Continued research detects mega-blooms

10 November 2020

Recognising that much science is a prerequisite for overcoming the challenges faced by the environment and society but as the nation faced lockdown in March, Amanda Solloway MP, Minister for Science, Research and Innovation issued some helpful guidance on science that should continue, including a paragraph highly pertinent to PML’s work in the western English Channel:

“Science, Research or technical work where the pausing of activity is either not possible or would severely impede research delivery – for example, this may include very long-term experiments or projects where the time frequency of observation is critical”.

Over the last thirty years or so PML scientists have made the weekly trip out to the L4 and E1 sampling stations to take measurements and sample for plankton; the longest running plankton sampling project at point sites in the UK. In parallel, box-core samples along with trawl catches have been adding to one of the longest running long-term data sets for benthic (seabed) and other marine life, begun over a century ago by colleagues at the Marine Biological Association.

Together the research has revealed many aspects of how our local seas work, how they change from week to week, season to season, year to year, and over the decades. Understanding this detail is critical to predicting what the future holds for our seas and the numerous goods and services they provide for the wider environment and ultimately ourselves.

Long-term, and importantly, regularly undertaken observations and measurements unlock some of these secrets; even missing a single week of collecting and measuring can lead to an important event being missed, an essential piece of the jig-saw puzzle of our knowledge about our own seas being overlooked.

Thanks to some innovative thinking on the part of PML’s science team, boat crew and health and safety advisors and adhering strictly to the best available advice, this valuable research has been able to continue as part of the UK’s Climate Linked Atlantic Sector Science (CLASS) programme. Social distancing and the maintenance of ‘bubbles’ has been strictly followed, even though the collecting trips take place in the open air out at sea.

PML is fortunate in having a planktologist and marine ecologist married-couple-team in the form of Claire and Steve Widdicombe, who were able to continue the sampling and observations, alongside other ’bubble’ members, Rachel Coppock and Becca May; the boat crew formed a second ‘bubble’.

“We gave a lot of thought to how we could continue this valuable time-series, putting everything in place to prioritize the health of the teams involved, and our hard work has been rewarded,” said Professor Steve Widdicombe, PML’s Director of Science.

“Our in situ sampling is the perfect way of ground-truthing the information we get from satellites flying overhead, put together we have detected and followed the largest coccolithophore ‘bloom’ we have ever seen in the English Channel. The ‘bloom’ made up of tiny single-celled Emiliania huxleyii wasn’t just large in extent, it was also very dense with up to 11 million cells per litre of seawater, so dense that the water was white with their calcite liths, we haven’t seen anything approaching this for the last 30 years,” he added.

And this was not the only huge bloom that might have been missed if the research had stopped; the team was able to identify another type of plankton – Karenia mikimotoi, a so-called HAB or harmful algal bloom, which has been implicated in the closure of aquaculture facilities such as fish and mussel farms. Part of PML’s work concerns refining methods of predicting HABs, so gaining such an important insight this summer has been a real boost in understanding how they form and spread.

Although the observations are still being worked through it is likely that the prolonged warm, dry spell accompanied by clear skies in May, provided the perfect conditions for these microscopic marine plants to thrive and multiply. What the research has provided is a key package of data that begins to demonstrate the edges of the environmental envelope, within which these species can thrive, bloom and die.

With a world that is changing rapidly, knowing what drives such marine phenomena is essential if we are to attempt to maintain the ecological balance that supports nature and provides a wide range of goods and services to humanity.

Related information

The UK’s Climate Linked Atlantic Sector Science (CLASS) programme aims to deliver the knowledge and understanding of the Atlantic Ocean system that society needs to make evidence-based decisions regarding ocean management. This research is especially crucial to address key knowledge gaps in our understanding of ocean variability, climate regulation and ocean services, and to assess how the ocean will evolve as a result of climate change and intensified human exploitation. To make sense of what is happening to our seas and how they may change in future CLASS will build on sustained ocean observation, world class model development and state-of-the art technology.