Publications by authors named "Jock W Young"

Lipid and fatty acid datasets are commonly used to assess the nutritional composition of organisms, trophic ecology, and ecosystem dynamics. Lipids and their fatty acid constituents are essential nutrients to all forms of life because they contribute to biological processes such as energy flow and metabolism. Assessment of total lipids in tissues of organisms provides information on energy allocation and life-history strategies and can be an indicator of nutritional condition.

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Nitrogen and carbon stable isotope data sets are commonly used to assess complex population to ecosystem responses to natural or anthropogenic changes at regional to global spatial scales, and monthly to decadal timescales. Measured in the tissues of consumers, nitrogen isotopes (δ N) are primarily used to estimate trophic position while carbon isotopes (δ C) describe habitat associations and feeding pathways. Models of both δ N and δ C values and their associated variance can be used to estimate likely dietary contributions and niche width and provide inferences about consumer movement and migration.

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Zooplankton biomass data have been collected in Australian waters since the 1930s, yet most datasets have been unavailable to the research community. We have searched archives, scanned the primary and grey literature, and contacted researchers, to collate 49187 records of marine zooplankton biomass from waters around Australia (0-60°S, 110-160°E). Many of these datasets are relatively small, but when combined, they provide >85 years of zooplankton biomass data for Australian waters from 1932 to the present.

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Considerable uncertainty remains over how increasing atmospheric CO and anthropogenic climate changes are affecting open-ocean marine ecosystems from phytoplankton to top predators. Biological time series data are thus urgently needed for the world's oceans. Here, we use the carbon stable isotope composition of tuna to provide a first insight into the existence of global trends in complex ecosystem dynamics and changes in the oceanic carbon cycle.

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Article Synopsis
  • Fatty acids are crucial nutrients in marine ecosystems, yet their distribution remains poorly understood; this study uses generalized additive mixed models to predict their spatial and temporal distributions.
  • The research focuses on key primary producers and essential omega-3 fatty acids in albacore tuna from the southwest Pacific, with significant predictors including location, sea surface temperature (SST), and fish size.
  • Findings reveal that rising SST may lead to a 12% decline in fatty acid content, raising concerns about the impact of climate change on marine food webs and energy availability for higher trophic levels.
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Fatty acids are a valuable tool in ecological studies because of the large number of unique structures synthesized. They provide versatile signatures that are being increasingly employed to delineate the transfer of dietary material through marine and terrestrial food webs. The standard procedure for determining fatty acids generally involves lipid extraction followed by methanolysis to produce methyl esters for analysis by gas chromatography.

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Article Synopsis
  • Lipids are crucial for metabolic energy in sharks, influenced by diet, reproduction, and migration, with this study focusing on white sharks' lipid profiles from muscle and liver tissue.
  • Muscle tissue had low lipid content primarily consisting of phospholipids and polyunsaturated fatty acids, while liver tissue was rich in triacylglycerols and monounsaturated fatty acids, indicating high energy demands.
  • The study found individual variations in lipid parameters without a clear link to specific environmental or biological factors, suggesting white sharks are generalist predators, and highlighted the need for further research on their nutritional and ecological health amidst environmental changes.
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