The first larval age and growth curve for bluefin tuna (Thunnus thynnus) from the Gulf of Mexico: Comparisons to the Straits of Florida, and the Balearic Sea (Mediterranean)

2017 ◽  
Vol 190 ◽  
pp. 24-33 ◽  
Author(s):  
Estrella Malca ◽  
Barbara Muhling ◽  
James Franks ◽  
Alberto García ◽  
Jason Tilley ◽  
...  
Author(s):  
Akihiro Shiroza ◽  
Estrella Malca ◽  
John T Lamkin ◽  
Trika Gerard ◽  
Michael R Landry ◽  
...  

Abstract Bluefin tuna spawn in restricted areas of subtropical oligotrophic seas. Here, we investigate the zooplankton prey and feeding selectivity of early larval stages of Atlantic bluefin tuna (ABT, Thunnus thynnus) in larval rearing habitat of the Gulf of Mexico. Larvae and zooplankton were collected during two multi-day Lagrangian experiments during peak spawning in May 2017 and 2018. Larvae were categorized by flexion stage and standard length. We identified, enumerated and sized zooplankton from larval gut contents and in the ambient community. Ciliates were quantitatively important (up to 9%) in carbon-based diets of early larvae. As larvae grew, diet composition and prey selection shifted from small copepod nauplii and calanoid copepodites to larger podonid cladocerans, which accounted for up to 70% of ingested carbon. Even when cladoceran abundances were <0.2 m−3, they comprised 23% of postflexion stage diet. Feeding behaviors of larvae at different development stages were more specialized, and prey selection narrowed to appendicularians and primarily cladocerans when these taxa were more abundant. Our findings suggest that ABT larvae have the capacity to switch from passive selection, regulated by physical factors, to active selection of presumably energetically optimal prey.


2011 ◽  
Vol 68 (6) ◽  
pp. 1051-1062 ◽  
Author(s):  
Barbara A. Muhling ◽  
Sang-Ki Lee ◽  
John T. Lamkin ◽  
Yanyun Liu

Abstract Muhling, B. A., Lee, S-K., Lamkin, J. T., and Liu, Y. 2011. Predicting the effects of climate change on bluefin tuna (Thunnus thynnus) spawning habitat in the Gulf of Mexico. – ICES Journal of Marine Science, 68: 1051–1062. Atlantic bluefin tuna (BFT) is a highly migratory species that feeds in cold waters in the North Atlantic, but migrates to tropical seas to spawn. Global climate-model simulations forced by future greenhouse warming project that upper-ocean temperatures in the main western Atlantic spawning ground, the Gulf of Mexico (GOM), will increase substantially, potentially altering the temporal and spatial extent of BFT spawning activity. In this study, an ensemble of 20 climate model simulations used in the Intergovernmental Panel for Climate Change fourth Assessment Report (IPCC-AR4) predicted mean temperature changes within the GOM under scenario A1B through to 2100. Associations between adult and larval BFT in the GOM and sea temperatures were defined using 20th century observations, and potential effects of warming on the suitability of the GOM as a spawning ground were quantified. Areas in the GOM with high probabilities of larval occurrence decreased in late spring by 39–61% by 2050 and 93–96% by the end of the 21st century. Conversely, early spring may become more suitable for spawning. BFT are therefore likely to be vulnerable to climate change, and there is potential for significant impacts on spawning and migration behaviours.


2019 ◽  
Vol 212 ◽  
pp. 63-71 ◽  
Author(s):  
Amaya Uriarte ◽  
Carolina Johnstone ◽  
Raul Laiz-Carrión ◽  
Alberto García ◽  
Joel K. Llopiz ◽  
...  

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