A Flexible Autonomous Robotic Observatory Infrastructure for Bentho-Pelagic Monitoring

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

WORKING GROUP ON NEPHROPS SURVEYS (WGNEPS ; outputs from 2020)

The Working Group on Nephrops Surveys (WGNEPS) is the international coordination group for Nephrops underwater television and trawl surveys within ICES. This report summarizes the na-tional contributions on the results of the surveys conducted in 2020 together with time series covering all survey years, problems encountered, data quality checks and technological improve-ments as well as the planning for survey activities for 2021.ICE

Predicting recruitment of 0-group gadoids in the Barents Sea - critical interaction between models and observations

The most important gadoid fish stocks of the Barents Sea spawn along the coast of Norway. The eggs, larvae and juveniles are transported northwards with the oceanic coastal currents from the spawning grounds towards their nursery and feeding areas in the Barents Sea. In this work, we present a conceptual model of the vertical dynamics of 0-group during the transport and settlement phase. Field observations of the vertical distribution and behaviour of 0-group fish recorded by a stationary acoustic system are compared to the conceptual model to validate critical assumptions. They also serve as an example of some critical observations needed to improve hydrodynamic modelling of the transport. We used two different vertical distribution algorithms for particles representing juvenile fish in a Lagrangian particletracking model. One is based on the behaviour described in the conceptual model and the other assumes random vertical distribution at a fixed depth range throughout the whole period. The distribution predicted from the vertical behaviour algorithms fits best to observations from surveys. Based on this experience we propose an observation program for collecting the needed observations to obtain a more realistic recruitment prediction model

Comparison of Northeast Atlantic mackerel (Scomber scombrus) distribution patterns in the Norwegian Sea using lidar, sonar, and trawl

In July 2002 the Institute of Marine Research (IMR), Bergen mapped the distribution and density of mackerel in the Norwegian Sea using lidar, sonar and trawl. A major objective was to test the efficiency of the lidar as a survey tool. Due to the lack of swim bladder and the fact that mackerel feeds close to the surface, traditional acoustic equipment is inefficient. The airborne NOAA fish lidar covered the same tracks as two commercial trawlers hired by IMR. The trawlers used a Simrad 24-36 kHz sonar to track the speed, volume, direction and depth of mackerel schools and they were trawling close to the surface. Most of the fish caught was mackerel (69% of catch weight) and the majority of the schools (64%) were recorded shallower than 40 meters. The mackerel was mainly distributed in the southern parts, while one of the trawlers also caught a significant amount in the northwest. These are the same areas where we got the strongest lidar return. The southern part of the surveyed area contained rich plankton layers showing up in the lidar return. These layers are easily distinguished from fish as they continue over long distances compared to the size of the schools. Fish data were therefore easily extracted during post-processing. The amount of plankton gradually decreased as we proceeded north giving clearer water and better lidar depth penetration. The lidar seems to be an interesting tool, giving plausible results, but still needs some development. Some aspects of future development are discussed