Sound Of Mull Research Articles

Potential Audibility of Three Acoustic Harassment Devices (AHDs) to Marine Mammals in Scotland, UK

The modelled acoustic characteristics of three Acoustic Harassment Devices (AHDs) deployed from a fully operational salmonid fish farm, located in the Sound of Mull, Scotland (UK) are presented, using empirical seabed and water column measurements at the same location. In the Beaufort Sea state 0, the depth range of 10--50 m is the maximum range at which AHDs are potentially audible to five marine mammal species. The species present within this survey region are: the harbour porpoise, Phocoena phocoena (99.1 km), the killer whale, Orcinus orca (110 km), the bottlenose dolphin, Tursiops truncatus (89.6 km), the common seal, Phoca vitulina (88 km), and the grey seal, Halichoerus grypus (69 km). Consequently, within the Sound of Mull, all three AHDs could be heard throughout the water column by all species. For two models of AHDs, a behavioural disturbance level of between 140 dB-180 dB is observed at 1.3 km. Habitat displacement is a cause for concern, particularly if several fish farms within a small area all deploy AHDs simultaneously. This can create a confusing sound field of varying intensity, which has potential to deter harbour porpoises from sections of their habitat. If positioned effectively, AHDs have the potential to deter all five marine mammal species from industrial operations such as aquaculture facilities. Source levels, propagation and transmission loss measurements were highly variable and should be considered as site specific, meaning new estimates should be made for each situation.

The potential of the marine bivalve mollusc Glossus humanus (L.) as a sclerochronological archive

In order to assess its potential as a sclerochronological archive, we present statistical and geochemical analyses of internal growth increment series in shells of the heart cockle Glossus humanus (L.), a large marine bivalve. The investigated samples were collected from Loch Sunart and the Sound of Mull, Scotland, United Kingdom. High-resolution stable isotope (δ18O) analyses and radiocarbon (14C) determinations indicated that G. humanus forms annual growth lines. Examination of the growth increment series revealed that the maximum longevity of G. humanus in this region was 78 years. Radiocarbon dating and crossmatching techniques, derived from dendrochronology, were used to provide an estimation of the temporal distribution of the fossil G. humanus. Of the shells that contained >25 growth increments, seven were found to statistically crossmatch, including shells from two distinct sites 15 km apart. The calibrated 14C determinations independently confirmed the crossmatching of three G. humanus shells from the Sound of Mull with a separately constructed Glycymeris glycymeris chronology and a further three G. humanus shells from site 3, in the main basin of Loch Sunart, but indicate a significant difference (site 1) in the antiquity of the two G. humanus populations. Radiocarbon dating indicated that, despite their fragile nature, G. humanus shells remain preserved in near original condition for at least 700 years. Given the small amount of available shell material, it is unlikely that G. humanus will become a key species for the construction of long absolutely dated sclerochronologies. However, these data do indicate that the annually resolved G. humanus growth series could be used to supplement series from other long-lived bivalves and facilitate the construction of a robust multispecies sclerochronology spanning the last 1000 years.

Pennsylvanian (Namurian and Westphalian) miospore assemblages from the west coast of Scotland

Examination of cored borehole sections of Pennsylvanian sediments in the Machrihanish Coalfield on Kintyre and samples from coastal exposures at Inninmore Bay on the Sound of Mull, demonstrate the existence of Westphalian (Langsettian to Bolsovian) sediments in both close proximity to the Highland Boundary Fault zone and in isolated outliers within the western parts of the Scottish Highlands. Earlier studies suggested a Duckmantian to Bolsovian age for the Inninmore Bay sections and the investigation of material from new sections in the area confirms this stratigraphical range. The borehole sections in the Machrihanish Coalfield demonstrate the unconformable relationship between the probable Namurian to Westphalian sediments of the Scottish Coal Measures Group and the underlying early Namurian Limestone Coal Formation. In addition to rich assemblages of western European miospore taxa, the Machrihanish populations contain examples of species such as Columinisporites ovalis, Paleospora fragila, Spackmanites irregularis and Vestispora colchesterensis which are characteristic of North American assemblages. The distinctive species Playfordiaspora cancellosa is reported from the British Carboniferous.

Marine boathouses of the Sound of Mull

Six early 19th-century boathouses adjacent to the Sound of Mull, a nodal route on the western seaboard of Scotland, are described and analysed. Earlier usage of the Sound is discussed, and the role of the boathouses considered in the context of change within a maritime landscape.

TheDartmouth, a British frigate wrecked off Mull, 1690 2. Culinary and related items

The Frigate Dartmouth, 5th rate, sank in a storm in the Sound of Mull on 9 October 1690 while on patrol for Williani of Orange in his campaign against the Catholic Scots of the Western Isles (see Adnams, 1974). She was then at the close of a distinguished career and very much a ‘work-horse’ of the Royal Navy. It may therefore be assumed that she was equipped with utensils, storage vessels and ceramics typical of an ordinary naval vessel of the time. By comparison with pottery and glass items found on contemporary wrecks, particularly that of the 5th rate frigate Sapphire, this paper investigates :

The Isle of Mull, Scotland: A Geographical Reconnaissance

aM / ~ULL is an eroded mountainous island, separated from the western highlands of Scotland by the narrow Sound of Mull and the somewhat wider Firth of Lorne (Figs. 1 and 2). The foundation rock of Mull, predominantly basalt with characteristic dike structure, has been heavily gouged and pitted, and its peaks rounded by the action of Pleistocene ice (Fig. 3). The soils of Mull, derived from the easily weathered basalt, are relatively fertile and well drained when compared to the siliceous granites and gneisses prevalent throughout the Scottish highlands and islands. These soils, and the extreme maritime climate of Mull, support rank sheep and deer pasture on all but the rocky mountain crests. Arable land, devoted to hay, oat, turnip, and potato crops, is confined to the relatively restricted low-lying parts of the island (Fig. 4). Progressive migration reduced the population of Mull from 10,538 in 1831 to 2,903 in 1931 (Table I). The move-

V.— The Outlier of Carboniferous Rocks at Bridge of Awe, Argyllshire

During an inspection of sections exposed in the recent road-widening operations between Taynuilt and Loch Awe, an opportunity was taken to re-examine the small outlier of Carboniferous rocks near the Bridge of Awe at the west end of the Pass of Brander (Geological Survey One-inch Map, Sheet 45). It was hoped also that the investigation would yield some points of comparison with the Carboniferous strata of Inninmore on the Sound of Mull (1). The Bridge of Awe sediments seem to have been first noticed by Macculloch in 1817 (2). The red colour of the beds and the fact that they outcrop in the midst of lavas of Lower Old Red Sandstone age led observers to regard them as belonging to the same formation. They were assigned this age in the ‘Summary of Progress of the Geological Survey for 1897’ (3), but in the following year Mr. D. Tait obtained from shales a little north of Bridge of Awe a few fragmentary plant remains which definitely proved the sediments to be Carboniferous (4). The accompanying sketch-map indicates the approximate limits of the outlier. It is largely concealed beneath alluvial deposits and the only sections are those exposed on the banks of the River Awe. The actual junction with the underlying lavas can be seen on the right bank below the bridge and at two localities on the left bank above it. The exposures above the bridge, however, can only be properly examined when the river is low. The writers were fortunate This 250-word extract was created in the absence of an abstract The authors desire to acknowledge the help given by Professor J. W. Walton and Dr. R. Crookall in the examination of material and the assistance of Mr. W. Manson in the field.

4. Notes on a Lucifer-like Decapod Larva from the West Coast of Scotland

Whilst examining my “tow-nettings” from the West Coast, I have met with a peculiar Decapod larva, which, so far as I know, is unlike anything previously described. In general appearance it is very like semi-adult forms of Lawifer, having an elongated “neck,” at the tip of which the eyes and antennae are carried. My specimens were obtained from two localities—1st, about half a dozen at about the same stage, from tow-nettings taken in Machrie Bay (west shore of Arran), 17th September 1886; and 2nd, about 20 specimens, some further advanced than those of the previous gathering, which were collected at a depth of 8 to 10 fathoms in the Sound of Mull, 24th August 1887. These were associated with various larval stages of Porcellana, Galathea, and other Decapods.

Note on the irregularities in magnetic inclination on the West Coast of Scotland

In the Report of the results of the Magnetic Survey of Scotland, undertaken at the request of the British Association by the late Mr. Welsh during the years 1857 and 1858, it is stated by Professor Balfour Stewart (by whom the observations were reduced and the report drawn up) that the values of all the elements as determined in and adjacent to the Island of Mull were apparently largely affected by local attraction, and from a comparison of the various observations Professor Stewart was led to place the centre of the disturbance a little to the south of the Mull stations, and at a considerable depth below the surface. The effect of this local attraction was most apparent in the determination of the dip, which at Tobermory was upwards of 57', and at Glenmorven, on the other side of the Sound, was 14' in excess of the probable normal value, that is, the value unaffected by local disturbance and dependent merely on geographical position, as deduced by combining together all the other observations for Scotland, in the manner adopted by Sir Edward Sabine in discussing the observations of the previous Survey of 1836. Dr. Stewart’s localisation of the centre of disturbance was based partly on a consideration of the abnormal values exhibited by the observations made at the two stations on the Sound of Mull, and partly on certain irregularities manifested by the determinations taken on Islay and in Skye. So far as the Mull observations themselves were concerned, the clue as to the exact locality of the area of disturbance was of the very slenderest. Mr. Welsh appears to have made only a single observation of the dip at Tobermory; and although observations were made with two needles at Glenmorven, the divergence between the resultant values happens to be greater than is exhibited by any other pair of dip observations throughout the survey. Nevertheless, as we shall show, we are able to confirm not only the general accuracy of Mr. Welsh’s observations on this particular point, but also Professor Stewart’s inference as to the probable locale of the area of disturbance.

VI. Notes on Mull and its Leaf-Beds

The first features of interest which strike the geologist on landing at Salen in the Sound of Mull are the mountains of Ben Greig and Ben More. The north face of Ben Greig, well seen from the north end of Loch Baa, is a fine precipitous cliff and presents a very curious appearance. The rocks composing it are chiefly granite and felsite with felstone dykes, and their peculiarly curved and stratified appearance is caused by contraction on cooling. The base of the mountain is of hornblendic granite, and there are veins and dykes of quartz, pitchstone, and felstone. Behind Ben Greig towers the glorious peak of Ben More, the mere remnant of a huge volcano which must have far exceeded Etna in bulk and extent. Ben More is very interesting, as here we have the skeleton of a volcano laid bare to its very feet. The lower part is built up of granite and felsite, often very porphyritic, intersected by dykes and veins of felstone and pitchstone; the upper portion is an enormous aggregation of tuffs, ashes and scoriæ, with dykes and lava flows of gabbro, dolerite, and basalt. Here then we have the life history of the volcano plainly shown us, with the two well marked groups of acidic and basic rocks, into which all eruptive rocks naturally fall, clearly separated from each other. First we have the acidic series, including granite, felsite, phonolite, felstone, pitchstone, and obsidian, distinguished by their paler colours when weathered, greater infusibility owing to This 250-word extract was created in the absence of an abstract

2. Notice of Recent Earthquake Shocks in Argyleshire in 1877

Two earthquake shocks have lately occurred in Argyleshire of so decided a character that a description of their effects, as observed at four of the Lighthouse stations on the west coast of Scotland, will, it is thought, be interesting to the Society.The first shock occurred on the 11th March, and was observed at the Lighthouse station of Hynish in the island of Tyree, and at Sound of Mull, near Tobermory, the distance between the two places being about 34 statute miles.