Electromagnetic changes

Localized electric and magnetic fields associated could alter behaviour (e.g. attract or repel) and migration patterns of sensitive species. Elasmobranch species (sharks, skates and rays) are relatively sensitive to electric fields, and diadromous species are expected to have relatively higher sensitivity to magnetic fields.

Local electric field of 1 volt per meter, or Local magnetic field of 10 telsa (μT) due to anthropogenic means.
Any activities with operational power cables or telecommunication cables (if equipped with power relays), and infrastructure that may create electormagnetic changes, e.g. electromagnetic surveys (CSEM) used in oil and gas. Field strength dissipates quickly and burial of cables increases distance between source and species receptors, so is an effective mitigation.
Scientific uncertainty on the sensitivity of species to this pressure is considerable, from individual physiology/behaviour to any population level implications.


The tables in this section reflect the output of the workshop (October 2019) when the pressures from human activities were assessed for the period 2014 to 2018 for the region. The summary text below the tables elaborates on some of the points that were made at the workshop.
This pressure assessment uses the FeAST classification which includes two abrasion pressures: surface abrasion & sub-surface abrasion. Some expert groups combined these as a single pressure "surface & sub-surface abrasion" whilst others focussed on using surface abrasion alone, hence there is a slight difference in handling for some regions.
The ranking of the pressures in terms of impact is a relative exercise within each region, and is not a statement of their absolute impact. Detailed comparison between regions on the basis of these relative pressure assessments is therefore not advisable.

Main pressures identified