Dr Sarah Hodgkiss is a hopeless phycophile….and is very happy with it ! She admitted as much as she gave Coastwise members the benefit of her deep knowledge and love of seaweed.
Since the 18th century, people have been fascinated by sea weed and Victorian lady enthusiasts benefitted from good advice on the best clothes to wear on the beach while collecting seaweeds, with definitely nothing worn above or below the ankle for fear of offending public sensibilities, or wetting the hem.
Seaweed size varies from the tiny – a 1.5mm epiphyte called Ochmapexus minimus – to the gigantic 10m kelps.
The diversity of the group is huge. It is polyphyletic and does not have a common ancestor. DNA analysis shows that the earliest red algaes originate from 2Bya, while some dinoflagellates have have developed within the last 250K years.
Identification can be very tricky and may necessitate a high-power microscope. Seaweeds have highly seasonal growth patterns, and Sarah demonstrated how nitrates and laminarin, a photosynthesized sugar, are stored from different times of the year when they are best produced to when they are needed.
Reproduction is varied as well, with dioecious varieties having separate males and females , and monoecious varieties containing both. Strangely, some varieties are semelparous, which means that despite their large biomass they die after reproduction – seemingly not a good survival strategy, but it seems to work.
As conclusion of a masterclass on seaweed Sarah gave members a quick tour of its use as patterns on clothes, cards and much else.