Algal reefs

Shallow marine environments include coral and algal reefs as well as other bioherms and many favour calcification by benthic fauna. Stromatolites and stromatolitic environments are also typical shallow marine formations. The shallow marine carbonate environment may be subdivided into more or less agitated waters with dominantly benthic fauna, calm shallow areas with carbonate muds (e.g. Bahama Banks) with ooids as typical forms of deposits and reef areas with their complicated patterns of calcification and deposition (Bathurst, 1975 Kinsey and Davies, Chapter 2.5). 

Ginsberg, R.N., Marszalek, D.S. and Schneidermann, N., 1971. Ultrastructure of carbonate cements in a Holocene algal reef of Bermuda. J. Sediment. Petrol, 41 472—482. 

Carpenter RC (1986) Partitioning herbivory and its effects on coral reef algal communities. Ecol Monogr 56 345-346... 

Hay ME (1981) Spatial patterns of grazing intensity on a Caribbean barrier reef herbivory and algal distribution. Aq Bot 11 97-109... 

Lewis SM (1985) Herbivory on coral reefs algal susceptibility to herbivorous fishes. Oecologia 65 370-375... 

Morrison D (1988) Comparing fish and sea urchin grazing in shallow and deeper coral reef algal communities. Ecology 69 1367-1382... 

Three cytotoxic peptides, patellamide D (31) and lissoclinamides 4-5 (32-33) were isolated from a Great Barrier Reef specimen of L. patella and identified by interpretation of spectral data. The peptides were found within the obligate algal symbiont of the genus Prochloron [65]. Another study of the same Australian L. patella reported lissoclinamide 6 (34), in addition to lissoclinamides 4-5 (32-33) and patellamide D (31). The structure of patellamide D (31) was obtained by X-ray crystallography and its conformation compared with those obtained by molecular modelling [66]. Patellamide D (31) has been reported to be a... 

The new red algal species Laurencia mariannensis from the Great Barrier Reef provides the novel sesquiterpene 297, along with the known pacifenol and deoxy-prepacifenol, which are now fully characterized by NMR for the first time (539). The Philippine Laurencia majuscula has furnished 13 novel halogenated sesquiterpenes 298-310, of which the major components are the majapolenes A (298, 299) (two diastereomers), which are also found in Laurencia caraibica (540). Most of these compounds occur as inseparable diastereomers. A collection of Laurencia majuscula from the South China Sea has yielded the cedrene-type sesquiterpene majusin (311) (541). A new sesquiterpene dichloroimine, stylotellane A (312), was isolated from the sponge Stylotella aurantium (Fig. 3.3) (542). 

Small sedentary grazers such as amphipods appear to select chemically defended seaweeds as host plants since they would otherwise be subject to intense predation by reef fishes however, they do not sequester metabolites as do other selective grazers such as sacoglossans and opistobranch molluscs.105 109 Grazing by amphipods induces increased concentrations of acutilol A acetate and acutilol B in Dictyopteris menstrualis and makes the seaweed less susceptible to attack by other predators 112 the same terpenes acted as antifoulants which prevented the settlement of bryozoan larvae.107 This evidence for multiple roles for algal metabolites may provide an explanation of previously documented differences in chemical composition in Dictyota.113... 

The red algal chamigrene sesquiterpene elatol (Structure 2.78) has been shown to deter feeding by reef fishes.93 Specimens of Laurencia elata from Southern Australia show a pronounced seasonal variation in elatol production. Incorporation studies using 14C acetate failed to confirm an acetate-mevalonate path for elatol production.125... 

Hay, M.E., Spatial patterns of herbivore impact and their importance in maintaining algal species richness, Proc. Fifth Ini. Coral Reef Congr., 4, 29, 1985. 

Levin, P.S. and Hay, M.E., Responses of temperate reef fishes to alterations in algal structure and species composition, Mar. Ecol. Prog. Ser., 134, 37, 1996. 

Hatcher, B. G., The interaction between grazing organisms and the epilithic algal community of a coral reef a quantitative assessment, Proc. 4th Int. Coral Reef Symp., 2, 515, 1981. 

Paul, V. J., Wylie, C., and Sanger, H., Effects of algal chemical defenses toward different coral-reef herbivorous fishes a preliminary study, Proc. 6th Int. Coral Reef Sym., 3, 73, 1988. 

Tsuda, R. T. and Kami, H. T., Algal succession on artificial reefs in a marine lagoon environment in Guam, J. Phycol., 9, 260, 1973. 

Borowitzka, M. A., Larkum, A. W. D., and Borowitzka, L. J., A preliminary study of algal turf communities of a shallow coral reef lagoon using an artificial substratum, Aq. Bot., 5, 365, 1978. 

Hatcher, B.G. and Larkum, A.W.D., An experimental analysis of factors controlling the standing crop of the epilithic algal community on a coral reef, J. Exp. Mar. Biol. Ecol., 69, 61, 1983. 

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