Man and animals are in reality vehicles and conduits of food, tombs of animals, hostels of Death, coverings that consume, deriving life by the death of others. Leonardo da Vinci

Plants are rather different – quietly converting sunlight into the food we need to survive; the shepherd with his grazing flock is the subject of a painting, the meadow, a beaucolic backdrop. In the worlds oceans, however, the plants that form the meadow are microscopic – completely invisible to the naked eye. Indeed, for most of the 20th century, the main players remained elusive even to the best optical microscopes!

Over the last decade or so satellite imagery, coupled to unmanned submersibles, have begun to reveal the true extent of marine ‘plant life’. We find a complex, dynamic pattern of blooms, and rapid disappearances keyed to the seasons, currents and climate. Alongside this, genetics has begun to unravel the complexities of the interrelationships between the different groups of marine plants – and animals…

Join us on Wednesday 13th February between⋅19:30 and 21:00 at the Gregson Centre, 33 – 35 Moor Gate, Lancaster LA1 3PY for a personal look at some of the recent research in this area.
Admission £3.00, everybody welcome!

I’d been asked to look for diatoms in Morecambe Bay, – the project was to help people understand life in the Bay, and marine life in general, so it was an opportunity to look at the base of the marine food-chain. I was a little worried about actually finding anything at this time of year – January and February are usually very quiet for phytoplankton, before the spring bloom starts. As a consequence I suggested we looked for epiphytic diatoms, ones that live on surfaces, rather than floating in the water column. In this search we were lucky, with every one of our samples having some diatoms in. This is perhaps the nicest micrograph, with a couple of free-swimming pennate diatoms. No-one is actualy sure how these small plants move, but they are most certainly capable of a fairly respectable pace under the microscope!

Tiny single celled plants called phytoplankton support the food chain of the world’s oceans. By locking up carbon dioxide during photosynthesis, they are also recognised as a vital component buffering the earth’s atmosphere from burning fossil fuels.

The numbers of phytoplankton are limited by the availability of sunlight and nutrients. Above 50°N in the Atlantic it had been assumed that winter turnover of water masses replenished the nutrient supply, and that the limiting factor for phytoplankton growth was a combination of grazing, and lack of silicates (a vital micro-nutrient for diatoms, pictured). Recently, however, experimental evidence, gathered by scientists at the University of Southampton, indicates that it is lack of iron, another important micro-nutrient, that is limiting the growth of phytoplankton.

Experiments elsewhere, aimed at increasing the amounts of carbon dioxide removed from the atmosphere, have tried to boost phytoplankton production by artificially adding more iron to water bodies.

From Science Daily