Showing papers on "Fringing reef published in 1985"
TL;DR: The results of these experiments suggest that patterns of settlement and juvenile survivorship of coral reef fishes are affected by complex interactions with other reef organisms (in this case, the activities of reef-associated grazers that modify available shelter) and by the frequency of encounters with predators.
Abstract: Factors affecting recruitment and early survivorship of juvenile coral reef fishes were studied on St. Croix, United States Virgin Islands. The faunal assemblage studied included diurnally active fishes found in the rubble/sand habitat. The most abundant members were: beaugregory {Ste- gastes leucostictus), foureye butterflyfish {Chaetodon capistratus), mahogany snapper {Lutjanus ma- hogoni), surgeonfishes {Acanthurus bahianus and A. chirurgus) and French grunt {Haemulon flavoli- neatum). During the period 1978-1981, sets of experimental reefs constructed from Strombus gigas shells were built in various locations relative to a major reef. Recruitment of juveniles of almost all species in the rubble/sand fish assemblage occurred more heavily on reefs that were built 20-40 m away from the main reef (into the lagoon) than on those built at the edge ofthe backreef. A series of experiments revealed that this is probably due to two factors: differences in available shelter and differences in encounter rates with predators. Seagrass and algae, which provide shelter to very small juvenile fishes, are absent in a "halo" zone close to the reef due to the feeding activities of reef-associated grazers (fishes and urchins). Experiments with artificially produced halos and artificial seagrass and algae showed that part of the explanation for the observed spatial pattern of fish recruitment is the spatial pattern of the shelter provided by seagrass and algae. Experiments in which potential prey fish were tethered demonstrated that the risk of predation for small juvenile fishes was considerably higher close to the reef than it was 20 m away. The results of these experiments suggest that patterns of settlement and juvenile survivorship of coral reef fishes are affected by complex interactions with other reef organisms (in this case, the activities of reef-associated grazers that modify available shelter) and by the frequency of encounters with predators. If they survive, all of the juveniles, regardless of where they initially settle, eventually migrate to a nearby reef. The species studies here differed in the degree to which juveniles use the sea-grass/algal habitat as a refuge from predation; these differences suggest that spatial patterns of recruitment, interacting with predation, may influence both population abundances and species com? position of older juveniles on the reef.
328 citations
TL;DR: A marked increase in the biomass of Cliona delirrix infesting Monfusrrea cavernosa substrate occurred in a portion of the Grand Cayman fringing reef affected by the discharge of untreated fecal sewage, suggesting the proliferation of a bioeroding organism in the sewage-stressed environment has caused a shift in the carbonate balance on the reef.
Abstract: A marked increase in the biomass of Cliona delirrix infesting Monfusrrea cavernosa substrate occurred in a portion of the Grand Cayman fringing reef affected by the discharge of untreated fecal sewage. It is suggested that the six-fold increase in bacteria biomass (both "coliforms" and natural marine bacterioplankton) in reef waters receiving the sewage effluent is linked to a five-fold increase in sponge biomass at the polluted site relative to a control site. The elevated density of C. delitrix biomass signifies a similar increase in the amount of M. cavernosa skeleton that has been eroded by this sponge and reduced to silt-sized sediment. Thus, the proliferation of a bioeroding organism in the sewage-stressed environment has caused a shift in the carbonate balance on the reef. Problem Reefs are highly diverse and complex biological communities that have evolved in the relatively stable environment of warm, shallow marine waters. They occur along the majority of the world's tropical coastlines, generating considerable attention from both the tourist industry and ecological and geological research. The continued welfare of the world's present reefs requires a more complete understanding of the potentially detrimental effects of anthropogenic distur- bances, in particular sewage loading. In considering how coral reefs respond to environmental stress, it has been suggested that maintenance of the highly diverse reef fauna requires either constant environmental conditions (FUTWMA, 1973) or periodic natural distur- bances at intermediate scales of intensity and frequency (CONNELL, 1975). In either event, the result of an excessive natural or anthropogenic disturbance is a
187 citations
TL;DR: Fiji is characterised by a higher percentage of domicolo~ls forms than any other well studied island group and Forty percent of Fijian taxa are new to science but this figure will undoubtedly be lowered when more Indo-Pacific island groups are explored.
Abstract: Eighty species of marine gammaridean Amphipoda are currently known from Fiji . During a three month period in late 1979. 77 species were collected. and these are described and figured . Keys for the identification of all known Fijian species are included . Fiji appears to share most of its taxa with Hawaii. Indonesia and the Indian Ocean. and few with eastern Polynesia. but this may reflect collecting intensity . Few taxa are shared with New Zealand . Forty percent of Fijian taxa are new to science . Forty-one percent of taxa are currently of endemic status but this figure will undoubtedly be lowered when more Indo-Pacific island groups are explored . Fiji is characterised by a higher percentage of domicolo~ls forms than any other well studied island group . The results of a quantitative survey of amphipods on a transect across a fringing reef in south Viti Levu are given . MYERS. A.A., 1985 . Shallow.water. coral reef and mangrove Amphipoda (Gammaridea) of Fiji . Records of the Australian Museum Supplement 5: 1-143 .
112 citations
TL;DR: Weathering of presently raised reef islands provides an analogue for the behaviour of Pleistocene reefs made emergent by glacio-eustatic falls in sea level Micro-erosion meter measurements on Grand Cayman Island, West Indies, have shown that high mean weathering rates (>100 mm yr−1) are restricted to the marine environment as mentioned in this paper.
53 citations
TL;DR: A subaerially exposed coral reef records a period of marine conditions following earliest Holocene transgression into the technically active, subsea level Enriquillo Valley, Dominican Republic as mentioned in this paper.
Abstract: A subaerially exposed coral reef records a period of marine conditions following earliest Holocene transgression into the technically active, subsea level Enriquillo Valley, Dominican Republic. Field mapping, detailed leveling of reef elevations, and I4C dating of fossil corals and mollusks reveal the following chronology of reef development in an unusual geologic and tectonic environment: (1) earliest Holocene ($$9760 \pm 100$$ yr B.P.) marine transgression and growth of oysters on an alluvial fan surface approximately 33 m below sea level (BSL); (2) colonization of reef corals at approximately 34 m BSL on the oyster shell deposits ($$8990 \pm 60$$ yr B.P.); (3) middle Holocene development of a typical Caribbean fringing reef in a protected environment ($$6200 \pm 80$$ to $$4760 \pm 90$$ yr B.P.); (4) late Holocene sedimentation over the reef with fossil bivalves ($$5710 \pm 90$$ to $$2820 \pm 40$$ yr B.P.) that record a gradual change from marine to brackish water that accompanied growth of shoreline th...
50 citations
TL;DR: The Gulf of Aqaba is dominated by alluvial fans that prograde directly into the sea and can be subdivided into four types: (1) largely inactive fans that merge into a braided fluvial system and pass seaward into sabkha flats, lagoons, mangroves and fringing reefs; (2) large alluial fans with one major entrenched channel and a fringing reef with a large incised canyon; (3) medium-sized (1.5 km long, 3.4 km wide) moderate to highly active
45 citations
43 citations
01 Jan 1985
25 citations
TL;DR: The history of Barbuda has been studied through aerial reconnaissance, mapping, logging, hand coring, facies and microfacies analysis as discussed by the authors, showing a pattern of progressively falling high sea level stands (from more than + 50 m down to the present level) on which are superimposed at least three major phases of subaerial exposure, when sea levels were close to, or below, their present level.
Abstract: The Pliocene to Holocene limestones of Barbuda have formed on a wide, shallow, outlying bank of the Lesser Antilles island arc, some 50 km east of the older axis of the Limestone Caribbees and 100 km east of the newer axis of the active Volcanic Caribbees. Contrasts with neighbouring islands of similar size include the lack of exposed igneous basement or mid-Tertiary sediments, the dominance of younger flat-lying carbonates, and the greater frequency of earthquake shocks. The history of emergence of the island has been studied through aerial reconnaissance, mapping, logging, hand coring, facies and microfacies analysis. These show a pattern of progressively falling high sea level stands (from more than + 50 m down to the present level) on which are superimposed at least three major phases of subaerial exposure, when sea levels were close to, or below, their present level. This sequence can be summarized as follows: 1, bank edge facies (early Pliocene Highlands Formation) deposited at not more than c. 50–100 m above the present sea level; 2, emergence with moderate upwarping in the north, associated with the Bat Hole subaerial phase forming widespread karst; 3, older Pleistocene transgression with fringing reefs and protected bays formed at + l0 to + l5 m high sea level stands (Beazer Formation); 4, Marl Pits subaerial phase with widespread karst and soil formation; 5, late Pleistocene transgression up to +6 m high stand with fringing and barrier reefs, protected backreefs and bays (Codrington Formation Phase I); 6, gradual regression resulting in emergence of reefs, enclosure of lagoons, and progradation of beach ridges at heights falling from c . 5 m to below present sea level (Codrington Phase II); 7, Castle Bay subaerial phase produced karst, caliche and coastal dunes that built eastwards to below present sea level; and 8, Holocene transgression producing the present mosaic, with reefs, lagoons and prograding beach ridge complexes, with the present sea level reached before c . 4085 years BP. The evidence suggests that slight uplift took place in the north of the island after early Pliocene times. Subsequent shoreline fluctuations are consistent with glacio-eustatic changes in sea level, indicating that the island has not experienced significant uplift during the Quaternary.
24 citations
01 Jan 1985
TL;DR: In this article, it was found that the northern reef of Orpheus Island has two distinctive areas: i) a northern part which has grown over a coarse Pleistocene boulder beach and has grown upward with the rise in sea level, reef flat develop~nt can~ncing prior to 6000 yrs BPj and ii) a southern part which is considerably younger and have grown over the accumulated debris from the southern reef.
Abstract: Best fringing reef development on north Queensland continental islands is normally found in lees ide locations but occasionally, as at Iris Point on Orpheus Island, significant reef develop~nt may be encountered on the windward side. Drilling investigations into this reef which is 2000 m long and up to 300 m wide, indicated that it has two distinctive areas: i) a northern part which has grown over a coarse Pleistocene boulder beach and has grown upward with the rise in sea level, reef flat develop~nt can~ncing prior to 6000 yrs BPj ii) a southern part which is considerably younger and has grown over the accumulated debris from the northern reef. Each area has a distinctly different reef top zonation related to its age and history. Growth of the Holocene reef over the boulder beach, including in situ corals of mid-Holocene age approximately 1 m higher than modern coral growth, supports -;arlie; suspicions that many well sorted boulder beaches on north Queensland islands are Pleistocene rather than Holocene in age.
Journal Article•
TL;DR: Makatea is an elevated (60 to 75 m) carbonate frame, ranging in age from the Miocene to the Late Pleistocene as mentioned in this paper, which is morphologically and sedimentologically an atoll -shaped reef tract (outer coral built rim, inner fine-sized to chalky, shelly deposits).
Abstract: Makatea Island, 245 km northeast of Tahiti, is an elevated (60 to 75 m) carbonate frame, ranging in age from the Miocene to the Late Pleistocene. It is morphologically and sedimentologically an atoll -shaped reef tract (outer coral built rim, inner fine-sized to chalky, shelly deposits). During periods of emergence, a dense karstic system has developed and, later, has been partly occulted by pyroclastic -derived phosphates. Uplifted and faulted during Pleistocene times, the island has recorded three high sea-level stands, from the Middle Pleistocene to the Late Holocene. The position of the Late Holocene peripheral fringing reef induces a marked paucity of marine flora and fauna. The algal turfs are dominated by Lobophora and, locally Turbinaria , whereas Porolithon ridges flourish on the high energy reef fronts. The coral communities are prospering along the outer slopes only ( Pocillopora, Acropora, Astreopora mainly). The distributional pattern of molluscs is rather similar to those of the other Tuamotu Islands; the dominant genera are Turbo, Drupa, Mitra, Conus, Tectarius, Thais, Littorina . The echinid Colobocentrotus is common, while Grapsids and Xanthids predominate among crustaceans.
TL;DR: In this paper, a small fringing reef in limestone facies was fouled in terrigenous sediments during the Oligocene transgression, and 27 species of coral were identified and the general character of corals and reef framework investigated.
Abstract: 1 km south of Cairo Montenotte, a small fringing reef in limestone facies was foumed in terrigenous sediments during the Oligocene transgression. It has a thickness of 40–60 m. The lower part consists of terrigenous-influenced to pure limestone and contains isolated corals, or concentrations of massive corals in coral mounds. The upper part is principally characterized by a dense framework of massive, sometimes branching corals. The coral fauna consists of 27 species, dominated byGonioporamosa orActinacis rollei. 23 species were found on the reef front, none of which predominate. The reef tapers off in various directions in small units of reef limestone and biocalcarenite. The coral fauna and the reef faccies are studied in detail. The vertical development of the coral limestones and lateral variations in the reef core, as well as the distal facies, are described. The corals are identified and the general character of corals and reef framework investigated. Communities and palaeoeecological relations are described.
01 Jan 1985
TL;DR: In this article, a first report on the general morphology, composition and condition of recent and fossil reefs of these areas is presented based on two months (September -October 1984) of research at nine different reef localities.
Abstract: Some fifty years after the Snellius I expedition (1929-1930) a Dutch-Indonesian joint expedition is carried out (1984-1985) in the Eastern Indonesian archpelago. Based on two months (September -October 1984) of research at nine different reef localities, a first report will be presented on the general morphology, composition and condition of recent and fossil reefs of these areas. The research areas that will be discussed are the following: Ambon: In the bay of Ambon fringing and patch reefs heavily damaged by silting up, caused by soi1. erosion on the island. North East Ambon an elevated reef from the old Pleistocene. Lucipara islands: Exposed very isolated atoll with some sand cays. Tukang Besi islands: Atoll reefs of Kaledupa. Binongko reef terraces; fossil cliffs modelled from massive Pleistocene reef limestone by coastal abrasion during tectonic uplift of the island; extensive reef terrace dating from the last interglacial; living reef not at the moment constructive. Sumba: East Sumba fringing reefs with influence of land and population. Young Pleistocene reef near Melolo, older terraces higher up. Komodo: Various fringing and patch reefs bordering the east side of the National Park of Komodo. Current swept reefs in the strait of Linta. Gililawa Laut and Tinandja lo~r Miocene reefs. Sumbawa: Fringing reefs in Telok Moti Toi and Sanggar bay near Tambora volcano (erupted in 1815). Coral growth in Bima bay. Pleistocene reef north east of Bima. Taka Bone Rate: Large pseudo atoll with small sand cay reefs (e.g. Tinandja) exposed reefs, coral banks and lagoons. Salayer: fringing reefs at west coast around islands Guang and Sahuluan. Pliocene reefs on both islands; Bahuluan with volcanic core. Sulawesi: Coral reef complex on the shallow shelf off South West Sulawesi, with three rows of reefs, most emerging as sand cay reefs. Because of young Holocene reg~ession in front of Ujung Pandang. Influence of sedimentation and population. Apart from these investigations during the Snellius II expedition, a long term project has been carried out since 1979 in the last area mentioned. A continuation of reef research is planned there, in close cooperation with UnHas (University of Ujung Pandang). The presentation of results will be accompanied by maps and photographs.
Journal Article•
TL;DR: The waters off the tropical coast of South China host a wide variety of reef corals, including Scleractinia, Hydrocorallinian, and Tubipora musica as mentioned in this paper.
Abstract: The waters off the tropical coast of South China host a wide variety of reef corals. From 1932 to 1978, 325 species in 62 genera and subgenera of reef coral (Scleractinia) as well as eleven species of Hydrocorallinian were identified as having a wide distribution in China. Although Heliporina and Tubiporina are widely distributed in the Indo-pacific region, particularly the two species Tubipora musica and Helipora caerulea (Pallas), they are not abundant in Chinese reefs. One species of Stylaster (Stylaster elegans Verrill) is found around the Xisha Islands.
01 Jan 1985
TL;DR: In this paper, nine holes were drilled with a submersible hydraulic drill into the slopes and reef flats of the Caubyna and Calituban reefs as well as of Olango Flat.
Abstract: Nine holes were drilled with a submersible hydraulic drill into the slopes and reef flats of the Caubyna and Calituban reefs as well as of Olango Flat. The maximum depth of core penetration was 11 m. 14C ages showed that the Caubyan and Caltituban reefs were formed within the last 6,000 years. Corals settled on a pre-existing relief prallel to the island of Bohol, building a framework for other carbonate-producing organisms. The reef flat south of Olango has a different structure. Formation took place during a Pleistocene high sea level, e.g. 125,000 years ago.
01 Jan 1985
TL;DR: In this paper, a transect mapping and petrologic studies reveal a new depositional model and limited diagenesis of a well-exposed Pleistocene reef outcrop at Ambergris Cay, northern Belize.
Abstract: Transect mapping and petrologic studies reveal a new depositional model and limited diagenesis of a well-exposed Pleistocene reef outcrop at Ambergris Cay, northern Belize. This emergent shelf-edge reef forms a rocky wave-washed headland at the northern terminus of the present-day 250 km long flourishing Belize Barrier Reef. Previously, the Belize reef outcrop was thought to extend southward in the subsurface beneath the modern barrier reef as a Pleistocene equivalent. The authors study indicate that this outcrop is a large, coral patch reef and not part of a barrier reef trend. Sixteen transects 12.5 m apart described in continuous cm increments from fore reef to back reef identified: extensive deposits of broken Acropora cervicornis; small thickets of A. palmata with small, oriented branches; and muddy skeletal sediments with few corals or reef rubble. Thin section and SEM studies show three phases of early submarine cementation: syntaxial and rosette aragonite; Mg-calcite rim cement and peloids; and colloidal Mg-calcite geopetal fill. Subaerial exposure in semi-arid northern Belize caused only minor skeletal dissolution, some precipitation of vadose whisker calcite, and no meteoric phreatic diagenesis. Facies geometry, coral assemblages, lack of rubble deposits, coralline algal encrustations and Millepora framework, and recognition of common but discretemore » submarine cements, all indicate that this Pleistocene reef was an isolated, coral-fringed sediment buildup similar to may large patch reefs existing today in moderate-energy shelf environments behind the modern barrier reef in central and southern Belize.« less
01 Jan 1985
TL;DR: The hypothesis that the sudden incorporation of tests and spines of innumerable urchins into the reef sediments would leave a clear record of the mortality event was tested and demonstrates the inadequacy of the reef sedimentary record to record many short-term although ecologically significant perturbations.
Abstract: During 1983, populations of the common long-spined echinoid Diadema antillarum were decimated by disease throughout the West Indies. Depending on the degree of recovery, this mass mortality could have profound effects on the coral reef ecosystem. The role of D. antillarum as a grazer of algae and agent of bioerosion is well documented. The hypothesis that the sudden incorporation of tests and spines of innumerable urchins into the reef sediments would leave a clear record of the mortality event was tested at Bonaire, Netherlands Antilles, where the mortality was witnessed in November, 1983. By August, 1984, there were every few live D. antillarum, no intact empty tests, but abundant broken up spines in the superficial sediments of the leeward fringing reefs. Sediment samples taken along a series of profiles from 6-36 m depth were analyzed for total echinoderm content and contribution of D. antillarum material. The echinoderm fraction shows a slight increase over pre-mortality levels as reported by Kobluk and Lysenko (1984), but it is not yet clear that this resulted from an increase in D. antillarum. Samples taken from cores 30 cm below the sediment surface show echinoderm fractions equal to or greater than surficial samples, suggesting that bioturbationmore » and turbulence have rapidly disseminated any sharp record of the event. The lack of a strong signal of this event demonstrates the inadequacy of the reef sedimentary record to record many short-term although ecologically significant perturbations.« less
Journal Article•
TL;DR: Foraminifera inhabiting Jamaican north-coast fringing reefs display variations in distributional patterns that are related to bathymetry and reef morphology as discussed by the authors, and approximately 150 species distributed among 80 genera were identified from the samples.
Abstract: Recent foraminifera inhabiting Jamaican north-coast fringing reefs display variations in distributional patterns that are related to bathymetry and reef morphology. Sediment samples containing foraminifera were collected along a profile that traversed the back reef (depth 1-2 m), fore-reef terrace (3-15 m), fore-reef escarpment (15-27 m), fore-reef slope (30-55 m), and upper deep fore reef (70 m). Approximately 150 species distributed among 80 genera were identified from the samples. Preliminary analyses indicate that diversity values (S, H') are lowest on the fore-reef terrace (79, 3.0, respectively), increase similarly in back-reef and fore-reef escarpment and slope settings (93, 3.4), and are highest on the deep fore reef (109, 3.7). Larger groupings (suborders) exhibit distinct bathymetric trends with miliolids occurring more commonly in back-reef (comprising 51% of the fauna) than in fore-reef (28%) zones, whereas agglutinated and planktonic species occur more commonly in deeper reef (> 15 m, 9% and 4%, respectively) than in shallower reef zones (< 15 m, 3%, and 0.5%, respectively). Among the more common species Amphistegina gibbosa (Rotolina) is much more abundant in fore-reef (3%) environments, and Sorites marginalis (Miliolina) occurs almost exclusively in the back reef, where it comprises 5.5% of the fauna. Q-mode cluster analysis, involving allmore » species collected, enabled the delineation of back-reef, shallow fore-reef, and deeper fore-reef biofacies, also indicating the potential utility of foraminiferal distributions in detailed paleoenvironment interpretations of ancient reef settings.« less
TL;DR: Foraminifera inhabiting Jamaican north-coast fringing reefs display variations in distributional patterns that are related to bathymetry and reef morphology as discussed by the authors, and approximately 150 species distributed among 80 genera were identified from the samples.
Abstract: Recent foraminifera inhabiting Jamaican north-coast fringing reefs display variations in distributional patterns that are related to bathymetry and reef morphology. Sediment samples containing foraminifera were collected along a profile that traversed the back reef (depth 1-2 m), fore-reef terrace (3-15 m), fore-reef escarpment (15-27 m), fore-reef slope (30-55 m), and upper deep fore reef (70 m). Approximately 150 species distributed among 80 genera were identified from the samples. Preliminary analyses indicate that diversity values (S, H^prime) are lowest on the fore-reef terrace (79, 3.0, respectively), increase similarly in back-reef and fore-reef escarpment and slope settings (93, 3.4), and are highest on the deep fore reef (109, 3.7). Larger groupings (suborders) e hibit distinct bathymetric trends with miliolids occurring more commonly in back-reef (comprising 51% of the fauna) than in fore-reef (28%) zones, whereas agglutinated and planktonic species occur more commonly in deeper reef (> 15 m, 9% and 4%, respectively) than in shallower reef zones ( End_of_Article - Last_Page 283------------
01 Jan 1985
TL;DR: The island of Barbuda contains an off-lapping sequence of horizontal carbonates which document a pattern of progressively falling sea level stands punctuated by at least three major intervals of subaerial exposure when sea level was at or below its present level as mentioned in this paper.
Abstract: The island of Barbuda, located some 75 km north of Antigua, contains an off-lapping sequence of horizontal carbonates which document a pattern of progressively falling sea level stands punctuated by at least three major intervals of subaerial exposure when sea level was at or below its present level. This sequence can be summarized as follows: (1) Pliocene Highlands Formation with deposition of bank edge, fore-reef deposits 50 to 100 m above present sea level; (2) Bat Hole subaerial phase with karst development; (3) early (.) Pleistocene Beazer Formation with fringing reefs, protected bays and development of sea caves at 10 to 15 m above present sea level; (4) Marl Pits subaerial phase with karst development and soil formation; (5) late (.) Pleistocene Codrington Formation Phase I with fringing and barrier reefs, back-reef lagoons and sea cave development at 5 m above present sea level; (6) late (.) Pleistocene Codrington Formation Phase II with prograding beach ridges and sea level falling from 5 m to below present level; (7) Castle Bay subaerial phase with karst development, caliche and coastal aeolian dunes; and (8) Holocene (post-3000 B.P.) Palmetto Point transgression with development of the present reef, lagoon and southwestern beach ridge complex.more » The evidence suggests that Burbuda has been relatively stable and has not undergone significant uplift during this period. Shoreline fluctuations appear consistent with glacio-eustatio sea level changes since the Pliocene.« less