Data from: Addressing grand ecological challenges in aquatic ecosystems: How can mesocosms be used to advance solutions?

Rapid and drastic anthropogenic impacts are affecting global
biogeochemical processes and driving biodiversity loss across Earth’s
ecosystems. In aquatic ecosystems, species distributions are shifting,
abundances of many species have declined dramatically, and many are
threatened with extinction. In addition to loss of diversity, the
ecosystem functions, processes and services on which humans depend are
also being heavily impacted. Addressing these challenges not only requires
direct action to mitigate environmental impacts but also innovative
approaches to identify, quantify and treat their effects in the
environment. Mesocosms are valuable tools for achieving these goals as
they provide controlled environments for evaluating effects of stressors
and testing novel mitigation measures at multiple levels of biological
organisation. Here, we summarise discussions from a survey of marine and
freshwater researchers who use mesocosm systems to synthesise their
opportunities and limitations for advancing solutions to grand ecological
challenges in aquatic ecosystems. While most research utilising mesocosm
systems in aquatic ecology has focused on quantifying the effects of
environmental threats, there is a largely unexplored potential for using
them to test solutions. To overcome spatio-temporal constraints, there are
opportunities to scale up the size and time-scales of mesocosm studies, or
alternatively, test the outcomes of habitat-scale restoration at a smaller
scale. Enhancing connectivity in future studies can help to overcome the
limitation of isolation and test an important aspect of ecological
recovery. Conducting ‘metacosm’ studies: co-ordinated, distributed
mesocosm experiments spanning wide climatic and environmental gradients
and utilising more regression-based experimental designs can help to
tackle the challenge of context dependent results. Finally, collaboration
of theoretical, experimental and applied ecologists and biogeochemists
with environmental engineers and technological developers will be
necessary to develop and test the tools required to advance solutions to
the impacts of human activities on Earth’s vulnerable aquatic ecosystems.