French Austral Lands and Seas

Invasive black and Norway rats, mice, rabbits and cats, and to a lesser extent reindeer on parts of Kerguelen, impact biodiversity values. Invasive plants including dandelions and a few grasses have also had a high impact. Some invertebrate introductions have had a major negative impact on endemic invertebrates. Trout on Kerguelen have also been introduced, with unknown impact on the ecosystem. In 2022, there were 68 invasive plant species recorded in Crozet, 63 in Kerguelen and 103 in the islands of St Paul and Amsterdam, and 7 invasive invertebrates in Kerguelen (6 insects and an earth worm) (Evaluation for the IUCN Green List, 2023).

A biosecurity strategy was adopted in 2022 and constitutes a milestone for the implementation of the management plan of the nature reserve and the environmental policy led by the French austral lands and seas authority. Operations to eradicate or control rats, rabbits and cats have been successfully undertaken on a number of islands, with the biggest success being the eradication of black rats and rabbits from Ile Saint-Paul in 1997, although unfortunately eradication of mice was not achieved (Micol & Jouventin, 2022). Cows, sheep and mouflon, introduced to a few islands, have all been removed. From April-September 2024 a very ambitious plan to eradicate Norway rats, cats and mice from Amsterdam was undertaken (TAAF, 2024a).

Avian influenza has recently affected populations of marine mammals (mainly Elephant seals) and a number of bird species on Crozet and Kerguelen (TAAF, 2025a). Avian cholera and other diseases appear to be affecting the Indian Yellow-nosed Albatross (Thalassarche carteri) (Jaeger et al., 2018) as well as possibly the Amsterdam Albatross (Diomedea amsterdamensis); Northern Rockhopper penguin (Eudyptes moseleyi) and Sooty Albatross (Phoebetria fusca) (Weimerskirch, 2004). In addition, introduced vertebrates may transport pathogens such as avian cholera, and introduced aphids may transmit phytovirus to endemic plants (State Party of France, 2018). A second national action plan 2018-2027 is being implemented to improve the conservation status of the Amsterdam albatross (Chaigne, 2018). Vaccination strategies and elimination of vectors (introduced vertebrates) as well as strategies to protect humans from avian influenza are being implemented (RNN &TAAF, 2018; TAAF, 2025a).

At the time of inscription, seven vessels were authorised to carry out longline fishing in the Kerguelen and Crozet zone and one vessel was authorised to fish in the Saint Paul and Amsterdam zone (State Party of France, 2018; IUCN, 2019). Currently, 8 vessels are authorized for longline fishing in the Kerguelen and Crozet EEZ. A new management plan is to be set up on the next fishing campaign and for 3 years until September 2028 (IUCN consultation, 2025). A limitation of the number of authorized fishing vessels is scheduled, excluding any additional ship to be authorized or even lower this number. In Saint-Paul and Amsterdam, 2 additional smaller vessels have been authorized since the time of inscription, but a management plan is also under revision to better supervise the fishery and set up a better model for economic income and environmental impacts mitigation.

Conservation measures put in place prior to the property's inscription have reduced the very high mortality of seabirds caused by longline fishing in Kerguelen and Crozet (more than 15,000 seabirds from 1996 to 2006, and still 1,236 individuals estimated being killed or wounded in 2007/2008; State Party of France, 2018; IUCN, 2019). Although albatrosses fly beyond the French EEZ (Weimerskirch et al., 2018a), they are unlikely to be killed by the legal fishery, as mainlywhite-chinned and a few grey petrels are the residual victims of the fishery (109 birds estimated being killed or wounded in 2023/2024; MNHN, 2024).
Although the level of fish bycatch in commercial fishing activities remains significant, especially for skates and sharks, with a recommendation that areas with high by-catch rates should be avoided (CCAMLR, 2024), new scientific insights have been obtained on skate species caught in Kerguelen and Crozet thanks to a dedicated research programme conducted from 2022 to 2025 (Faure, 2023; Faure et al., 2023; Faure et al., 2024; Faure et al., 2025). The results have improved understanding of the impacts of the fishery on the 3 different species of rays populations, and helped to develop management measures (e.g. move-on rules, condition assessment and best-practice handling by fishermen on-board fishing vessels). New management measures, including incentives on interannual individual fishing quotas, are envisaged to mitigate catches of lantern sharks (Etmopterus sp.) during the next few years.

Pressures on deep-sea benthic habitats are also difficult to quantify (upcoming scientific publications from the MNHN will provide better insights on historical impacts, evaluated to be low on VME communities; MNHN, comm.pers.), and there are still issues with depredation behaviour by killer whales and sperm whales (Tixier et al., 2016; Tixier et al., 2020). The next management plan aims to encourage fishing companies to collaborate on mutual projects to cope with this problem.

At the same time, illegal fishing appears to be under control (CCAMLR, 2024).

With only three small bases on each main island, the impact of human activity on the site (with an average of some 340 people visiting/year for logistic support, scientific studies and national reserve operations, including around 170 residents at the 3 bases for at least part of the year) is minimal but not inexistent. The threat of an oil spill when transporting heating oil to each base, and the risk of fire (see below) are probably the greatest risks despite very strict security measures. Very occasional ships passing through the property (mainly the Marion Dufresne that visits the islands four times/year, and passing warships and fishery vessels) could have a catastrophic accident causing pollution, although this is unlikely. Keeping human disturbance from the inhabited bases to a minimum and managing waste and light pollution, as well as a programme to rehabilitate the old bases to make them more environmentally friendly, is in place. The very rare tourism - authorization can be requested by occasional sailors - is carefully controlled and is not an issue (State Party of France, 2018; IUCN, 2019).

Although the State Party periodic report (2023) states that "the increase in the frequency and intensity of droughts is likely to increase the risk of natural fires. None, however, have been recorded in recent years", this report omitted mention of the fire on the cliffs of Entrecasteaux from February-March 2021 (TAAF, 2021), which affected the entire colony of Yellow-nosed Albatross Thalassarche carteri (EN), representing some 65% of the global population and already under pressure from avian cholera (Jaeger et al., 2018). On 13 January, 2025 another fire destroyed a large area (as of February 2025, 50% of the island), burning sphagnum bog and populations of the only tree on the island Phylica arborea. The fire reached the base which had to be evacuated, and essential electrical, water and communication equipment as well as the nursery propagating Phylica arborea for reintroduction was destroyed (TAAFb, 2025). The impact of the fire on fur seals during this period cannot be ascertained yet, however, the French southern and Antarctic lands authority carried out two technical missions in February and in April 2025 to assess the origin of the fire (still unknown) and the environmental impact of the fire on biodiversity in relations with the scientific partners (IUCN consultation, 2025).

Patagonian toothfish (Dissostichus eleginoides) supports valuable fisheries across the Southern Ocean under the management of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Revenue from the highly lucrative Patagonian Toothfish catch is a source of revenue for the TAAF. This includes within the property and the surrounding French Exclusive Economic Zone (EEZ). A juridical exception (la “Déclaration du Président”) allows the TAAF to set-up their own regulations within the EEZ although most of the CCAMLR management principles and rules are applied, in particular related to fisheries management (French scientists from the MNHN, who assess TAAF toothfish fisheries, take part in all CCAMLR scientific meetings and working groups). Nevertheless, some rules are specific to the TAAF, like the HCR (Harvest Control Rule) objective of maintaining 60% of the toothfish spawning biomass in 35 years, which is more ambitious than the lower objective of 50% defined by the CCAMLR.

Total Allowable Catches (TAC) are set annually by the TAAF receiving substantiated recommendations from the National Natural History Museum (MNHN) in Paris, who analyse detailed data collected from the fishery (especially thanks to systematic fisheries controllers on-board each fishing vessel) and process the modelling (according to a more prudent GSY model, IUCN consultation 2025) and stock assessment of the fishery under complete specifications of the CCAMLR (the MNHN presents scientific articles on these assessments every year at the CCAMLR scientific committee). The TAAF also receive general advisory guidance from an independent Scientific Council composed of scientists.

This management system appeared to be satisfactory at time of inscription (State Party of France, 2018; IUCN, 2019). However, concern over low recruitment of Patagonian Toothfish stocks throughout the Antarctic (Ortscheidt, 2023; CCAMLR, 2024) resulted in an alert from the MNHN in its last recommendations report in 2024. Two scenarios were presented to the TAAF, based on two different hypothesis on the recruitment series used in the stock assessment. Considering the ongoing CCAMLR framework and the remaining uncertainties related to available data, the scenario with the use of historical recruitment series in stock assessment was considered by the TAAF to set up the TAC for the 2024-2025 fishing campaign, leading to a reduction of the Kerguelen TAC of 410 tonnes (-8,17 %), thus equal to 5,540 tonnes (TAAF, 2024). For a more cautious approach, members of the Scientific Council of the reserve asked to reduce total allowable catches (TAC) to a range of 3,500-4,000 tonnes for 2025 (CS, 2024). Following the recommendation of the MNHN, the TAC initially set to 5020 tonnes in 2022 for three fishing campaign has been reduced to 4610 tonnes for the campaign starting in September 2024 (IUCN consultation, 2025). Additionally, the TAAF have set-up several measures to better estimate this crucial recruitment index (funding and carrying out the 1.3 M€ POKER V scientific campaign in September-October 2024 to study 2-4 years old toothfish nurseries in Kerguelen, and preparing annual similar campaigns and other recruitment assessment methods for the 3 next years) and mitigate the impact of the fishery on the youngest stages of toothfish caught by fishing vessels (thanks to radical technical measures – spatial closures of areas with higher young toothfish biomass -and strong incentives against fishing companies to target younger stages of toothfish, planned to be set-up in the upcoming management plan).The new triennial Patagonian toothfish management plan was adopted in 2025 (2025-2028) and will include specific objectives and means to better evaluate the stocks (e.g. yearly POKER campaign, study of toothfish nurseries).

The Patagonian Toothfish fisheries at Crozet and Kerguelen have received MSC certification in 2013 and 2017 (renewed in 2018 and 2024) (MSC, 2024) however, the MSC also note that seven ships operate the Patagonian Toothfish fishery, when from 2023 there were eight (TAAF, 2022), even if this new ship hasn’t led to an increase of the TAC nor to the global fishing effort of the fishery (in number of hooks deployed by campaign) during the 3 last fishing campaigns. On the other hand, the lobster pot fishery at Saint-Paul and Amsterdam received MSC certification in 2020 (MSC, 2020) although there are still issues concerning the determination of the TAC of this fishery, and the number and type of boats allowed (CS, 2024).

Climate change impacts both marine and terrestrial species. Temperature variation may impact breeding success of birds and marine mammals (i.e. need to go further for feeding), and is one hypothesis for the decline of the King Penguin population on Ile aux Cochons (Weimerskirch et al. 2018b; Kintisch, 2020), as well as the Northern Rockhopper Penguin on Amsterdam (RZSS, 2017). Change in ocean acidity will also impact marine life, and rising ocean surface temperatures could reduce the upwelling of nutrients around the islands that are essential to food chains (including the amount and distribution of prey species which could cause rapid changes in their population (e.g. Cherel et al., 2018), Changes in temperature and humidity may favour introduced species over native (State Party of France, 2018; IUCN, 2019).