Monterey, CA, United States
Monterey, CA, United States

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Estess E.E.,Tuna Research and Conservation Center | Klinger D.H.,Stanford University | Klinger D.H.,Princeton University | Coffey D.M.,Tuna Research and Conservation Center | And 11 more authors.
Aquaculture | Year: 2017

We utilized a unique opportunity to study the growth and bioenergetics of a highly migratory and commercially valuable marine fish under controlled environmental conditions. We maintained yellowfin tuna (Thunnus albacares) in holding tanks throughout a twenty-year period, routinely collecting data on mass and length of individual fish over time. The water temperature of the holding tanks was maintained at 19.9 ± 0.9 °C (mean ± s.d.) and the yellowfin tuna were fed a diet amounting to 176 ± 36 kJ·kg− 1 of tuna biomass·day− 1 across the study period. We integrated length records (n = 249) with a prior model of yellowfin tuna age to generate a von Bertalanffy growth function for this captive scenario with the parameters 224.26 cm straight fork length (SFL), 0.099, and − 1.721 years for L∞, k, and to, respectively. We combined our growth model and analyses of tuna tissue energy with metabolic data from various sources to estimate a bioenergetic budget for this difficult-to-study species. We found that the captive tunas in this experiment grew significantly slower than yellowfin tuna studied in the wild and in other captive scenarios. Our energetic budget indicates that only 7.8% of an ingested meal's energetic content was utilized for growth. Furthermore, we calculated an average food conversion ratio of 37.2:1 for an 8.4 kg yellowfin tuna when fed a mixed-diet of squid, sardine, and vitamin gelatin. We conclude with a discussion of the various factors influencing tuna bioenergetics including the role of water temperature, diet, and inter-species competition on growth and energy assimilation. These findings are uniquely suited to the relatively cool temperatures and low energy diet maintained in this captive scenario, an important consideration for others hoping to draw on these results for comparative research. © 2016


Estess E.E.,Tuna Research and Conservation Center | Coffey D.M.,Tuna Research and Conservation Center | Coffey D.M.,University of Hawaii at Manoa | Shimose T.,Seikai National Fisheries Research Institute | And 6 more authors.
Aquaculture | Year: 2014

Tuna bioenergetics can be described by the following relationship: the energy available for growth is equal to the food energy minus all metabolic costs. These costs include routine metabolic rate, specific dynamic action, increased activity level, eliminated waste, and gonadal development. Captive populations of Pacific bluefin tuna (Thunnus orientalis) were held at ~20°C in fiberglass tanks and fed on a regular schedule with a diet formulated to achieve an energetic content of 176±36kJ·kg-1 of biomass·day-1 (mean±s.d.). To conduct a bioenergetic study, growth rates during the captive period and tissue energy values post-mortem were empirically determined. Daily growth rates were obtained from a von Bertalanffy growth function based on curved fork length (CFL) measurements of live fish and post-mortem morphometrics. The parameters obtained for the captive bluefin growth function were 225.13cm straight fork length (SFL), 0.173, and -0.497years for L∞, k, and to, respectively. The growth equation, SFL=225.13·(1-e (-0.173(t-(-0.497)))) in conjunction with the length-mass regression (where body mass M=4.98×10-6×SFL 3.3186) gave a daily growth increase of 32.60±2.40g·day-1 for Pacific bluefin tuna of 2.2years of age and 11.4±1.0kg (the average age and mass of a fish in the study). The average tissue energy value from four sampled tuna was 7.66±0.40kJ·g-1, and applying the daily growth increase estimate provides a daily energy gain of 249.7kJ, which is 12.4% of an ingested meal's total energy content. A food conversion ratio of 17.8:1 is estimated for a meal consisting solely of sardines and 22.6:1 for a mixed diet consisting of sardines, squid, and a gelatin-vitamin mixture at the stated feeding regimen. This paper presents the first data on actual food conversion ratios and bioenergetic utilization for Pacific bluefin tuna. © 2014.


Bradley C.J.,University of Hawaii at Manoa | Madigan D.J.,Tuna Research and Conservation Center | Madigan D.J.,Stanford University | Block B.A.,Monterey Bay Aquarium Research Institute | Popp B.N.,University of Hawaii at Manoa
PLoS ONE | Year: 2014

Compound specific isotopic analysis (CSIA) of amino acids has received increasing attention in ecological studies in recent years due to its ability to evaluate trophic positions and elucidate baseline nutrient sources. However, the incorporation rates of individual amino acids into protein and specific trophic discrimination factors (TDFs) are largely unknown, limiting the application of CSIA to trophic studies. We determined nitrogen turnover rates of individual amino acids from a long-term (up to 1054 days) laboratory experiment using captive Pacific bluefin tuna, Thunnus orientalis (PBFT), a large endothermic pelagic fish fed a controlled diet. Small PBFT (white muscle δ15N∼11.5 ‰) were collected in San Diego, CA and transported to the Tuna Research and Conservation Center (TRCC) where they were fed a controlled diet with high δ15N values relative to PBFT white muscle (diet δ15N∼13.9‰). Half-lives of trophic and source amino acids ranged from 28.6 to 305.4 days and 67.5 to 136.2 days, respectively. The TDF for the weighted mean values of amino acids was 3.0 ‰, ranging from 2.2 to 15.8 ‰ for individual combinations of 6 trophic and 5 source amino acids. Changes in the δ15N values of amino acids across trophic levels are the underlying drivers of the trophic 15N enrichment. Nearly all amino acid δ15N values in this experiment changed exponentially and could be described by a single compartment model. Significant differences in the rate of 15N incorporation were found for source and trophic amino acids both within and between these groups. Varying half-lives of individual amino acids can be applied to migratory organisms as isotopic clocks, determining the length of time an individual has spent in a new environment. These results greatly enhance the ability to interpret compound specific isotope analyses in trophic studies. © 2014 Bradley et al.


Cermeno P.,Stanford University | Quilez-Badia G.,WWF Mediterranean Programme | Ospina-Alvarez A.,WWF Mediterranean Programme | Ospina-Alvarez A.,University of Santiago de Chile | And 7 more authors.
PLoS ONE | Year: 2015

We analyzed the movements of Atlantic tuna (Thunnus thynnus L.) in the Mediterranean Sea using data from 2 archival tags and 37 pop-up satellite archival tags (PAT). Bluefin tuna ranging in size from 12 to 248 kg were tagged on board recreational boats in the western Mediterranean and the Adriatic Sea between May and September during two different periods (2000 to 2001 and 2008 to 2012). Although tuna migrations between the Mediterranean Sea and the Atlantic Ocean have been well reported, our results indicate that part of the bluefin tuna population remains in the Mediterranean basin for much of the year, revealing a more complex population structure. In this study we demonstrate links between the western Mediterranean, the Adriatic and the Gulf of Sidra (Libya) using over 4336 recorded days of location and behavior data from tagged bluefin tuna with a maximum track length of 394 days. We described the oceanographic preferences and horizontal behaviors during the spawning season for 4 adult bluefin tuna. We also analyzed the time series data that reveals the vertical behavior of one pop-up satellite tag recovered, which was attached to a 43.9 kg tuna. This fish displayed a unique diving pattern within 16 days of the spawning season, suggesting a use of the thermocline as a thermoregulatory mechanism compatible with spawning. The results obtained hereby confirm that the Mediterranean is clearly an important habitat for this species, not only as spawning ground, but also as an overwintering foraging ground. © 2015 Cermeño et al.


Klinger D.H.,Stanford University | Dale J.J.,Stanford University | Machado B.E.,Stanford University | Incardona J.P.,National Oceanic and Atmospheric Administration | And 2 more authors.
Marine Pollution Bulletin | Year: 2015

During the 2010 Deepwater Horizon incident, the continuous release of crude oil from the damaged Macondo 252 wellhead on the ocean floor contaminated surface water habitats for pelagic fish for more than 12. weeks. The spill occurred across pelagic, neritic and benthic waters, impacting a variety of ecosystems. Chemical components of crude oil are known to disrupt cardiac function in juvenile fish, and here we investigate the effects of oil on the routine metabolic rate of chub mackerel, Scomber japonicus. Mackerel were exposed to artificially weathered Macondo 252 crude oil, prepared as a Water Accommodated Fraction (WAF), for 72 or 96. h. Routine metabolic rates were determined pre- and post-exposure using an intermittent-flow, swim tunnel respirometer. Routine energetic demand increased in all mackerels in response to crude oil and reached statistical significance relative to unexposed controls at 96. h. Chemical analyses of bile from exposed fish revealed elevated levels of fluorescent metabolites, confirming the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in the exposure WAF. The observed increase in metabolic demand is likely attributable to the bioenergetic costs of contaminant detoxification. These results indicate that short-term exposure (i.e. days) to oil has sub-lethal toxicity to mackerel and results in physiological stress during the active spill phase of the incident. © 2015 Elsevier Ltd.


Klinger D.H.,Stanford University | Dale J.J.,Stanford University | Gleiss A.C.,Stanford University | Brandt T.,Tuna Research and Conservation Center | And 8 more authors.
Comparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology | Year: 2016

Specific dynamic action (SDA), the increase in metabolic expenditure associated with consumption of a meal, represents a substantial portion of fish energy budgets and is highly influenced by ambient temperature. The effect of temperature on SDA has not been studied in yellowfin tuna (Thunnus albacares, Bonnaterre 1788), an active pelagic predator that occupies temperate and subtropical waters. The energetic cost and duration of SDA were calculated by comparing routine and post-prandial oxygen consumption rates. Mean routine metabolic rates in yellowfin tuna increased with temperature, from 136 mg O2 kg-1 h-1 at 20 °C to 211 mg O2 kg-1 h at 24 °C. The mean duration of SDA decreased from 40.2 h at 20 °C to 33.1 h at 24 °C, while mean SDA coefficient, the percentage of energy in a meal that is consumed during digestion, increased from 5.9% at 20 °C to 12.7% at 24 °C. Digestion in yellowfin tuna is faster at a higher temperature but requires additional oxidative energy. Enhanced characterization of the role of temperature in SDA of yellowfin tuna deepens our understanding of tuna physiology and can help improve management of aquaculture and fisheries. © 2016 Elsevier Inc.


PubMed | Stanford University and Tuna Research and Conservation Center
Type: | Journal: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology | Year: 2016

Specific dynamic action (SDA), the increase in metabolic expenditure associated with consumption of a meal, represents a substantial portion of fish energy budgets and is highly influenced by ambient temperature. The effect of temperature on SDA has not been studied in yellowfin tuna (Thunnus albacares, Bonnaterre 1788), an active pelagic predator that occupies temperate and subtropical waters. The energetic cost and duration of SDA were calculated by comparing routine and post-prandial oxygen consumption rates. Mean routine metabolic rates in yellowfin tuna increased with temperature, from 136 mg O2 kg(-1)h(-1) at 20 C to 211 mg O2 kg(-1)h at 24 C. The mean duration of SDA decreased from 40.2h at 20 C to 33.1h at 24 C, while mean SDA coefficient, the percentage of energy in a meal that is consumed during digestion, increased from 5.9% at 20 C to 12.7% at 24 C. Digestion in yellowfin tuna is faster at a higher temperature but requires additional oxidative energy. Enhanced characterization of the role of temperature in SDA of yellowfin tuna deepens our understanding of tuna physiology and can help improve management of aquaculture and fisheries.

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