Anchor Bay Research Articles

Microvertebrates from the Rhaetian bone beds at Blue Anchor Bay, Somerset

Abstract The cliff and foreshore sections at Blue Anchor Bay, north Somerset, provide a detailed picture of the transitional Triassic–Jurassic succession. The site has been recorded as a location for fossil fishes for over 200 years, and yet the assemblages from the bone beds have not been described. Here, we present new observations on the two bone beds and find major faunal differences: the classic basal bone bed at Blue Anchor Bay contains an assemblage dominated by osteichthyan teeth, unexpected because elsewhere the ichthyofauna is usually dominated by chondrichthyans. The upper bone bed at Blue Anchor Bay is indeed more typical, being dominated by teeth of hybodont chondrichthyans. We report two unusual finds, first five teeth of the rare shark Parasycylloides turnerae, only the fifth such record in the UK. Further, we report here for the first time a tooth of the pycnodontiform Eomesodon, the first report of this taxon from the Triassic of the UK or Europe. The two bone beds are distinguished not only by different assemblages, but also by evidence of different degrees of anoxia and water depth: the upper bone bed contains abundant pyrite and marcasite, indicating highly anoxic conditions, and perhaps deposition in deeper water than the basal bone bed.

Stormwater outlets: A source of microplastics in coastal zones of Cape Town, South Africa

The runoff from stormwater outlets are potential sources of microplastics (MPs) in coastal zones. The characteristics and concentrations of MPs in coastal water, sediment and biota (mussels, whelks and sea urchins) were measured in summer (2020/2021) (dry season) and winter (2021) (wet season) from three sites (Camps Bay, Mouille Point and Three Anchor Bay) in Cape Town. MPs were characterised visually using a stereo microscope and chemically using spectroscopy. MP concentrations were higher in water and sediment during winter, and higher in biota in summer. Compared to control sites, MPs were higher at all impact sites sampled. MPs extracted were mainly black polyester (PEST) fibres, 1000 to 2000 μm in length averaging 0.15 MPs/L in water, 52.11 MPs/kg dry weight in sediment and 1.35 MPs/g soft tissue wet weight in biota. The results indicate that coastal stormwater systems are potential sources of MPs in the coastal environment of Cape Town.

Paleo-environmental evidence of ecosystem change in Lake St. Clair region of Laurentian Great Lakes basin: contrasting responses to land-use change and invasive mussels

The Laurentian Great Lakes have been subject to substantial modification from diverse anthropogenic stressors, including nutrient enrichment, climate change, chemical and biological pollutants, and invasive species, yet little is known of the relative historical influence of these factors. Here we analyze diverse fossil metrics from vibracores at two sites, a bay area (Anchor Bay) and a tributary (Clinton River) in the Lake St. Clair ecosystem to determine the ecological responses from land-use practices and invasive mussel invasions. Sediment cores spanning over 100 years indicated that the expansion of non-native Dreissena polymorpha and Dreissena rostriformis (dreissenid mussels) into Anchor Bay site after the mid-1990s was associated with ~ 60 to 95% reduction in algal and cyanobacterial abundances and twofold increase in sedimentary organic matter (SOM) and bioavailable phosphorus. These increases in SOM and bioavailable phosphorus are relatively similar to increases inferred from the late nineteenth century when large portions of the watershed were cleared and drained for agriculture. In contrast, the Clinton River site experienced a continuous increase in the influx of nutrients, organic matter, and elevated sedimentary phototrophic pigments during the twentieth century and into the twenty-first century. Site comparisons suggest different mechanisms inducing changes in primary production varied, where Anchor Bay was mainly affected by the comparatively recent (since ca. mid-1990s) endogenous influence of invasive species, while the Clinton River site was primarily influenced by the input of exogenous anthropogenic nutrients over the past 100 years. These new findings illustrate that watershed management and policies within large lakes with multi-jurisdictional (national) Area of Concerns should consider site-specific regulatory mechanisms.

Allacanthochasmus artusandAllacanthochasmus varius(Trematoda: Cryptogonimidae) in Adult White Bass,Morone chrysops, from Lake St. Clair, Michigan, U.S.A.

ABSTRACT: A total of 55 adult white bass, Morone chrysops (Rafinesque, 1820) (Moronidae), collected in May and June 2014 from Anchor Bay, Lake St. Clair, Michigan, U.S.A., were examined for intestinal helminths. Of those found, 2 trematode species (Allacanthochasmus artus and Allacanthochasmus varius) were of interest due to their high prevalences and intensities. Allacanthochasmus artus infected all white bass with a mean intensity ± SD of 203.5 ± 243.9, and A. varius infected 53 white bass with a mean intensity ± SD of 263.9 ± 202.1 and mean abundance ± SD of 262.8 ± 198.1. Individuals of A. artus and A. varius were primarily found in the anterior and posterior intestine, respectively. Fifty-three white bass were concurrently infected with A. artus and A. varius. Allacanthochasmus artus and A. varius are reported for the first time from white bass in Lake St. Clair, and their mean intensities are the highest reported to date in this fish host from the Great Lakes.

Historical Associations of Molecular Measurements of Escherichia coli and Enterococci to Anthropogenic Activities and Climate Variables in Freshwater Sediment Cores.

This study investigated the long-term associations of anthropogenic (sedimentary P, C, and N concentrations, and human population in the watershed), and climatic variables (air temperature, and river discharge) with Escherichia coli uidA and enterococci 23S rRNA concentrations in sediment cores from Anchor Bay (AB) in Lake St. Clair, and near the mouth of the Clinton River (CR), Michigan. Calendar year was estimated from vertical abundances of (137)Cs. The AB and CR cores spanned c.1760-2012 and c.1895-2012, respectively. There were steady state concentrations of enterococci in AB during c.1760-c.1860 and c.1910-c.2003 at ∼0.1 × 10(5) and ∼2.0 × 10(5) cell equivalents (CE) per g-dry wt, respectively. Enterococci concentrations in CR increased toward present day, and ranged from ∼0.03 × 10(5) to 9.9 × 10(5) CE/g-dry wt. The E. coli concentrations in CR and AB increased toward present day, and ranged from 0.14 × 10(7) to 1.7 × 10(7) CE/g-dry wt, and 1.8 × 10(6) to 8.5 × 10(6) CE/g-dry wt, respectively. Enterococci was associated with population and river discharge, while E. coli was associated with population, air temperature, and N and C concentrations (p < 0.05). Sediments retain records of the abundance of fecal indicator bacteria, and offer a way to evaluate responses to increased population, nutrient loading, and environmental policies.

Dynamic characteristics of an active coastal spreading area using ambient noise measurements—Anchor Bay, Malta

Dynamic characteristics of an active coastal spreading area using ambient noise measurements—Anchor Bay, Malta

A Comprehensive Approach to Investigate Maltese Coastal Landslides

SOLDATI, M., BONACHEA, J., BRUSCHI, M.V., CORATZA, P., DEVOTO, S., GONZÁLEZ-DIAZ, A., MANTOVANI, M., PASUTO, A., PIACENTINI, D., REMONDO, J and SCHEMBRI, J.A., 2011. A Comprehensive Approach to Investigate Maltese Coastal Landslides. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 472–473. Grosseto, Tuscany, Italy, ISSN 0749-0208.This paper presents geomorphological and engineering-geological studies carried out along the north-western coast of Malta by research groups belonging to the University of Modena and Reggio Emilia (Italy), the National Research Council (Italy), the University of Malta and the University of Cantabria (Spain). The research are funded by Fondazione Cassa di Risparmio di Modena and the European Centre for Geomorphological Hazards (CERG) and focus on the evolution of coastal landslides with emphasis on the issues of hazard and risk, with respect to the recreational infrastructures present in the area and to the several tourists that visit this stretch of coast.The area of study extends for about 12 km2 in Northern Malta and elevation ranges from the coast to about 110 m above the sea level. In this part of the Island, slope failures are abundant and strictly linked to lithological and structural factors. In fact, in the north-western area of Malta, between Paradise Bay and Gnejna Bay, three geological units outcrop that deeply control the morphological setting and the evolution of landscape: Globigerina Formation, Blue Clay Formation and Upper Coralline Formation. The Upper Coralline Limestone, the younger Formation of Malta Island, forms a karst plateau, bordered by vertical cliffs of varying heights, which ranges from a few meters to 30 m. At the foot of the limestone slopes Blue Clays Formation crops out which develops gently slopes that in some cases can reach directly the sea. The different mechanical behaviour of clays and limestone favours the development of lateral spreading phenomena, which occur in particular at Anchor Bay, at Ghajn Tuffieha Bay and along the western sector of Marfa Ridge. The occurence of this type of mass movement causes the presence of vertical joints and cracks near the calcareous slopes, due to the fragile response of rock material.Properties of the cracks, such as their aperture and persistence, depend on the different stages of lateral spreading phenomena; in the areas where the phase of evolution is more mature fractures reach lengths that can exceed 200 meters. A consequence of the presence of these wide discontinuities is the accumulation of large boulders along the coast, due to the detachament and fall of blocks from the vertical cliffs. The deposits are wide and the blocks are slowly scattered on the large terrace gently sloping towards the sea. In order to study and understand the complex evolution of coastal slope failures, a multidisciplinary approach has been applied and a complex system of monitoring has been installed. The research carried out so far has included a retrospective study of slope instability events along the north-west coast of Malta, collection and analysis of climatic data, multi-temporal analysis of aerial photos, geomorphological survey and mapping. In addition, the research plan foresees LIDAR surveys and radar interferometric analyses. The results obtained have permitted to outline the causes and evolution of coastal landslides in the north-western coast of Malta, with specific focus on rock spreading phenomena whose movement velocity and direction have been monitored since 2006 in two field sites. GPS network are located at Il-Qarraba and Anchor Bay. The analysis of monitoring data has shown that lateral spreading phenomena are active in both sites and that the displacements range from a few mm/yr to more then 3 cm/yr. The integration of new monitoring data to be acquired will permit the evaluation and mapping of landslide hazard. The final results of the research are aimin

Leeches (Annelida: Hirudinida) Parasitizing Fish of Lake St. Clair, Michigan, U.S.A.

Abstract In order to identify leech species prevalent in Lake St. Clair, Michigan, U.S.A,. and understand their effect on fish hosts, fish were collected during May 2006 and 2007 from Anchor Bay, Lake St. Clair in the Laurentian Great Lakes Basin. Throughout the study, 2,117 fish from 21 species were examined for the presence of leeches. Overall, 1,064 leeches were collected from 165 individual fish and identified morphologically. Hosts included the channel catfish, freshwater drum, northern pike, northern shorthead redhorse sucker, quillback sucker, rock bass, smallmouth bass, walleye, and yellow perch. Leeches attached to hosts had a prevalence of 7.79%, with a mean intensity of 6.45 leeches/infected fish and an abundance of 0.50 leeches/examined fish. Collected leeches were identified as Actinobdella pediculata (Glossiphonidae), Placobdella montifera (Glossiphonidae), and Myzobdella lugubris (Piscicolidae), which was the most commonly occurring species. The freshwater drum had the highest prevalence, m...

&lt;i&gt;Jerome Bixby's 'The Man from Earth'&lt;/i&gt; (review)

Reviewed by: Jerome Bixby's 'The Man from Earth' Rodney Hill (bio) Jerome Bixby's 'The Man from Earth' (Richard Schenkman USA 2007). Anchor Bay. NTSC region 1. 1.78:1 letterboxed anamorphic. US$26.98. As the name above the title might suggest, the greatest strength of Jerome Bixby's The Man from Earth lies in its thought-provoking script. As a screenwriter, Jerome Bixby (1923–98) was best known for penning four memorable episodes of Star Trek (US 1966–9), including 'Mirror, Mirror' (6 October 1967), which [End Page 161] introduced the concept of a parallel universe into the Star Trek universe. His short story 'It's a Good Life' (1953) was adapted by Rod Serling for The Twilight Zone (1959–64; broadcast 3 November 1961), was remade as one of the segments of Twilight Zone: The Movie (Dante, Landis, Miller and Spielberg US 1983) as well as prompting a sequel, 'It's Still a Good Life' (19 February 2003), for The Twilight Zone (Canada/US 2003). Bixby also co-authored the original story that was the basis for the film, Fantastic Voyage (Fleischer US 1966), which curiously was then novelised by sf icon Isaac Asimov. In The Man from Earth, Bixby's protagonist, John Oldman (David Lee Smith), decides that he must leave his comfortable, tenured position as a history professor at an unnamed university because of a rather singular problem: he does not age, or so he claims. He can only stay in one place for a few years without arousing unwanted suspicions, and so must move on to start a new life every ten years or so. The story takes place over the course of a long afternoon and evening, at an impromptu gathering of Oldman's colleagues – representing a broad range of academic disciplines, from art history to biology and anthropology – who have come to bid him a fond farewell, during which he finally shares with them his big secret: that he has lived for over 10,000 years. Their responses (like those of the viewer, perhaps) range from incredulity ('You must be joking!') to indignation ('How dare you pull such a prank on us?') to genuine curiosity and wonder ('Tell us more!', 'Can this be true?'). Throughout the evening, each tries with little success to poke holes in the punningly named Oldman's story, but gradually some of them come around to a cautious acceptance of his claims. Although the overly sarcastic Art (William Katt), who is responding to an apparent midlife crisis by dating one of his students and sporting an ill-advised ponytail, might at first seem like an easy cliché, he actually offers an interesting counterpoint to Smith's 10,000-year-old man. If we cringe at the sight of Art cuddling with a 20-year-old co-ed, how awkward must it be for the centuriesold Oldman to be romantically involved with anyone? Aside from such practical questions – which also include, what are John's earliest memories? and when did he realise that he was immortal? – a couple of big surprises are sprung near the end of act two, leading into a rather sudden and mildly confusing resolution. The first and more startling of these revelations comes after Oldman tells of his wanderings 'towards the east', during which he met and studied with the Buddha. This bit of news spurs his colleagues into a rapid series of questions, finally leading to, 'Did you ever meet any figures from the Biblical tradition?' Oldman's hesitation here only serves to make his listeners more insistent that he answer their question, and he reluctantly admits that he was the man who became known as Jesus. However, he is quick to point out that he never claimed [End Page 162] to be divine, and says that his simple teachings (based on Buddhist principles) have often been overlooked in favour of a needlessly complicated mythos that casts the figure of Jesus as a deity. Having gradually acclimatised the audience to the hard-to-swallow premise of a caveman who has lived into the twenty-first century, Oldman's story takes a giant leap that shakes the very foundations of some worldviews – ironically, by...

Predictive model of San Andreas fault system paleogeography, Late Cretaceous to early Miocene, derived from detailed multidisciplinary conglomerate correlations

Paleogeographic reconstruction of the region of the San Andreas fault system in western California, USA, was hampered for more than two decades by the apparent incompatibility of authoritative lithologic correlations. These led to disparate estimates of dextral strike-slip offsets across the San Andreas fault, notably 315 km between Pinnacles and Neenach Volcanics, versus 563 km offset between Anchor Bay and Eagle Rest peak. Furthermore, one section of the San Andreas fault between Pinnacles and Point Reyes had been reported to have six pairs of features showing only ~ 30 km offset, while several younger features in that same area were reported consistent with ~ 315 km offset. Estimates of total dextral slip on the adjoining San Gregorio fault have ranged from 5 km to 185 km. Sixteen Upper Cretaceous and Paleogene conglomerates of the California Coast Ranges, from Anchor Bay to Simi Valley, were included in a multidisciplinary study centered on identification of matching unique clast varieties, rather than on simply counting general clast types. Detailed analysis verified the prior correlation of the Upper Cretaceous strata of Anchor Bay at Anchor Bay with a then-unnamed conglomerate at Highway 92 and Skyline Road (south of San Francisco); and verified that the Paleocene or Eocene Point Reyes Conglomerate at Point Reyes is a tectonically displaced segment of the Carmelo Formation of Point Lobos (near Monterey). The work also led to three new correlations: Point Reyes Conglomerate with granitic source rock at Point Lobos; a magnetic anomaly at Black Point (near Sea Ranch) with a magnetic anomaly near San Gregorio; and strata of Anchor Bay with previously established source rock, the potassium-poor Logan Gabbro of Eagle Rest peak, at a more recently recognized subsurface location just east of the San Gregorio fault, south of San Gregorio. From these correlations, a Late Cretaceous to early Oligocene paleogeography was constructed which was unique in utilizing modern shapes of tectonic blocks in a paleogeographic resolution synthesizing both the proposed 315 and ~ 30 km San Andreas fault offsets, as well as honoring the lithologic correlation of Anchor Bay with Eagle Rest peak. The model has proved predictive. Since its first introduction, in April and June 1998, other authors have reported seven subsequently identified correlative pairs of geological and geophysical features consistent with it. These required both lateral and temporal expansion of the model: The paleogeography now incorporates 58 pairs of correlative features, covers the period from 70 to 21.3 Ma, and extends from Pelona and Orocopia to the Mendocino triple junction. The model supports the view that fault is not the boundary between the Pacific and North American plates is a wide zone encompassing the San Andreas fault system. However, the model suggests the San Andreas fault is a temporary assemblage of separate segments having different motions, and is neither the primary plate boundary, nor the dominant fault of the San Andreas fault system. By improving resolution of complex spatial–temporal distribution of slip along this evolving tectonic margin, the model provides a firmer foundation for resolution of geophysical issues such as slab window and Pacific Plate subduction models.

ISIS: An Instrument for Measuring Erosion Shear Stress In Situ

An instrument for measuring shear stress for erosion in situ(ISIS) has been developed to measure the erosion shear stress of muddy sediments on intertidal mud flats. Erosion shear stress is defined in this paper as the minimum applied bed shear stress required to initiate erosion and remove sediment from the bed surface. An applied shear stress is generated by the flow through and around a specially shaped bell head, which draws water radially across the bed into the centre of the bell head. The applied shear stress is a function of the distance from the bell head to the bed surface and the discharge through the system. The design of ISIS was assisted by the use of a computational numerical flow modelling package. The operating conditions giving the most even shear stress across the whole test section were discharges of 0·01–0·6 ls −1, and bell-to-bed distance of 4–8 mm giving a shear stress of 0·02–5 Nm −2. The ISIS system was calibrated using hot film shear stress probes. The calibration data gave a 92% fit to the calibration function for shear stress. Laboratory measurements with ISIS of the erosion shear stress of mud beds consolidated for c. 1·5 days, showed surface shear stresses of 0·11–0·24 Nm −2. These were very similar to values of surface erosion shear stress measured for the same mud in an annular flume. The ISIS system was used to measure surface erosion shear stresses on the mud flats at Portishead and Blue Anchor Bay in the Severn Estuary, U.K. Surface erosion shear stresses at Portishead were generally in the range 0·2–0·5 Nm −2. The surface erosion shear stresses measured at Blue Anchor Bay, which included mud and sand, ranged between 0·1–1·9 Nm −2.

Relationships of Phytomacrofauna to Surface Area in Naturally Occurring Macrophyte Stands

Most studies of the relationships between freshwater macrophytes and phytomacrofauna, or the macroinvertebrates associated with the macrophytes, have been based on individual plant collections or samples from monotypic plant stands. We describe the phytomacrofauna assemblages within naturally occurring, taxonomically mixed stands, and consider how macrophyte surface area and plant morphology influenced phytomacrofauna diversity and abundance. Samples of submersed macrophytes and phytomacrofauna were collected April-November 1979 in Anchor Bay of Lake St. Clair. Only the portions of macrophytes within the water column and invertebrates from above the sediment were considered. Densities of phytomacrofauna were not consistently related to fluctuations in macrophyte surface area, indicating that the use of macrophyte structure by the invertebrates changed during the year. Both the abundance and species richness of the phytomacrofauna were strongly related to macrophyte species richness reflecting the response...