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Direct quantification of energy intake in an apex marine predator suggests physiology is a key driver of migrations.

Whitlock RE, Hazen EL, Walli A, Farwell C, Bograd SJ, Foley DG, Castleton M, Block BA - Sci Adv (2015)

Bottom Line: We quantified the energy intake of Pacific bluefin tuna in the California Current using a laboratory-validated model, the first such measurement in a wild marine predator.Movements were not always consistent with maximizing energy intake: the Pacific bluefin move out of energy rich waters both in late summer and winter, coincident with rising and falling water temperatures, respectively.We hypothesize that temperature-related physiological constraints drive migration and that Pacific bluefin tuna optimize energy intake within a range of optimal aerobic performance.

View Article: PubMed Central - PubMed

Affiliation: Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950, USA. ; Sveriges Lantbruksuniversitet, Sötvattenslaboratoriet, Stångholmsvägen 2, Drottningholm 178 93, Sweden.

ABSTRACT
Pacific bluefin tuna (Thunnus orientalis) are highly migratory apex marine predators that inhabit a broad thermal niche. The energy needed for migration must be garnered by foraging, but measuring energy intake in the marine environment is challenging. We quantified the energy intake of Pacific bluefin tuna in the California Current using a laboratory-validated model, the first such measurement in a wild marine predator. Mean daily energy intake was highest off the coast of Baja California, Mexico in summer (mean ± SD, 1034 ± 669 kcal), followed by autumn when Pacific bluefin achieve their northernmost range in waters off northern California (944 ± 579 kcal). Movements were not always consistent with maximizing energy intake: the Pacific bluefin move out of energy rich waters both in late summer and winter, coincident with rising and falling water temperatures, respectively. We hypothesize that temperature-related physiological constraints drive migration and that Pacific bluefin tuna optimize energy intake within a range of optimal aerobic performance.

No MeSH data available.


Related in: MedlinePlus

Tracks with estimated HIF (kcal day−1) for two archival tagged bluefin tuna.Tracks are broken into yearly sections, and the first point in each panel is marked with a white triangle. (A to C) HIF track for archival tag 1002020, deployed in August 2002. White triangles correspond to 28 August 2002 (A), 1 January 2003 (B), and 1 January 2004 (C). (D to F) HIF track for archival tag 1003088, deployed in July 2003. White triangles correspond to 7 August 2003 (D), 1 January 2004 (E), and 1 January 2005 (F).
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Figure 2: Tracks with estimated HIF (kcal day−1) for two archival tagged bluefin tuna.Tracks are broken into yearly sections, and the first point in each panel is marked with a white triangle. (A to C) HIF track for archival tag 1002020, deployed in August 2002. White triangles correspond to 28 August 2002 (A), 1 January 2003 (B), and 1 January 2004 (C). (D to F) HIF track for archival tag 1003088, deployed in July 2003. White triangles correspond to 7 August 2003 (D), 1 January 2004 (E), and 1 January 2005 (F).

Mentions: The time series of foraging events in wild Pacific bluefin tuna (median length, 108 cm) as measured by peritoneally implanted archival tags ranged between 61 and 876 days in length (mean, 274 days). The time series data recorded from an archival tagged Pacific bluefin tuna with predicted visceral temperature at rest are shown in Fig. 1 (A to C) (longer time series can be found in figs. S2 and S3). Tracks showing the spatial context for daily energy intake estimates for individual fish are shown in Fig. 2 and fig. S4.


Direct quantification of energy intake in an apex marine predator suggests physiology is a key driver of migrations.

Whitlock RE, Hazen EL, Walli A, Farwell C, Bograd SJ, Foley DG, Castleton M, Block BA - Sci Adv (2015)

Tracks with estimated HIF (kcal day−1) for two archival tagged bluefin tuna.Tracks are broken into yearly sections, and the first point in each panel is marked with a white triangle. (A to C) HIF track for archival tag 1002020, deployed in August 2002. White triangles correspond to 28 August 2002 (A), 1 January 2003 (B), and 1 January 2004 (C). (D to F) HIF track for archival tag 1003088, deployed in July 2003. White triangles correspond to 7 August 2003 (D), 1 January 2004 (E), and 1 January 2005 (F).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643779&req=5

Figure 2: Tracks with estimated HIF (kcal day−1) for two archival tagged bluefin tuna.Tracks are broken into yearly sections, and the first point in each panel is marked with a white triangle. (A to C) HIF track for archival tag 1002020, deployed in August 2002. White triangles correspond to 28 August 2002 (A), 1 January 2003 (B), and 1 January 2004 (C). (D to F) HIF track for archival tag 1003088, deployed in July 2003. White triangles correspond to 7 August 2003 (D), 1 January 2004 (E), and 1 January 2005 (F).
Mentions: The time series of foraging events in wild Pacific bluefin tuna (median length, 108 cm) as measured by peritoneally implanted archival tags ranged between 61 and 876 days in length (mean, 274 days). The time series data recorded from an archival tagged Pacific bluefin tuna with predicted visceral temperature at rest are shown in Fig. 1 (A to C) (longer time series can be found in figs. S2 and S3). Tracks showing the spatial context for daily energy intake estimates for individual fish are shown in Fig. 2 and fig. S4.

Bottom Line: We quantified the energy intake of Pacific bluefin tuna in the California Current using a laboratory-validated model, the first such measurement in a wild marine predator.Movements were not always consistent with maximizing energy intake: the Pacific bluefin move out of energy rich waters both in late summer and winter, coincident with rising and falling water temperatures, respectively.We hypothesize that temperature-related physiological constraints drive migration and that Pacific bluefin tuna optimize energy intake within a range of optimal aerobic performance.

View Article: PubMed Central - PubMed

Affiliation: Tuna Research and Conservation Center, Stanford University, Hopkins Marine Station, Oceanview Boulevard, Pacific Grove, CA 93950, USA. ; Sveriges Lantbruksuniversitet, Sötvattenslaboratoriet, Stångholmsvägen 2, Drottningholm 178 93, Sweden.

ABSTRACT
Pacific bluefin tuna (Thunnus orientalis) are highly migratory apex marine predators that inhabit a broad thermal niche. The energy needed for migration must be garnered by foraging, but measuring energy intake in the marine environment is challenging. We quantified the energy intake of Pacific bluefin tuna in the California Current using a laboratory-validated model, the first such measurement in a wild marine predator. Mean daily energy intake was highest off the coast of Baja California, Mexico in summer (mean ± SD, 1034 ± 669 kcal), followed by autumn when Pacific bluefin achieve their northernmost range in waters off northern California (944 ± 579 kcal). Movements were not always consistent with maximizing energy intake: the Pacific bluefin move out of energy rich waters both in late summer and winter, coincident with rising and falling water temperatures, respectively. We hypothesize that temperature-related physiological constraints drive migration and that Pacific bluefin tuna optimize energy intake within a range of optimal aerobic performance.

No MeSH data available.


Related in: MedlinePlus