标题：
AZFP profiler声学浮游动物鱼类剖面仪，Insights from Winter 2021–22 Using an Acoustic Zooplankton Fish Profiler
摘要：
Abstract—Improved understanding of the role of the ocean in moderating climate and sustaining complex food webs is required to support ocean stewardship and ocean protection goals being pursued through Indigenous-led initiatives across Canada’s coastlines. The traditional territorial waters of the Nunatsiavut in the Labrador Sea contain a rich and diverse marine ecosystem regulated by a combination of physical oceanography and the presence of seasonal sea ice cover, transported southward by wind and ocean currents. The Nunatsiavut Government operates a growing research program to understand and monitor this complex biophysical system to support effective environmental management. As part of this research program, they are now in the fifth year of monitoring over-winter ocean and sea ice conditions at an offshore site near Nain, Labrador. Measurements made at this site have included water temperature, salinity, dissolved oxygen, turbidity, currents, and ice drafts and velocities. Combining these measurements to understand the ocean’s role in moderating climate and complex food webs is an important step in support of Indigenous-led research initiatives and ocean stewardship across Canada’s coastlines. The Nunatsiavut Government has collaborated with ASL Environmental Sciences to further develop environmental mon itoring at this site by supporting the first-ever deployment of the new ASL instrument known as the AZFP-ice. The AZFP ice is designed to collect high temporal and spatial resolution measurements of ice draft and simultaneous biological obser vations from its calibrated (±1 dB) multifrequency acoustical sensors. The AZFP-ice is a calibrated, scientific, singlebeam echosounder. The AZFP-ice uses a narrow beam 417 kHz center frequency channel to obtain ice keel depth, similar to ASL’s Ice Profiling Sonar (IPS). Simultaneous biological observations are realized using three separate channels, collecting calibrated backscatter measurements at 125 kHz, 200 kHz, and 769 kHz center frequencies. Building on ASL’s experience with the Acoustic Zooplankton Fish Profiler (AZFP) sonar system, the AZFP-ice is designed to operate autonomously for up to 12 months at a time. The AZFP-ice also features an upgraded electronics package that allows up to 1 TB of data to be stored internally. Its endurance and its internal memory capacity allow for excellent temporal coverage and make the instrument well-suited for deployment in challenging environments. The (ex situ) factory calibration allows backscatter to be measured on an absolute scale, which facilitates downstream processing such as the so-called ‘dB differencing’ approach that is common in fisheries acoustics. This paper introduces the new AZFP-ice and showcases its capabilities as a tool for environmental monitoring. An IPS-5 was located near the AZFP-ice, allowing for a comparison of the observed ice characteristics. Preliminary analysis of the data collected during an over-winter deployment from 2021 to 2022 indicates that the AZFP-ice facilitates sea-ice characterization. Much of the over-winter period is dominated by landfast ice, and segments of ice from break-up to ice clearing are compared from the closely spaced AZFP-ice and IPS-5. During the period of landfast ice, the ice dynamics are simple as the ice responds to the thermodynamic forcing. Daylight hours are greatly reduced in the winter, but this environment does not experience 24-hour darkness, unlike high-latitude environments. While the ice may be motionless, the other AZFP-ice frequencies indicate that below the ice activity continues during this period of reduced daylight. In this paper, the AZFP-ice’s acoustical observations of the under-ice biology are presented and discussed as we review examples from this deployment. The AZFP-ice is shown to provide a unique combination of measurements in a single instrument, offering researchers a physical context (i.e. ice thickness) alongside biological data.
Index Terms—sonar, underwater acoustics, instrumentation, ice characteristics, plankton.
摘要：更好地了解海洋在调节气候和维持复杂食物网方面的作用，以支持通过加拿大海岸线土著主导的倡议实现的海洋管理和海洋保护目标。拉布拉多海Nunatsiavut的传统领海包含丰富多样的海洋生态系统，受物理海洋学和季节性海冰覆盖的共同调节，由风和洋流向南输送。Nunatsiavut政府正在开展一项不断发展的研究计划，以了解和监测这一复杂的生物物理系统，以支持有效的环境管理。作为这项研究计划的一部分，他们现在已经进入了在拉布拉多奈因附近的一个海上地点监测冬季海洋和海冰状况的第五年。在该地点进行的测量包括水温、盐度、溶解氧、浊度、水流、冰气流和速度。将这些测量结果结合起来，了解海洋在调节气候和复杂食物网中的作用，是支持加拿大海岸线土著主导的研究倡议和海洋管理的重要一步。
索引术语 sonar、水下声学、仪器仪表、冰的特性、浮游生物、鱼探仪、AZFP、IPS5 冰剖面仪
