Biobanks have significant value for genomic research on environmental questions. Environmental samples such as water, soil, or filtered air, are becoming widely used for “environmental DNA” (eDNA) analysis. The primary use for eDNA is to identify “DNA barcodes”, unique short sequences that are used to mark the presence of any species or organism. eDNA analysis can identify the presence of a huge range of organisms from residual DNA in environmental samples by fairly simple, affordable analyses using high throughput DNA sequencing. It is being applied as a marine biodiversity monitoring tool in particular because ocean biodiversity is difficult to measure by other methods, and because seawater contains easily purified DNA bound up with other biomolecules derived from recently living cells. eDNA analysis is an experimental method dependent of DNA sequencing technology that is continually evolving. This means that the results of eDNA surveys performed now, or in the past, will not be comparable to the results of surveys analysed with future DNA sequencing technologies. Biobanks of environmental samples are the only long-term solution to this problem, as they allow all samples to be analysed at a future time point with a single technology.
Biobanks are also significant for environmental genomics research focused on single species. An excellent example is the development of “epigenetic clocks”, which are a molecular tool for estimating the age of animal species from tissue samples. Epigenetic clocks solve a problem in management of animal populations, where the age profile of the population is a critical factor, but in many species is very hard to estimate. A key aspect of developing an epigenetic clock is that samples with known age must be available to calibrate the rate of change of methylated DNA that the clock measures. I developed the first epigenetic clock for wild animals to determine the age of humpback whales. With this method, we can take a skin sample from a whale and determine its age. Age estimates of humpback whales are otherwise almost impossible without lethal sampling, as they are fully grown at 5-9 years old and may live as long as 95 years, with no obvious external features that indicate their age. To develop this epigenetic clock, I used tissue samples from a long-term biobank of whale biopsies.
I will talk about applications of biobanked environmental samples in environmental monitoring, and biobanks of tissue samples from animals in epigenetic clock development. Both types of biobank have great value in gathering the scientific knowledge that we need to manage our environment well.