What do you have on the “Junk Food Hypothesis?”
In a previous inquiry, the source, wild oceans mentions “junk food’ hypothesis. Can you find that for me? Thank you
Yes, I found it. It’s from a report by Wild Oceans (formerly the National Coalition for Marine Conservation, or NCMC), titled “Taking the Bait: Are America’s Fisheries Out-Competing Predators for their Prey?” (likely from around 2005–2006 based on the citations).
You can access the full PDF here: [https://wildoceans.org/wp-content/uploads/TakingTheBait.pdf](https://wildoceans.org/wp-content/uploads/TakingTheBait.pdf). (LINK)
Relevant Excerpt (from the section on accounting for forage in fishery management):
“This thinking oversimplifies the nutritional needs of predators. Faced with hunger, a predator may dine on whatever it can find that fits into its mouth, but this does not mean that its energy requirements are met. Caloric value, digestibility and foraging effort must be considered. The deleterious effects of not considering these variables are predicted by the “junk-food hypothesis,” which has been proposed as a reason for the decline of the Steller sea lion (Rosen and Trites 2000). When predators are unable to locate their preferred prey, they will substitute whatever is available including less nutritious alternatives. This can lead to nutritional stress, which can have serious effects on the health of the predator. Females experiencing nutritional stress may not have sufficient energy to reproduce successfully. Young animals needing to fulfill the high energetic demand of growth may exhibit deformities and become more vulnerable to predation themselves. In time, consuming junk-food species can lead to a decline in the quantity and quality of the predator population.” (link)
It references the original scientific work by Rosen and Trites (2000) on pollock and Steller sea lions, applying the idea more broadly to how overharvesting or shifts in high-quality forage fish (like lipid-rich species) can force predators onto lower-quality “junk food” prey. This aligns closely with the kinds of discussions you’ve had about Atlantic cod, striped bass, menhaden, herring, mackerel, lipids/energy density, and ecosystem impacts. (link
The report overall argues for better ecosystem-based management (EBFM) that protects forage fish for predators rather than just maximizing single-species harvests. Let me know if you’d like me to pull more sections, check the full Rosen & Trites paper, or connect it to specific NEFSC data or other sources you’ve referenced before!
Do you have any other articles on junk food in marine ecosystems?
Yes, the “junk food hypothesis” (JFH) or “junk-food hypothesis” is a concept in marine ecology that has been explored in several studies, primarily in the context of seabirds, marine mammals (especially Steller sea lions), and forage fish shifts. It generally posits that when high-energy, high-lipid prey (e.g., herring, capelin, or other fatty fish) become less available, predators switch to lower-quality alternatives (lower energy density, less nutritious “junk food”), leading to nutritional stress, reduced reproduction, poorer body condition, or population declines—even if overall prey abundance seems sufficient. (link)
Here are some key articles and resources beyond the Wild Oceans/”Taking the Bait” report:
Foundational/Classic Papers
– Rosen, D.A.S. & Trites, A.W. (2000). “Pollock and the decline of Steller sea lions: testing the junk-food hypothesis.”Canadian Journal of Zoology*.
This is the seminal experimental study feeding captive Steller sea lions pollock (lower energy) vs. herring (higher energy). It tested the hypothesis directly. (link)
– Fritz, L.W. & Hinckley, S. (2005). “A critical review of the regime shift–’junk food’–nutritional stress hypothesis for the decline of the western stock of Steller sea lion.”Marine Mammal Science*.
A detailed critique examining evidence for/against the idea in the Alaska context, looking at regime shifts, prey quality, and sea lion declines. (Link)
Seabird-Focused Studies
– Grémillet, D. et al. (2008). “A junk-food hypothesis for gannets feeding on fishery waste.”Proceedings of the Royal Society B*.
Examines Cape gannets supplementing with fishery discards (lower quality) and impacts on reproduction. Strong support for JFH in this case. (link)
– Piatt, J.F. & Kitaysky, A.S. (various years, e.g., 2000s studies). “Testing the junk-food hypothesis on marine birds: Effects of prey type on growth and development.”
USGS and related work on seabirds like kittiwakes, linking prey quality (energy density/lipids) to chick growth and colony productivity. (link)
– Österblom, H. et al. (2008). “Junk-food in marine ecosystems.” Oikos.
A broader review applying the hypothesis across systems (North Pacific, North Sea, Baltic), discussing relevance to ecosystem resilience, climate/ocean changes, fishing, and management. (link)
Other Related Discussions
– Popular/science communication pieces, such as those from the Geophysical Institute (Alaska) or Anthropocene Magazine, often summarize the Steller sea lion or seabird cases for a wider audience. (link)
These ideas tie directly into broader topics like ecosystem-based fisheries management (EBFM), forage fish conservation, and climate-driven prey shifts—areas you’ve explored with Atlantic cod, menhaden, herring, mackerel, and lipid/energy density questions. In the Atlantic/Gulf of Maine context, similar concepts appear in discussions of predator condition (e.g., bluefin tuna, striped bass, right whales) when high-lipid forage declines.
If you’d like PDFs/summaries of specific papers, data extractions (e.g., energy densities from tables), or searches narrowed to New England/Atlantic species, let me know!