The distribution of epifauna on Ecklonia radiata (C. Agardh) J. Agardh and the effect of disturbance

https://doi.org/10.1016/0022-0981(83)90115-6Get rights and content

Abstract

The epifaunal community of the kelp, Ecklonia radiata (C. Agardh) J. Agardh, was investigated at Portsea, Australia. The per cent cover of epifauna on the primary blade of Ecklonia was significantly greater on plants from the inner and outer pilings than on those from low on the pilings, under the pier and from an adjacent reef. Species diversity, but not the per cent cover of epifauna, was significantly greater on crinkled than on smooth plants. Various factors of disturbance were measured, including lashing by other plants, which increased with the density of plants. Other abrasive forces were found to increase closer to the bottom, as did the density of gastropods on the fronds. For each site, the number of disturbance factors present was summed giving a disturbance index (D), which was negatively correlated with per cent cover. Transplants and laboratory experiments indicated that three of these disturbance factors reduced the abundance of hydroids, but that increasing the amount of plant lashing had no effect on Tricellaria porteri MacGill.

Seven species were chosen for further analysis. The abundance of most species correlated with either plant length or bushiness, although the variation accounted for had a range of 1–43%. For all species, the percentage of zones which were colonized on the Ecklonia blade increased distally, following the age gradient. While the abundance of some species also increased distally, that of hydroids decreased. Membranipora membranacea L. was found to smother the hydroids on 60% of their encounters but neither the distribution nor the abundance of hydroids was altered in the absence of Membranipora. It appears that disturbance rather than competition is the major modifying influence of this community.

References (40)

  • J.H. Connell

    Diversity in tropical rainforests and coral reefs

    Science

    (1978)
  • D.J. Crisp

    Factors influencing the settlement of marine invertebrate larvae

  • D.J. Crisp

    Surface chemistry, a factor in the settlement of marine invertebrate larvae

    Bot. Gothob. Acta Univ. Gothob.

    (1965)
  • D.J. Crisp et al.

    Effects of extracts from fucoids in promoting settlement of epiphytic Polyzoa

    Nature (London)

    (1960)
  • P.K. Dayton

    Competition, disturbance, and community organization: the provisions and subsequent utilisation of space in a rocky intertidal community

    Ecol. Monogr.

    (1971)
  • P.K. Dayton

    Dispersion, dispersal and persistence of the annual intertidal alga, Postelsia palmaeformis Ruprecht

    Ecology

    (1973)
  • P.K. Dayton

    Experimental evolution of ecological dominance in a rocky intertidal algal community

    Ecol. Monogr.

    (1975)
  • W.J. Fletcher

    Factors affecting the composition and abundance of the epifaunal community of Ecklonia radiata

  • J. Harris

    The ecology of marine epifaunal communities on the pilings of Portsea pier, Victoria

  • P.J. Hayward et al.

    The distribution of settled larvae of the bryozoans Alcyonidium hirsutum (Fleming) and Alcyonidium polyoum (Hassall) on Fucus serratus L

    J. Mar. Biol. Assoc. U.K.

    (1974)
  • Cited by (25)

    • Interactive effects of canopy-driven changes in light, scour and water flow on microscopic recruits in kelp

      2021, Marine Environmental Research
      Citation Excerpt :

      Given high-density forests also have low light at the substratum (Layton et al., 2019a; Toohey and Kendrick, 2008; Wernberg, 2005), which is adequate for microscopic sporophyte survivorship but not always growth (Miller et al., 2011; Novaczek, 1984; Tatsumi and Wright, 2016), these low scour, low light conditions may represent a positive environment-engineer feedback on survivorship of microscopic E. radiata recruits. Moreover, because E. radiata with shorter stipes and a canopy lying closer to the substratum cause more scour than E. radiata with longer stipes (Fletcher and Day, 1983; Kennelly, 1989; Toohey et al., 2004), the removal of early life-cycle stages by scour may be very localised due to variation in E. radiata stipe length and morphology. A single E. radiata may only abrade a certain part of the substratum depending on its morphology and the extent to which it is blocked by neighbouring, resulting in scour ‘blind-spots’ and micro-scale (mm to cm) variation in mortality from scour.

    • Diversity of kelp holdfast-associated fauna in an Arctic fjord - inconsistent responses to glacial mineral sedimentation across different taxa

      2018, Estuarine, Coastal and Shelf Science
      Citation Excerpt :

      Delicate arborescent hydroids were much more affected than tougher bryozoan colonies. The reduced cover of hydroids on plants was explained by the damaging effect of sand abrasion, lashing by fronds or by clogging (Fletcher and Day, 1983). Hydrozoans are known to be susceptible to sedimentation and siltation (Moore, 1977).

    • Bearing the burden of boat harbours: Heavy contaminant and fouling loads in a native habitat-forming alga

      2011, Marine Pollution Bulletin
      Citation Excerpt :

      Reciprocal experimental transplants at several locations are, however, necessary to formally separate habitat effects from those caused by characteristics of the kelp. Despite many studies showing differences in distribution of epibiota among sections of laminae of algae (e.g. Brumbaugh et al., 1994; Fletcher and Day, 1983; Ryland, 1974, 1976), this study found no such differences for kelps at most locations. Our survey indicated, however, substantially greater fouling on the distal section of laminae at two of the four marina locations.

    • Palaeoecology and evolution of marine hard substrate communities

      2003, Earth-Science Reviews
      Citation Excerpt :

      Overgrowth may cause the death (mortality) of the overgrown organism or may be non-fatal. For example, overgrowth of the exoskeletal tube of a serpulid worm need not cause death of the worm if the aperture remains open to allow continued access by the tentacle crown of the worm to the water column, and the bases of erect organisms are sometimes overgrown with no obvious detrimental effects on the erect parts (e.g., Fletcher and Day, 1983). Survival in these circumstances is sometimes referred to by marine biologists as epizooism.

    View all citing articles on Scopus
    1

    Present address: School of Biological Sciences (A08), University of Sydney, Sydney, 2006, Australia.

    View full text