Ireland has a rich Antarctic history, with Bransfield, Crozier, Shackleton, Crean and others acting as key Irish individuals in Antarctic exploration. Recognized as a source of Irish national pride, memorials, stamps, coins and a government research vessel all commemorate their polar feats. Today, a large proportion of Ireland's citizens visit the Antarctic region and Irish researchers produce high levels of academic outputs on Antarctic topics relative to many other nations. However, Ireland has not acceded to any Antarctic Treaty System instruments, despite a 20 year campaign to do so by cross-party Irish politicians. Ireland has the largest population of any nation in the European Union (EU) yet to accede to the Treaty and is much larger than some existing Treaty signatory states. However, Treaty accession provides no entitlement to participate in Antarctic governance, which is reserved for Consultative Parties, and therefore undertaking the associated legal and administrative work may be considered a poor use of available resources. Ireland's attainment of consultative status would be an even more complex and resource-intensive goal, but collaboration with the EU and other global partners could be a cost-effective solution that may also indirectly support Ireland's ambitions for Observer status at the Arctic Council.

Most of the Ross Sea has been designated a marine protected area (MPA), proposed ‘to protect ecosystem structure and function’. To assess effectiveness, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) selected Adélie (Pygoscelis adeliae) and emperor (Aptenodytes forsteri) penguins, Weddell seals (Leptonychotes weddellii) and Antarctic toothfish (Dissostichus mawsoni) as ecosystem change ‘indicator species’. Stable for decades, penguin and seal populations increased during 1998–2018 to surpass historical levels, indicating that change in ecosystem structure and function is underway. We review historical impacts to population trends, decadal datasets of ocean climate and fishing pressure on toothfish. Statistical modelling for Adélie penguins and Weddell seals indicates that variability in climate factors and cumulative extraction of adult toothfish may explain these trends. These mesopredators, and adult toothfish, all prey heavily on Antarctic silverfish (Pleuragramma antarcticum). Toothfish removal may be altering intraguild predation dynamics, leading to competitive release of silverfish and contributing to penguin and seal population changes. Despite decades of ocean/weather change, increases in indicator species numbers around Ross Island only began once the toothfish fishery commenced. The rational-use, ecosystem-based viewpoint promoted by CCAMLR regarding toothfish management needs re-evaluation, including in the context of the Ross Sea Region MPA.