Marine biodiversity has gotten lost in the talk about what Brexit means for the UK. While some attention has been paid to commercial fisheries, including a recently-launched Parliamentary inquiry, the post-Brexit future of UK marine habitats and species has received almost no press. The UK’s marine biodiversity is beautiful, productive, and unique. Our marine species and habitats support a wealth of essential ecosystem services, including commercial fisheries, and deserve as much consideration as our post-Brexit economy, immigration, and trade systems.
The UK’s high level objective for marine environment is simply for the UK to have “clean, healthy, safe, productive and biologically diverse oceans and seas” (Defra, 2009). Currently, this is implemented via a host of legislation, much of which originates in the EU. The Marine Strategy Framework Directive (MSFD) is one key EU policy (along with the Water Framework Directive, Habitats Directive, etc) through which the UK is delivering its high level objective. The MSFD requires Good Environmental Status (GES) for all parts of European marine ecosystems, including biodiversity, food webs, commercial fish, and pollution. As a member of the EU, the UK must deliver GES for its waters, thereby sustainably using the marine ecosystem while protecting its species and habitats, or face infraction. When we leave the EU, however, what will happen to the UK’s marine biodiversity?

Under the MSFD, Good Environmental Status must be achieved for each of these 11 ecosystem aspects (qualitative descriptors). Figure from OSPAR .
Without the legal enforcement of the EU through the MSFD there is a real danger that the UK will not deliver its current environmental protection and sustainable use objectives. Right now we are managing our marine biodiversity proactively – with clear environmental targets and objectives which must be (in the future) regionally coherent with our EU neighbours. Brexit might come with a reduced ambition for biodiversity targets, however, particularly if priorities shift from marine conservation to economic interests such as commercial fishing and coastal development. Without the legal impetus of the EU to proactively and meaningfully manage marine biodiversity, there is a risk that our management strategy may transition to a disaster-based method, where we only respond to environmental emergencies.
If funding is moved away from marine biodiversity management and monitoring, which is a real threat due to economic considerations, our ability to provide evidence for decision making will be damaged. Monitoring data are needed to detect changes in the marine environment, inform indicators, and determine whether we are meeting environmental targets. Detection of change is the first step to effectively managing our marine environment, but is dependent on the collection and analysis of robust scientific data. The UK has led the development and operationalisation of MSFD biodiversity indicators, but further work remains, particularly around linking state changes to pressures and determining the drivers of change. This information is required to help decision makers decide if and where to implement management measures, and knowledge and data gaps weaken our ability to sustainably manage the marine environment. Monitoring data also supports wider scientific advances, including blue skies research. Historically, the UK has been a leader in advancing the field of marine science, a position that may be vulnerable after Brexit.

Priorities for marine biodiversity after Brexit.
The marine ecosystem does not recognise political boundaries. Mobile species, such as fish and cetaceans, swim between EEZs, and therefore require transboundary management measures. It is unrealistic to manage UK waters in isolation. International collaboration is required to address transboundary challenges. Currently, the UK plays a prominent role in ICES and OSPAR, greatly influencing the European science-policy landscape. The UK has been leading the research required to support implementation of the MSFD’s biodiversity elements and contributes strongly to ICES working groups which, among many other important science-policy duties, deliver recommendations for fishing quotas. Additionally, more than 30,000 Europeans, many of which are scientists, work in UK universities (Royal Society, 2017), giving the UK access to skills that its own citizens do not possess. UK scientists work alongside European scientists, pushing science forward and devising new and innovative ways to examine and manage our environment. One of the most wonderful parts of being a scientist is working with people from different countries and in different disciplines – for all of the numbers around these statements see the Royal Society’s Snapshot of the UK’s Research Workforce. With the Immigration Bill still in debate, freedom of movement of people is in jeopardy, risking isolation of UK scientists from the rest of the European scientific community, and presenting challenges to our current close collaborative relationships. In turn, the cross-border collaboration which is essential for progressing delivery of the MSFD and a wider Ecosystem Approach to management, and for advancing scientific research, is in jeopardy.

Possible scenarios for managing UK marine biodiversity after Brexit.
Of course the status of UK marine biodiversity post-Brexit is not simply ‘good’ or ‘bad’, or ‘black’ or ‘white’. There are gradations of cost and opportunity. One of our best case scenarios is continued delivery of the MSFD through OSPAR, with sustained sustainability ambition. A medium case scenario could be to leave the MSFD completely, but continue to proactively manage UK marine habitats and species in isolation. This scenario, however, would have transboundary risks for mobile species, and would largely negate the ecosystem approach, unless we find some way to work closely with our European neighbours. Either of these scenarios, however, could provide the opportunity for the UK to better manage our marine biodiversity, perhaps through integrating marine environmental management with fisheries management. A worst case scenario would be to leave the MSFD completely and stop proactively managing species and habitats, instead only responding during environmental catastrophes or disasters. The scenario we end up with in March 2019 could be one of these or something else altogether. Either way, marine biodiversity deserves to be recognised as an important and special attribute of UK waters, which should be managed proactively, sustainably, and with an Ecosystem Approach.
Abigail McQuatters-Gollop,
Plankton and Policy
This blog post was inspired by a talk I gave at the October 2017 British Ecological Society/Marine Biological Association “The Marine Environment after Brexit: the future for science and policy” event in London.