Today we had to collect washed up seaweeds for a craft workshop on seaweed pressing. We love the pressing process as a way to engage people with seaweeds.

The day is perfect and I had more time than I usually do to collect. The seaweeds best for pressing are red seaweed that tend to grow at the bottom or below the intertidal zone. When they become dislodged from their holdfasts, dying, they wash up. A northerly wind blew from the land, making the nearshore water calm – it was bliss.

Over the last half a year we have been trying to learn a little how to interpret these beautiful satellite images of familiar landmasses and unfamiliar cloud masses, not often sure what exactly we are looking at. One thing has been certain over the last few months – it’s been mostly warm and dry. We have seen many clear outlines of the cornish coast send down to us via audio file from the satellites.

It feels sadly fitting to have spent these months with our ground station, thinking more about weather, whilst the coast our work focuses on is current experiencing the warmest heat waves since records began.

Throughout April and May we have seen an ‘unprecedented’ marine heatwave in the northeastern Atlantic. The Met Office has described this heatwave as being unusual in its intensity and persistence.

The last time this was observed was in 2023, at the time the most severe marine heatwave recorded in this part of the ocean. Then, both Ruth and I were working harvesting seaweed at every low tide on The Lizard peninsular. Unaware of the data being gathered that summer, we anecdotally saw a large bleaching and dieback of our favourite seaweed Dulse. We worried about its recovery after this local marine heatwave and we wondered what data was being gathered on the effect of heat on the very shallow waters of the intertide. The Dulse seemed to recover well but we couldn’t help wonder how many of these events the ecosystem could withstand. Now working less physically close to this ecosystem, seeing more extreme marine heatwaves, we are left even more concerned for their future.

Today, whilst the tide is metres above most species, I swim in the unseasonably warm waters and gather dead floating seaweeds, a tool to teach people about the ecosystem. I wonder how many of them have died prematurely due to heat or if this is just the normal natural lifecycle.