Future marine biodiversity and ecosystem functioning research issues
The European Network of Excellence on Marine Biodiversity and Ecosystem Functioning (MarBEF) has, over the past five years of its existence, moulded a scientific community that has never been so conceptually and operationally united and productive. However, marine science is still developing and we still understand the ocean less than the terrestrial environment. For us, the oceans are foreign habitats which we may enter but not yet inhabit.
MarBEF scientists have focused on and identified many critical marine biodiversity issues, which are now much clearer than before, but MarBEF has also revealed areas of weakness that require concentrated effort. These are as follows:
Impacts of global climate change
Although there is now strong evidence for changes in the global climate, the medium term and long-term effects on the marine environment are still open to debate. Marine systems, from polar ice to coral reefs are charismatic systems which are highly vulnerable to temperature, sea-level and storm frequency changes.
Evidence of migrational responses to climate are accumulating and act as an early warning of the nature of community alteration in the face of global change scenarios. Studies of modifications to ecosystem variation and functionality resulting from climate change must remain of the highest priority over the coming ten years. Some of these studies require long-term databases that are now recognised as being highly valuable and important to maintain.
Many current topics in marine biodiversity research are taking place on very large spatial scales and over long-term periods. They are among other things creating baseline assessments in the marine realm, for assessing impacts of climate change on marine biodiversity, and studying the mechanisms by which alien species are introduced.
Therefore, MarBEF recognised that its scientists would require analyses on a global scale and it funded the LargeNet project. LargeNet collected and integrated a large amount of data, comprising pelagic, rocky shore and soft-bottom benthos data from across Europe. This data established a baseline for current biodiversity analyses and future investigations within a changing world. This scale of data collection is necessary to be able to understand and anticipate the consequences of environmental variations on biodiversity. The database has, for example, been employed to assess the current biodiversity status and future changes in marine communities. See also here.
Synergy of anthropogenic impacts additional to global warming
The oceans have been used as a means of transport, resource acquisition and disposal for centuries. While attitudes to the exploitation of the seas are changing, there is still a requirement to understand and manage the transport pathways and the effects of pollutants arising from ocean exploitation. These pathways include run-off of contaminants from the land, direct input through energy (thermal pollution), liquid and solid waste from vessels and accidental addition of xenobiotic material.
Research has often focused on a single stress factor, but multi-stress systems and modelling are also required. This area of work has particular implications given the overlap between stresses resulting from environmental change. Marine exploitation carries with it a number of responsibilities toward environmental management. Biodiversity impacts include those caused by introduced invasive species and consequent biodiversity and functionality effects.
In addition, fisheries practice (e.g., benthic trawling) has the capacity to cause major localised and regional impact of the shelf ocean systems. In terms of non-fisheries impacts, study of the diverse impacts (noise, habitat disturbance, resource removal) caused by commercial companies (gravel extraction, dredging, oil industry) must continue to be a central issue in protecting oceanic systems. Research to characterise ecosystem- and region-specific impacts of multiple stressors is essential for the effective implementation of the new Marine Strategy Framework Directive.
Coastal management can only be performed if its based on sound knowledge and international cooperation. The passage from knowledge generation to knowledge-based management should not stop our quest for new knowledge, the two should in fact stimulating each other. The speed at which new knowledge can be translated into management practice needs to be improved. The calls for future research development must be aimed at filling gaps in our knowledge – gaps that must be identified by the scientific community, the developers of policy and the stakeholders.
Phase shifts: alternate stable states
Theoretically, a single may exist in a number of possible states, or ‘alternate stable states.’ These alternatives are often considered to represent “good” or “poor” conditions – for example, the switch from a diverse pelagic food web (good) to a low-diversity system dominated by jellyfish (poor). The various alternate stable states for each system must be recognised, triggers causing shifts between them must be characterised, and impacts of shifts assessed.
Habitat diversity is of paramount importance in sustaining biodiversity. This is recognised by the EC Habitats Directive, but marine habitats are poorly represented by this directive. European marine habitats must be classified under a consistent rationale and then mapped, as has already been done for terrestrial habitats.