I myself am uneducated on this area, and people more educated than me can chime in if I got something wrong, but I found an article that may interest you:

China and the Antarctic: Presence, policy, perception, and public diplomacy by Nong Hong (2021).

There’s no sci-hub copy available though but I’ll try summarize from my quick read-through.

China rejects expansion of the MPAs due to conflicting interpretations between the duality of “rational use” and “conservation” as stipulated in the CCAMLR (the Commission for the Conservation of Antarctic Marine Living Resources).

Another example exhibiting China’s willingness to ‘play by the rules’ are in the MPAs in the Ross Sea and East Antarctica [77]. All CCAMLR resolutions require consensus for approval. In October 2012, China was in agreement with Russia and Ukraine to oppose this proposal, as it believes that the scientific evidence is not solid enough to justify the creation of such large, restricted areas. In their views, in the absence of clear scientific analysis, “rational use” should gain greater consideration over “conservation” in any future agreement. Beijing also objected to the lengthy time period in which the proposed boundaries will be imposed (until 2064 for the Ross Sea and 2043 for the East Antarctic Reserve) [52].

Another concern of China involves the management and enforcement of marine protected area restrictions. China does not yet have the capacity to consistently contribute to enforcement activities. That responsibility will fall on the United States and Antarctic territorial claimants, including New Zealand, Australia, Chile, Argentina and the United Kingdom. MPA enforcement could cause China to lose influence over maritime governance and put it at a distinct disadvantage if existing territorial claimants try to reassert their sovereignty over disputed regions [49], [64]. The Ross Sea region MPA was expanded as a result of inserting an additional zone, (Krill Research Zone), which was proposed by China and represented a compromise between China and USA reached in 2015 [103]. China agreed to the terms of the new Ross Sea MPA since it included a Krill Research Zone which reflects China's long-standing view on the balance between conservation and rational use. The MPA was activated in December 2017 and will then be reviewed in 2052 with another consensus vote needed for a continuance [71]. Hence, China's changing position towards marine protected areas in the Southern Ocean sets a positive implication for future Antarctic governance. The Antarctic case provides concrete evidence that China’s rise in Antarctica provides a poignant example of how active engagement in global governance institutions can simultaneously enhance China’s power and foster peace and security in the international system [52].

I am unsure about the specific areas mentioned in the news article, but I am taking on the assumption that it may be due to similar reasons.

We must also be aware that China is often portrayed as an environmental polluter versus the ecofriendly West, which has been going on, for what, decades now? So I’d be extremely sceptical about any claims about the environment by the country with the largest historical carbon emissions and highest carbon emissions per capita, the United States, who year after year downplays their necessary carbon intensity goals (and other environmental conservation goals) to deride Global South countries for not doing enough. Not to mention the psyops and NGOs.

Also a quick look through the mentioned organisation in the article - the Antarctic and Southern Ocean Coalition, showcases totally not nepo babies and overwhelmingly American government affiliated people on the board (mainly USAID but some others), an organisation based in Washington DC (of course), and in general staff who are all are Western educated and/or a Westerner.