Rintaro Ono

Pelagic Fishing at 42,000 Years Before the Present and the Maritime Skills of Modern Humans

Abundant fish remains from a shelter in East Timor imply that humans were fishing the deep sea by 43,000 years ago. By 50,000 years ago, it is clear that modern humans were capable of long-distance sea travel as they colonized Australia. However, evidence for advanced maritime skills, and for fishing in particular, is rare before the terminal Pleistocene/early Holocene. Here we report remains of a variety of pelagic and other fish species dating to 42,000 years before the present from Jerimalai shelter in East Timor, as well as the earliest definite evidence for fishhook manufacture in the world. Capturing pelagic fish such as tuna requires high levels of planning and complex maritime technology. The evidence implies that the inhabitants were fishing in the deep sea.

Island of Pelagic Fishermen: Temporal Changes in Prehistoric Fishing on Fais, Micronesia

ABSTRACT This article presents an analysis of fish bones and prehistoric fishing on Fais in the western Caroline Islands, Micronesia. In total 18 marine fish families (26 taxa) were identified including two families of sharks (Carcharhinidae and Lamnidae). Our analysis with use of vertebrae for identification reveals that the total MNI (Minimum Number of Individuals) of inshore and offshore (outer-reef to pelagic zone) fish species is almost constant in Fais from initial settlement to early prehistoric times (AD 400 to 800) due to a drastic increase in the tuna catch. However, the number of tuna dramatically decreased after AD 1200. Although the exact reason(s) for such increase and decrease in tuna capture is uncertain, the increase could be related to changes in fishing technology, population increase, and possible climatic changes, while the drastic decrease seems directly related to accessibility of marine resources due to climatic change, particularly between AD 1200 and 1500. Based on these results, we further discuss the character of Fais fishing by comparing it with fishing on islands in other parts of Oceania.

Discovery of Iron Grapnel Anchors in Early Modern Ryukyu and Management of Underwater Cultural Heritage in Okinawa, Japan

The Yarabuoki underwater site contains seven iron grapnel anchors and Early Modern Okinawan ceramic jars and is dated to the 16th–19th centuries. The site lies at a depth of 12–32 m off the western coast of Ishigaki Island in Okinawa, Japan. Based on underwater archaeological and broadband multibeam surveys, as well as historical research of the artefacts and Early Modern Ryukyuan shipping, we discuss the possible anchor and vessel types in Ryukyu and Eastern Asia in Early Modern times. We also discuss the efficacy of low-cost ROV for assisting surveys in shallow-water environments and the value of educational programmes for promoting the management and conservation of underwater cultural heritage.

Observation support system of an ROV for underwater archaeology

In this paper, we propose an observation support system of a Remotely Operated Vehicle (ROV) for underwater archaeology. In general, it is difficult for unskilled users to drive an ROV for underwater observation because a camera mounted on an ROV always moves due to external disturbances and objects easily move out of the field of view (FOV) of the camera. Once an object is out of the FOV, users cannot easily find out it again. The observation support system is used to help unskilled users to drive an ROV. To realize the proposed system, object detection based on image processing is a key component. We apply the SURF (Speeded Up Robust Features) algorithm to detect archaeological objects, and investigate the performance of the algorithm using video images recorded by our ROV in an underwater archaeological site.

Development of Regional Maritime Networks during the Early Metal Age in Northern Maluku Islands: A View from Excavated Glass Ornaments and Pottery Variation

ABSTRACT In this paper we discuss the results of excavation at the Aru Manara site in the Northern Maluku islands along with a description of the recovered pottery assemblage and results of compositional analysis of glass ornaments. By comparing our data to those from other sites in the area, we suggest the possible development of regional maritime networks in and around the Northern Maluku Islands during the Early Metal Age. The lowest level of the site contained a large number of secondary human burials, burial pots, and jars with distinctive anthropomorphic and zoomorphic motifs (including human faces and lizards), and possible baked clay ornaments. These all date to between ca. 2100 and 1900 years BP, corresponding to the Early Metal Age in Island Southeast Asia. The site also produced numerous glass beads and bracelets. X-ray fluorescence analysis confirms a high proportion of potash glass that possibly originated from China, Mainland Southeast Asia or India and is common in sites in Thailand and Vietnam dating to between 2500 and 2100 years BP. There was a minor occurrence of high alumina-soda glass beads known as Indo-Pacific beads that originated from India to Southeast Asia and which are commonly found in sites dated between 2300 and 1500 years BP or later. The glass ornaments from different areas, combined with variable pottery, indicates the possible development of maritime and cross-regional networks to the Northern Maluku Islands.

Early Metal Age interactions in Island Southeast Asia and Oceania: jar burials from Aru Manara, northern Moluccas

New evidence from the rockshelter site of Aru Manara, on the island of Morotai, in the northern Moluccas, East Indonesia, suggests an earlier than previously assumed date for extensive interactions between this area of Southeast Asia and the wider Pacific. Shared mortuary customs and associated ceramic grave goods, along with other practices such as megalithic traditions, appear to start in the Late Neolithic, but become more widespread and consolidated in the Early Metal Age. Excavations at Aru Manara show that the northern Moluccas may have figured prominently in the newly established network of interaction evidenced at this time, making it an important location in the spread and dispersal of people and culture throughout Island Southeast Asia and into Oceania.

A basic experiment for image-based position measurement of objects at sea

This paper presents an image-based position measurement of underwater objects using a low-cost maritime mobile robot with a monocular camera. Visual recognition of distant underwater objects is possible in the water with high transparency, for example, in the coastal sea area of Okinawa prefecture, Japan. In this paper, we apply the proposed method to estimate the position of an old anchor that is at a deep of 30 [m] and is estimated to be hundreds-of-years-old in an archaeological site in Ishigaki Island. We explain the measurement principle of the proposed method and the developed system. Moreover, we describe the experiment conducted off the coast of Ishigaki Island and show the experimental results of the proposed method.