Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry
We employed ultrasonic transmitters to follow (for up to 48 h) the horizontal and vertical movements of five juvenile (6.8–18.7 kg estimated body mass) bluefin tuna (Thunnus thynnus) in the western North Atlantic (off the eastern shore of Virginia). Our objective was to document the fishes’ behavior...
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ftoceandocs:oai:aquadocs.org:1834/31053 2023-05-15T17:32:03+02:00 Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry Brill, Richard Lutcavage, Molly Metzger, Greg Bushnell, Peter Arendt, Michael Lucy, Jon Watson, Cheryl Foley, David 2002 application/pdf 155-167 http://hdl.handle.net/1834/31053 en eng http://fishbull.noaa.gov/1002/01brillf.pdf 0090-0656 http://hdl.handle.net/1834/31053 http://aquaticcommons.org/id/eprint/15200 403 2014-05-30 07:23:21 15200 United States National Marine Fisheries Service Biology Fisheries Management Oceanography article TRUE 2002 ftoceandocs 2023-04-06T17:04:19Z We employed ultrasonic transmitters to follow (for up to 48 h) the horizontal and vertical movements of five juvenile (6.8–18.7 kg estimated body mass) bluefin tuna (Thunnus thynnus) in the western North Atlantic (off the eastern shore of Virginia). Our objective was to document the fishes’ behavior and distribution in relation to oceanographic conditions and thus begin to address issues that currently limit population assessments based on aerial surveys. Estimation of the trends in adult and juvenile Atlantic bluefin tuna abundance by aerial surveys, and other fishery-independent measures, is considered a priority.Juvenile bluefin tuna spent the majority of their time over the continental shelf in relatively shallow water (generally less then 40 m deep). Fish used the entire water column in spite of relatively steep vertical thermal gradients (≈24°C at the surface and ≈12°C at 40 m depth), but spent the majority of their time (≈90%) above 15 m and in water warmer then 20°C. Mean swimming speeds ranged from 2.8 to 3.3 knots, and total distance covered from 152 to 289 km (82–156 nmi). Because fish generally remained within relatively con-fined areas, net displacement was only 7.7–52.7 km (4.1–28.4 nmi). Horizontal movements were not correlated with sea surface temperature. We propose that it is unlikely that juvenile bluefin tuna in this area can detect minor horizontal temperature gradients (generally less then 0.5°C/km) because of the steep vertical temperature gradients (up to ≈0.6°C/m) they experience during their regular vertical movements. In contrast, water clarity did appear to influence behavior because the fish remained in the intermediate water mass between the turbid and phytoplankton-rich plume exiting Chesapeake Bay (and similar coastal waters) and the clear oligotrophic water east of the continental shelf. Article in Journal/Newspaper North Atlantic IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications |
institution |
Open Polar |
collection |
IODE-UNESCO: OceanDocs - E-Repository of Ocean Publications |
op_collection_id |
ftoceandocs |
language |
English |
topic |
Biology Fisheries Management Oceanography |
spellingShingle |
Biology Fisheries Management Oceanography Brill, Richard Lutcavage, Molly Metzger, Greg Bushnell, Peter Arendt, Michael Lucy, Jon Watson, Cheryl Foley, David Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry |
topic_facet |
Biology Fisheries Management Oceanography |
description |
We employed ultrasonic transmitters to follow (for up to 48 h) the horizontal and vertical movements of five juvenile (6.8–18.7 kg estimated body mass) bluefin tuna (Thunnus thynnus) in the western North Atlantic (off the eastern shore of Virginia). Our objective was to document the fishes’ behavior and distribution in relation to oceanographic conditions and thus begin to address issues that currently limit population assessments based on aerial surveys. Estimation of the trends in adult and juvenile Atlantic bluefin tuna abundance by aerial surveys, and other fishery-independent measures, is considered a priority.Juvenile bluefin tuna spent the majority of their time over the continental shelf in relatively shallow water (generally less then 40 m deep). Fish used the entire water column in spite of relatively steep vertical thermal gradients (≈24°C at the surface and ≈12°C at 40 m depth), but spent the majority of their time (≈90%) above 15 m and in water warmer then 20°C. Mean swimming speeds ranged from 2.8 to 3.3 knots, and total distance covered from 152 to 289 km (82–156 nmi). Because fish generally remained within relatively con-fined areas, net displacement was only 7.7–52.7 km (4.1–28.4 nmi). Horizontal movements were not correlated with sea surface temperature. We propose that it is unlikely that juvenile bluefin tuna in this area can detect minor horizontal temperature gradients (generally less then 0.5°C/km) because of the steep vertical temperature gradients (up to ≈0.6°C/m) they experience during their regular vertical movements. In contrast, water clarity did appear to influence behavior because the fish remained in the intermediate water mass between the turbid and phytoplankton-rich plume exiting Chesapeake Bay (and similar coastal waters) and the clear oligotrophic water east of the continental shelf. |
format |
Article in Journal/Newspaper |
author |
Brill, Richard Lutcavage, Molly Metzger, Greg Bushnell, Peter Arendt, Michael Lucy, Jon Watson, Cheryl Foley, David |
author_facet |
Brill, Richard Lutcavage, Molly Metzger, Greg Bushnell, Peter Arendt, Michael Lucy, Jon Watson, Cheryl Foley, David |
author_sort |
Brill, Richard |
title |
Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry |
title_short |
Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry |
title_full |
Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry |
title_fullStr |
Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry |
title_full_unstemmed |
Horizontal and vertical movements of juvenile bluefin tuna (Thunnus thynnus) in relation to oceanographic conditions of the western North Atlantic, determined with ultrasonic telemetry |
title_sort |
horizontal and vertical movements of juvenile bluefin tuna (thunnus thynnus) in relation to oceanographic conditions of the western north atlantic, determined with ultrasonic telemetry |
publishDate |
2002 |
url |
http://hdl.handle.net/1834/31053 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
http://aquaticcommons.org/id/eprint/15200 403 2014-05-30 07:23:21 15200 United States National Marine Fisheries Service |
op_relation |
http://fishbull.noaa.gov/1002/01brillf.pdf 0090-0656 http://hdl.handle.net/1834/31053 |
_version_ |
1766129980403613696 |