Title picture: Cloudscapes, Stornoway, 1 February 2017

Thursday, 9 April 2009

A few of this week's pics




Cyclone Jade

Jade is a tropical cyclone that is currently moving south from Madagascar, and will soon disappear off the weather maps. The storm moved along the east coast of the Indian Ocean island over the past few days, claiming 8 lives and making 3300 people homeless. The cyclone season is ending by the end of this month, and has once more claimed many lives and caused much devastation in Madagascar, one of the poorest nations in the world. In January, two cyclones hammered the island at the same time - Fanele from the west and Eric from the east.

Paralytic shellfish poisoning

I was asked on Twitter this morning which website issues warnings for paralytic shellfish poisoning (PSP). This danger involves shellfish (bivalve molluscs), which ingest algae from the seawater. The toxins contained in the algae accumulates in the shellfish and can accumulate to dangerous levels. Each week, samples are taken from waters around Scotland and Northern Ireland and are assayed using a method called HPLC for the presence of the toxins. The results are published here.

It is worth bearing in mind that algae are plants, and using sunlight and photosynthesis for their energy requirement. Therefore, algal blooms will occur mostly in summer with their attendant risk of PSP. They are becoming an increasing problem, due to pollution like run-off of fertiliser from the land into the sea.

If PSP levels reach the warning level, local authorities will issue a press release specifying which area has been closed to shellfish harvesting. As far as I can tell, Comhairle nan Eilean Siar issued such a prohibition in 2006 on Loch Roag - a major shellfish harvesting area.

Thursday 9 April

Overcast and drizzly at the moment, but the sun is trying to come through. We can expect a force 8 southerly gale later today and a maximum of 15C. Current temperature is 8C, so I've got doubts about that. Those living near the sea will be aware that we are having springtides at the moment. This affects ferry sailings around our coasts. The service between Leverburgh in Harris (55 miles south of here) and Berneray (off Uist) is reduced to one sailing a day (from 3) due to low tides. It also affects the flights at Barra airport (which is a beach). This combination of factors led one visitor to exclaim 2 years ago: "What a place! At low tide the ferry can't sail and at high tide the planes can't fly!"