Plant Cuttings

Rejoice, ‘tis the real Bloom’s Day (to be sure…)

Image: Leopold Bloom, as sketched by James Joyce.
Image: Leopold Bloom, as sketched by James Joyce.

June 16th is the date upon which certain individuals around the world celebrate Irish writer James Joyce’s 1904-set literary classic Ulysses. Termed Bloom’s Day – after Leopold Bloom, the famously impenetrable novel’s main character, whose Dublin comings-and-goings are minutely catalogued over a 24-hour period – this is only a day-long phenomenon. A recently discovered bloom of another – phytoplankton – kind, and which lasts far longer than one day, is reported by Kevin Arrigo et al. But such blooms – a ‘rapid increase or accumulation in the population of algae… in an aquatic system’  – are common enough, and the well-documented, annual spring bloom is crucial in driving the productivity of the oceans, so what’s so special about this one? Well, it’s only gone and ‘developed beneath the 0.8- to 1.3-m-thick first-year sea ice on the Chukchi Sea continental shelf’, in the Arctic. Hitherto light levels beneath ice have been considered too low to promote blooming of algae. Although algal blooms can be harmful, this one, which was identified in July 2011, extended more than 100 km laterally beneath the ice to depths greater than 50 m and consisted predominantly of diatom genera, which are not harmful. Furthermore, phytoplankton biomass in open waters in that region was markedly lower than in the sub-ice bloom. Whether any much-publicised ice-thinning (which has been linked to global warming) in that area might have permitted greater light penetration, thus encouraging blooming, and/or if extra supplies of the essential micronutrient iron are being introduced in the region from melting icebergs is partly responsible remains to be seen, but it would be a paradoxical bonus to that otherwise doom-and-gloom global warming scenario because phytoplankton are regarded as one hope for sequestration of excess atmospheric CO2. One thing’s for sure: this revelation not only means that the textbooks will need to be rewritten (again…), but also – and more importantly – estimates of ocean productivity in those cold northern waters will require serious revision – upwards! The legendary reproductive powers of these protists – in which their numbers can increase 100 % in a day (and known – allegedly – as the Dublin rate) – makes these more than fec-und enough for even the most sedentary of TV-based Irish clergyman. And if there was any lingering doubt about the power of algae, phytoplankter’s land-dwelling relatives have been known to halt the urgent and essential terrestrial communication activities of the once-mighty monolithic monopoly in the UK known as the Royal Mail!

About the author

Nigel Chaffey

Nigel is a botanist and full-time academic at Bath Spa University (Bath, near Bristol, UK). As News Editor for the Annals of Botany he contributes the monthly Plant Cuttings column to that august international botanical organ. His main goal is to inform (hopefully, in an educational, and entertaining way...) about plants and plant-people interactions.