In their Policy Forum “Challenges to the future conservation of the Antarctic” (13 July, p. [158][1]), S. L. Chown et al. discuss concerns about the Antarctic Treaty System's (ATS's) ability to navigate future challenges. We believe ATS has demonstrated that it is both robust and adaptable. ![Figure][2] United. Treaty nation flags fly over the South Pole. CREDIT: PETTY OFFICER 2ND CLASS JOHN K. SOKOLOWSKI/U.S. NAVY Chown et al. raise the issue of marine resource harvesting, biological prospecting, and potential mineral and hydrocarbon exploitation. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) regulates the harvesting of marine resources in the Southern Ocean, and it has arguably the most highly developed system for ecosystem-based management of any international agreement ([ 1 ][3]). Underpinning CCAMLR's decision-making processes is the precautionary approach which, as it has evolved, has set very conservative catch limits on fish stocks and provided other mechanisms for reducing harvesting impacts. The Southern Ocean krill fishery is arguably the largest underexploited fishery in the world. For many years, CCAMLR has been developing mechanisms in advance of projected escalation of interest in the fishery, including setting precautionary catch limits, establishing small-scale management areas, and invoking trigger points where, when a predesignated catch is exceeded, additional conservation measures will apply. In their discussion of the submissions of several Antarctic claimant states to the Commission on the Limits of the Continental Shelf (CLCS), Chown et al. have misconstrued both the actions of those Antarctic Treaty Parties and the effects of those actions. All Antarctic Treaty Parties are bound by the Antarctic mining ban ([ 2 ][4]). Submission of data to the CLCS in relation to Antarctic or other continental shelves has no bearing on that ban or a party's obligation to uphold it. Mitigating unacceptable human impacts in Antarctica is a substantial focus for the Antarctic Treaty Consultative Parties, as Chown et al. note. There is no evidence that human interest in Antarctica will outpace the capacity of the ATS to respond. The historically steady climb in Antarctic tourism numbers from the 1990s has been reversed since the 2008 financial crisis ([ 3 ][5]) and also since the International Maritime Organization introduced a ban on the use and carriage of heavy and intermediate fuel into the Antarctic Treaty Area in 2011 ([ 4 ][6]). Tourism is subject to ongoing monitoring, oversight, and management, mainly through the International Association of Antarctica Tour Operators (IAATO)—an organization mindful of the extraordinary responsibilities it carries for maintaining the integrity of the pristine Antarctic environment. Local impact is minimized by a system of site guidelines and rules about behavior ashore—the latter originally adopted by IAATO in its by-laws and later formalized by the ATS. The Antarctic Treaty Consultative Parties have addressed past challenges firmly and overtly within the Antarctic Treaty's twin pillars of peace and science ([ 5 ][7]). Reforms to the operation of the Antarctic Treaty Consultative Meeting, increased opportunities for engagement with relevant international organizations, and the presence of nongovernmental organizations as observers to ATS meetings and as members of national delegations since the mid-1980s all work to strengthen the institutional resilience of the ATS. The number of parties acceding to instruments of the Antarctic Treaty System has steadily increased (including, notably, Malaysia and Pakistan in 2011). At the same time, the Antarctic Treaty Consultative Parties have increased engagement with relevant international organizations: among them, the UN Food and Agriculture Organization regarding IUU fishing; the International Hydrographic Office in relation to charting Antarctic waters; and the International Maritime Organization in the development of the Polar Shipping Code. We concur that the challenges facing the region defy complacency. The quickening pace of global change requires scientists and policymakers to work together. With this as a fundamental underpinning for future action, we believe the ATS is well placed to meet these challenges. 1. [↵][8] 1. A. Constable , Fish Fisheries 12, 138 (2011). [OpenUrl][9][CrossRef][10][Web of Science][11] 2. [↵][12] Article 7, Protocol on Environmental Protection to the Antarctic Treaty, Antarctic Treaty Secretariat ([www.ats.aq/e/ep.htm][13]). 3. [↵][14] International Association of Antarctica Tour Operators, Tourism Statistics ( ). 4. [↵][15] Annex I, Chapter 9, “Special requirements for the use or carriage of oils in the Antarctic area,” International Convention for the Prevention of Pollution from Ships (MARPOL) (International Maritime Organization Resolution MEPC.189(60), 26 March 2010). 5. [↵][16] Articles I and III of the Antarctic Treaty, Antarctic Treaty Secretariat ([www.ats.aq/documents/ats/treaty_original.pdf][17]). [1]: /lookup/doi/10.1126/science.1222821 [2]: pending:yes [3]: #ref-1 [4]: #ref-2 [5]: #ref-3 [6]: #ref-4 [7]: #ref-5 [8]: #xref-ref-1-1 View reference 1 in text [9]: {openurl}?query=rft.jtitle%253DFish%2BFisheries%26rft.volume%253D12%26rft.spage%253D138%26rft_id%253Dinfo%253Adoi%252F10.1111%252Fj.1467-2979.2011.00410.x%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [10]: /lookup/external-ref?access_num=10.1111/j.1467-2979.2011.00410.x&link_type=DOI [11]: /lookup/external-ref?access_num=000290540700003&link_type=ISI [12]: #xref-ref-2-1 View reference 2 in text [13]: http://www.ats.aq/e/ep.htm [14]: #xref-ref-3-1 View reference 3 in text [15]: #xref-ref-4-1 View reference 4 in text [16]: #xref-ref-5-1 View reference 5 in text [17]: http://www.ats.aq/documents/ats/treaty_original.pdf