Sequencing the 'Sea Lettuces'; key links between terrestrial agriculture and marine ecosystems

Lead Research Organisation: Durham University
Department Name: Biological and Biomedical Sciences


The green macroalgae, or seaweeds, are one of the most common sights on beaches and shorelines around the UK, providing food and shelter for many marine animals. The most familiar of these green seaweeds are the Ulva species; the 'sea lettuces'. These are particularly important because they act as a link between the land and the seas; increased nutrient run-off from agricultural fertilisers, or from urban sewage treatment plants, can lead to higher nutrient levels in the rivers and seas that border farmlands and cities. These enriched waters, which can also occur naturally through the spring upwelling of nutrient-rich deeper sea waters, can, in turn, see extraordinarily rapid growth of the seaweeds that live in them; the so-called 'green tides' that can choke coastal waters worldwide and which are responsible for threatening the Olympic sailing regatta at Qingdao in 2008, covering beaches along the south coast of the UK in 2010, and fouling the Breton coast annually.

We still know very little, however, about these astonishingly important organisms. The proposed research aims to provide the first genome sequence of one of these green seaweeds, Ulva compressa, giving us a first look at their genomic architecture and at the genes which allow them to grow so dramatically. The UK has a strong tradition of green seaweed research, and this proposal would add to that tradition by providing a framework on which to hang 'Next Generation' genomic experiments that look at the ecology and biology of marine seaweeds.

Planned Impact

As detailed in the Case for Support, the Ulva genome and transcriptome sequences will stimulate the development of a molecular toolkit for the green seaweeds, including a) higher-resolution taxonomic markers, b) population genomic tools, and c) improved green seaweed transformation techniques. Once these have been developed and applied, which is expected to take 1-2 years of work beyond the end of this Small grant proposal, an improved molecular toolkit will benefit the following groups:

I. The Environment Agency, and its devolved counterparts, which will benefit from improved understanding of the ways in which invasive species spread and affect marine biodiversity. The green seaweeds contain a number of such invasive species, most notably Caulerpa taxifolia and Codium fragile, but the factors which determine whether or not a particular green seaweed species will become invasive are not well understood. Given the huge effect which invasive species can have on biodiversity, and given that guidelines established by the Convention on Biological Diversity recommend the prevention of migration by possible invasive species, the development of high resolution taxonomic markers from the Ulva genome and transcriptome will help the EA, SEPA, and NIEA by elucidating the various pathways by which marine invasive seaweeds may be introduced and spread.

II. Policy makers and advisors, such as the Government Office for Science and the Joint Nature Conservation Committee. Under certain conditions, Ulva species bloom to give green tides. These foul tourist beaches, are increasingly common in areas with rising populations, and the EU Water Framework Directive has identified them as an important indicator of estuarine quality. As Ulva growth is usually nitrogen limited, green tides are thought to be triggered by sudden increases in the levels of nitrate run-off from agricultural fertilisers and sewage plants. A compounding factor is that water treatment plants are not designed to remove nitrate from sewage, nor are they well designed to cope with surges in rainfall, and the concomitant surges in nutrient influx into estuarine catchment areas. There is, moreover, much debate in European policy circles about how green tides should be managed, partly because we do not know the extent to which bloom formation is dependent on specific Ulva haplotypes. The elucidation of any genetic component to green tide formation would bolster the UK's commitment to evidence-based science policy, helping to decide whether efforts to combat green tides should focus on water treatment plants, altering fertiliser composition, or improving marine bioremediation, possibly through the use of other, non-bloom forming, seaweeds.

III. Algal and 'blue' biotechnology companies. Although Ulva grows abundantly in a diverse range of habitats and its mariculture as a human and animal food staple is common in Asia, its economic potential remains underexploited in European waters. The green seaweeds are, however, attracting increased interest as potential biofuel and biotechnology sources, with particular efforts being made to counter, or exploit, their biofouling and bioadhesive ability. The Ulva genome and transcriptome sequences will, therefore, be of immediate interest to biotechnology companies interested in the economic potential of algal secondary metabolites; this impact of our proposal will be further enhanced by the development of improved transformation techniques, which will allow genetic modification of green seaweed metabolism for bioprospecting and 'white' biotechnology.


10 25 50
publication icon
Wichard T (2015) The green seaweed Ulva: a model system to study morphogenesis. in Frontiers in plant science

Related Projects

Project Reference Relationship Related To Start End Award Value
NE/J014370/1 31/07/2012 27/02/2013 £10,647
NE/J014370/2 Transfer NE/J014370/1 30/09/2013 28/02/2014 £401
Description 1. Academic goals and progress
This award was given to sequence the genome of a green seaweed, Ulva rigida. Genome sequencing consists of three main stages: a) 'Sequencing': the preparation and sequencing of fragments of pure DNA, which is not trivial because it's hard to avoid contamination, b) 'assembly': the assembling together of the sequenced fragments into a draft genome, which is a computationally intense jigsaw puzzle, and c) 'annotation': the educated assignation of biological function to the sequences.

We have prepared and submitted material for the first two stages and are currently preparing material for the third.

2. Academic dissemination
This project will be one of the first genome sequences of a green seaweed and is attracting considerable international interest. We have a review in press in 'Frontiers in Plant Science' and will be presenting our work at the annual meeting of the Society for Experimental Biology and at this year's European Phycological Congress.

3. Staff development and collaborations
The aware itself doesn't employ any staff and staff costs at collaborating institutions are being funded through other sources (EU and departmental sources). However, a particular strength of the work to date has been the very strong links forged between groups at Durham, Birmingham, Gent (Belgium), and Jena (Germany). A number of grant applications have already come from these links (see below) and more are expected. In addition, PhD students (funded through other sources; see below) are expected to be significant users of the information generated during this work.

4. Further academic development
The outcomes of this project have strongly supported three recent successful funding applications (and have been explicitly mentioned in two of the applications):

a) A £2m BBSRC-DBT award (BB/K020552; 'SuBBSea') as part of the RCUK India funding stream.
b) An EU COST award (Phycomorph) to look at fundamental processes that drive development in plants and green algae.
c) A recent EU PhD ITN (ALFF) will fund studentships in the UK and NW Europe who will use the genome sequence as the starting point for mechanistic investigations into algal biology and disease resistance. We are currently working closely with the PI of this EU ITN to ensure rapid dissemination of results.
Exploitation Route Our original proposal identified two main potential classes of beneficiaries and links to both are being developed well.

1. Seaweeds are a promising biofuel and bioremediation crop. Using results from this project, we are trialling algal growth facilities as a way of reducing pollution from plants owned by Northumbrian Water in the UK (Bran Sands, Teesside) and local water purification sites in India. We are also in discussions with a variety of industrial partners through a link that the PI has developed with NEPIC (North East Process Industry Cluster).

2. Seaweeds are keystone species in coastal areas. Accordingly, the PI has developed links with Durham County Council (responsible, through the Durham Heritage Coast partnership, for local coastal ecosystems) to monitor patterns of seaweed distribution and estimate their contribution to local ecosystem health. This forms part of a bid that Durham County Council will be submitting in 2015-2016 for European Regeneration funding.
Sectors Agriculture, Food and Drink,Energy,Environment,Pharmaceuticals and Medical Biotechnology

Description IBCARB Summer studentship
Amount £2,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 05/2016 
End 08/2016
Description NERC AB-SIG
Amount £10,000 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 08/2015 
End 02/2016
Title qPCR in Ulva mutabilis 
Description Using the genome database generated from work in these two grants, we have generated a range of primers for qPCR in Ulva mutabilis. We are currently using these to measure gene expression in these species. 
Type Of Material Technology assay or reagent 
Year Produced 2020 
Provided To Others? No  
Impact None yet 
Title Ulva mutabilis genome assembly 
Description This is the genome assembly for Ulva mutabilis. It is currently being annotated. 
Type Of Material Database/Collection of data 
Year Produced 2016 
Provided To Others? Yes  
Impact We have established an international consortium to annotate the Ulva mutabilis genome. 
Description SEA Consultants 
Organisation SEA Consultants
Country United States 
Sector Private 
PI Contribution SEAN Consultants are an aquaculture SME based in Blyth, Northumbria. We are working with them to establish commercial macroalgal cultures for food, feed and biofuel purposes. We provide expertise in macroalgal cultivation and analysis.
Collaborator Contribution Our partners provide commercial scale growth chambers, cover nutrient and consumable costs, and labour to grow macroalgal cultures at large scale for several months.
Impact Preliminary data as of 1 month ago
Start Year 2015
Description BIS vsit 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact The Durham Energy Institute arranged a visit to BIS to discuss energy policy; I presented a report on macroalgal biofuel. We're following this up with a written report.
Year(s) Of Engagement Activity 2015