Are there any blue sea­weeds?

BBC Wildlife Magazine - - Our Wild World - Stu­art Black­man

ABlue sea­weeds are con­spic­u­ous by their ab­sence, though there may be one ex­cep­tion, de­pend­ing on the an­gle from which you view it. Rain­bow wrack, a com­mon Bri­tish rock­pool species, has an opales­cent qual­ity that can make the plant ap­pear blue, green or pink. The colours are pro­duced not by pho­to­syn­thetic pig­ments, but by mi­cro­scopic, oil-based struc­tures that scat­ter light in all di­rec­tions, much like real opals do. This opales­cence may in­crease light ab­sorp­tion when the sea­weed is sub­merged. At low tide, the plant switches off the ef­fect, per­haps to pro­tect it­self from the full glare of the sun.

Show­ing its true colours?

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.