A central objective of the Ross Sea region Marine Protected Area (MPA) is to protect areas important to the life cycle of Antarctic toothfish (Dissostichus mawsoni), a top fish predator and by far the region’s most important commercial species. Juvenile toothfish predominate in deep basins along the inner continental shelf, whereas adults are found mostly along the continental slope and spawning areas on the Pacific-Antarctic Ridge. The inner basins connect to the continental slope via glacial troughs and predictable transport along each trough results in exchange with the Antarctic Slope Current as it flows westward. From the slope, two transport pathways, an eastern one from Iselin Bank and a western one that turns cyclonically along the flank of the Southeast Indian Ridge, connect northward to the Pacific-Antarctic Ridge, where the northern arm of the Ross Gyre and the Antarctic Circumpolar Current flow eastward. Using a circulation model to compare transport pathways connecting toothfish life history areas, we consider which inshore basins are likely most important in contributing to adult spawning aggregations; how transport pathways from each may be expected to influence distributions along the continental slope and Pacific-Antarctic Ridge; and how zonal transport pathways may promote export to areas downstream of the marine reserve. Although the MPA protects some critical life history pathways for toothfish, others remain vulnerable to commercial fishing, and we argue that those in adjacent areas along the Iselin Bank, Pacific-Antarctic Ridge and the Amundsen Sea might usefully be protected, discussing the range of policy instruments available. We also recommend consideration of transport pathways in deliberations for a proposed network of Southern Ocean MPAs, introducing a system-based tool using chemical tracers in otoliths that can test for toothfish movement between areas connected along the Antarctic Slope Current and Antarctic Circumpolar Current.

罗斯海地区海洋保护区 (MPA) 的一个中心目标是保护对南极牙鱼 ( Dissostichus mawsoni)生命周期很重要的区域)，一种顶级鱼类捕食者，也是该地区迄今为止最重要的商业物种。幼鱼主要分布在内陆架的深水盆地，而成鱼主要分布在大陆坡和太平洋-南极海脊的产卵区。内盆地通过冰川槽连接到大陆坡，沿着每个槽的可预测运输结果与向西流动的南极坡流进行交换。从斜坡开始，两条运输通道，一条来自伊塞林岸的东部通道，一条沿东南印度洋脊侧翼旋风转向的西部通道，向北连接到太平洋-南极洋脊，即罗斯环流的北臂和南极环极电流向东流动。使用循环模型来比较连接牙鱼生活史区域的运输路径，我们考虑哪些近海盆地可能对成体产卵聚集最重要；预计每条线路的运输路径将如何影响沿大陆坡和太平洋-南极海脊的分布；以及区域运输路径如何促进向海洋保护区下游地区的出口。尽管 MPA 保护了牙鱼的一些关键生活史途径，但其他一些仍然容易受到商业捕捞的影响，我们认为伊塞林海岸、太平洋-南极海脊和阿蒙森海沿岸邻近地区的那些可能会受到有益的保护，并讨论了政策范围可用的仪器。