4 Survey results and discussion

The results from the surveys are based on 27 responses in total. Twelve responses were received to the Stakeholder survey and 15 responses to the Researcher survey. Stakeholders were represented by people in management, advisory or civil servant positions at various relevant ministries, environment agencies and research institutions in Iceland, the Faroe Islands and Norway, including representatives of relevant International Organisations (Table 1). Although no written responses were from Greenland, we communicated with the Arctic Hub to ensure best possible inclusion of the views of Greenlandic stakeholders.

Responding researchers represented various research institutions in Iceland, the Faroe Islands, Norway, Sweden, and Finland (Table 1). Although no responses were from researchers representing Greenland, some of the other respondent perform relevant work in Greenland.

Table 1. Stakeholders, international organizations and research institutions represented*

*Other relevant international organisation than those listed might be represented.  

The stakeholders were overall engaged in the defined focus areas in marine issues (Fig 1). Biodiversity / Climate change was the focus area of highest interest, while the lowest number of stakeholders were engaged in the field of Marine Resource Management. The climate change and loss of biodiversity are higly urgent issues and of current political focus. In addition, Biodiversity / Climate Change is often an essential component of the other two focus areas. Therefore, those focusing on Marine Resource Management and Impact Assessment might, in one way or other, also need to have the Biodiversity / Climate Change aspect in mind, while it is not necessarily so the other way around.

Q: What is your level of engagement in these areas of marine issues?

Figure 1. Level of engagement (Stakeholders)

Overall, the stakeholders seemed to have fairly good insight into the concept of eDNA and two thirds were positive towards implementation of eDNA in marine monitoring while one third was neutral or undecided (Fig 2). It is noteworthy that no one leaned towards not recommending eDNA for implementation into marine monitoring.

What is your level of awareness of environmental DNA (eDNA) and your approach to it’s implementation in marine monitoring?

Figure 2. Level of awareness and approach to implementation (Stakeholders)

The high level of engagement demonstrated by the stakeholders is likely skewed by the fact that mainly people engaged in this issue answer on behalf of their institution. The survey was distributed to many more than those who answered, which might be an indication of a more balanced picture with some stakeholders not being as engaged as those who responded.

From the Researcher Survey it was possible to see what those applying eDNA methods in research and monitoring in the Northeast Atlantic are focusing on. Overall, the research respondents cover a wide area of research fields, habitats and taxonomic groups. Their project roles were mainly as researchers and project managegers while a few provided technical or adminstrative support.

When asked what the aim of their research was, most mentioned Biodiversity / Climate change (86.7%). Well over half of the respondents indicated Marine Reseource Mangement as relevant (66.7%) while fewest worked with impact assessment (46.7%).  

All researchers working with Biodiversity indicated that they work with conservation and/or establishing baselines. Over fifty percent answered that they were also focusing on Climate change while almost 40% focused on invasive species. Only one respondent focused on endangered species in particular.

The research performed by the respondents working with biodiversity and climate change is mainly concentrated around the open ocean or coastal waters, but other environments such as the seabed and kelp forests are also being investigated (Fig 3). Their research covered a wide array of larger taxonomic groups such as bacteria, viruses, phytoplankton, zooplankton, invertebrates, fish and marine mammals.  

Q: What environment or habitat are you focusing on?

Figure 3. Marine habitats investigated in Biodiversity/Climate Change studies (Researchers)

Researchers working with marine resource management focused on both pelagic and demersal fish, invertebrates, phytoplankton and zooplankton. When asked about their research focus, 80% responded that they worked with ecosystem dynamics while 40% worked with stock assessments of economically important species (Fig 4). A few focused more specifically on invasive species, species at risk or food availability.

Q: What best fits the focus of your research?

Figure 4. Research focus in Marine Resource Management (Researchers)

Researchers working with impact assessment mainly focused on the coastal environment (71.4%) and the seabed (42.9%). Kelp forests and the open ocean were mentioned only a few times. Focus of the impact assessments was mainly the aquaculture industry and human activity/traffic while the oil drilling industry was mentioned once.

As within the area of Biodiversity/climate change and marine resource management although fewer in number the researchers working with Impact assessments investigated a wide array of taxonomic groups (Fig 5).

Q: Which larger taxonomic group are you working with?

Figure 5. Taxonomic groups covered in Impact Assessment studies (Researchers)

In order to get an understanding of potential differences in implementation challenges in the selected focus areas, researchers were asked to state which technical approaches they used in the application of eDNA, as different approaches might entail different requirements before implementation.  

The technical approaches that could be selected included targeted approaches and metabarcoding (Fig 6a–c). The targeted approaches, where only one specific taxon at a time is investigated, were also divided into analyses of presence/absence determination, abundance estimation, and/or population genetics.

The results showed that the targeted approaches were most frequently used for abundance estimates, as more than half of the researchers in every focus area used this approach in their studies.

In Biodiversity/Climate Change studies targeted approaches were equally often applied to presence/absence determination. In Marine Resource Management presence/absence determination was used by 50% of the researchers and in Impact Assessment studies less than thirty percent of the researchers used presence/absence determination. Population studies were performed by between 15–30% of all the researchers.

Metabarcoding, where entire communities of any selected higher taxonomic groups are investigated for analysis of community structure and dynamics, was in all focus areas used more frequently than the targeted approaches. Metabarcoding was used used by 70–100% of the researchers, the lowest percentage being in Marine Resource Mangagement and the highest in Impact Assessment.

Figure 6a–c. Technical approaches used in application of eDNA (Reserchers)

Q: What approach do you use?
a. Biodiversity/Climate change

Q: What approach do you use?
b. Marine Resource Management

Q: What approach do you use?
c. Impact Assessment

In many instances eDNA is known by reputation rather than by experience. This means that researchers and especially stakeholders are susceptible to sometimes expecting unrealistic or unsubstanciated things of the application of eDNA. The potentially detrimental effect of this situation is that stakeholders either dismiss the application of eDNA or set very specific requirements for its implementation.   

In order to promote a correct implementation of eDNA methods to marine monitoring it is necessary to identify these discrepencies in the understanding of what the strengths, weaknesses and potentials of eDNA methods are. What could and should we apply it to at the present, what should we not use eDNA methods for and what are promising future perspectives that we need to research.

One important aspect is discerning when eDNA methods can replace more time consuming and expensive traditional methods and when they provide a complementary or independent approach that improves monitoring.

Researchers were asked if they perform studies comparing eDNA methods with more traditional methods and what the results were. Eighty percent of the researchers perform such studies and compare various types of estimates such as diversity, abundance, biomass, community structure and presence/absence. Researchers were also asked to state if their comparisons showed concordance, discordance or varying results within the different types of measurements (Fig 7).

Q: What do you compare between eDNA and other methods in your work and what are the results?

Figure 7. Results from comparisons of eDNA with traditional methods (Researchers) 

According to the researchers, the comparisons of eDNA with more traditional methods often showed varying results. Some reported direct concordance in their comparisons and some discordance. In addition, several comments were made about their “comparative work” being at an early stage, making it premature to decide how comparative the different methods are.

Keeping this in mind, both researchers and stakeholders were also asked about their view on the comparison of eDNA methods with more traditional methods, because this could say something about what they expect of the application of eDNA methods.

Overall, the researchers did not think the eDNA methods necessarily need to be directly comparable with traditional methods before implementation, but that it mostly depends on the application (Fig 8).

Q: Do you think eDNA methods need to be directly comparable
with other traditional methods before implementation?

Figure 8. Comparison of eDNA with traditional methods (Researchers)

This is in contrast to the stakeholders’ view. When asked if they think eDNA methods need to demonstrate directly comparable results with more traditional methods before implementation, only 8.3% answered “No” and over 40% answer “Yes”, while another good 40% answered that it depends on the application (Fig 9).

However, when comparing the answers from stakeholders in Norway with those from Iceland and the Faroe Islands, there also seemed to be a regional difference. In Iceland and the Faroe islands more than 70 percent of the stakeholders responded that eDNA methods need to demonstrate directly comparable results with more traditional methods before implementation. In comparison, no one in Norway had this view and their responses were quite similar to the responses from the researchers.

Q: Do you think eDNA methods need to demonstrate directly
comparable results with more traditional methods before implementation?

Figure 9. Comparison of eDNA with traditional methods (Stakeholders)

The varying results in comparative studies and reasons and implications of the discrepancies in the perception of eDNA as a replacing or complementary method need to be included in discussions across regional and professional boundaries. This could promote a common understanding of the potential role of eDNA methods in marine monitoring and the process needed to reach the implementation stage.

Stakeholders were also asked to state their view on some of the common statements made about the application of eDNA methods (Fig 10). Most agreed that eDNA methods are arelatively non-invasive method, that it has good potential in detection of rare or invasive species and that it can be used to address issues in marine monitoring of international focus. However, all did not agree that it can easily increase spatial and temporal sampling and even more disagreed that it can provide more effective monitoring (Fig 10).

Q: Do you agree with these statements about the benefits of implementation of eDNA?

Figure 10. Stakeholders’ view on common statements about eDNA

The concept of eDNA methods providing a more effective monitoring relies on a range of factors, including which role these methods will have. Therefore, it is valuable to see that this might be a concern for stakeholders. There is of course a difference in monitoring expenses whether eDNA can replace other more expensive and time consuming methods or if eDNA methods are added as a complementary approach for improved monitoring.

Currently, both researchers and stakeholders have a lot of focus on the standardization process of eDNA protocols as this is a fundamental requirement for national and international collaboration. In addition, minimizing the risk of putting time, effort and funding in producing data that might become obsolete within a short timeframe due to the application of out-dated protocols is important for all parties.

Because eDNA methods are still relatively new and continuously evolve, the standardization process at regional scale or beyond is difficult. There are different views on what the main challenges are for standardization/alignment of eDNA protocols. However, the issues researchers felt were most challenging (Fig 11), when responding to the UNIFIeD survey, were:

Q: What are the main challenges for standardization/alignment of eDNA protocols?

Figure 11. Challenges for standardization (Researchers)

In the survey, reseachers stated that their funded projects including eDNA were predominantly short term projects of duration between ½ to 2 years, while funding for projects of longer duration (3–5 years) was a third less frequent. Funding for long term monitoring programs including eDNA was selected a few times, mainly as funding from international research funds.

Most researchers answered that their funding came from national or international research funds or was funded in-house. Some mentioned industry funding while national policy based funding was only mentioned once.

Some of the questions in the survey explored the technical issues about the researchers’ eDNA protocols and the answers relate to the complexity of standardizing eDNA protocols.

All but one worked with sea samples, while 60% of the respondents worked with sediment or bulk samples. Almost thirty percent of the researchers stated that they always used the same protocol when working with sea samples. In comparison, this value was 11.1% for the sediment and bulk samples (Fig 12).

Q: Which sample types do you work with and do you use a standard protocol for each sample type?

Figure 12. Sample types and protocols (Researchers)

For both sample types, most answered that they used the same method if possible. Although the majority of the researchers did not consistently use the same protocol, it is also clear that most attempt to adhere to a standardized protocol if possible. The option “various protocols” was on average only 21.8% while all other options aspire to some level of standardization.

Due to the multitude of possibilities in sediment and bulk sampling, the survey was not expanded in that area. However, sea water sampling protocols were investigated further and Niskin bottles and pumps were described as the most commonly used methods for sampling, while deployed automatic sampling was mentioned only once.

Equally many researchers used open and closed/sterivex filtering systems, and some used both methods for filtering (Fig 13). The most commonly used mesh size was ~0.2 um, but some used larger mesh sizes and some used several for size fractioning samples.

Q: What is your typical filtering method?

Figure 13. Sea water sampling methods (Researchers)

Concerning storage of filters, samples and DNA, the overall responses showed little consistency in the methods used (Fig 14). The filters were stored in -18 and -80 degrees Celsius, in ethanol and some responded that it varied depending on practicality or duration. The storage methods used for sediment and bulk samples were more restricted as they were consistently frozen, although both freezing temperatures were used. Respondents also stored DNA in various ways. Overall, freezing filters, samples and DNA was the most applied method for storage.

Q: How do you store the filters, samples and extracted DNA?

Figure 14. Storage of filters, samples and DNA (Researchers)

Researchers were also asked if and how they archive their filters, samples and DNA. The results showed that more than 40% of the filters, samples and DNA are not archived in any formal system (Fig 15). Between 40% and 50% of the researchers used an in-house Biobank system, while only about 7% archived their filter, samples and DNA in an open access Biobank system.

Q: How do you archive the filters, samples and extracted DNA?

Figure 15. Archiving of filters, samples and DNA (Researchers)

A factor that complicates the issue of adhering to a standardized protocol is that the decision about which protocol to use is very seldom standard for any particular institution or department but relies on the individual researchers forming the projects (Fig 16).

Q: Who typically decides which protocol to use?

Figure 16. Decision of which protocol to use (Researchers)   

According to the responses in the survey, this decision is often taken by the various project consortiums, the relevant work package leader or the project manager. This gives the leading researchers in the various projects a large responsibility in terms of standardization and alignment on a larger regional scale.

When asked what the choice of ptotocol typically is based on, 80% of the researchers stated that the choice is project or purpose based (Fig 17). In addition, over 25% said that the decision is based on practicality or opportunity.

Q: What is the choice of protocol based on?

Figure 17. Basis for choice of ptotocol (Researchers)

However, there are attempts to align to current gold standards and/or international schemes as a third of the respondents stated that the choice of protocol is also based on an alignment to international schemes. Ocean Best Practices https://www.oceanbestpractices.org/ was recommended as a source for finding protocols to align to. In addition to specific protocols in various scientific papers, the web page also contains the OBON Community practices repository https://repository.oceanbestpractices.org/handle/11329/1804 , which includes more general and inclusive guidelines for working with eDNA such as the EU COST Action DNAqua-Net report (Bruce et al. 2021).

In order to get an insight into the process of implementation of eDNA methods in marine monitoring in the respective countries, stakeholders were asked to state their view on at what stage the implementation was for the three focus areas in their respective countries.

From their responses, there seemed to be very few instances of eDNA methods presently being implemented (Fig 18). However, in the field of Biodiversity / Climate change 83.3% of the respondents stated that eDNA methods were currently being tested or planned for trial in this field.

Q: Overall, at what stage is implementation of eDNA methods in these fields in your country?

Figure 18. Stage of implementation of eDNA methods (Stakeholders)

For Marine Resource Management 25% of the stakeholders did not know what the current status was and 16.7% stated that eDNA methods were not on the agenda. However, almost 60% of the respondents knew of eDNA methods being implemented, tested or planned for trial. For Impact assessment, a third of the stakeholders stated that implementation was not on the agenda and an additional 16.7% did not know the status. Therefore, Impact assessment was the focus area that seemed to have the least progress in implementation of eDNA methods.

Another feature to be noticed is that there were several more responses from the Faroe Islands and Iceland, who had similar responses to this question, stating that the implementation of eDNA methods was not on the agenda than from Norway (Fig 18). Also, there were many different answers to the same questions, especially for Iceland and the Faroe Islands, indicating that there are no national strategies or common understanding of the process of implementation. In Norway there seemed to be a slightly better consensus, and some Norwegian stakeholders commented that they intend to “highlight the need for standardization of methods and coordination of guidelines from the scientific community”. In addition, they wish to address the infrastructure for the storage of data and reference materiale, samples, etc.

In comparison, in Finland there has been a coordinated work led by the Finnish Environment Institute (SYKE) to prepare a national strategy for the implementation of eDNA methods in monitoring (Norros et al. 2022) as well as guidelines for using eDNA in marine phytoplankton monitoring in Finland (Jerney et al. 2022). In Sweden, the LIFE-DNAquatic project, funded by the Swedish Environmental Protection Agency’s Research Grant in collaboration with the Swedish Agency for Marine and Water Management, was initiated to establish guidelines for using eDNA methods for monitoring of aquatic environments in Sweden. This work resulted in two reports (Hellstrøm et al. 2021a, 2021b) that Swedish researchers in the field can adhere to.

These and other similar Nordic initiatives could provide an opportunity for others to draw inspiration from and consider in terms of international alignment in the process of forming their own eDNA strategies and guidelines.

In the UNIFIeD survey, stakeholders identified budget restrictions and lack of validation of eDNA methods as the main challenges for implementation (Fig 19). In the Faroe Islands and Iceland, where the responses again were similar, the lack of biomonitoring programs and low priority in the administration were also considered a major challenge. Overall, the stakeholders in Norway estimated the situations to be less problematic than the stakeholders in Iceland and the Faroe Islands as a third of the responses from Norway were “not a problem” while only 14.3% of the stakeholders in the Faroe Islands and Iceland chose that statement.

Q: What are the main challenges for implementation of eDNA methods in marine monitoring?

Figure 19. Main challenges for implementation (Stakeholders)

The researchers stated that the lack of national biomonitoring programs and lack of continuity in funding were the main challenges for the implementation process.

The higest ranking challenges as estimated by the researchers were:

It seems that researchers and stakeholders do not disagree on what the major challenges are, although there are minor differences in ranking of the main issues. For researchers, biomonitoring programs and more long-term funding provide valuable opportunities for testing and validating eDNA methods, which the researchers also state is a challenge. Some relevant monitoring programs mentioned by the researchers are listed in Table 2.

Table 2. Monitoring programs mentioned by the researchers

Stakeholders estimated that validating the eDNA methods was the most needed constructive measure (Fig 20) for the implementation process. Since the collective responses in the UNIFIeD survey seemed to illustrate that the validation and implementation of eDNA methods in marine monitoring requires a coordinated effort from researchers and stakeholders, a joint discussion between researchers and stakeholders on how to proceed might be a way forward. 

Q: Please rank the following constructive measures according to what you think is most needed/wanted

Figure 20. Constructive measures (Stakeholders)