Cresci Alessandro, Durif Caroline M F, Larsen Torkel, Bjelland Reidun, Skiftesvik Anne Berit, Browman Howard I
Institute of Marine Research, Austevoll Research Station, Sauganeset 16, N-5392 Storebø, Norway.
PNAS Nexus. 2022 Aug 27;1(4):pgac175. doi: 10.1093/pnasnexus/pgac175. eCollection 2022 Sep.
High-voltage direct current (HVDC) subsea cables are used to transport power between locations and from/to nearshore and offshore facilities. HVDC cables produce magnetic fields (B-fields) that could impact marine fish. Atlantic haddock () is a demersal fish that is at risk of exposure to anthropogenic B-fields. Their larvae drift over the continental shelf, and use the Earth's magnetic field for orientation during dispersal. Therefore, anthropogenic magnetic fields from HVDC cables could alter their behavior. We tested the behavior of 92 haddock larvae using a setup designed to simulate the scenario of larvae drifting past a B-field in the intensity range of that produced by a DC subsea cable. We exposed the larvae to a B-field intensity ranging from 50 to 150 µT in a raceway tank. Exposure to the B-field did not affect the spatial distribution of haddock larvae in the raceway. Larvae were categorized by differences in their exploratory behavior in the raceway. The majority (78%) of larvae were nonexploratory, and exposure to the artificial B-field reduced their median swimming speed by 60% and decreased their median acceleration by 38%. There was no effect on swimming of the smaller proportion (22%) of exploratory larvae. These observations support the conclusion that the swimming performance of nonexploratory haddock larvae would be reduced following exposure to B-field from HVDC cables. The selective impact on nonexploratory individuals, and the lack of impact on exploratory individuals, could have population-scale implications for haddock in the wild.
高压直流（HVDC）海底电缆用于在不同地点之间以及近岸和离岸设施之间输送电力。高压直流电缆会产生磁场（B场），这可能会对海洋鱼类产生影响。大西洋黑线鳕（Melanogrammus aeglefinus）是一种底栖鱼类，有暴露于人为产生的B场的风险。它们的幼体在大陆架上漂流，并在扩散过程中利用地球磁场进行定向。因此，高压直流电缆产生的人为磁场可能会改变它们的行为。我们使用一种设计用于模拟幼体漂过直流海底电缆产生的强度范围内的B场场景的装置，测试了92只黑线鳕幼体的行为。我们在一个跑道式水槽中将幼体暴露于强度范围为50至150微特斯拉的B场中。暴露于B场并未影响跑道中黑线鳕幼体的空间分布。幼体根据它们在跑道中的探索行为差异进行分类。大多数（78%）幼体是非探索性的，暴露于人工B场使它们的平均游泳速度降低了60%，平均加速度降低了38%。对较小比例（22%）的探索性幼体的游泳没有影响。这些观察结果支持了这样的结论：非探索性黑线鳕幼体在暴露于高压直流电缆产生的B场后，其游泳性能会降低。对非探索性个体的选择性影响以及对探索性个体缺乏影响，可能会对野生黑线鳕种群产生种群规模的影响。
