Abstract. Dynamics of ocean boundary currents and associated shelf processes can influence onshore/offshore transport of water, critically impacting marine organisms that release long-lived pelagic larvae into the water column. The western rock lobster, Panulirus cygnus, endemic to Western Australia, is the basis of Australia's most valuable wild-caught commercial fishery. After hatching, western rock lobster larvae (phyllosoma) spend up to 11 months in offshore waters before ocean currents and their ability to swim, transport them back to the coast. The abundance of western rock lobster puerulus (settlement phase post phyllosoma) has historically been observed to be positively correlated with the strength of the Leeuwin Current, and an index of puerulus numbers is used by fisheries managers as a predictor of subsequent lobster abundance 3–4 years later. In 2008 and 2009 the Leeuwin Current was strong, yet a settlement failure occurred throughout the fishery prompting management changes and a rethinking of environmental factors associated with their settlement. Thus, understanding factors that may have been responsible for the settlement failure is important for fisheries management. Oceanographic parameters likely to influence puerulus settlement were derived for a 17 year period to investigate correlations. Analysis indicated that puerulus settlement at adjacent monitoring sites have similar oceanographic forcing with kinetic energy in the offshore and the strength of the Leeuwin Current being key factors. Settlement failure years were synonymous with “hiatus” conditions in the south-east Indian Ocean, and periods of sustained cooler water present offshore. Post 2009, there has been an unusual but consistent increase in the Leeuwin Current during the early summer months with a matching decrease in the Capes Current, that may explain an observed settlement timing mismatch compared to historical data. Our study has revealed that a culmination of these conditions likely led to the recruitment failure and subsequent changes in puerulus settlement patterns.

中文翻译：

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使用海洋学模型来调查失踪的绿萝的奥秘

摘要。海洋边界流的动力学和相关的陆架过程会影响水的陆上/近海运输，严重影响将长寿命的远洋幼虫释放到水体中的海洋生物。西部岩龙虾，Panulirus cygnus是西澳大利亚特有的，是澳大利亚最有价值的野生商业渔业的基础。孵化后，西部岩龙虾幼虫（叶状体）在近海水域中度过长达 11 个月的时间，然后洋流及其游泳能力将它们运回海岸。历史上观察到西部岩龙虾 puerulus（叶状体后的沉降阶段）的丰度与 Leeuwin 海流的强度呈正相关，渔业管理人员使用 puerulus 数量指数作为后续龙虾丰度的预测指标 3-4多年后。2008 年和 2009 年，Leeuwin 海流强劲，但整个渔业都发生了沉降失败，促使管理发生变化，并重新思考与其沉降相关的环境因素。因此，了解可能导致定居失败的因素对于渔业管理很重要。在 17 年的时间里推导出了可能影响 Puerulus 沉降的海洋参数，以研究相关性。分析表明，相邻监测点的普鲁鲁斯沉降具有相似的海洋强迫，近海动能和列温海流强度是关键因素。沉降失败年与印度洋东南部的“中断”条件以及近海持续存在较冷水的时期同义。2009 年之后，在初夏的几个月里，Leeuwin 海流出现了异常但持续的增加，而 Capes 海流的相应减少，这可能解释了与历史数据相比观察到的沉降时间不匹配。