Ecology of understory kelp environments. 2. Effects of kelps on recruitment of benthic invertebrates

• Published in: Journal of experimental marine biology and ecology 1990-01, Vol.143 (1-2), p.27-45
• Main Authors: Duggins, DO, Eckman, JE, Sewell, A T
• Format: Article
• Language: English
• Subjects: Macrocystis; Marine; Membranipora membranacea; Pseudochitinopoma occidentalis; Tubulipora
• ISSN: 0022-0981
• DOI: 10.1016/0022-0981(90)90109-P

Previous studies demonstrated that understory kelps altered rates of mass and particulate transport beneath kelp canopies. This study examined the implications of these physical effects, plus shading by canopies, on the recruitment of four taxa of benthic invertebrates. Using field manipulations of understory kelp density and substratum orientation, we examined the effect of kelps on invertebrate recruitment and assessed the mechanisms involved. These mechanisms included reduced flow, increased sedimentation, reduced light intensity and reduced microalgal cover. All effects were significant to recruitment, but their relative importance varied among taxa. Two species examined, the serpulid polychaete Pseudochitinopoma occidentalis and the cheilostome bryozoan Membranipora membranacea have long-lived planktonic larvae. Kelp canopies affected recruitment of these two species in different ways. Pseudochitinopoma recruitment was reduced by sedimentation and light but was unaffected by ambient flow directly. Recruitment of Membranipora exhibited patterns consistent with that of passive transport of larvae with higher recruitment in high flow, no-kelp environments. Its recruitment was reduced by higher sedimentation beneath canopies, but showed no response to changes in light intensity.