The Slope Sea in the Northwest Atlantic Ocean, located between the Gulf Stream and the continental shelf of the Northeast United States, is a recently-documented possible major spawning ground for Atlantic bluefin tuna (Thunnus thynnus). Larval surveys and a habitat modeling study have shown that suitable spawning habitat occurs in the Slope Sea, but the degree to which this habitat varies interannually is an open question. Here, we perform a decade-long (2009–2018) numerical modeling analysis, with simulated larvae released uniformly throughout the Slope Sea, to investigate the interannual variability in the water temperature and circulation criteria deemed necessary for successful spawning. We also quantify the influence of Gulf Stream meanders and overshoot events on larval retention and their effect on habitat suitability rates throughout the Slope Sea, defined as the percentage of simulated larvae released at a given location that satisfy criteria related to water temperature and retention near nursery habitat. Average environmental oceanographic conditions over the decade are most favorable in the western part of the Slope Sea, specifically in the Slope Gyre and away from the immediate vicinity of the Gulf Stream. Variability in domain- and summertime-averaged yearly spawning habitat suitability rates is up to 25% of the mean decadal-averaged values. Yearly habitat suitability correlates strongly with the Gulf Stream overshoot but does not correlate well with other oceanographic variables or indices, so an overshoot index can be used as a sole oceanographic proxy for predicting yearly bluefin spawning habitat suitability in the Slope Sea. Selective spawning can weaken the correlation between habitat suitability and Gulf Stream overshoot. Effort should be put towards collecting observational data against which we could validate our findings.

位于西北大西洋的斜坡海，位于墨西哥湾流和美国东北部大陆架之间，是最近记录的大西洋蓝鳍金枪鱼（Thunnus thynnus）可能的主要产卵场。）。幼虫调查和栖息地建模研究表明，合适的产卵栖息地出现在坡海中，但是该栖息地的年际变化程度是一个悬而未决的问题。在这里，我们进行了长达十年（2009-2018年）的数值模拟分析，模拟的幼体在整个斜坡海中均匀释放，以调查水温的年际变化和成功产卵所必需的循环标准。我们还量化了湾流蜿蜒和过冲事件对幼虫滞留的影响及其对整个斜坡海的栖息地适宜性的影响，定义为在给定位置释放的模拟幼虫的百分比，该幼虫满足与水温和苗圃附近的滞留有关的标准栖息地。十年间，海洋环境的平均环境条件最有利于坡海西部，特别是在坡环流和远离墨西哥湾流的地区。产区和夏季平均产卵栖息地适宜性年均变化率高达十年平均值的25％。年度栖息地的适宜性与墨西哥湾流超调高度相关，但与其他海洋变量或指数却没有很好的相关性，因此，超调指数可作为唯一的海洋代理来预测坡海的蓝鳍产卵栖息地的年度适宜性。选择性产卵可削弱栖息地适应性与墨西哥湾流过冲之间的相关性。应该努力收集可以验证我们发现的观测数据。