A5057484707- Marine and fisheries research
- Marine animal studies overview
- Underwater Acoustics Research
- Fish Ecology and Management Studies
- Ultrasonics and Acoustic Wave Propagation
- Ichthyology and Marine Biology
- Marine Bivalve and Aquaculture Studies
- Marine Biology and Ecology Research
- Marine and coastal ecosystems
- Cephalopods and Marine Biology
- Acoustic Wave Phenomena Research
- Geophysical Methods and Applications
- Geological Modeling and Analysis
- Animal Behavior and Reproduction
- Water Quality Monitoring Technologies
- Flow Measurement and Analysis
- Arctic and Antarctic ice dynamics
- Animal Vocal Communication and Behavior
- Linguistic Variation and Morphology
- Underwater Vehicles and Communication Systems
- Education, Healthcare and Sociology Research
- Advanced Sensor Technologies Research
- Isotope Analysis in Ecology
- Historical Astronomy and Related Studies
- Species Distribution and Climate Change
Norwegian Institute of Marine Research
2014-2024
Acoustics (Norway)
2020-2023
Australian Antarctic Division
2022
University of Tasmania
2022
NOAA National Marine Fisheries Service Northwest Fisheries Science Center
2020
National Oceanic and Atmospheric Administration
2020
NOAA National Marine Fisheries Service
2020
National Institute of Water and Atmospheric Research
2001-2015
University of Canterbury
1994-1998
Vertical migrations by marine organisms contribute to carbon export consumption of surface phytoplankton followed defecation in the deep ocean. However, biogeochemical models lack observational data, leading oversimplified representation cycling migrating organisms, such as Antarctic krill ( Euphausia superba ). Using a numerical model informed 1 year acoustic observations East Antarctic, we estimated total particulate organic (POC) flux from fecal pellets be 9.68 milligrams per square meter...
Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within remains fragmented and not quantified. Increasing base is constrained by inability traditional sampling methods adequately sample processes at spatio-temporal scales which they occur. By combining satellite acoustic observations over spatial 10 s km horizontally 100 m vertically, supported hydrographical we show that anticyclonic shape distribution density marine...
Sonars and echosounders are widely used for remote sensing of life in the marine environment. There is an ongoing need to make acoustic identification species more correct objective thereby reduce uncertainty abundance estimates. In our work, data from multi-frequency working simultaneously with nearly identical overlapping beams processed stepwise a modular sequence improve data, detect schools categorize targets by means Large Scale Survey System software (LSSS). Categorization based on...
Abstract Assessment of open‐ocean ecosystems relies on understanding ecosystem dynamics, and development end‐to‐end models represents an approach that addresses these challenges. These incorporate the population structure dynamics marine organisms at all trophic levels. Satellite remote sensing ocean colour direct at‐sea measurements provide information lower levels models, fisheries studies top predator species. However, suffer from a lack observations for so‐called mid‐trophic levels,...
Analytical and numerical scattering models with accompanying digital representations are used increasingly to predict acoustic backscatter by fish zooplankton in research ecosystem monitoring applications. Ten such were applied targets simple geometric shapes parameterized (e.g., size material properties) represent biological organisms as fish, their predictions of compared those from exact or approximate analytical models, i.e., benchmarks. These comparisons made for a sphere, spherical...
Mapped wave-envelope elements of variable radial order are presented for the computation time-harmonic, unbounded, three-dimensional acoustical fields. Their application to transient problems is described in a companion article (Part II). Accuracy assessed by comparison computed and analytic solutions multi-pole fields generated vibrating sphere. Solutions also plane wave scattering. Elements m+l shown be capable modeling components m, although provision adequate transverse resolution...
Abstract Sustainable management of fisheries resources requires quantitative knowledge and understanding species distribution, abundance, productivity-determining processes. Conventional sampling by physical capture is inconsistent with the spatial temporal scales on which many these processes occur. In contrast, acoustic observations can be obtained from centimetres to ocean basins, seconds seasons. The concept marine ecosystem acoustics (MEA) founded basic capability detect, classify,...
Abstract Antarctic krill is a key species in the Southern Ocean and subject to most extensive fishery Antarctic. The Norwegian Institute of Marine Research has conducted acoustic-trawl monitoring off South Orkneys annually since 2011 collaboration with fishing industry. Average biomass within 60000 km2 survey area ranged from 1.4 7.8 million tonnes period 2011–2020, strongly supporting that this among regions Scotia Sea consistently highest densities. There were no significant (p ≈ 0.18,...
Abstract Ryan, T. E., Kloser, R. J., and Macaulay, G. J. 2009. Measurement visual verification of fish target strength using an acoustic-optical system attached to a trawlnet. – ICES Journal Marine Science, 66: 1238–1244. It is difficult make acoustic target-strength (TS) measurements behaving naturally in deep-water habitats. The may avoid the instrumentation, and, if measured, there uncertainty about their species orientation relative incident sound. To address these issues, novel (AOS)...
Regular monitoring is an important component of the successful management pelagic animals interest to commercial fisheries. Here we provide a biomass estimate for Antarctic krill ( Euphausia superba ) in eastern sector Commission Conservation Marine Living Resources (CCAMLR) Division 58.4.2 (55°E 80°E; area = 775,732 km 2 using data collected during acoustic-trawl survey carried out February and March 2021. Using acoustic day-time trawl data, areal density was estimated as 8.3 gm -2 giving...
Abstract Although it is well known that the slopes of target strength (TS) and length relationships vary widely, common in fisheries acoustics to force TS–length regression through a slope 20. Is time abandon this practice? The theoretical justification was TS should be proportional cross-sectional area, area scale as square linear dimension (fish length). There are now many species other than gadoids subject acoustic surveys, them do not have same morphology gadoid fishes. regressions...
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 527:13-29 (2015) - DOI: https://doi.org/10.3354/meps11257 Acoustic surveys of euphausiids and models baleen whale distribution in Barents Sea P. H. Ressler1,2,*, Dalpadado2, G. J. Macaulay2, N. Handegard2, M. Skern-Mauritzen2 1Alaska Fisheries Science Center, NOAA National Service, Seattle, WA 98115, USA...
Wideband (38 and 50–260 kHz) target strength of organisms were measured in situ using a towed platform mesopelagic (200–1000 m depth) layers. Organisms with gas-inclusion are strong scatterers sound acoustically distinct from lacking one. In the zone, some fish species physonect siphonophores have gas-inclusion. Trawl multinet biological sampling as well photographic evidence indicate that study area (eastern mid-Atlantic Ocean) majority gas-bearing fish. Subsequently, two-layer...
Aggregation is commonly thought to improve animals' security. Within aquatic ecosystems, group-living prey can learn about immediate threats using cues perceived directly from predators, or collective behaviours, for example, by reacting the escape behaviours of companions. Combining different modalities may accuracy antipredatory decisions. In this study, we explored sensory that mediate responses herring (Clupea harengus) when in a large school (approximately 60 000 individuals). By...
Estimates of the distribution and density Antarctic krill (Euphausia superba Dana, 1850) were derived from a large-scale survey conducted during austral summer in Southwest Atlantic sector Southern Ocean across Scotia Sea 2018-19, '2018-19 Area 48 Survey'.Survey vessels provided by Norway, Association Responsible Krill harvesting companies Aker BioMarine AS, United Kingdom, Ukraine, Republic Korea, China.Survey design followed transects Commission for Conservation Marine Living Resources...
Broadband echosounder systems provide very high range resolution that could resolve different parts of fish and hence estimates size. The potential for, accuracy of, direct acoustic sizing was tested on fish-like targets known dimensions orientations. Prolate spheroids, 91–477 mm long, with without an air-filled inclusion (simulating a swim-bladder), made from polyvinyl-alcohol-cryogel, were suspended in beam rotated while the backscattered signal recorded. echoes linear frequency modulated...
Abstract The use of quantitative broadband echosounders for biological studies and surveys can offer considerable advantages over narrowband echosounders. These include improved spectral‐based target identification significantly increased ability to resolve individual targets. An understanding current processing steps is required fully utilise further develop acoustic methods in marine ecology. We describe the involved data from raw frequency dependent strength () volume backscattering using...
Abstract O'Driscoll, R. L., de Joux, P., Nelson, R., Macaulay, G. J., Dunford, A. Marriott, P. M., Stewart, C., and Miller, B. S. 2012. Species identification in seamount fish aggregations using moored underwater video. – ICES Journal of Marine Science, 69: 648–659. Acoustic surveys New Zealand deep-water seamounts often show up to 150 m high on the summit. Although bottom trawls slopes catch predominantly orange roughy (Hoplostethus atlanticus), species composition midwater plumes is...
Abstract Kloser, R. J., Ryan, T. E., Macaulay, G. and Lewis, M. E. 2011. In situ measurements of target strength with optical model verification: a case study for blue grenadier, Macruronus novaezelandiae. – ICES Journal Marine Science, 68: 1986–1995. (TS) isolated fish surrounding dense schools need to be representative the schooling calculate their echo-integrated biomass. Using synchronous acoustic from pelagic fishing net, standard length (81 cm, n = 128), tilt-angle (−9°), net-disturbed...
We describe a method to allow acoustic sampling at depths not reachable by the higher frequencies of ship hull-mounted echosounders and observe abundance behaviour individual organisms in front trawls. A self-contained scientific echosounder with 120 kHz transducer was mounted forward-facing on headline macrozooplankton trawl that obliquely towed from 0 1000 m depth, investigate mesopelagic fauna. With use echosounder, we were able estimate organism densities trawl, vertical profiles target...