Picture of the week: Hammerhead Pirouette

These nine pictures represent a shark feed sequence of 4-sec duration.  Píctures were taken by clicking repeatedly (as shown from the upper left to lower right)  with my  Nikon D7200 and Tokina 10-17 lense. The clockwise spiral of the hammerhead in front of the divemaster resembles the classical movement pattern of a bull (called Gaonera ) interacting with the bullfighter. With every turn of the bull, the public in Spain will then shout "¡Olé!",  to express their appreciation. In this case,  the ‘bullfighter’ was  Neal  Watson from Bimini who playfully moved the bait in a circle above his head in front of the mouth of the shark.

Highlighted: Old age Coelacanths

The Coelacanths are members of the order of Coelacanthiformes that currently includes two species: the West Indian Ocean species (Latimeria chalumnae) primarily found near the Comoro islands off the east coast of Africa and the Indonesian Coelacanth (Latimeria menadoensis). Coelacanths, also called ‘’the living fossil’’,   were thought to have become extinct around 66 million years ago, but were rediscovered in 1938 off the coast of South Africa. They can become around 2 meters long and weigh 90 kilos. By examining imperceptible annual calcified structures (circuli) on the scales,  maritime biologist concluded in Current Biology,   that the fish has slow growth, can grow very old, around 85 years, and that the species only reach maturity at the age of 55 years, when it also becomes capable of producing offspring.

Highlighted: Ras Muhammed: a string of pearls in the Northern Red Sea

Ras  Muhammed has become the most famous reef site in the northern Red Sea. The beauty and serenity of these stunning ancient reefs at the edge of the Sinai desert can be best experienced on a  liveaboard, allowing you to start an early morning dive when the day boats from Sharm loaded with divers have not arrived. Ras Muhammed contains two pinnacle-shaped reefs,  Shark reef and  Yolanda reef,  surrounded by splitting circular currents.  The gently sloping coral plateau at the side of the open sea lies at around 20 meters until it drops to a steep wall of hundreds of meters.  Depending on the particular pattern of currents on a certain day, divers venturing a clock-wise swim around Yolanda reef may experience first little or no current. When turning right they may be facing increasing currents above the shallower part at the back of Yolanda, which changes again in a strong outflowing current, allowing a pleasant drift back to their original position via the 'saddle', the channel between  Shark and Yolanda reef (see inset).

News: Toxic cargo causes a disaster in Sri Lanka waters.

Toxic cargo  of a sunken burning chargo ship causes one of the worst environmental  disasters Sri Lanka has ever seen. The ship was carrying a whole array of hazardous chemicals: nitric acid, used for explosives; epoxy resins, used for paints and primers; and ethanol and lead ingots, used for manufacturing vehicle batteries.Whales and dolphins frequent the oceans, and the coastal belt also provides a nesting ground for sea turtles: out of the seven types of sea turtles in the world, the Sri Lankan coast welcomes five of them. As the ship caught fire, images circulated on social media of fish, moray eels, rays and turtles washed up on the beaches.

News: Mysterious mass extinction of pelagic sharks 19 million year ago?

Studying shark teeth buried in deep-sea sediment, Sibert and Rubin revealed in  Science that current shark diversity could be a small remnant of a much larger array of forms that were decimated by a previously unidentified major ocean extinction event. Investigators quantified the morphological variation of shark denticles (small tooth-like particles in the skin  of the shark, see inlet) in the sediment samples from the South Pacific and the North Pacific

News: Turkish sea-snot spreading in sea of Marmora

The sea of Marmora (also called Marmara)  is the inland sea within the borders of Turkey, that connects the Black Sea to the Aegean Sea. Scientists say the current sea-snot invasion in the sea of Marmora is a result of climate change and pollution contributing to the proliferation of the organic matter, also known as marine mucilage, which contains a wide variety of microorganisms and can flourish when nutrient-rich sewage flows into seawater.  The snot spreads on the surface as well as deeper layers of the sea.  The sea of Marmara is surrounded by a dense population of around 25 million people living mostly in cities like Izmit en Bursa, where gutters are mostly free to dump industrial waste with heavy metals in the sea.  The fishing, as well as tourist industries in the area, fear new major economic losses after the pandemic.

E-Book. Click on the Icon to download the PDF file

 This ‘E-book’  contains an updated collection of around 80  blog articles from the last three years.  I here provide two separate content lists, a list in which the articles are ordered according to the five most often recurring themes, and a chronological list. A simple click on the title will hopefully guide you to the article of your choice. For download,  click  next to the  PDF icon