Spatial and ontogenetic variation in the trophic ecology of skipjack tuna, Katsuwonus pelamis, in the eastern Pacific Ocean

Understanding regional migration, residency dynamics, and associated trophic ecology can inform recovery strategies for pelagic species such as Pacific bluefin tuna (Thunnus orientalis) (PBFT). PBFT residency duration in the eastern Pacific is uncertain, particularly for larger individuals (here, >100 cm or ∼3+ years of age). We applied a previously tested “chemical tracer toolbox” (Fukushima-derived radiocesium and 13C and 15N stable isotope signatures) to examine migratory and residency patterns and dietary inputs of 428 age 1–6+ PBFT collected from 2012 to 2015 in the eastern Pacific Ocean. Age 1–3 individuals were a mix of residents and recent (≤500 day) migrants, while 98% of age 3–4 and 100% of age 4–6.3 year old PBFT were resident for >500 days in the eastern Pacific. Zooplanktivorous forage (e.g., sardine, anchovy, pelagic red crab, and trophically similar species) of the California Current Ecosystem constituted 57%–82% of diet across PBFT sizes. Migration timing estimates show that PBFT may spend 2–5 years in the eastern Pacific Ocean before returning to the western Pacific.

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Large‐scale patterns of green turtle trophic ecology in the eastern Pacific Ocean

Ecosphere ◽

10.1002/ecs2.3479 ◽

2021 ◽

Vol 12 (6) ◽

Author(s):

Jeffrey A. Seminoff ◽

Lisa M. Komoroske ◽

Diego Amorocho ◽

Randall Arauz ◽

Didiher Chacón‐Chaverrí ◽

...

Keyword(s):

Pacific Ocean ◽

Green Turtle ◽

Large Scale ◽

Trophic Ecology ◽

Eastern Pacific ◽

Eastern Pacific Ocean

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Simultaneous behavior of skipjack (Katsuwonus pelamis), bigeye (Thunnus obsesus), and yellowfin (T. albacares) tunas, within large multi-species aggregations associated with drifting fish aggregating devices (FADs) in the equatorial eastern Pacific Ocean

Marine Biology ◽

10.1007/s00227-013-2290-9 ◽

2013 ◽

Vol 160 (11) ◽

pp. 3005-3014 ◽

Cited By ~ 21

Author(s):

Kurt M. Schaefer ◽

Daniel W. Fuller

Keyword(s):

Pacific Ocean ◽

Eastern Pacific ◽

Eastern Pacific Ocean ◽

Katsuwonus Pelamis ◽

Fish Aggregating Devices

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Vertical Movements and Habitat Utilization of Skipjack (Katsuwonus pelamis), Yellowfin (Thunnus albacares), and Bigeye (Thunnus obesus) Tunas in the Equatorial Eastern Pacific Ocean, Ascertained Through Archival Tag Data

Reviews: Methods and Technologies in Fish Biology and Fisheries - Tagging and Tracking of Marine Animals with Electronic Devices ◽

10.1007/978-1-4020-9640-2_8 ◽

2009 ◽

pp. 121-144 ◽

Cited By ~ 25

Author(s):

Kurt M. Schaefer ◽

Daniel W. Fuller ◽

Barbara A. Block

Keyword(s):

Pacific Ocean ◽

Habitat Utilization ◽

Eastern Pacific ◽

Thunnus Albacares ◽

Eastern Pacific Ocean ◽

Katsuwonus Pelamis ◽

Vertical Movements ◽

Archival Tag ◽

Thunnus Obesus

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Evaluation of a fishing captain's ability to predict species composition, sizes, and quantities of tunas associated with drifting fish-aggregating devices in the eastern Pacific Ocean

ICES Journal of Marine Science ◽

10.1093/icesjms/fsu012 ◽

2014 ◽

Vol 71 (7) ◽

pp. 1774-1780 ◽

Cited By ~ 4

Author(s):

Daniel W. Fuller ◽

Kurt M. Schaefer

Keyword(s):

Pacific Ocean ◽

Species Composition ◽

Eastern Pacific ◽

Purse Seine ◽

Thunnus Albacares ◽

Eastern Pacific Ocean ◽

Mixed Species ◽

Katsuwonus Pelamis ◽

Thunnus Obesus ◽

Fish Aggregating Devices

Abstract Experiments were conducted to evaluate a fishing captain's ability to predict species composition, sizes, and quantities of tunas associated with drifting fish-aggregating devices (FADs), before encirclement with a purse-seine net. Operating in the equatorial eastern Pacific Ocean, during 11 May–23 July 2011, Captain Ricardo Diaz detected small quantities of bigeye (Thunnus obesus) and yellowfin (Thunnus albacares) tunas within large FAD-associated aggregations dominated by skipjack tuna (Katsuwonus pelamis). The captain's predictions were significantly related to the actual total catch and catch by species, but not to size categories by species. His predictions of species composition were most accurate when estimates of bigeye and yellowfin tuna were combined. If purse-seine captains are able to make accurate predictions of the proportion of bigeye and yellowfin tunas present in mixed-species aggregations associated with FADs, managers may wish to consider incentives to fishers to reduce the fishing mortality on those species.

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