Resilience of benthic deep-sea fauna to mining activities

Abstract

With increasing demand for mineral resources, extraction of polymetallic sulphides at hydrothermal vents, cobalt-rich ferromanganese crusts at seamounts, and polymetallic nodules on abyssal plains may be imminent. Here, we shortly introduce ecosystem characteristics of mining areas, report on recent mining developments, and identify potential stress and disturbances created by mining. We analyze species' potential resistance to future mining and perform meta-analyses on population density and diversity recovery after disturbances most similar to mining: volcanic eruptions at vents, fisheries on seamounts, and experiments that mimic nodule mining on abyssal plains. We report wide variation in recovery rates among taxa, size, and mobility of fauna. While densities and diversities of some taxa can recover to or even exceed pre-disturbance levels, community composition remains affected after decades. The loss of hard substrata or alteration of substrata composition may cause substantial community shifts that persist over geological timescales at mined sites.

Exploring the Ecology of Deep-Sea Hydrothermal Vents in a Metacommunity Framework

“…The tubeworm-associated macrofauna sequentially changed in dominance from polychaetes to limpets and total faunal richness at vent sites recovered to 75-90% of pre-eruption values within 2 years, representing 30-60% of species from the larger regional species pool Marcus et al, 2009;Gollner et al, 2017). Notably, during the short observation periods after the eruptions in both Pacific regions, death of foundation species in small aggregations resulted from cessation of vent flow.…”

Editorial: Biodiversity of the Clarion Clipperton Fracture Zone

“…It does seem to be clear, though, that nodules have both significant economic and ecological value (Fritz 2016). In particular, the removal or burial of nodules by mining activities will erase the biota that depend on nodules for habitat, and will also affect the soft-sediment fauna through sediment compression and disruption of near-surface sediment layers (Miljutin et al 2011;Vanreusel et al 2016;Jones et al 2017;Gollner et al 2017). Due to the slow growth rates of nodules (ca.…”

“…Due to the slow growth rates of nodules (ca. 10 mm/My) and overall very low sedimentation rates, short-term recovery is unlikely; the nodules and noduledependent fauna may take millions of years to recover, and even the partial recovery of the motile sediment-dwelling fauna may take hundreds to thousands of years (Smith et al 2008b;Miljutin et al 2011;Wedding et al 2013;Gollner et al 2017). Additionally, mining impacts may be farreaching, beyond the actual mining block, that would affect benthic and pelagic communities largely through the dispersion of sediment plumes, as well as (potentially toxic) discharge water from mine tailings (ECORYS 2014;Gollner et al 2017).…”

The Benthic Megafaunal Assemblages of the CCZ (Eastern Pacific) and an Approach to their Management in the Face of Threatened Anthropogenic Impacts

“…Midas) and the present joint action on deep seabed mining impact initiated under the Strategic Research and Innovation Agenda of the JPI Healthy and Productive Seas and Oceans programme funded by EU's Horizon 2020. The results we present here contribute toward the urgently required full description of the referential state of the areas to be mined (Gollner et al, 2017).…”

“…The temporal and spatial scales of disturbances will naturally determine whether these habitats are able to sustain themselves or change to the extent that the original pristine state can never be recovered (Gundersen and Pritchard, 2002;Berkes et al, 2003;Gollner et al, 2017). The extent of impacts will have crucial consequences for management, since it is easier to repair a damaged ecosystem than restore, it once destroyed.…”