Marine Hard Substrata Research Articles

The first observations of Ischnochiton (Mollusca, Polyplacophora) movement behaviour, with comparison between habitats differing in complexity.

Most species of Ischnochiton are habitat specialists and are almost always found underneath unstable marine hard-substrata such as boulders. The difficulty of experimenting on these chitons without causing disturbance means little is known about their ecology despite their importance as a group that often contributes greatly to coastal species diversity. In the present study we measured among-boulder distributional patterns of Ischnochiton smaragdinus, and used time-lapse photography to quantify movement behaviours within different habitat types (pebble substrata and rock-platform). In intertidal rock-pools in South Australia, I. smaragdinus were significantly overdispersed among boulders, as most boulders had few individuals but a small proportion harboured large populations. I. smaragdinus individuals emerge from underneath boulders during nocturnal low-tides and move amongst the inter-boulder matrix (pebbles or rock-platform). Seventy-two percent of chitons in the pebble matrix did not move from one pebble to another within the periods of observation (55–130 min) but a small proportion moved across as many as five pebbles per hour, indicating a capacity for adults to migrate among disconnected habitat patches. Chitons moved faster and movement paths were less tortuous across rock-platform compared to pebble substrata, which included more discontinuities among substratum patches. Overall, we show that patterns of distribution at the boulder-scale, such as the observed overdispersion, must be set largely by active dispersal of adults across the substratum, and that differing substratum-types may affect the degree of adult dispersal for this and possibly other under-boulder chiton species.

Islands in a Sea of Mud: Insights From Terrestrial Island Theory for Community Assembly on Insular Marine Substrata.

Most marine hard-bottom habitats are isolated, separated from other similar habitats by sand or mud flats, and can be considered analogous to terrestrial islands. The extensive scientific literature on terrestrial islands provides a theoretical framework for the analysis of isolated marine habitats. More individuals and higher species richness occur on larger marine substrata, a pattern that resembles terrestrial islands. However, while larger terrestrial islands have greater habitat diversity and productivity, the higher species richness on larger marine hard substrata can be explained by simple surface area and hydrodynamic phenomena: larger substrata extend further into the benthic boundary, exposing fauna to faster current and higher food supply. Marine island-like communities are also influenced by their distance to similar habitats, but investigations into the reproductive biology and dispersal ability of individual species are required for a more complete understanding of population connectivity. On terrestrial islands, nonrandom co-occurrence patterns have been attributed to interspecific competition, but while nonrandom co-occurrence patterns have been found for marine fauna, different mechanisms are responsible, including epibiontism. Major knowledge gaps for community assembly in isolated marine habitats include the degree of connectivity between isolated habitats, mechanisms of succession, and the extent of competition on hard substrata, particularly in the deep sea. Anthropogenic hard substrata of known age can be used opportunistically as "natural" laboratories to begin answering these questions.

Towards an integration of scale and complexity in marine ecology

Manipulative field experiments provide a window into the complexity of nature. Yet there is concern that we lack resolution by conducting experiments on a scale that is too small and short to include the relevant complexity of the study system. We addressed this issue by asking how and why the scale (local and global spatial extent, spatial grain, duration) and complexity (number of species, factors, treatment combinations) of experiments performed on marine hard substrata (rocky intertidal, RI; coral reef, CR; rocky subtidal, RS; mangrove root, MR) has changed by assessing 311 total experiments published since 1961 in Ecology and Ecological Monographs and since 1967 in Journal of Experimental Marine Biology and Ecology. We show that the local spatial extent and all metrics of complexity increased as a positive, log‐linear function of time. In contrast, the size of experimental units (spatial grain) decreased with time. Quantile regression analysis revealed that these trends are largely driven by changes in the upper bounds of experimental scale and complexity; most studies are still relatively simple in design and conducted over small areas. A structural equation model (SEM) incorporated the direct and indirect effects of six metrics indicating that the complexity of field experiments has increased both as a direct effect of time and because experiments have become smaller in spatial grain. The SEM also showed longer experiments tended to be more complex. We show striking habitat differences, as subtidal experiments (CR, RS) involved more species and were carried out on the largest global spatial scales. RI experiments were the longest.Future prospects to incorporate more of the complexity of nature into field experiments include site replication, as only 34.7% of all experiments were conducted at more than one site, open experimental designs monitored by technology, and integrating experimental manipulations with long‐term monitoring to achieve mechanistic insight across scales relevant to human alteration of the biosphere. The increasing resolution of remote sensing also creates opportunities to track experiment‐driven changes in community structure across large scales. We suggest applying these methods to a wider class of problems to enhance our understanding of marine communities and ecosystems.

Large gryphaeid oysters as habitats for numerous sclerobionts: a case study from the northern Red Sea

The shell of a living specimen of the Indo-Pacific gryphaeid giant oyster Hyotissa hyotis was colonized by numerous encrusting, boring, nestling and baffling taxa which show characteristic distribution patterns. On the upper valve, sponge-induced bioerosion predominates. On the lower valve intergrowth of chamid bivalves and thick encrusting associations—consisting mostly of squamariacean and corallinacean red algae, acervulinid foraminifera, and scleractinian corals—provides numerous microhabitats for nestling arcid and mytilid bivalves as well as for encrusting bryozoans and serpulids. Such differences between exposed and cryptic surfaces are typical for many marine hard substrata and result from the long-term stable position of the oyster on the seafloor. The cryptic habitats support a species assemblage of crustose algae and foraminifera that, on exposed surfaces, would occur in much deeper water.

Scaling of colonization processes in streams: Parallels and lessons from marine hard substrata

Abstract Understanding colonization processes specifically requires a comprehensive understanding of the frequency and scales over which dispersal occurs, which in turn determines the degree of linkage within and between populations and possibly results in metapopulation structure. What is our level of such knowledge for stream systems? We examine colonization processes in streams using a framework produced by analogous literature on sessile, marine species, which are comparatively well‐known and may provide insights for stream biota. For simplicity, we separate dispersal into two, somewhat artificial scales: microscale (between habitat patches ‐ cm to m) and mesoscale (between groups of patches ‐ tens to thousands of metres), and consider dispersal links between them. Traditional views on dispersal developed similarly in both systems, with a strong initial focus on mesoscale dispersal followed by an awareness that some species do not disperse usually over these scales and that there are a wide range of dispersal profiles. In both habitats, there are few data on actual dispersal distances, and longevities are sometimes used to infer them instead. Organisms can be transported by water currents (marine larvae, stream larvae) or wind (adult insects), the directions and strengths of which are relatively predictable at mesoscales. However, behavioural choices of organisms during dispersal can change their potential dispersal distances and directions markedly. Additionally, predictability of transport processes at microscales is very poor. As a consequence, simple, lone biological measures (like longevity) or simple, lone physical measures (like discharge) are useless for predicting dispersal frequencies and scales in most cases. Mortality during dispersal is also extremely important but there are few data; this represents a major information gap in both sets of literature. Finally, if organisms end dispersal by searching for and being able to respond to specific cues, then we may be able to predict colonization by looking at the distribution of such cues; different cues are likely though to vary greatly in space and time. There is potential for dispersal ‘structure’ to develop in rivers of different hydrology, and for sets of correlated life‐history characters to result in dispersal at particular scales, but there are very few stream studies that bear on these issues unambiguously. Progress in understanding the scales of dispersal, in both habitats, will require a lot more studies designed formally to test clear hypotheses about the scales of dispersal, rather than continuing a status quo of generating essentially anecdotal information

Taphonomic Effects and Preserved Overgrowth Relationships among Encrusting Marine Organisms

Overgrowth relationships in the fossil record of encrusting organisms on marine hard substrata have been used to infer success in competitive interactions, particularly for modular organisms such as colonial invertebrates and coralline algae. However, this interpretation has been questioned to varying extenteven by those who have used the procedure-because of the possibility that any individual observation may represent growth over a senescent organism or dead skeletal remains. Where sufficient numbers of overgrowth relationships are available to demonstrate that the proportions of overgrowths between two modular taxa are not essentially equal, the competitive superiority of the more frequently overgrowing taxon should be accepted. The degree of success of the more frequently overgrowing taxon was at least as great as seen in the fossil record and was probably substantially greater, depending upon the percent of bare surface on the substratum. RESEARCH LETTERS 279

Field settlement locations on subtidal marine hard substrata: Is active larval exploration involved?

The role of larval exploration of surfaces in determining spatial patterns of settlement was examined in the field in a low-energy environment by comparing locations where larvae first contacted topographically complex surfaces to locations where larvae metamorphosed. The barnacle Balanus amphitrite and the bryozoan Bugula neritina both metamorphosed more frequently around the bases of bumps on surfaces than would be predicted from the distribution of initial surface contacts. Neither differential mortality nor passive erosion of larvae explains these results. Larvae also did not leave the surfaces once contacted. So, in this low-flow environment, the processes that govern the delivery of larvae to surfaces also determined where settlement occurs on a scale of tens of centimeters. Exploratory larval behavior was important over smaller spatial scales (mm–cm).

Ecology of intertidal and sublittoral cryptic epifaunal assemblages. II. Nonlethal overgrowth of encrusting bryozoans by colonial ascidians

Total overgrowth of encrusting cheilostome bryozoans by sheet-like colonial ascidians is commonly observed in epifaunal sessile assemblages on marine hard substrata. Although death of the overgrown colony is the usual outcome, we show here that such interactions need not necessarily lead to the demise of the bryozoans, despite continuous total covering for perhaps several months. Because colonial ascidians were essentially “early” colonists of the experimental panels, most of our data pertain to small bryozoans. Colonies of several bryozoan species spanning a wide range of sizes did, nonetheless, survive overgrowth in both the intertidal and sublittoral. The importance of repeated, as opposed to single, overgrowth observations is discussed in relation to the analysis of competitive relationships among epifaunal organisms.

Surface topography influences competitive hierarchies on marine hard substrata: a field experiment: Walters, L.J. and D.S. Wethey, 1986. Biol. Bull. mar. biol. Lab., Woods Hole, 170(3):441–449

Surface topography influences competitive hierarchies on marine hard substrata: a field experiment: Walters, L.J. and D.S. Wethey, 1986. Biol. Bull. mar. biol. Lab., Woods Hole, 170(3):441–449

Succession on marine hard substrata: the adaptive significance of solitary and colonial strategies in temperature fouling communities

Succession on marine hard substrata: the adaptive significance of solitary and colonial strategies in temperature fouling communities

Succession on marine hard substrata: A fixed lottery.

Community development is described for a temperate fouling community near Bremerton, Washington. Multivariate and functional group analyses are undertaken which reveal certain underlying patterns in the observed succession. These patterns include a steady increase in the dominance of solitary animals over their colonial counterparts, as well as a gradual convergence upon a few relatively persistent species assemblages. In our discussion of these results, a Markov model for succession on marine hard substrata is introduced. Implications of the model and its limitations are explored in terms of community development and stability. Finally, an attempt is made to reconcile the model's results with our field observations.

Competition on Marine Hard Substrata: The Adaptive Significance of Solitary and Colonial Strategies

Most solitary and colonial animals inhabiting marine hard substrata differ fundamentally in their ability to use space. Colonial animals are superior space competitors because (1) indeterminate growth allows continuous lateral substratum occupation without requiring intervening stages of sexual reproduction and recruitment, and (2) they are less susceptible to fouling and overgrowth. Solitary animals survive in the seas because (1) various morphological and behavioral attributes (escape in size, aggregative behavior) protect them in spatial competition with colonial animals or because (2) predation, physical disturbance, or competition with plants prevents monopolization of substrata by colonial animals. Focus on ecological strategies circumvents arguments regarding the solitary or colonial identity of problematical groups such as sponges. The evolution of specific competition mechanisms by colonial animals has provided the basis for competitive networks which have further favored the evolution of highe...

THE PHYSIOLOGY OF SKELETON FORMATION IN CORALS. II. CALCIUM DEPOSITION BY HERMATYPIC CORALS UNDER VARIOUS CONDITIONS IN THE REEF

Previous articleNext article No AccessJournal ArticlesTHE PHYSIOLOGY OF SKELETON FORMATION IN CORALS. II. CALCIUM DEPOSITION BY HERMATYPIC CORALS UNDER VARIOUS CONDITIONS IN THE REEFTHOMAS F. GOREAU and NORA I. GOREAUTHOMAS F. GOREAUDepartment of Physiology, University College of the West Indies and The New York Zoological Society Search for more articles by this author and NORA I. GOREAUDepartment of Physiology, University College of the West Indies and The New York Zoological Society Search for more articles by this author Department of Physiology, University College of the West Indies and The New York Zoological SocietyPDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Biological Bulletin Volume 117, Number 2October 1959 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.2307/1538903 Views: 195Total views on this site Citations: 4Citations are reported from Crossref © 1959 Marine Biological LaboratoryPDF download Crossref reports the following articles citing this article:Zoe Dellaert, Phillip A. Vargas, Patrick J. La Riviere, and Loretta M. Roberson Uncovering the Effects of Symbiosis and Temperature on Coral Calcification, The Biological Bulletin 242, no.11 (Jan 2022): 62–73.https://doi.org/10.1086/716711Robin Elahi and Peter J. Edmunds Tissue Age Affects Calcification in the Scleractinian Coral Madracis mirabilis, The Biological Bulletin 212, no.11 (Sep 2016): 20–28.https://doi.org/10.2307/25066577E. Tentori and D. Allemand Light-Enhanced Calcification and Dark Decalcification in Isolates of the Soft Coral Cladiella sp. During Tissue Recovery, The Biological Bulletin 211, no.22 (Sep 2016): 193–202.https://doi.org/10.2307/4134593 J. B. C. Jackson Competition on Marine Hard Substrata: The Adaptive Significance of Solitary and Colonial Strategies, The American Naturalist 111, no.980980 (Oct 2015): 743–767.https://doi.org/10.1086/283203

Influence of X-Rays on Limb Regeneration in Urodele Amphibians

Influence of X-Rays on Limb Regeneration in Urodele Amphibians