Pauline Machful, Annie Portal, Jed Macdonald, Valerie Allain, Joe Scutt Phillips, Joanne Potts, Simon Nicol
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引用次数: 0
Abstract
Context
Understanding tuna diet and its drivers can provide valuable insights into the dynamics of pelagic ecosystems and their capacity to adapt to environmental and human-induced stressors.
Aims
To reconstruct tropical tuna dietary histories by using different metrics of stomach fullness and to assess their association with fisheries-related, environmental and biological covariates.
Methods
We examined stomachs from 8229 skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares) and bigeye tuna (T. obesus) captured in the western and central Pacific Ocean between 2001 and 2021, classified each on the basis of categorical and continuous fullness metrics, then built statistical models to gauge covariate effects.
Key results
Only models for the binary fullness metric (i.e. empty or non-empty) performed well. Tuna with empty stomachs were more likely to be caught on active gear (e.g. purse seine) and earlier in the day. Skipjack and bigeye tuna with empty stomachs were more likely to be associated with floating objects (e.g. fish-aggregating devices).
Conclusions
Our results add to the evidence that tropical tunas forage more effectively during the day and more actively when not associated with floating objects. At the individual level, tuna stomach fullness is highly variable.
Implications
Further research is needed to understand the factors governing this promising indicator of ecosystem change.
期刊介绍：
Marine and Freshwater Research is an international and interdisciplinary journal publishing contributions on all aquatic environments. The journal’s content addresses broad conceptual questions and investigations about the ecology and management of aquatic environments. Environments range from groundwaters, wetlands and streams to estuaries, rocky shores, reefs and the open ocean. Subject areas include, but are not limited to: aquatic ecosystem processes, such as nutrient cycling; biology; ecology; biogeochemistry; biogeography and phylogeography; hydrology; limnology; oceanography; toxicology; conservation and management; and ecosystem services. Contributions that are interdisciplinary and of wide interest and consider the social-ecological and institutional issues associated with managing marine and freshwater ecosystems are welcomed.
Marine and Freshwater Research is a valuable resource for researchers in industry and academia, resource managers, environmental consultants, students and amateurs who are interested in any aspect of the aquatic sciences.
Marine and Freshwater Research is published with the endorsement of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Academy of Science.
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