Causal Approach to Determining the Environmental Risks of Seabed Mining.

Laura Kaikkonen,Anna Törnroos,Inari Helle,Laura Uusitalo,Sakari Kuikka,Kirsi Kostamo,Henrik Nygård,Riikka Venesjärvi

doi:10.1021/acs.est.1c01241

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.

Highlights

The increasing global demand for rare earth elements and other metals[1,2] is driving interest in extracting minerals from the seafloor
This study evaluates the ecological risks of seabed mining using a causal probabilistic approach
By interviewing a multidisciplinary group of experts, we outline a basis for an ecological risk assessment model

Summary

Introduction

The increasing global demand for rare earth elements and other metals[1,2] is driving interest in extracting minerals from the seafloor. While most exploration concerns mining the deep seabed,[4] the high cost and technological challenges of operating in the deep sea are driving further interest in mineral extraction from shelf seas.[5] To avoid unbridled development of maritime activities, the impacts of new types of activities should be carefully evaluated prior to permitting them.[6] dealing with impacts of activities that have not yet taken place means that there is no observational data on the impacts, with high uncertainties on both the implementation of the activity and its consequences for the environment This uncertainty creates a challenge to estimate the impacts in a way that is scientifically robust, while accounting for the knowledge gaps to support decision-making

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