Assessing the drift of fish aggregating devices in the tropical Pacific Ocean

IF 4.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Science Pub Date : 2024-01-16 DOI:10.5194/os-20-31-2024

Philippe F. V. W. Frankemölle, P. Nooteboom, J. Scutt Phillips, L. Escalle, S. Nicol, E. van Sebille

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引用次数: 0

Abstract

Abstract. The tropical Pacific Ocean is characterized by its dominant zonal flow, strong climate dependence on the El Niño–Southern Oscillation (ENSO) and abundant tuna stocks. Tuna fisheries in the West and Central Pacific Ocean accounted for 55 % of the world-wide tuna catch in 2019 and are one of the main sources of income in many Pacific island nations. One of the dominant fishing methods in this region relies on the use of drifting fish aggregating devices (dFADs): rafts with long underwater appendages (on average 50 m deep) that aggregate fish. Although currents such as the North Equatorial Countercurrent (NECC) and South Equatorial Current (SEC) in the tropical Pacific Ocean vary strongly with ENSO, little is known about the impact of this variability in flow on dFAD dispersion. In this study, virtual Lagrangian particles are tracked for the period 2006 to 2021 over the domain in a 3D hydrodynamic model and are advected in simulations with only surface flow, as well as simulations using a depth-averaged horizontal flow over the upper 50 m, representing virtual dFADs. Zonal displacements, eddy-like behaviour and ENSO variability are then studied for both types of virtual particles. It was found that virtual particles advected by surface flow only are displaced up to 35 % farther than virtual dFADs subjected to a depth-averaged flow, but no other major differences were found in dispersion patterns. The strongest correlations between ENSO and virtual dFAD dispersion for the assessed variables were found in the West Pacific Ocean, with Pearson correlation coefficients of up to 0.59 for virtual dFAD displacement. Connections between ENSO and eddy-like behaviour were found in the western part of the SEC, indicating more circulation and meandering during El Niño. These findings may be useful for improving sustainable deployment strategies during ENSO events and understanding the ocean processes driving the distribution of dFADs.

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评估热带太平洋集鱼装置的漂移情况

摘要热带太平洋的特点是其主要的带状流、对厄尔尼诺-南方涛动（ENSO）的强烈气候依赖性和丰富的金枪鱼种群。2019 年，中西太平洋的金枪鱼捕捞量占全世界金枪鱼捕捞量的 55%，是许多太平洋岛国的主要收入来源之一。该地区的主要捕鱼方法之一是使用漂流集鱼装置（dFADs）：带有长长水下附属装置（平均 50 米深）的鱼排，用于集鱼。尽管热带太平洋中的北赤道逆流（NECC）和南赤道流（SEC）等洋流会随厄尔尼诺/南方涛动（ENSO）发生强烈变化，但人们对这种洋流变化对 dFAD 扩散的影响知之甚少。在这项研究中，虚拟拉格朗日粒子在三维流体力学模型中对 2006 年至 2021 年期间的海域进行了跟踪，并在仅有表面流的模拟和使用深度平均水平流对上层 50 米的模拟中进行了平流，代表虚拟的 dFAD。然后研究了这两种虚拟粒子的带状位移、涡状行为和厄尔尼诺/南方涛动的变化。研究发现，仅受地表流平流的虚拟粒子比受深度平均流平流的虚拟 dFAD 粒子的位移最远可达 35%，但在扩散模式上没有发现其他重大差异。在西太平洋，厄尔尼诺/南方涛动与虚拟 dFAD 扩散之间的相关性最强，虚拟 dFAD 位移的皮尔逊相关系数高达 0.59。在 SEC 的西部发现了 ENSO 与涡状行为之间的联系，表明厄尔尼诺现象期间环流和蜿蜒更多。这些发现可能有助于在厄尔尼诺/南方涛动期间改进可持续部署战略，并了解驱动 dFAD 分布的海洋过程。

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来源期刊

Ocean Science 地学-海洋学

CiteScore

5.90

自引率

6.20%

发文量

审稿时长

6-12 weeks

期刊介绍： Ocean Science (OS) is a not-for-profit international open-access scientific journal dedicated to the publication and discussion of research articles, short communications, and review papers on all aspects of ocean science: experimental, theoretical, and laboratory. The primary objective is to publish a very high-quality scientific journal with free Internet-based access for researchers and other interested people throughout the world. Electronic submission of articles is used to keep publication costs to a minimum. The costs will be covered by a moderate per-page charge paid by the authors. The peer-review process also makes use of the Internet. It includes an 8-week online discussion period with the original submitted manuscript and all comments. If accepted, the final revised paper will be published online. Ocean Science covers the following fields: ocean physics (i.e. ocean structure, circulation, tides, and internal waves); ocean chemistry; biological oceanography; air–sea interactions; ocean models – physical, chemical, biological, and biochemical; coastal and shelf edge processes; paleooceanography.