Rafetus swinhoei: Last known female Swinhoe's Softshell Turtle has died, bringing the species to the brink of extinction.

The last known female Swinhoe's Softshell Turtle, Rafetus swinhoei, has died. The Turtle, which was 1.56 m long and weighed 93 kg was found dead at Hoan Kiem Lake in Hanoi, Vietnam, on Sunday 23 April 2023, by a volunteer with a local Turtle conservation program. A necropsy will be carried out to determine the cause of death (the term 'autopsy' is reserved for investigations of Human deaths). The Hoan Kiem Turtle was confirmed to be female during a capture-release survey in 2020, bringing hopes that it might be possible to start a breeding program for the species; the previous last known female died in a zoo in China in 2016, having never laid any eggs, despite mating with a male owned by the zoo several times.

The Hoan Kiem Lake Swinhoe's Softshell Turtle in 2016. Asian Turtle Program.

Swinhoe's Softshell Turtles were formerly known from two geographic regions, the Yangtze River Basin in China and the Red River Basin in Vietnam (fossil specimens suggest the species had a wider range in the Pleistocene and Early Holocene), but the population has been effectively wiped out in both areas, due to hunting, egg collecting, and habitat modification by Humans. The global population now comprises a single male population in Suzhou Zoo in Jiangsu Province, China, and a second male known only from environmental DNA in Xuan Khanh Lake near Hanoi.

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Archaeologists uncover megalithic tomb in Duqm Province, central Oman.

An archaeological expedition organised by the Institute of Archaeology of the Czech Academy of Sciences has uncovered a large megalithic tomb at Nafūn in Duqm Province, central Oman, according to a press release issued on 14 April 2023. The tomb is quite unlike anything discovered previously in Southern Arabia, and is thought to date from between 5000 and 4600 BC. It was uncovered by a team comprising archaeologists from the Czech Republic, Oman, the United States, Great Britain, Ukraine, Iran, Italy, Slovakia, Austria, and France.

A Neolithic tomb uncovered at Nafūn in Duqm Province, central Oman. Roman Garba & Alžběta Danielisová/Institute of Archaeology of the Czech Academy of Sciences in Prague.

Archaeologists from the Czech Academy of Sciences have been carrying out work in Oman for many years, principally studying the ancient migration routes taken by ancient Humans between 1.3 million and 300 000 years ago, from Africa along the southeastern coast of Arabia and into Eurasia. However the tomb is of Neolithic origin (much later), and tells part of a completely different story.

The tomb comprises a circular megalithic structure, covering a pair of circular burial chambers, containing Human remains thought to have come from several dozen individuals. Near to this site are a collection of 48 rocks covered in engravings, in a range of styles thought to date from between 5000 and 1000 BC. A wide range of Late Stone Age tools have also been found in the area.

An archaeologist examining rock art at Nafūn in Duqm Province, central Oman. A film has been placed over the engravings to enable the scientist to trace them. Roman Garba & Alžběta Danielisová/Institute of Archaeology of the Czech Academy of Sciences in Prague.

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Outbreak of Diphtheria in Nigeria claims 73 lives.

Since the beginning of 2023, 557 confirmed cases of Diphtheria have been detected in Nigeria, affecting 21 of the 36 states and the Federal Capital Territory. In December 2022, the Nigeria Centre for Disease Control and Prevention was notified of suspected Diphtheria outbreaks in Kano and Lagos States. From 14 May 2022 to 9 April 2023, 1439 suspected cases have been reported, of which 557 (39%) have been confirmed, including 73 deaths among the confirmed cases (a case fatality ratio of 13%), according to a press release issued by the World Health Organization on 27 April 2023. Nigeria has previously reported Diphtheria outbreaks, with the most significant reported in 2011 affecting the rural areas of Borno State, in the northeast of the country. Diphtheria is a highly contagious vaccine-preventable disease which spreads between people mainly by direct contact or through the air via respiratory droplets. The disease can affect all age groups, however unimmunized children are particular at risk. It is potentially fatal. The disease can be treated by administering Diphtheria antitoxin as well as antibiotics. Vaccination against Diphtheria has reduced the mortality and morbidity of Diphtheria dramatically.

The Nigeria Centre for Disease Control and Prevention was notified of suspected Diphtheria outbreaks in Kano and Lagos States on 1 December 2022. In January 2023, the number of confirmed cases increased, peaking at over 150 cases in epidemiological week 4 of 2023 (ending 28 January - an epidemiological week is a standardized method of counting weeks to allow for the comparison of data year after year); since then, a weekly decreasing trend has been observed. From 14 May 2022 to 9 April 2023, 1439, suspected Diphtheria cases were reported from 21 states in Nigeria, with the majority (83%) of cases reported from Kano (1188), Yobe (97), Katsina (61), Lagos (25), Sokoto (14) and Zamfara (13). Of the 1439 suspected cases, 557 (39%) were confirmed (51 laboratory-confirmed, 504 clinically compatible and two epidemiologically linked), 483 (34%) were discarded, and 399 (28%) are pending classification. Laboratory-confirmed cases were reported from Kano (45), Lagos (3), Kaduna (1), Katsina (1), and Osun (1) states. Among the 557 confirmed cases, 73 deaths were recorded, for a case fatality ratio of 13%. The case fatality ratio has dropped significantly since the beginning of the outbreak due to, among other factors, increased access to Diphtheria antitoxin.

Distribution of Diphtheria cases by state in Nigeria from epidemiological week 19, 2022 to epidemiological week 14, 2023. World Health Organization.

Nigeria had recorded diphtheria outbreaks in the past, but not on this scale. The most significant outbreak reported was between February and November 2011 in the rural areas of Borno State, north-eastern Nigeria, where 98 cases were reported. 

Diphtheria is a highly contagious vaccine-preventable disease caused by exotoxin-producing Mycobacterium Corynebacterium diphtheriae It spreads between people mainly by direct contact or through the air via respiratory droplets. The disease can affect all age groups, however unimmunized children are particular at risk. It is potentially fatal.  Symptoms often come on gradually, beginning with a sore throat and fever. In severe cases, the Bacteria produce a poison (toxin) that causes a thick grey or white patch at the back of throat. This can block the airways, making it hard to breathe or swallow, and also creates a barking cough. The neck may swell in part due to enlarged lymph nodes. Treatment involves administering Diphtheria antitoxin as well as antibiotics. Vaccination against Diphtheria has reduced the mortality and morbidity of diphtheria dramatically. Diphtheria is fatal in 5-10% of cases, with a higher mortality rate in young children. However, in settings with poor access to Diphtheria antitoxin, the case fatality ratio can be as high as 40%. 

Under the leadership of the Nigeria Centre for Disease Control and Prevention, coordination and monitoring of Diphtheria surveillance and response activities in the country are ongoing through the weekly Diphtheria National Technical Working Group meetings. Rapid Response Teams have been deployed to Katsina, Osun and Yobe States and re-deployed to Kano and Lagos States to support response activities. Harmonization of surveillance and laboratory data across states and laboratories is ongoing. Sensitization/training of clinical and surveillance officers has taken place in states where Rapid Response Teams have been deployed, on the presentation, prevention, and surveillance of Diphtheria. Cascaded training has been conducted in the effected states by some of the laboratory scientists/physicians trained at the Nigeria Centre for Disease Control and Prevention National Reference Laboratory in Abuja. Procurement for reagents and sample collection and transportation materials/media processes has been initiated. Drug sensitivity tests are ongoing at Nigeria Centre for Disease Control and Prevention National Reference Laboratory on isolates sent in from states. Distribution of Diphtheria antitoxin to the affected states has been ongoing since December 2022. Strengthening of routine immunization activities across the country continues. 

Diphtheria cases are under-reported in Nigeria, with few reports of outbreaks in the past. The last outbreak was reported between February and November 2011 in the village of Kimba and its surrounding settlements in Borno State, north-eastern Nigeria, where 98 cases were reported. The Diphtheria toxoid-containing vaccine third dose coverage in Nigeria is suboptimal. According to the 2021 Nigeria Multiple Indicator Cluster Survey and National Immunization Coverage Survey, the third dose of pentavalent vaccine coverage was 57% in 2021.

Distribution of Diphtheria cases by state in Nigeria from epidemiological week 19, 2022 to epidemiological week 14, 2023. World Health Organization.

The country is currently faced with several public health emergencies such as Lassa Fever, Cholera, Monkeypox, Meningitis and a humanitarian emergency in the northeast of the country. Due to insecurity, especially in north-eastern Nigeria, vaccination coverage remains suboptimal, especially in the areas controlled by non-state armed groups. Therefore, the outbreak of Diphtheria further complicates and strains the already overstretched resources. The global supply of Diphtheria antitoxin is limited, and this may affect the availability of the required doses in a timely manner.

The overall risk of Diphtheria in Nigeria was assessed as high at the national level, low at the regional level, and low at the global level.

The World Health Organization recommends that epidemiological surveillance ensuring early detection of Diphtheria outbreaks should be in place in all countries, and all countries should have access to laboratory facilities that allow for the reliable identification of toxigenic Corynebacterium diphtheriae. For the adequate medical management of cases, sufficient quantities of Diphtheria antitoxin should be available nationally or regionally.

The World Health Organization also recommends early reporting and management of suspected Diphtheria cases to initiate timely treatment of cases and follow-up of contacts and ensure the supply of diphtheria antitoxin. Case management should be carried out following the World Health Organization guideline and involve administering antitoxin to neutralize the toxin and antibiotics to kill the Bacteria, reducing complication and mortality.  

As vaccination is key to preventing cases and outbreaks, high-risk populations such as children under five years of age, schoolchildren, close contact of Diphtheria cases, and healthcare workers, should be vaccinated with Diphtheria-containing vaccines on a priority basis. A coordinated response and community engagement can support control of the ongoing outbreak.

Although travelers do not have a special risk of Diphtheria infection, it is recommended that national authorities remind travelers going to areas with Diphtheria outbreaks to be appropriately vaccinated in accordance with their national vaccination scheme. A booster dose is recommended if more than five years have passed since the last dose. The World Health Organization does not recommend any travel and/or trade restrictions to Nigeria based on the information available for this event.

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Sphyrna mokarran: Critically Endangered Great Hammerhead Shark found dead in Alabama.

A female Great Hammerhead Shark, Sphyrna mokarran, has been found dead on a beach in Alabama. The Shark, which was found to be pregnant with 40 pups, was found floating in shallow water off Orange Beach, and pulled ashore by a group of members of the public on 20 April 2023. They informed Orange Beach Coastal Resources, who in turn contacted the Marine Fisheries Ecology Group at Mississippi State University. The Shark was taken to the university for a necropsy (the term 'autopsy' is reserved for Humans), although the cause of death could not immediately be determined. The Shark had not eaten for some time, but it is normal for female Hammerheads to fast while pregnant, so this is unlikely to have been the cause of death. Several of the Shark's organs have been sent for chemical testing. It is possible that the Shark could have been caught and then released by fishermen, only to die later of the shock, something which the species is known to be prone to.

A female Great Hammerhead Shark found dead of Orange Beach, Alabama, on 20 April 2023. Orange Beach Coastal Resources.

The Shark was 4.3 m in length and was carrying 40 unborn pups, each about 40 cm in length. Given the current conservation status of the species, this represents a significant loss (although it is highly unlikely that all 40 babies would have survived till adulthood under any circumstances). The University of Mississippi intends to preserve the baby sharks for used in educational outreach programs.

Unborn Shark pups recovered from the uterus of a dead Great Hammerhead Shark which washed up in Alabama. Mississippi State University Fisheries Ecology Group.

Great Hammerhead Sharks are found throughout tropical and warm temperate areas of the Atlantic, Indian, and Pacific Oceans, although genetic studies have suggested that this global population is in fact made up of two genetically distinct species, one found only in the Atlantic and the other in the Indo-Pacific. Population data is available from the Northwest Atlantic, Gulf of Mexico, and Indian Ocean, and in all places the species has shown a dramatic population loss over the past three generations, for which reason it is classified as Critically Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. 

Distribution map for the Great Hammerhead Shark, Sphyrna mokarran. International Union for the Conservation of Nature.

The Northwest Atlantic population of Great Hammerhead Sharks is believed to have been overfished between 1983 and 1997, although there is uncertainty about how the population has fared since, with some studies suggesting that they have been spared overfishing since 2001, while others indicate that this has continued. Although the size of this population is uncertain, it is believed to have declined by at least 20% over the past three generations, a period estimated at 74.4 years for the Atlantic Ocean.

A Great Hammerhead Shark in life. Jeremy Stafford-Deitsch/International Union for the Conservation of Nature.

Another study, based upon data collected from long-line surveys off the coast of the US, has indicated that the population of Great Hammerhead Sharks has recovered somewhat in the Northwest Atlantic since 2005, and that this may even represent a slight increase in the population over a three generation time-span.

In the Indian Ocean, data collected by the Ocean Natal Shark’s Board's bather protection program between 1978 and 2003 suggests that the Great Hammerhead Shark population fell by an average of 6.5% per year over that time, which would equate to a 99.3% reduction over three generations (calculated as 71.1 years in the Indian Ocean).

Data on the Great Hammerhead Shark population, data gathered by the International Union for the Conservation of Nature from 20 separate fishing fleets operating in the area between 1998 and 2008 found a 61.7% decrease in the population over the ten year period, although this data was not considered reliable enough to extrapolate a three-generation trend.

In the Mediterranean, data on the Great Hammerhead as a separate species is not available, but overall data on Hammerhead Sharks, Shpyrna spp., indicates that the group has suffered a 99.99% decline in population since the early nineteenth century, effectively disappearing from this area. 

In the North and West Central Pacific it was again impossible to extract information for Great Hammerheads as a species, but data collated by the International Union for the Conservation of Nature suggests that the species is caught infrequently in these regions, probably indicating that it is present at only very low levels. Data is also limited from the coast of West Africa and tropical Indian Ocean, but fishing activity here is known to have increased significantly in recent decades, presumably applyinf pressure upon the species.

Based upon the data from the Northwest Atlantic, Gulf of Mexico, and southern Indian Ocean, the Great Hammerhead Shark population has undergone significant declines in population since the mid-twentieth century, although with some signs of a limited recovery in areas where properly run management schemes have been implemented. The Atlantic Population is believed to have undergone a decline of more than 50% over three generations, with a possible recovery in the Northwest Atlantic in recent years. In the Indo-Pacific region the Great Hammerhead Shark population appears to have declined by more than 80% over the last three generations, with no sign of a recovery anywhere in this range. 

Based upon this data the International Union for the Conservation of Nature classifies the Great Hammerhead Shark as Critically Endangered.

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Magnitude 7.3 Earthquake off the south coast of Sumatra, Indonesia.

The Indonesian Meteorological, Climatological, and Geophysical Agency recorded a Magnitude 7.3 Earthquake at a depth of about 84 km, between the islands of Nias and Hibala, off the south coast of Sumatra, Indonesia at about 3.00 am Western Indonesian Time on Tuesday 25 April 2023 (about 8.00 pm on Monday 24 April GMT). There have been no reports of any damage or casualties following this event, but people have reported feeling the event across the Nias Archipelago, Sumatra and southern Peninsula Malaysia, with reports of shaking going on for about 30 seconds. A tsunami warning was issued following the quake, but in the event the wave associated with the quake was only about 11 cm high when it reached Sumatra.

The approximate location of the 25 April 2023 Nias Archipelago Earthquake. USGS.

The Indo-Australian Plate, which underlies the Indian Ocean to the west of Sumatra, is being subducted beneath the Sunda Plate, a breakaway part of the Eurasian Plate which underlies Sumatra and neighbouring Java, along the Sunda Trench, passing under Sumatra, where friction between the two plates can cause Earthquakes. As the Indo-Australian Plate sinks further into the Earth it is partially melted and some of the melted material rises through the overlying Sunda Plate as magma, fueling the volcanoes of Sumatra.

The Subduction zone beneath Sumatra. NASA/Earth Observatory.

This does not happen at a 90° angle, as occurs in the subduction zones along the western margins of North and South America, but at a steeply oblique angle. This means that as well as the subduction of the Indo-Australian plate beneath the Sunda, the two plates are also moving past one-another. This causes rifting within the plates, as parts of each plate become stuck to the other, and are dragged along in the opposing plate's direction. The most obvious example of this is the Sumatran Fault, which runs the length of Sumatra, with the two halves of the island moving independently of one-another. This fault is the cause of most of the quakes on the island, and most of the island's volcanoes lie on it.

The movement of the tectonic plates around Sumatra. NASA/Earth Observatory.

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Asteroid 2023 HW3 passes the Earth.

Asteroid 2023 HW3 passed by the Earth  distance of about 209 000 km (54% of the the average distance between the Earth and the Moon or 0.14% of the distance between the Earth and the Sun), with a velocity of about 15.06 km per second, slightly before 7.35 am GMT on Sunday 23 April 2023. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2023 HW3 has an estimated equivalent diameter of 3-10 m (i.e. it is estimated that a spherical object with the same volume would be 3-10 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) more than 31 km above the ground, with only fragmentary material reaching the Earth's surface.

The relative positions of 2023 HW3, the Earth, and the Moon at 7.00 am on Sunday 23 April 2023. JPL Small Body Database.

2023 HW3 was discovered on 22 April 2023 (the day before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2023 HW3 implies that the asteroid was the 97th object (asteroid W3 - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 26, A2 = 51, etc., which means that W3 = (25 x 3) + 22 = 97) discovered in the second half of April 2023 (period 2023 H - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

2023 HW3 is calculated to have a 973 day (2.66 year) orbital period, with an elliptical orbit tilted at an angle of 19.1° to the plain of the Solar System which takes in to 0.92 AU from the Sun (92% of the distance at which the Earth orbits the Sun) and out to 2.92 AU (2.92 times the distance at which the Earth orbits the Sun, or almost twice the distance at which the planet Mars orbits). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). 

The relative positions of 2023 HW3 and the Earth at 7.00 am on Sunday 23 April 2023. JPL Small Body Database.

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