Biotically constrained palaeoenvironmental conditions of a mid-Holocene intertidal lagoon on the southern shore of the Arabian Gulf: evidence associated with a whale skeleton at Musaffah, Abu Dhabi, UAE

Abstract

a b s t r a c tWhale remains (a left and right mandible, scapula, humerus and fragmentary radius and ulna as well as parts of the cranium and rostrum) belonging to a probable humpback whale (Megaptera cf. novaeangliae) were found in the well-described sabkha sequence exposed in the Musaffah Industrial Channel, Abu Dhabi, United Arab Emirates. More precisely, the whale remains were found in a series of sediments representing a range of lagoonal facies. The sediments surrounding the whale bones were age-dated at approximately 5200 14 C yrs BP and are therefore interpreted to correspond to the previously documented late Flandrian sea-level peak, preceding a fall in sea-level which culminated in the supratidal sabkha overprint of the carbonates. Associated with the whale remains is an assemblage of molluscs, foraminifera and ostracods. Together with the inferred presence of sea grass and algae, these facies are interpreted to indicate a very shallow subtidal to intertidal lagoonal environment. Cirripede remains found associated with the skeleton were identified as those of the whale barnacle Coronula diadema and hence had their origins with the whale. Significantly, the low species diversity of microfossils suggests that higher salinities existed in the mid-Holocene lagoon than are present in modern counterparts. This is here inferred to be related to the onset of continental aridity in Arabia during the mid-Holocene.

Late Quaternary sea-level changes of the Persian Gulf

“…The reported δ 13 C values are appropriate for the nature of the materials being considered in the study (Walker, 2005). The calibrated ages are internally consistent with the oldest age (6887-6567 cal yr BP) being recorded from the hardground, an age of 5304-4957 cal yr BP being recorded for a barnacle identified as Coronula diadema that is believed to have been attached to the whale's skin in life (Stewart et al, 2011) and so dates the whale at death and the youngest ages (5285-4574 cal yr BP) being recorded from the sediments surrounding the skeleton. These ages are consistent with previously published radiocarbon ages for the upper part of the Mussafah Channel sedimentary sequence (Strohmenger et al, 2010;Stewart et al, 2011).…”

Humpback whales of the Persian Gulf

“…More precisely, the whale remains were found in a series of sediments representing a range of lagoonal facies. The sediments surrounding the whale bones were age-dated (14C) at approximately 5200 yrs BP (Holocene) and are therefore interpreted to correspond to the previously documented late Flandrian sea-level peak, preceding a fall in sea-level which culminated in the supratidal sabkha overprint of the carbonates (Stewart et al, 2011). Megaptera novaeangliae has existed since at least the latest Middle Pleistocene (Nagasawa and Mitani, 2004), in the western North Pacific (Japan), and the Arabian Sea humpback whale population is thought to have been isolated from others since 70,000 yrs (Pomilla et al, 2014).…”

“…Musaffah Industrial Channel, Abu Dhabi, UAE Stewart et al (2011) found whale remains (a left and right mandible, scapula, humerus and fragmentary radius and ulna as well as parts of the cranium and rostrum) belonging to a 'probable humpback whale (Megaptera cf. novaeangliae)' in the well-described sabkha sequence exposed in the Musaffah Industrial Channel, Abu Dhabi, UAE.…”

“…Megaptera novaeangliae has existed since at least the latest Middle Pleistocene (Nagasawa and Mitani, 2004), in the western North Pacific (Japan), and the Arabian Sea humpback whale population is thought to have been isolated from others since 70,000 yrs (Pomilla et al, 2014). The fan-shaped scapula without coracoid and acromion processes (see figure 6, in Stewart et al 2011), the absent or reduced olecranon of the ulna, and the relatively more laterally directed zygomatic processes of the squamosal compared to Balaenoptera (Tomilin, 1967;Winn and Reichley, 1985;Deméré et al, 2005) demonstrate that there is no doubt about its taxonomic identity as humpback whale.…”

The benthic sea-silk-thread displacement of a sessile bivalve, Pinctada imbricata radiata (Leach, 1819) in the Arabian-Persian Gulf

“…The study species Pinctada imbricata radiata is a recognized bioengineering ecosystem-builder responsible for the formation of numerous seascapes within the semi-enclosed region of the western Arabian-Persian Gulf [4,5]. A marine region with naturally occurring extreme environmental conditions [1–3] which can be dated from the mid-Holocene [25]. The pearl oyster endures a considerable suit of natural and anthropogenic stressors within the Gulf region [3–6,26,27].…”