Causal Approach to Determining the Environmental Risks of Seabed Mining

Abstract

Mineral deposits containing commercially exploitable metals are of interest for seabed mineral extraction in both the deep sea and shallow sea areas. However, the development of seafloor mining is underpinned by high uncertainties on the implementation of the activities and their consequences for the environment. To avoid unbridled expansion of maritime activities, the environmental risks of new types of activities should be carefully evaluated prior to permitting them, yet observational data on the impacts is mostly missing. Here, we examine the environmental risks of seabed mining using a causal, probabilistic network approach. Drawing on a series of expert interviews, we outline the cause-effect pathways related to seabed mining activities to inform quantitative risk assessments. The approach consists of (1) iterative model building with experts to identify the causal connections between seabed mining activities and the affected ecosystem components and (2) quantitative probabilistic modeling. We demonstrate the approach in the Baltic Sea, where seabed mining been has tested and the ecosystem is well studied. The model is used to provide estimates of mortality of benthic fauna under alternative mining scenarios, offering a quantitative means to highlight the uncertainties around the impacts of mining. We further outline requirements for operationalizing quantitative risk assessments in data-poor cases, highlighting the importance of a predictive approach to risk identification. The model can be used to support permitting processes by providing a more comprehensive description of the potential environmental impacts of seabed resource use, allowing iterative updating of the model as new information becomes available.

Quantifying Earth system interactions for sustainable food production: an expert elicitation

“…Related to the impacts of Land system change on BI Land, when we recalculated the Lade et al (2020) estimate with our definition for interaction strength, their estimate of the strengths becomes moderate while ours is very strong. A recent study by De Palma et al (2021) finds that the reduction of Biodiversity Intactness Index (BII) is half of the relative reduction in forest cover, which is closer to Lade et al's (2020) findings than ours. An earlier empirical approach, which estimates species loss relative to habitat disturbance for tropical forests (Alroy 2017), finds that the relationship for certain taxonomic groups can be above the 1:1 ratio, consistent with our assessment.…”

Quantifying Earth system interactions for sustainable food production via expert elicitation

“…Even though modelling has traditionally been based on collected quantitative data, the further we increase the complexity of what we aim to model, the higher the data demand becomes. Thus, using expert knowledge has become common and is applied in different fields and for various purposes-for example, in ecosystem modelling 43 , risk assessment 44 and even augmenting machine learning models 45 . Our expert elicitation on complex Earth system process interactions is a notable step forward in better understanding of processes that would otherwise remain unknown.…”

Effects of Migration and Diffusion of Suspended Sediments on the Seabed Environment during Exploitation of Deep-Sea Polymetallic Nodules

“…Factors affecting the mining process include water depth at the extraction site the depth of extracted sediment, and the processing return technique. Geologists and ecologists have included several environmental factors in their causal maps, includin variables describing sediment characteristics and composition, water column chemistry and hydrological parameters [133]. The causal relationship between polymetallic nodul mining and marine ecological environment systems is evaluated by giving weight t each influencing factor and introducing methods such as expert scoring, weight analysi In any case, current monitoring technology continues to develop steadily.…”

“…Factors affecting the mining process include water depth at the extraction site, the depth of extracted sediment, and the processing return technique. Geologists and ecologists have included several environmental factors in their causal maps, including variables describing sediment characteristics and composition, water column chemistry, and hydrological parameters [133].…”