Showing posts with label Indian Ocean. Show all posts
Showing posts with label Indian Ocean. Show all posts

Sunday, 7 December 2025

Number of dead in Sri Lanka following Cyclone Ditwah has now reached 619.

The number of people known to have died after Cyclone Ditwah made landfall in Sri Lanka on 28 November 2025 has reached 219, making the storm the worst natural disaster to befall the nation since the Boxing Day Tsunami of 2004. A further 209 people are still recorded as missing since the storm, with 18 people listed as having been injured. About 2 million people (almost 10% of the population) are thought to have been affected in some way by the storm, with 4071 homes destroyed and 71 121 damaged by flooding and landslides, as has much of the island's infrastructure and agricultural land. Authorities in Sri Lanka are warning that there is still a high risk of landslides, as monsoon rains fall onto already soaked hillside soils. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

Flooding in the Gampaha District of Colombo, Sri Lanka, following the passage of Cyclone Ditwah. Incept Change/UNICEF. 

Cyclone Ditwah was first detected as a tropical depression off the south coast of Sri Lanka by the Indian Meteorological Department on 26 November 2025. This depression increased in strength, becoming first a deep depression and then a cyclonic storm of 27 November. It crossed over Sri Lanka on the night of 28-29 November, bringing catastrophic levels of rainfall, then moved out over the Bay of Bengal. The storm continued to move northwatds along the Coromandel Coast, in the process bringing more flooding to the states of Tamil Nadu and Puducherry, which led to three Human and 149 Cattle deaths, as well as flooding much farmland, and damaging or destroying 234 homes. The storm weakened as it moved northward, eventually making landfall in Tamil Nadu as a low pressure system on 3 December.

Flood damage beside the Mahaweli River in Kandy, Sri Lanka, following the passage of Cyclone Ditwah. Reuters.

Tropical storms are caused by the warming effect of the Sun over tropical seas. As the air warms it expands, causing a drop in air pressure, and rises, causing air from outside the area to rush in to replace it. If this happens over a sufficiently wide area, then the inrushing winds will be affected by centrifugal forces caused by the Earth's rotation (the Coriolis effect). This means that winds will be deflected clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere, eventually creating a large, rotating Tropical Storm. They have different names in different parts of the world, with those in the Indian Ocean being referred to as cylcones.

The structure of a tropical cyclone. Wikimedia Commons.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

The formation and impact of a storm surge. eSchoolToday.

Cyclone Ditwah is not considered to be a large storm, but has caused extensive damage due to the large volumes of water it dropped onto Sri Lanka. It has been estimated that the cost of repairing the infrastructure damage caused by the storm will be about US$7 billion, coupled with a loss of income from the destruction of the agricultural and tourism sectors. Sri Lanka had a gross domestic product of about US$99 billion in 2024, but suffers from high levels of government debt. In 2023 the country was obliged to borrow US$3 billion from the International Monetary Fund to help with debt servicing, after a period of economic contraction in 2022 which led inflation to reach 57%. 

Sri Lanka is considered to have met the first United Nations' Millennium Development Goal, halving extreme poverty between 1990 and 2015, but 12% of the country is still considered to be living below the extreme poverty line, and 53% below the poverty line. While the country has made progress on growing its economy and lifting its people out of poverty, climatic events such as Cyclone Ditwah can set progress back significantly, and are predicted to become more common as the climate warms. Countries in the Global South are predicted to be particularly badly impacted by effects of global warming, despite having done little to cause the crisis; Sri Lanka is considered to have produced about 0.03% of global greenhouse gas emissions since the onset of the Industrial Revolution.

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Saturday, 18 October 2025

Chelonia mydas: The Green Sea Turtle no longer considered to be Endangered as population recovers.

Green Sea Turtles, Chelonia mydas, is a widespread marine Turtle, found across tropical and sub-tropical regions of the Pacific, Indian, and Atlantic Oceans, as well associated seas. Due to this widespread distribution, it is probably also the most numerous Turtle species. However, it has historically been hunted by Humans across its range, with both adults and eggs being considered desirable foods and the skin used to make leather for luxury goods. High levels of hunting, combined with a slow reproductive cycle (the average generation time for Green Sea Turtles is 45 years) led to the species being listed as Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species in 1982, and subsequently all trade in Green Turtles or Green Turtle-derived products been banned under the Convention on International Trade in Endangered Species.

A Green Sea Turtle, Chelonia mydas. Xanthe Rivett/International Union for the Conservation of Nature.

The conservation status of Green Sea Turtles has subsequently been reviewed in 1986, 1988, 1990, 1994, 1996, 2004, and 2023. During this time many countries across its range have enacted laws to protect both the species and its breeding grounds, and raised public awareness across the globe of the threat to a fairly charismatic species has made the consumption of Turtles and their eggs much less acceptable in many places (although the practice has never completely ceased). 

On 10 October 2025 the conservation status of the Green Sea Turtle was updated from Endangered to Least Concern. This is based upon the observation of 526 000 clutches of eggs hatching successfully in 2024, a 28% increase on the estimated breeding success rate for the mid twentieth century; because adult Green Sea Turtles are solitary animals widely distributed across the worlds oceans, it has never been possible to assess their adult population directly.

This does not mean that all threats to Green Sea Turtles have been eliminated. The species is still consumed in places, it is widely caught as a by-catch of fishing fleets, and it breeds on sandy tropical beaches highly desirable to developers. It is also considered to be vulnerable to the effects of global warming, as well as plastic waste in the oceans. Several populations of Green Sea Turtles are still considered to be locally threatened. Nevertheless, there is not now thought to be any immediate danger of the species becoming extinct.

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Saturday, 15 March 2025

Studying Beaked Whales entangled in Tuna nets in the northwest Indian Ocean.

Beaked Whales, Ziphiidae, spend the majority of their time in deep oceanic waters, spending most of their lives beyond the continental shelves, and little at the surface. This makes them one of the least well-understood groups of Cetaceans, or Mammals of any kind. Some species have few, if any, sitings ar sea, being known almost exclusively from bodies washed ashore in varying states of decomposition. Because of this, the taxonomy of Beaked Whales is less well-established than is the case for most Mammal groups, with new species and nomenclature revisions being published every few years. 

Studying Whales caught as bycatch offers a cost-effective way to study poorly understood Cetacean populations, providing insights into populations which can help shape conservation policies. Such data collection is often accomplished by training fishermen themselves as citizen scientists. Drift gillnets are widely used many parts of the world to target Tuna, but are also noted for the large amount of large-Vertebrate bycatch they produce. In the northwest Indian Ocean drift gillnets are widely used by the fishing fleets of Iran and Pakistan, presenting a threat to Whales in this area, but also presenting an opportunity for scientists to gather data on these Animals.

In a paper published in the journal Zoology in the Middle East on 13 February 2025, Muhammad Shoaib Kiani of the Institute of Marine Science at the University of Karachi, Mohsen Rezaie-Atagholipour of the Qeshm Environmental Conservation Institute, Rab Nawaz and Muhammad Moazzam of the World Wide Fund for Nature - Pakistan, Bushra Shafiq also of the  Institute of Marine Science at the University of Karachi, Haleh Ali Abed of the Midaf Nature Conservation Society, and Koen Van Waerebeek, also of the Qeshm Environmental Conservation Institute and of the Centro Peruano de Estudios Cetológicos, present the results of a long-term study of Beaked Whale entanglements in Tuna gillnets in Iranian and Pakistani waters.

A citizen science program was established in Pakistan in 2012, in which fishermen on pelagic gillnet Tuna vessels were trained to collect data on Cetacean bycatch. In Iran reviews of mass media at local and national levels, looking for Cetacean-related stories, have been carried out since 2018, and a series of interviews of fishermen was carried out in 2022.

Kiani et al. discovered eight incidents in which entangled Cetaceans could be identified as Beaked Whales in the waters of the Gulf of Oman and Arabian Sea, two in Iranian territory, five in Pakistani territory, and one in international waters.

The first recorded incident happened on 10 February 2015, when fishermen on board the Pakistani vessel Al-Azaan discovered a live Beaked Whale caught in a gillnet they had deployed 95 km to the west of the Swatch (the undersea canyon formed where the Indus River enters the ocean) and 177 km off the coast of Sindh, an area where the seafloor is about 1.5 km deep. 

Based upon video evidence, this Whale was estimated to be 5-6 m long, and slender with a slightly protrudent melon (mass of adipose tissue on the forehead), and a long snout without protruding teeth. This Animal lacked the scars associated with tooth-raking typically seen in male Beaked Whales, and is therefore assumed to have been a female.

The Whale had a brownish-grey dorsal surface, slightly paler on the head, and had a large, Dolphin-like fin about two thirds of the way along its body. This is, along with its location in the tropical Indian Ocean, is considered to be consistent with a Longman’s Beaked Whale, Indopacetus pacificus. This species was first described in 1928 from the skull of a Whale found in Queensland Australia in 1882, with a second skull being found on the shore of Somalia, East Africa, in 1955. For a long time, these two specimens were all that was known of this species, however, recent studies have established that Whales washed up on the shores of the Philippines, Maui (Hawaii), Taiwan, Myanmar, the Andaman Islands, South Africa, and Japan, previously identified as Southern Bottlenose Whales, Hyperoodon planifrons, were in fact Longman’s Beaked Whales, and based upon this data, 65 sightings of live Whales in the  Indian and Pacific oceans have been assigned to the species.

The Whale encountered by the Al-Azaan became entangled in a net as it was being retrieved, allowing the crew to release it without apparent harm by cutting away part of the net. This process took about 30 minutes, and while the Whale is thought to have been unharmed, one of the fishermen received minor injuries.

(a)-(h). Successive steps in gillnet disentanglement operation of a Longman’s Beaked Whale, Indopacetus pacificus, in Pakistani waters. Note the head with moderately bulbous melon (e), (h), long rostrum (f), (g), (h) tubular in dorsal view (h), limited linear scarring (e) and large falcate dorsal fin (f, g). Selected frames were taken from a video. Kiani et al. (2025).

The second recorded incident happened on 31 March 2017, when an un-named Pakistani vessel encountered a 4 m long Whale 383 km off the coast of Pakistan, again in the Swatch area, an area where the sea slightly more than 3 km deep. 

This Whale had a distinct, but non-bulbous melon, a long slender snout, and a low, sub-triangular dorsal fin. The skin of the Whale was a uniform grey, slightly darker towards the tail, and it had no visible scarring of any type. It was not possible to identify this Whale to species level, but it was probably a member of the genus Mesoplodon, possibly Deraniyagala’s Beaked Whale, Mesoplodon hotaula, or Ginkgo-toothed Beaked Whale, Mesoplodon ginkgodens, although this species has never been recorded in the Indian Ocean, or even Ramari’s Beaked Whale, Mesoplodon eueu, although this species tends  to lighten towards the tail, and is a cold-water species, never previously recorded in the western Indian Ocean north of Mozambique. 

The third incident was recorded in August 2017, when a fisherman from Bandar-e-Konarak on the coast of Sistan and Baluchestan Province, Iran, sent a video to the Iranian National News Agency, IRIB News, showing a Whale entangled in a gill net. This incident is thought to have happened in the waters of Iran’s Exclusive Economic Zone, and probably close to Bandar-e-Konarak. 

The Whale could be seen to blow, suggesting that it was alive and breathing. It appears to be a Beaked Whale with no visible teeth. The bulbosity of the melon cannot be determined from the video. The fluke (tail) of the Whale can be seen, and from comparison to the arm of a fisherman, is estimated to be between about 140 cm wide, which would equate to a Whale 4.7-4.9 m in length. The fluke also lacks a median notch, confirming that the Animal is a Ziphiid.

An unidentified middle-sized Beaked Whale, with a melon of unclear bulbosity, net-entangled within Iran’s Exclusive Economic Zone waters off Sistan and Baluchistan Province, northern Gulf of Oman, in August 2017. (a), (b) Flukes without central notch and tailstock; (c) the only registered blow and vague view of the head. Both Mesoplodon sp. and Indopacetus pacificus would be possible. Kiani et al. (2025).

The fourth incident occurred on 18 January 2018, when a small-to-medium sized Beaked Whale was recorded trapped in gillnet 474 km from the coast of Pakistan, an area where the sea is slightly under 3.2 km deep. This Whale was 3.5-4.5 m long, with a medium length snout and a non-bulbous melon and no central notch on its fluke; its colour and/or markings could not be determined due to poor light. This is consistent with it being a member of the genus Mesoplodon. The Pakistani fishermen who encountered this Whale were able to disentangle it from their nets, and report if swam away in good condition. 

The fifth incident occurred on 19 March 2019, when two Beaked Whales, interpreted as a mother and calf, became entangled in the same gillnet off Churna Island, 96 km from the coast of the Pakistani Mainland. The waters here are shallow, at 295 m.

The calf was described as the size of an adult Common Bottlenose Dolphin, making it 3.0-3.5 m in length, while it was not possible to estimate the size of the larger Whale. The smaller Whale had a dark grey upper surface,  and a whitish underside. It had a short snout, and no sign of a bulbous melon, its dorsal fin hooked, no notch could be seen in the tail. These Whale are also interpreted as belonging to the genus Mesoplodon. The fishermen reported successfully disentangling both Whales.

The sixth recorded incident happened in February 2022, when Iranian fishermen reported encountering a Whale caught in a drift gillnet 1300 km off the coast of Bandar-e-Beris in eastern Sistan and Baluchestan Province. Video footage of the incident shows a medium-sized Beaked Whale with a medium-length Dolphin-like beak, and a non-steeply sloping melon, consistent with a member of the genus Mesoplodon. The video also shows that the Whale has two apical or slightly sub-apical mandibular teeth, indicating that it was male, as well as a dark eye-patch, an almost straight mouth, and a small, slightly hooked tail. The length of the Whale is uncertain, but it appears to be about 4.5-5.5 m.

An unidentified Mesoplodon sp. bycaught in far offshore waters of the northern Arabian Sea, 1300 km from Bandar-e-Beris at the eastern side of Iran’s Sistan and Baluchestan Province, in February 2022. (a), (c) Two erupted (sub)apical mandibular teeth indicate an adult male. (b) Dolphin-like, medium-length rostrum, gently sloping melon and smallish dorsal fin. Kiani et al. (2025).

The final incident happened in early June 2023, when a large Beaked Whale became entangled in a drift gillnet in the coastal Iranian Gulf of Oman, about 37 km from the port of Chabahar in eastern Sistan and Baluchestan Province. This Animal was clearly an adult male, with numerous took-rake scars and erupted apical teeth. It was estimated to have been 5.8-6.0 m in length, with an erect, Dolphin-like dorsal fin, and way brownish grey in colour with a lighter head. This is interpreted as being consistent with either a Longman’s Beaked Whale, Indopacetus pacificus, or a Cuvier’s Beaked Whale, Ziphius cavirostris. 

An adult male Beaked Whale being liberated after accidental entanglement in Tuna gillnet in coastal waters of the Gulf of Oman, some 37 km from Chabahar, Iran, in early June  2023. (a) Large body size with two erupted teeth at the apex of the mandibula; (b) a tall, erect, falcate, Dolphin-like dorsal fin, a moderately long and well-defined rostrum; (c) with numerous tooth rakes on anterior body; and (d) some degree of bulbosity in the melon. The morphology of the Beaked Whale is congruent with Indopacetus pacificus, but Ziphius cavirostris cannot be excluded. Kiani et al. (2025).

The first of these incidents is regarded as the first record of Longman’s Beaked Whale, Indopacetus pacificus, in Pakistani waters, with incidents five and seven representing potential additional sightings. A beached individual assigned to the species was recorded in Gujarat State, India, in 2014, making the Pakistan entanglement the second record of the species in the northwest Indian Ocean. Previously a skull has been recorded from the coast of Somalia in 1955, a member of the species was sighted from Socotra Island, Yemen in 1971, and another in the waters of the southern Bay of Bengal in 2009. Five Longman’s Beaked Whales have been recorded as bycatch from Sri Lanka, although these have been disputed, and fourteen sightings and a stranding recorded from the Maldives. 

Incidents two, four, six, and possibly five represent the first records of Mesoplodon sp. in Iranian and Pakistani waters, although none of these specimens could be confidently identified to species level. 

Drift gillnets are considered to be one of the most significant anthropogenic threats to Whales, although evidence to support this is absent in many areas. Kiani et al.'s study shows entanglement is a clear threat to Beaked Whales in the northwestern Indian Ocean, as while all of the reported Whales were freed, it is likely that a greater number of Whales were not released safely, and therefore not reported.

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Saturday, 18 January 2025

Plectranthias raki: A new species of Perchlet from the Maldives.

The term 'Perchlet' applies to a wide variety of small Perciform Fish. The genus Plectranthias is a member of the Serranidae, the family which also includes Sea Bass and Groupers, amongst other groups. It currently contains 66 described species from mesophotic reef environments in the Atlantic, Pacific, and Indian Oceans. Plectranthias are small Fish, typically 5-10 cm long with the largest species reaching about 20 cm, which live in holes or crevices, from where they ambush small, mobile invertebrates. The small size and cryptic nature of Plectranthias means that they are not well studied, with most species described from a very small number of specimens.

In a paper published in the journal ZooKeys on 16 January 2024, Bart Shepherd of the Steinhart Aquarium at the California Academy of Sciences, Hudson Pinheiro of the Department of Ichthyology at the California Academy of Sciences, and the Center for Marine Biology at the University of São Paulo, Ahmed Najeeb, also of the Department of Ichthyology at the California Academy of Sciences, and of the Maldives Marine Research Institute, Claudia Rocha, again of the Department of Ichthyology and of the Department of Microbiology at the California Academy of Sciences, and Luiz Rocha, once again of the Department of Ichthyology at the California Academy of Sciences, describe a new species of Plectranthias from the Kuramathi Outer Reef on Rasdhoo Atoll in the Maldives.

The new species is described from two specimens collected by hand-netting at a depth of 118 m, in December 2022, and confirmed as a new species by gene-sequencing. It is named Plectranthias raki, where 'raki' means 'feeling shy to confront people' in the Dhivehi language which is spoken in the Maldives.

Living specimen (not retained) of Plectranthias raki photographed at 110 m depth at Dhaalu Atoll, Maldives. Luiz Rocha in Shepherd et al.  (2025).

The two specimens of Plectranthias raki are 66.15 and 70.41 mm long, and pinkish white in colour with a series of irregular orange-red patches, these being more red towards the tail and more yellow towards the head. Both have dorsal fins with fifteen rays, anal fins with seven rays, pectoral fins with thirteen rays, and tail fins with nine upper rays and eight lower rays.

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Thursday, 5 December 2024

The beads of Mozambique Island.

Mozambique Island, on the northern coast of the African country of the same name, was the first place where Portuguese explorers, having rounded the Cape of Good Hope, encountered the trade networks of the Indian Ocean. At this time the island was ruled by a Muslim sheikh, with merchants using the island as a base from which to trade with the African interior or wider Indian Ocean needing his permission to do so, with all such merchants needing to be Muslims themselves. The island was quickly brought under Portuguese rule, with a Captain appointed to rule the island on behalf of the Portuguese Crown, and became a crucial stopover on the journey between Lisbon and Goa. While the Portuguese Captain in theory had control over all commerce occurring in the port, in practice many commodities were not regulated, and the island gained as a reputation as place where fortunes could be made with little interference from the Portuguese authorities.

During the Early Modern Era, beads were extensively used by European traders as a means of currency, being both a portable, high value item, and a desirable commodity which they could control the supply of. This certainly appears to have been the case on Mozambique Island, where large numbers of beads, many of them apparently derived from shipwrecks off the coast of the island, are today collected from the island's sandy beaches and made into necklaces, which are then sold to tourists.

In a paper published in the journal World Archaeology on 22 November 2024, Tânia Manuel Casimiro of História, Territórios e Comunidades at Nova University Lisbon, Yolanda Duarte of Archaeology at Eduardo Mondlane University, and Jéssica Iglésias, also of História, Territórios e Comunidades at Nova University Lisbon, present the results of an analysis of the origin of beads from Mozambique Island, and the implications of this for the history of the island.

Today, beads are collected by shovelling sand from the beaches into 25-50 kg bags and taking these to a flat, clean surface, where the sand can be sifted through for beads. No permit is needed for this activity, and no attention paid to the archaeological context of the beads by the collectors. However, some of the necklaces made by the bead-gatherers have been obtained by local people with an interest in the island's heritage, and it is from such collections that Casmiro et al. gained the beads used in their study.

Process for recovering the beads. Casmiro et al. (2024).

Casmiro et al. examined a sample of 12 166 beads, recording the material they were made from, as well as their style. Many of the glass beads were apparently Venetian, with Venice being a major manufacturing centre for beads used as colonial trade goods from the sixteenth century onwards, although Casmiro et al. note that many 'Venetian' beads were in fact made in other European cities in imitation of the Venetian style. However, such beads are clearly of European origin, easily distinguished from Indian beads (also very common around the Indian Ocean) which tend to be carved from a mineral such as carnelian or agate. Because of the way in which the beads were obtained, it was not possible to date them by context, although it was possible to build up a limited chronology for beads from the sixteenth to nineteenth century, with a few beads coming from outside this period.

Strings of beads sold to tourists on Mozambique Island. Casmiro et al. (2024).

The majority of the beads (10 626) were made of glass. Most of these were of a single colour, with examples of white, black, blue, green, yellow, orange, and red beads being found, along with some which combine a several colours. These glass beads also vary greatly in shape, with tubular, oblate, cylindrical, ellipsoidal, spherical, bicone, and barrel-shaped beads all present. After glass beads, the most common were stone beads,  followed by coral, shell, bone, ivory, and plastic.

A 'Venetian' glass chevron bead transformed into a pendant. Casmiro et al. (2024).

The most common glass beads (7789 examples) are seed beads, small spherical beads at most a few millimetres across, which have been manufactured in Europe since at least the fifteenth century. Another common type are Green Heart Beads (540 examples), cylindrical glass beads made up of layers of different glass, with the innermost being green, giving a shimmering, multi-hued effect, which were produced in Venice between the fifteenth and eighteenth centuries.

(Top) Glass Heart Beads. (Bottom) Seed beads. Casmiro et al. (2024).

Hudson's Bay Beads (235 examples), sometimes also known as White Heart Beads, or Cornaline d’Aleppo, were made in Venice between 1830 and the early 1900s. These again were cylindrical beads with multiple layers, this time having an inner layer of white or yellow glass.

Hudson's Bay Beads. Casmiro et al. (2024).

Chevron beads (11 examples) were elongate beads made by building up multiple layers of glass onto a central star-shaped moulded cane. These beads were invented in the late fifteenth century by craftswoman Marietta Barovier of Murano, and made at a number of glassworks in Murano and Venice, and probably elsewhere, although it is not generally possible to tell where an individual bead was made.

Chevron beads from Mozambique Island. Casmiro et al. (2024).

A-Speo beads (186 examples) were made by drawing out a thick glass straw, which was then chopped into short segments. These segments were then placed on a metal rod, and placed in a furnace to melt them into a rounded shape (the name 'a-speo' derives from the Italian phrase for 'to skewer'). This technique was probably invented in Venice or Murano, but was practiced in many areas of Europe. 

A-speo beads from Mozambique Island. Casmiro et al. (2024).

Skunk beads (14 examples), were made in Venice (and probably other European bead-making centres) in the eighteenth and nineteenth centuries, by adding small globules of glass to an a larger glass bead of a different colour, to give a speckled effect. These were most commonly black with added white speckles, hence the name 'skunk beads', but other colour patterns were also produced. 

Skunk beads from Mozambique Island. Casmiro et al. (2024).

Tubular beads (12 examples) were first made in Venice in the fifteenth century, but due to their ease of manufacture, continued to be made at centres across Europe for the next six centuries. Padre, or Pekin Glass, beads were made in Venetian and Czech workshops in the nineteenth century, in imitation of blue glass beads from China, themselves made as a cheaper substitute for jade beads.

(Top) Tubular beads and (bottom) Pekin Glass beads from Mozambique Island. Casmiro et al. (2024).

Millefiori beads are glass with complicated floral patterns, made since Roman times. They are manufactured by producing glass canes with a flower-shaped cross-section, which are then cut into thin slices, which are in turn incorporated within blown glass products, including beads. The name millefiori derives from the Italian for 'thousand flowers'.

Millefiori beads from Mozambique Island. Casmiro et al. (2024).

Eye beads (2 examples), which superficially resemble eyes, have been made around the Mediterranean Basin, the Middle East, and South Asia for thousands of years, often as a charm against the Evil Eye. The earliest forms were made of clay, but the manufacture of glass eye beads can be traced back to about 1500 BC.

'King' or 'Golo' beads (2 examples) were made in Europe in the nineteenth and twentieth centuries as a high value trade item for African markets. There were large, striped, biconed beads which came in a range of colours, though green beads with yellow, black, and red stripes were the most common.

Dog Teeth, or ruffled beads (two examples) were made in Venice in the late nineteenth and early twentieth centuries, mostly for trade with Nigeria. These are black beads with an irregular shape, and a 'ruffle' of white marks (or 'teeth') around their centre.

A single Nueva Cadiz bead was found on Mozambique Island. These were squared, tubular beads in a distinctive blue colour, made originally in Venice for trade with the Americas, but which were subsequently made in a number of other European cities. These beads are very common at sites on the Atlantic coast of Africa, but surprisingly rare at sites on the Indian Ocean.

The single Nueva Cadiz bead found on Mozambique Island. Casmiro et al. (2024).

Bohemian beads (1147 examples) were made in the modern Czech Republic, where they developed a range of distinct techniques of their own, notably pressed glass. These beads often have vertical and horizontal lines, circular incisions, coloured bands, phytomorphic and zoomorphic decorations.

Bohemian beads from Mozambique Island. Casmiro et al. (2024).

Russian blue beads (183 examples) were a distinctive type of Bohemian bead produced in the eighteenth centuries. These beads were multifaceted with six, seven, or eight sides, and typically a transparent blue, although amber, green, and clear examples are also known.

Russian blue beads from Mozambique Island. Casmiro et al. (2024).

Vaseline beads (1 example), sometimes also called uranium beads because of the uranium used to tint the glass green, were large faceted of shaped beads made in Bohemia in the late  nineteenth and early twentieth centuries.

Haj beads (5 examples) were made in Bohemian the early twentieth century for export to the city of Mecca, where they were sold to pilgrims, often becoming heirloom objects within their families. Two of the examples found on Mozambique Island had moon-and-star symbols, while the remaining three had the name of the Prophet Mohammed written upon them.

Dutch opalescent beads (9 examples), sometimes known as moon beads, were glass beads made to resemble pearls by adding ash to the glass, made in the Netherlands, Bohemia, Germany, and Venice, in the eighteenth and nineteenth century.

Dogon beads (187 examples) are large, chunky beads with a rough texture, which were produced in Amsterdam and possibly Germany in the seventeenth and eighteenth centuries, principally for trade with the Dogon people of southern Mali, but were also traded to other areas of Africa.

Dogon beads from Mozambique Island. Casmiro et al. (2024).

Prosser beads (9 examples), sometimes known as Kakamba Prosser Beads after a town in what is now the Republic of Congo where they were popular. These were made in the nineteenth century by a French craftsman called Jean-Félix Bapterosses, who modified a technique developed by the Prosser Brothers of London to cold-press glass and porcelain buttons, instead producing disk-shaped opalescent beads.

While the majority of the examined beads were glass, stone beads were also common, with 996 in the collection. The most abundant stone types are jet and carnelian, with agate and garnet beads also quite common. Stone beads have been manufactured around the world, which can make it difficult to determine the origin of individual beads, although most stone beads found around the Indian Ocean originate from India or Southeast Asia. This potentially makes these beads the oldest on Mozambique Island, with some examples likely to have reached the island before the first Europeans.

Stone beads from Mozambique Island. Casmiro et al. (2024).

Three beads from Mozambique Island were identified as being of Chinese origin, although details of these are not given. China began to export large volumes of beads in the early twentieth century, something it does to this day, and has produced beads from porcelain, wood, cinnabar, cloisonné, enamelled metal, stones, and glass, among other materials.

Filigree is a form of intricate metalwork consisting of tiny beads and twisted threads soldered together, made in the Islamic world largely between the fifteenth and seventeenth centuries. Fifty five silver elements from Mozambique Island are probably derived from filigree jewellery, most likely originating from Mauritania.

Beads derived from Animal materials such as shell, bone, ivory, and coral were also quite common (469 examples), although it is difficult to assess where these came from, as these materials are available, and have been worked, across much of the globe.

Plastic beads (8 examples) are clearly of twentieth century origin, since the first plastic (Bakalite) was invented by the Belgian-American chemist Leo Hendrick Baekelandin 1909. Plastic beads are cheap and easy to manufacture, and are produced in many countries. The low number of these on Mozambique Island suggests that they may never have been a commercial import, but may have been brought to the island by people wearing them, or possibly even have floated there on ocean currents.

Finally, five items were found in the collection that probably did not start out as beads, but which had been repurposed as such. These were a black glass button or pendant, two jet buttons, a rectangular piece of jet with three diagonal incisions of unknown origin, and what appeared to be the bottom half of a Frozen Charlotte doll (a type of rigid doll, typically made out of china, made between about 1850 and about 1920, mostly in Germany for the US market).

Casmiro et al.'s study revealed the presence of a wide range of beads, made from a variety of substances, on Mozambique Island. Despite this variety, about 90% of the beads were glass, and of European origin. Glass trade beads have been considered to be powerful symbols of European colonial influence, which seems to be particularly relevant on Mozambique Island, a vital trade hub within the Portuguese Empire. The beads of the same designs as those found on Mozambique Island have been found at other sites around the world, although overwhelmingly in colonial contexts.

Glass beads were, of course, made before the fifteenth century, and it can sometimes be hard to differentiate these from later beads, but none of the glass beads found on Mozambique Island appear likely to be this old. The stone, and animal-derived, beads found on the island may date to before the arrival of Europeans in the area, although such beads continue to be made until the present day, making it hard to be certain of their age. Mozambique Island is known to have been a trading hub before the arrival of the Portuguese, but it appears to have become much more important once integrated into the global Portuguese network.

Curiously, the high abundance of European beads on Mozambique Island is in contrast to the situation in South Africa, where European beads are unusual at archaeological sites, but beads from India quite common. It has been suggested that this South African preference for Indian beads may have been established before the arrival of European traders, and that with South African customers unwilling to switch, European traders may instead have imported beads from India to cater for this market.

Casmiro et al. also note that the beads once brought to Africa by Europeans to trade for commodities such as slaves, ivory, and gold, have now taken on a new role in places such as Mozambique Island, being traded back to European tourists as a means of gaining hard currency, a much needed twenty first century trade commodity.

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