Shore Rock Research Articles

Diploneis serrata (Bacillariophyceae): The use of structural mechanistic analysis to resolve morphological classification and molecular identification of a new record diatom species from Kenting, Taiwan

We demonstrated the use of the OpenSees framework for structural and geotechnical system simulations (National Science Foundation-Pacific Earthquake Engineering Center-PEER) and the ABAQUS software for finite element analysis to infer the performance of the cell valve in the diatom Diploneis serrata (the strength and stiffness of the cell wall's valve interstriae) under sheer and normal loads. The visualization of finite element analysis together with ultrastructural microscopic studies, both morphological and molecular (using 18S rDNA markers) helped us to resolve and classify the diatom Diploneis serrata collected from a microcosm made of intertidal submerged benthic shore rocks from Kenting National Park, Taiwan. The neat equilateral triangle pattern of the areolae in D. serrata allow us to construct a physical description of the striae structure. Based on the unique triangular areola in D. serrata, the structure of different areola shapes was simulated, and the difference in structural stability was discussed. The result shows the triangular areolae subjected to shear loads provided significantly larger stiffness and strength we deduce as a structural reinforcement strategy against predation. Based on the strength of the physical simulation structure, we attempt further to infer the possible evolutionary and environmental adaptation significance of the areola arrangement pattern. This line of thinking may help resolve difficult taxa within the diatoms, a task that could aide their use as ecological biomarkers in field observations.

Diagnostic ratios for the rapid evaluation of natural attenuation of heavy fuel oil pollution along shores

Marine oil spills are typically followed by complex clean-up and monitoring operations of the shorelines affected. In this regard, determination of the changes in the chemical composition of the spilled product is crucial for evaluation purposes. The “GC-MS fingerprint” approach requires the identification of several key parameters in order to differentiate between weathering processes. In this context, we performed a 900-day study (eight sampling campaigns) of natural attenuation on a rocky shore affected by a heavy fuel oil spill. The residues coating the rocks were studied by extraction, separation and evaluation of SARA fractions, followed by GC-MS analysis for saturates and aromatics. The results identified a group of diagnostic ratios with irregular capabilities to differentiate between volatilization, photodegradation, and biodegradation (using n-alkanes, isoprenoids and PAHs), while a second group of primarily stable ratios (using dibenzothiphenes, tricyclics and hopanes) was also obtained. Notably, this is the first time that some of these ratios have been used for marine spill monitoring purposes. The ratios were applied not only to evaluate weathering at the study site, but also to obtain a comparison with the degradation of floating oil slicks—a demonstration that weathering of the latter was quicker than that of oil on the shore rocks. Additionally, Pyrolysis-GC-MS analysis of the asphaltene fraction of residues coating the rocks revealed moderate changes in the composition of this initially recalcitrant fraction. These changes were consistent with those found in the proportion of resins and asphaltene fractions over time.

Trace metals and rare earth elements in Rock Oyster Saccostrea cucullata along the east coast of Peninsular Malaysia

Trace metals and rare earth elements (REEs) in the soft tissue of rocky shore Rock Oyster, Saccostrea cucullata, along the east coast of Peninsular Malaysia were determined. Significant inter-spatial variations ( p < 0.05) in trace metals and REEs were recorded. Significant positive correlations ( p < 0.01) were found among REEs concentrations. A few significant correlations were found for trace metals and REEs. Average distribution of metals indicated that Johor State had the highest concentrations compared with Pahang and Terengganu for all metals, except for Pb and Cu. This could most likely be attributed to the highly urbanized and industrialized activities such as sewage discharge. The metal accumulation patterns in the oyster indicated enrichment of essential metals. Sites with relatively high concentrations of the contaminant metals Hg, Cu, Pb and Zn were related to their close proximity to industrial and urban sites or to boating and aquaculture activities. Relative enrichment of Cu, Pb and Zn in oysters in the whole study even from relatively pristine areas is thought to be derived from natural sources as these metals are significantly correlated to REEs distribution. The distribution of REEs show close similarity between all sampling sites, suggesting that they are of similar origins. In all sites, typical saw-tooth chondrite-normalized patterns were observed, which strongly suggested the REEs bioaccumulated in oyster tissues is derived from geogenic sources. Typical deviations from this pattern were found for Ce and Eu and could be explained by their redox chemistry. Results of light to heavy REEs (LREE/HREE) ratios suggested REEs fractionation in coastline marine environment produced more light REEs and less heavy REEs absorbed in the soft tissue of S. cucullata. The ratio of La/Yb in the oyster of 27.3 was remarkably similar to Terengganu River basin soil of 33.0 and to Terengganu River sediment of 27.6. Comparison of metal concentration with maximum permissible limits of toxic metals in food established in different countries, as well as Malaysian Food Act 1983 and Food Regulations 1985 Fourteen Schedule, indicated values were well within safety levels, except for Cu and Zn. Along with its wide distribution on rocky shore areas along the east coast, the present results of trace metals and REEs recorded in soft tissue of S. cucullata collected from 14 sites along the east coast of Peninsular Malaysia served as baseline data for future reference.

Does the effect of low temperature on osmoregulation by the prawn Palaemon elegans Rathke, 1837 explain winter migration offshore?

Osmoregulation by the European glass prawn Palaemon elegans Rathke, 1837 was impaired at low temperature (2°C) and high salinities (full strength sea water 35 PSU). Under these conditions, small individuals showed stronger osmoregulatory ability than larger individuals. This observation could partially explain differences in winter migrations off the UK coast where mainly large P. elegans go offshore, leaving smaller individuals in high shore rock pools, a finding consistent with winter experiments in situ.

Seaside Tiger Herons

Tiger Herons (Tigrisoma) are little studied and generally characterized in the literature as being relatively uncommon birds of forested streams and wetlands. Contrary to these expectations, we found Bare-throated Tiger Herons (Tigrisoma lineatum) on the Pearl Islands of the Gulf of Panama to be birds of open, wave-exposed rocky seashores. We also found them to be common birds, inhabiting most shoreline coves. They fed over much of the tidal cycle along beaches and rocky shores, especially on and near surf-washed rocks. They caught crabs and fish by standing and walking slowly and methodically. Feeding efficiency was low, averaging about one prey item per hour. Plumage coloration is highly cryptic against shore rocks; but, in contrast, the bird becomes quite obvious when it expands its bare yellow throat, especially when accentuating a distinctive stretch display used to claim shore-line territory and for within-pair interactions. Tiger herons in the Pearls nested high in trees on ocean-facing cliffs. The habitat choice and behavior of this population of tiger herons that we report extend understanding of the biological scope of the subfamily of tiger herons.

Effect of grazing on coralline algae in seasonal, tropical, low-shore rock pools: spatio-temporal variation in settlement and persistence

Low-shore rock pools in Hong Kong are dominated by crustose coralline algae (CCA) all year round. Experiments manipulating grazer access to new surfaces and those with established CCA were used to investigate the spatial and temporal effects of grazers on establishment and persistence of CCA. During establishment, CCA were always the first macroalgae to recruit to new surfaces. Predictable algal colonization patterns were observed, although the extent and timing varied spatially (between pools) and temporally (with season and year). Grazing was the primary factor controlling the dominance of the CCA in low-shore rock pools, and seasonal differences in algal composition were only pronounced in the absence of grazers. On new surfaces, where grazers were excluded, the settling CCA were overgrown by competitively superior brown crustose algae (Ralfsia spp.) in summer and by non-crustose macroalgae (Ulva spp., Enteromorpha compressa, Hincksia mitchelliae and/or Colpomenia sinuosa) in winter. On CCA-colonized surfaces, E. compresa was, however, the dominant macroalga in winter in the absence of grazers. As a result of thermal stress in summer, the established CCA were commonly bleached, and new patches of bare surface were subsequently released. Such physical disturbance, hence, re-initiated colonization processes. The rapid re-colonization of CCA on new surfaces by lateral growth and new settlement suggests that CCA are resilient in nature, which results in them being the dominant macroalgae in the low- shore rock pools, all year round, in the presence of grazers.

Natural attenuation and bioremediation of Prestige fuel oil along the Atlantic coast of Galicia (Spain)

Heavy fuel oil spilled from the oil tanker Prestige in November 2002 affected hundreds of km of Spanish shoreline. We carried out a two year study at two highly contaminated sites in order to monitor natural attenuation of the residues coating shore rocks and to test the effectiveness of bioremediation with an oleophilic fertilizer (S200). The methodology included an innovative approach for oil load calculation (based on image analysis techniques), the analysis of the fate of hydrocarbons by means of chemical biomarkers and different microbiological techniques for isolating and examining hydrocarbon degraders. Considerable hydrocarbon depletion from shorelines (≈100% for light-medium linear alkanes and ≈35% for aromatics such as pyrene) was observed within the first months after the spill. However, this natural attenuation effect dramatically slowed down in the following year, although partial enhancement (especially for the aromatic fraction) was attained as a result of the application of S200 to stimulate indigenous microorganisms. In addition, one of the main outcomes of this work concerns the remarkable hydrocarbon depletion achieved at points where fresh water flowed through the shore rocks. The study of samples collected where this natural attenuation phenomenon took place made it possible to isolate heterotrophic bacteria and fungi that are likely to cooperate with cyanobacteria in hydrocarbon biodegradation. The overall results strongly advocate the implementation of new bioremediation approaches, including alternatives such as the use of natural fresh water to irrigate polluted areas.

Toxicity of antifouling biocides to the intertidal harpacticoid copepod Tigriopus japonicus (Crustacea, Copepoda): Effects of temperature and salinity

Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 × 3 × 4 factorial design (i.e. two temperatures: 25 and 35 °C; three salinities: 15.0‰, 34.5‰ and 45.0‰; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96h-LC50s of Cu and TBT were 1024 and 0.149 μg l −1 respectively (at 25 °C; 34.5‰) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using ‘concentration’ as the covariate and both ‘temperature’ and ‘salinity’ as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle.

Diet-dependent UVAR and UVBR resistance in the high shore harpacticoid copepod Tigriopus brevicornis

This study tested the hypotheses (1) that the upper shore rock pool harpacticoid cope- pod Tigriopus brevicornis is protected against ultra-violet radiation (UVR) by the orange pigment astaxanthin, and (2) that astaxanthin levels would be greater in summer than winter. Wild orange copepods lost their pigment and became white if fed on yeast in the dark; their colour was restored when they were fed microalgae. White T. brevicornis were significantly more susceptible to UVR than wild or restored orange T. brevicornis. At similar intensities of radiation, copepods showed dura- tion of survival in the order UVAR > UVBR. Astaxanthin protected T. brevicornis against UVAR and UVBR, with the degree of effectiveness of protection being in the order UVAR > UVBR. There was no significant increase in astaxanthin levels during summer in T. brevicornis collected from 3 different shores. It is suggested that UVAR protection by astaxanthin largely follows from its effectiveness as an antioxidant, and that there are adequate plant resources available to maintain astaxanthin levels in T. brevicornis throughout the year.

Environmental Tolerances of Three Species of The Harpacticoid Copepod GenusTigriopus

The harpacticoid copepod genusTigriopusis characteristic of shallow upper shore rock pools in both hemispheres.Tigriopusare necessarily physiologically tolerant as the pools feature extreme physicochemical conditions; their lower limit on the shore is apparently set by competition/predation. There are several species, differentiated by relatively minor morphological distinctions; speciation appears to be favoured by restricted gene flow between populations, even over short distances. This paper briefly reviews the literature concerned with the taxonomy, physiology and ecology of the genus, and compares environmental conditions and salinity/thermal tolerance data for three species: T.brevicornisfrom Scotland, T.fulvusfrom Madeira, and a previously undescribed population of the Southern Ocean ‘T. angulatus’ group from subantarctic South Georgia. Particularly interesting was a low upper lethal temperature in‘T. angulatus’(21·9°C) that probably restricts the species to relatively large pools that buffer environmental thermal extremes. Unlike the other species,T. fulvuscannot withstand freezing conditions. Evidence is presented to show that the South GeorgianTigriopusdiffers slightly, but significantly, in its morphology from two sibling species that inhabit the subantarctic Kerguelen and Crozet Islands but which cannot interbreed. If the South Georgian copepods are indeed a separate species and do not occur elsewhere (e.g. the Falklands), this indicates rapid speciation within the genus; the coasts of South Georgia were covered by an icecap until 10,000–14,000 years ago and no rock pool habitats were then available. It is suggested thatTigriopusmay have reached South Georgia by rafting withinEnteromorphatubes.

A new species of marine nemertean from Anglesey, North Wales, with a discussion of the genusParoerstediaFriedrich, 1955

A new species of marine nemertean, Paroerstedia nigrimaculata sp. nov., is described and illustrated from a single specimen found among Corallina in a lower shore rock pool at Rhosneigr, Anglesey, North Wales. No Paroerstedia species has been recorded previously from the British Isles. The systematics of the genus and its contained species are discussed.

Short-term effects of sessile organisms on colonization of intertidal boulders

This study examined how the sessile organisms on boulders (algae on the tops; polychaetes, bryozoans, ascidians, and sponges on the undersides) influenced the rates of colonization of other species. Experiments showed that the sessile organisms occupying space on the undersides of boulders reduced the rate at which other sessile species recruited. This was true for rocks in their normal orientation and for those which had been experimentally overturned and disturbed. This preemption of space reduced diversity on the undersides of boulders low on the shore where space was in short supply. Grazers and predators (primarily molluscs) moved more quickly onto rocks with sessile organisms than onto those without and the rate of recolonization also varied with rock size. Thus, observed patterns in number and abundance of species with rock size were at least partially due to selection among rocks by these species. High on the shore rocks of medium size (300–600 cm 2 in surface area) had more species. This pattern is often explained by the intermediate disturbance model (as the result of the interaction of disturbance and competition) but here it resulted from selective colonization of different sized rocks. Overall, the sessile organisms on boulders influenced their colonization by other species. This influence is important since these communities are often disturbed and frequently recovering from disturbance.

A Laboratory Study on the Effect of Predation by Limpets and Whelks on Barnacles, Chthamalus challengeri HOEK, at Early Stage of their Settlement

The experimental area was located on Tokawa-cho, Choshi City, Chiba, in which the acrylic panels were fixed to the shore rocks and exposed to the barnacles settlement for a given time. In experimental tanks, barnacles settled on the panels were consumed by the limpets which are commonly seen at this shore. The limpets used could be categorized into four groups; L1 (4∼5mm), L2 (8∼9mm), L3 (12∼13mm) and L4 (22∼23mm). The groups L2 and L4 respectively consumed 24 barnacles larvae for 18 hours, and the group L3 8 larvae, but the group L1 could not consume barnacles of any size.The limpets of 1.79∼3.16cm shell length damaged the barnacles larvae which had grown up to 1.2mm in about 14∼15 days after their settlement. The other predious shell, Thais claviger, is emphasised as one of the grazers in this shores, and it might consume more barnacles larvae than limpets, though details are unknown.According to the above observation, the influence of limpets on the formation of barnacles' life zone could be discussed, especially on the critical period of barnacles just after their settlement.

Bog Iron: Massachusetts Mineral Heritage

Click to increase image sizeClick to decrease image size Additional informationNotes on contributorsPalmer E. SevrensA long-time member of both the Boston Mineral Club and the North Shore Rock and Mineral Club, Palmer Sevrens is interested in all aspects of the mineral hobby. He spends much of his time field collecting, bringing home everything from hand specimens to micromounts.

The Reef Flat and ‘Two-Meter Eustatic Terrace’ of Some Pacific Atolls

Research Article| July 01, 1970 The Reef Flat and ‘Two-Meter Eustatic Terrace’ of Some Pacific Atolls NORMAN D NEWELL; NORMAN D NEWELL American Museum of Natural History, and Columbia University, New York, New York 10024 Search for other works by this author on: GSW Google Scholar ARTHUR L BLOOM ARTHUR L BLOOM Department of Geological Science, Cornell University, Ithaca, New York 14850 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1970) 81 (7): 1881–1894. https://doi.org/10.1130/0016-7606(1970)81[1881:TRFATE]2.0.CO;2 Article history received: 21 Aug 1969 rev-recd: 22 Feb 1970 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation NORMAN D NEWELL, ARTHUR L BLOOM; The Reef Flat and ‘Two-Meter Eustatic Terrace’ of Some Pacific Atolls. GSA Bulletin 1970;; 81 (7): 1881–1894. doi: https://doi.org/10.1130/0016-7606(1970)81[1881:TRFATE]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Characteristics of Indo-Pacific coral reefs long cited as evidence of a recent decline in sea level include: (1) the reef “flat” or pavement, (2) intertidal and supratidal flat erosion remnants of cemented coral rubble, and (3) erosion of the shores of reef islets.Our examination of 25 low islands and 8 high islands in the Caroline and Marshall Islands during the 1967 Scripps Institution of Oceanography Expedition CARMARSEL leads us to conclude that the reef flats in the western Pacific generally are not simply erosional platforms but represent an equilibrium surface between upward accretion by reef-building organisms and erosion at the mean level of low tides.Intertidal and supratidal coral rubble and calcareous sand accumulate above low-tide level during storms forming all of the visible land in the visited low islands. This rubble is currently being cemented and welded to the reef flats between tidal limits, and probably is also being cemented as beachrock and island conglomerate below the fluctuating water table of the cays.Topographically highest cemented carbonate rocks of the Caroline and Marshall Islands are uniformly less than 2 m above the adjacent reef flat, and entirely in the intertidal zone, hence, within the tidal range of present sea level.Flat horizontal surfaces of small extent occur on shore rocks, locally truncating inclined beds of beach rock. These surfaces roughly correspond to the upper limit of contemporary cementation somewhat modified by gravel scour. Comparison with rock platforms of a slightly elevated atoll of the Tuamotus, Raroia, indicates that the Marshall and Caroline Islands do not display expectable features of uplift or of subsiding sea level. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Ancient Sculpturings in Tiree

The sculpturings of the island are (1) prehistoric carvings of such figures as cups and ovals on the living rock-surface and on a standing-stone; (2) prehistoric carvings of large, deep, mostly oval cavities on the shore rocks; and (3) Early Christian carvings on slabs. The latter include cruciform figures. An account of all the known examples on the island is presented.