All articles tagged with #food web
New research shows invasive rats on Indian Ocean islands decimate seabirds, cutting nutrient inputs to coral reefs and rewiring reef food webs. The loss of seabird-derived nutrients shifts the base of the ecosystem from cryptobenthic fishes to invertebrates, altering predator energy pathways and illustrating a complex, uneven nutrient impact across rat-infested and rat-free reefs.
A Danish study finds jellyfish from two species feeding on polychaete worms, a burrowing bottom-dweller, marking the first documented instance. Across a year, 45 of 166 Aurelia aurita and 3 of 71 Mnemiopsis leidyi were found with worms in their guts, typically when worms rise to spawn at night. This seasonal feeding burst adds a new layer to fjord energy flow and could affect ecosystems if the invasive M. leidyi expands.
Fossil data from the Dry Mesa Quarry reconstruct a dense Jurassic food web in which abundant hatchling sauropods provided a reliable prey source for large predators, shaping predator dynamics across the Late Jurassic and helping explain how later giants like Tyrannosaurus rex could accumulate calories to grow to enormous sizes.
Reconstructing a detailed Jurassic ecosystem from Dry Mesa Quarry fossils shows that baby sauropods were abundant prey, forming many predator links and feeding carnivores like Allosaurus and Torvosaurus. This plentiful supply may have kept top predators smaller for a time and influenced later evolutionary shifts toward larger hunters such as Tyrannosaurus rex.
Invasive flathead catfish have become top predators in the Susquehanna River, disrupting the local food web by outcompeting native species and altering their diets, which may destabilize the ecosystem over time.
A recent study reveals that in the Arctic, sea stars, particularly from the Pterasteridae family, are top predators in the benthic (seafloor) ecosystem, challenging the traditional view that polar bears are the ultimate predators in the region. These sea stars play a crucial role in maintaining ecosystem balance by hunting and scavenging, highlighting the complexity of Arctic food webs and the importance of benthic predators for overall ecosystem health.
Kelp forests along the Gulf of Maine have declined significantly, leading to a shift in the local food web where fish now rely more on phytoplankton instead of kelp for energy, fundamentally altering ecosystem dynamics and highlighting the importance of kelp as a foundational species.
The Arctic ice alga Melosira arctica contains ten times as many microplastic particles as the surrounding seawater, posing a threat to creatures that feed on the algae at the sea surface. Clumps of dead algae also transport the plastic with its pollutants particularly quickly into the deep sea, explaining the high microplastic concentrations in the sediment there. The microplastic could enter the food web of deep-sea dwellers and also at the sea surface, potentially affecting human health. The Arctic ecosystem is already threatened by the climate crisis, and reducing the production of new plastic is the most effective way to reduce plastic pollution.