Jonah Piovia-Scott gave me the heads up on two recent papers from
their group – more information after the jump.
The effects of seaweed deposition on shoreline terrestrial ecosystems in the Bahamas
Two new papers evaluate the effect of seaweed deposition on the plants and animals inhabiting shoreline ecosystems in the Exumas. The study by Wright et al. shows that seaweed deposition events increased the growth rate of brown anoles (Anolis sagrei) by augmenting prey availability. This increased growth rate allows females to attain reproductive size earlier and produce more offspring in their first year of life, boosting lizard densities. The Piovia-Scott et al. study shows that increased lizard densities in areas with high levels of seaweed deposition reduce herbivory on shoreline plants (as the lizards also consume herbivores that feed on these plants). However, overall herbivory levels are higher in areas with lots of seaweed because the nutrients released by the seaweed make plant foliage more nutritious, which leads to greater herbivory.
Seaweed deposition in the Bahamas may be increasing, as overfishing, eutrophication and other factors facilitate a shift from coral-dominated to algae-dominated marine ecosystems. These studies show that seaweed-derived resources can enter shoreline terrestrial ecosystems through multiple pathways, and have important effects on the plants and animals found there. Our research group is continuing to explore the effects of seaweed on Bahamian shorelines. We are currently engaged in a multi-year study in the Snake Creek area of Abaco investigating how the timing and magnitude of seaweed inputs affect terrestrial ecosystem responses.