Heard Island and McDonald Islands Marine Reserve proposed proclamation and proposal to prepare a draft management plan

In addition to my own research to better understand and predict the distribution of biodiversity on the Kerguelen Plateau in the HIMI area (e.g. Hill et al. 2017, 2020), including assessment of the impact of the existing marine protected area / sanctuary zone (unpublished), I also base my submission on the information contained in the independent review by Constable et al. (2024) Understanding the marine ecosystems surrounding Heard Island and McDonald Islands (HIMI) and their conservation status.

Given the high conservation value of the Australian HIMI territory, and that only 17% of the Australian EEZ is currently protected in the current HIMI marine reserve, it is commendable that the current proposal seeks to expand the size of the current reserve by a factor of just over four times (to cover 91% of the Australian EEZ). It is also commendable that the proposed expansion of the reserve area provides protection from oil, gas and mining exploration / extraction.

The ecological importance of the HIMI region is well summarised in the Constable et al. (2024) review. The area contains a range of endemic species, and species not found elsewhere in Australia. There are several known ‘hotspots’ of biodiversity. The marine ecosystem and its productivity supports a large number of seabirds and top marine predators as well as important commercial fisheries.

However, geological, biological and ecological knowledge of the region is far from complete. Knowledge of benthic habitats and the species and communities they support in particular is rudimentary at best, especially in deeper areas, and for most of the area below 750-100 m is essentially unknown. This means that it is not possible to assess the actual or potential impacts of various anthroprogenic pressures such as fishing, tourism, climate change, etc., and thus it would be prudent that the principle of precaution would prevail in these areas. Even basic swath mapping of deeper areas is wanting, and so it is possible – indeed highly likely – that key geomorphological (and thus ecological) features are yet to be mapped.

Thus, while I am highly supportive of the proposal for an expanded reserve, in the context of multiple use I suggest it is clear that in the current proposal insufficient protection is afforded to deeper areas, including the depths between ~750-2,500 m which is the focus of the Patagonian toothfish fishery. The proposed reserve configuration and multiple use rules suggests that fishing has been prioritised over conservation, and I would urge that this is reconsidered. This would also appear to be the case regarding some important shallower areas. Given what we know of the impact of bottom trawling and the ecological importance (including high biodiversity) of some of the shallower areas in the HIMI region such as the Gunnari ridge, in modern society it is surely inexcusable to allow bottom trawling in these habitats. To my knowledge, Australia is the only nation that allows bottom trawling in the Southern Ocean; it must be asked why the practice is not ceased, particularly in areas of known high biodiversity and conservation value.

In terms of known features and characteristics, there is a strong case to be made that important areas such as the Williams ridge and seamount chain, Gunnari ridge, the southern canyons, and the western plateau are much under-protected in the design outlined in the current proposal.

The Williams ridge complex is a known biodiversity ‘hotspot’, and among the most biodiverse areas in the EEZ. It is an important area for foraging penguins and Antarctic fur seals, but its physical and ecological complexity makes it highly vulnerable to degradation from both pelagic and demersal fisheries.

Because mackerel icefish aggregate at the Gunnari ridge, it is an important forgaing area for penguins, other seabirds and seals. Any fisheries in this area has the potential to significantly impact this important aspect of ecosystem functioning. I have already mentioned that, given the high benthic diversity of the area (although not thoroughly studies or mapped), it is unconscionable to permit bottom trawling here.

The southern canyons are another important geomorphic feature that provide important habitat for seal and penguin foraging and which support characteristic and unique demersal fish communities, and the semi-pelagic mackerel icefish.

The western plateau supports a unique demersal fish community and is an important spawning area for Patagonian toothfish. Robust protection of this area would benefit both the toothfish stocks (a target species) and conservation.

Literature Cited:
Constable AJ, Cresswell ID, Bax NJ, Reid K. 2024. Understanding the marine ecosystems surrounding Heard Island and McDonald Islands (HIMI) and their conservation status. The Australian Marine Conservation Society.

Hill NA, Foster SD, Duhamel G, Welsford D, Koubbi P, Johnson CR. 2017. Model-based mapping of assemblages for ecology and conservation management: A case study of demersal fish on the Kerguelen Plateau. Diversity and Distributions, 23: 1216-1230.

Hill N, Woolley SNC, Foster S, Dunstan PK, McKinlay J, Ovaskainen O, Johnson CR. 2020. Determining marine bioregions: A comparison of quantitative approaches. Methods in Ecology & Evolution 11: 1258-1272. doi: 10.1111/2041-210X.13447.

see item 2

see item 2

My views are summarised under item 2

I look forward to the announcement of an expanded HIMI reserve that provides robust protection of ecosystem functioning and biodiversity hotspots, and which invokes the precautionary principle for areas where existing knowledge is poor / non-existent.

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