Ribbon weed, Posidonia australis, meadow in Shark Bay, Western Australia
Ribbon weed, Posidonia australis, meadow in Shark Bay, Western Australia

Single seagrass plant stretches 180km

Large, perennial, seagrass meadows of the Poseidon’s ribbon weed and the wire weed (Amphibolis antarctica) dominate much of the marine ecosystem in the UNESCO World Heritage Site of Shark Bay, Australia.

Two years ago, scientists discovered some of the seagrass there was a clone of a Poseidon’s ribbon weed (Posidonia australis) that had 40 chromosomes instead of the typical 20. They think half those chromosomes may come from the ribbon weed and half from an unknown species.

Developing a Scuba Sixth Sense

A term that has crept into discussions of scuba diving safety comparatively recently is “situational awareness,” a concept that originally arose in the field of aviation but has now been extended to a wide range of human activities, from medicine and motoring to personal security and law enforcement. Simon Pridmore offers insights and advice on safe diving with a scuba sixth sense.