangement of crawler and stationary platforms at the Lofoten-Vesterålen (LoVe) observatory network (Norway). Visual and acoustic imaging along with standard oceanographic sensors have been combined to support advanced and continuous spatial-temporal monitoring near cold water coral mounds. Just as important is the automatic processing techniques under development that have been implemented to allow species (or categories of species) quantification (i.e., tracking and classification). At the same time, real-time outboard processed three-dimensional (3D) laser scanning has been implemented to increase mission autonomy capability, delivering quantifiable information on habitat features (i.e., for seascape approaches). The first version of platform autonomy has already been tested under controlled conditions with a tethered crawler exploring the vicinity of a cabled stationary instrumented garage. Our vision is that elimination of the tether in combination with inductive battery recharge trough fuel cell technology will facilitate self-sustained long-term autonomous operations over large areas, serving not only the needs of science, but also sub-sea industries like subsea oil and gas, and mining

Acoustics is the primary means of long-range and wide-area sensing in the ocean due to the severe attenuation of electromagnetic waves in seawater. While it is known that densely packed fish groups can attenuate acoustic signals during long-range propagation in an ocean waveguide, previous experimental demonstrations have been restricted to single line transect measurements of either transmission or backscatter and have not directly investigated wide-area sensing and communication issues. Here we experimentally show with wide-area sensing over 360° in the horizontal and ranges spanning many tens of kilometers that a single large fish shoal can significantly occlude acoustic sensing over entire sectors spanning more than 30° with corresponding decreases in detection ranges by roughly an order of magnitude. Such blockages can comprise significant impediments to underwater acoustic remote sensing and surveillance of underwater vehicles, marine life and geophysical phenomena as well as underwater communication. This makes it important to understand the relevant mechanisms and accurately predict attenuation from fish in long-range underwater acoustic sensing and communication. To do so, we apply an analytical theory derived from first principles for acoustic propagation and scattering through inhomogeneities in an ocean waveguide to model propagation through fish shoals. In previous experiments, either the attenuation from fish in the shoal or the scattering cross sections of fish in the shoal were measured but not both, making it impossible to directly confirm a theoretical prediction on attenuation through the shoal. Here, both measurements have been made and they experimentally confirm the waveguide theory presented. We find experimentally and theoretically that attenuation can be significant when the sensing frequency is near the resonance frequency of the shoaling fish. Negligible attenuation was observed in previous low-frequency ocean acoustic waveguide remote sen

This paper presents the ecology and policy basis as well as the technology solution for a Martera funded project (ARIM). The project develops platforms for bentho-pelagic monitoring using an arrangement of crawler and stationary platforms. A combination of visual and acoustic sensing along with standard oceanographic sensors supports advanced and continues spatial-temporal monitoring. Just as important is the automatic processing techniques under development that will allow habitat and species (or categories of species) to be automatically recognized and reported during the mission and thus support science and monitoring services without backing from expensive ship time. First version develops autonomy under controlled conditions with a tethered crawler exploring the neighbourhood of a cabled stationary instrumented garage. Our vision is that fuel cell technology will enable us to use the system for selfsustained long-term autonomous operations for science as well as for industry purposes

The wide-area group behaviour of spawning Atlantic cod and herring is investigated. By a combination of Ocean Acoustic Waveguide Remote Sensing (OAWRS) and conventional sensing methods, first-look images of the instantaneous population density are obtained of entire Atlantic cod spawning groups, stretching for tens of kilometres in the Nordic Seas. This structural information made it possible to quantify the spawning group size distribution of cod over a roughly 30-year period from conventional line-transect data acquired annually by vertical echo sounding in the Nordic Seas. The size distribution is found to be consistent with the log-normal probability density often found in growth processes that depend on many independent parameters. Nordic Seas cod populations are found to distribute into many vast behavioural groups during spawning with relatively stable mean size despite larger variations in total annual population. When sustained at pre-industrial levels, the total spawning population is found to greatly exceed the mean spawning group size. As an apparent consequence of this large differential, when the total population, or overall scale, declined to within a standard deviation of this mean cod spawning group quantum, or inner-group-behavioural scale, return to pre-industrial levels required decades. Findings for Atlantic herring are similar, where summing the spawning group populations measured in a single instantaneous OAWRS image per day over the 8-day peak spawning period enabled accurate enumeration of the entire Georges Bank herring spawning population to within 7% of the independent NOAA estimate for 2006. These results may be relevant to other oceanic fish., United States. Office of Naval Research, National Science Foundation (U.S.), Norwegian Institute of Marine Research