Final Report Summary - CACHE (CACHE: CAlcium in a CHanging Environment)
The EU is the 4th highest producer world-wide of Crassostrea gigas, with an EU-27 value of 295M€ (at 2007) and produces 86% of the global production of Mytilus edulis (EU-27 value 231M€ (2007)) http://ec.europa.eu/fisheries/cfp/aquaculture/index_en.htm. The EU aquaculture industry directly and indirectly employs approximately 80,000 individuals, many in rural areas where job opportunities are limited. Globally, aquaculture is the fastest growing food producing sector, accounting for almost 50% of the animal protein consumed, with the expectation that this will rise to 65% by 2030, due to the increasing emphasis on fish products as important components of a healthy diet (http://www.fao.org/fishery/aquaculture/en). Thus, commercial shellfish contribute significantly to the EU “Blue Economy” and represent a growth area for the future.
However, surprisingly little is known about how marine animals regulate calcium to produce a shell, how these processes might be affected when the environmental conditions change and what the consequences are at the population level. This lack of knowledge significantly impacts on our ability to accurately predict future biodiversity and the consequences for the commercial aquaculture industry.
In addition, materials science is increasingly turning to molluscs as a target for biomimetic or “bioinspired” materials for the development of novel high-performance materials. Examples include the nacreous layer of the shell as a potential source of materials with high elasticity and high toughness; the holdfast of marine mussels (byssus) with its exceptional adhesive properties presenting novel solutions for wet adhesion; whilst the study of biomineralisation may lead to new synthetic crystallisation processes. Exploitation of marine resources for biotechnology (Blue biotechnology) is still relatively unexplored with a gross value of €0.8 billion within the EU, but offers great potential for highly skilled employment and significant downstream opportunities. Hence, fundamental knowledge on shell secretion and maintenance may generate novel biomimicry and biomimetic solutions to current industrial processes and produce novel bioactive compounds. Within the project, this was investigated alongside how shell waste generated by the aquaculture industry could be used for sustainability solutions and carbon sequestration.
The aim of the CACHE project was to increase the knowledge of calcium regulation and shell production in the natural marine environment, alongside developing an understanding of how molluscs will be affected by climate change. In addition, predictions have been produced within the project for the future aquaculture industry and analyses carried out on the uses of shell waste in the circular economy and for biomimetic purposes.
For the main body of the project, an integrative approach was taken using four of the most important commercially exploited molluscan species: Pecten maximus (king scallop); Crassostrea gigas (Pacific oyster); Mytilus edulis (blue mussel) and Mya arenaria/truncata (soft shell clams) as model organisms. Natural variation in shell production was studied in combination with experimental manipulations to quantify the costs of making a shell, the adaptive potential to climate change and identify novel genes and proteins that underpinned production of the shell.
To achieve this aim, the goals of the CACHE project were to:
1. Quantify natural variation in shell thickness and production across a latitudinal gradient and relate this to environmental parameters and the underlying population genetics.
2. Identify whether the genetic variability of aquaculture stocks is different to natural populations.
3. Identify calcium sources (and constraints) for shell production and the energetic costs of shell production.
4. Identify levels of phenotypic flexibility in shell production using experimental manipulation and population genetic approaches and use the results to establish the impact of climate change on aquaculture production.
5. Identify whether selective breeding could produce strains of shellfish more resilient to the effects of climate change.
6. Identify genes and proteins involved in shell production and calcium regulation.
7. Expand the genetic resources available for the four model species.
8. Functionally characterise biomineralisation transport and regulatory mechanisms.
9. Identify the major uses of shell waste within the circular economy and identification of constraints in their potential uptake.
10. Identify key areas in the development of the biomimicry applications inspired by shells, with the possibilities for biotechnology exploitation.
11. Model the climate change impacts on shellfish production at a country and global scale with reference to the aquaculture industry.
Web site: http://www.cache-itn.eu