Recently I was lucky enough to go to the Natural History Museum in London for the launch of their Seaweed Collections Online. Jane Pottas and Jo Wilbraham have spent the last year collecting images and information from 14 different institutions aiming to make seaweed data from regional herbariums more accessible (see the RBGE write-up here).
The team selected aound 150 different species of seaweed from the c.650 species found around the UK. Species were selected for reasons such as their conservation status (rarity), if they provide an ecosystem service (such as an important habitat) or if their distribution is changing (perhaps through environmental change).
430 images of specimens of seaweeds which were collected between the 1840s and 1964 were photographed from the Manchester Museum collection for the project and are now available through the online catalogue.