Beyond static spatial management: Scientific and legal considerations for dynamic management in the high seas

Abstract

Natural and human stressors in the high seas act across a wide range of spatial and temporal scales. These include direct interaction such as fisheries bycatch or indirect interaction like warming oceans and plastic ingestion. Area-based management tools (ABMTs), such as marine protected areas and time-area closures, are a widely accepted and a broadly successful form of management used to mitigate localized human impacts on marine species and ecosystems. Protection provides an opportunity for population recovery, which can then propagate outside of the closure. As the United Nations negotiates a new treaty on the conservation and sustainable use of biodiversity beyond national jurisdiction, efforts to design and implement high seas ABMTs at appropriate scales are critical to ensure that these spatial protection measures are most effective and climate-ready in the face of changing oceans. Here we identify the four most important temporal scales – contemporary, intra-annual, multi-annual and multidecadal – for aligning high seas ABMTs to relevant ecological, oceanographic and atmospheric processes. From this, we explore how managers and decision-makers can integrate this knowledge when implementing a new treaty.

Spatial and life history variation in a trait-based species vulnerability and impact model

“…With the addition of life stage distributions and stressor intensity distributions, management strategies may identify high and low impact areas to mitigate impact effectively for specific life stages. The need to include spatiotemporal variation into models will become even more acute as efforts shift toward dynamic spatial management [36,72]. Management strategies could apply multiple life stage time-of-use closures across specific zones as a more cost-effective approach instead of a single larger blanket closure for the species.…”

“…Modelling ecosystem-scale impacts for dynamic species is further complicated by spatiotemporal variation in exposures to stressors as species move between key habitat areas, and the stressors themselves may also be dynamic and synergistic [9,[31][32][33][34]. Creating a spatially-explicit model by coupling species ranges with spatial stressor distributions provides conservation managers with explicit geographic information on where species are most intensely impacted by stressors and facilitates the development of effective conservation actions [22,35,36].…”