Sm. Lindsay et al., MODELING INTERACTIONS OF BROWSING PREDATION, INFAUNAL ACTIVITY, AND RECRUITMENT IN MARINE SOFT-SEDIMENT HABITATS, The American naturalist, 148(4), 1996, pp. 684-699
In marine soft-sediment habitats, the sediment surface is altered by a
ctivities of sediment dwellers (infauna). Such biogenic disturbance ca
n influence recruitment success if settling larvae and juveniles avoid
disturbed sites or if juveniles die as a result of disturbance after
settling. Because infauna commonly lose exposed body parts to browsing
predators and disturb less sediment as a result, we developed a simul
ation model to examine the interactions between browsing predation, in
faunal adult activity, and recruitment. Sediment disturbance in the mo
del was based on data for the polychaete Abarenicola pacifica. We simu
lated the activity of two general types of predators: prey nippers, wh
ich damaged adults only, and sediment biters, which damaged adults and
consumed settled juveniles. As both types of predation rates increase
d, habitat rejection by settlers decreased, but juvenile mortality inc
reased as settlers landing near damaged adults were killed when those
adults resumed activity. When prey nippers were active, the interactio
n between predation and infaunal activity determined recruitment succe
ss, and juvenile mortality was highest at intermediate predation rates
. When sediment biters were active, they controlled recruitment succes
s by directly consuming larvae. At low adult worm densities, habitat r
ejection by settlers and juvenile mortality were both low, and browsin
g predation did not affect recruitment success. At higher adult densit
ies, net recruitment success increased with the rate of predation by p
rey nippers (the magnitude of increase depended on bite rate and the l
ength of time juveniles were susceptible to mortality), but it was nev
er enhanced by sediment biters.