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PETROMAKS2-Stort program petroleum

High-throughput metabarcoding of eukaryotic diversity for environmental monitoring of marine sediments (Metamon)

Alternative title: Genetisk strekkoding av eukaryotisk mangfold for miljøovervåking av marine sedimenter (Metamon)

Awarded: NOK 6.2 mill.

As search for and use of available marine oil and gas sources continues, operations extend towards often sensitive, previously unexploited ocean areas where also the biology, such as fish and corals, are not well known. The ocean is one of the planet?s important sources of food but is also providing other highly valued "services" such as uptake of carbon dioxide, regulating the climate and generating oxygen that most life forms on earth are dependent on. To understand and properly manage ocean industrial activities such as oil and gas exploration and production, we need to know who lives in the ocean and how these species are affected by industrial activity. Only by knowing the impact from industrial activities we can limit that impact to a minimum and make sure that the ocean is returned to the original state after the activity is finished. The better methods we have to detect any impact, the quicker we can respond to situations that are unacceptable. Until now the methods in use to do this are based on taking samples of the seafloor and determine who lives in the mud using microscopes, similar to how this was done 100 years ago. While a continuation of the methods is important to be able to compare data with old records, we need to take advantage of the overwhelming advances achieved in the science of molecular biology and computing. It is now possible to take a small sample of the seafloor and, using DNA analyses and computer databases, determine who lives in that area. In this project we are addressing three challenges in adopting this new technology. ? Eukaryote microorganism (18S) distribution showed great promise for consistent results due to the more even distribution of these smaller organisms, and we suggest testing additional microorganism 18S and prokaryote 16S markers. An additional advantage of 16S is that prokaryotes may react more quickly to impact. ? De novo biotic indices are very promising but need more data. Supervised machine learning predictions (AI) were not significant in the MetaMon dataset, but again, are limited by the current amount of data. ? Quantitative ddPCR is a promising approach, especially the Capitella assay. More data are needed to establish secure correlations to further bioindicator taxa. ? Time series are needed to validate metabarcoding data consistency over multiple sampling events and time. ? While uneven distribution is a concern for macrofauna, we recommend building upon MetaMon COI findings to investigate the extent of this increased dataset noise, and sieved bulk samples as a possible alternative metabarcoding method for this organism group. ? More direct involvement by policymakers would enable input on optimal direction for future routine monitoring.

MetaMon developed sediment sampling and processing guidelines made to maximize the amount of the organism community recovered through sediment sampling design and processing. MetaMon demonstrated the use of quantitative ddPCR on two assays, based on correlation between environmental impact and individual OTUs in the metabarcoding dataset, showing the utility in this approach for quantitative detection of indicator species for environmental impact. The main MetaMon study showed that metabarcoding data can detect environmental oil and gas impact with the use of new biotic indices. For metabarcoding macrofauna data, a more elaborate separate sieved bulk sample protocol could be considered as an alternative to sediment extraction. MetaMon represents a significant step forward to mature metabarcoding specifically, and eDNA generally, in Norwegian Shelf offshore monitoring.

As global exploitation of available petroleum resources continues, operations extend towards often sensitive, previously unexploited ecosystems and sometimes also biologically unexplored areas. It is important to initially map the baselines of ecosystem parameters such as biodiversity, and subsequently monitor such areas in order to detect, understand and remediate environmental responses to stressors. The natural heterogeneity and complexity of communities means that accurate monitoring requires high resolution, both temporally and spatially. Sustainable use of resources further call for ecosystem based management approaches requiring higher frequency and a more complete sample of taxa that are assessed. Increased resolution and taxonomic coverage is economically challenging using current microscopy-based monitoring practices. Instead, DNA sequencing-based methods have been suggested as a cost-efficient alternative for monitoring, offering additional insights into ecosystem function and disturbance. These new methods exploit recent progress in molecular biology, sequencing and computing technology as well as a growing species archive of DNA sequences. Regional data on performance as well as standardized methods for this technology are lacking. Before a wide introduction and regular use in marine baseline studies and monitoring, the DNA technology must also be tested in parallel with microscopy-based methods, standardised methods must be developed, and an assessment of the "taxon gap" in data repositories carried out. By achieving these three objectives the proposed project will contribute to better understanding of the molecular technology, a higher acceptance amongst authorities managing marine resources and a wider use of molecular methods in biodiversity monitoring.

Funding scheme:

PETROMAKS2-Stort program petroleum