The Terrestrial Macroinvertebrates of the Sub-Antarctic Iles Kerguelen and Ile de la Possession. Maurice Hulle

and the Îles Kerguelen.

      Box 1.1. Main scientific expeditions of the 19th and early 20th Centuries

Since the installation of the bases, scientific missions have been able to take place each year with stays of several months, first thanks to the “Mission de Recherche des Terres Australes et Antarctiques Françaises”, which became the “Institut Français pour la Recherche et la Technologie Polaires” (IFRTP) in 1992, and finally, the “Institut Polaire Français Paul-Émile Victor” (IPEV) since 2002. Fifteen new native species have been described since then. Many scientists have succeeded each other in the field. They collected many samples, which they identified themselves or entrusted the identification to specialized colleagues.

      These expeditions also made it possible to draw up a complete list of the introduced species and to follow the history of their acclimation and expansion. This was the case, for example, for the ground beetle Merizodus soledadinus introduced at Port-Couvreux, Îles Kerguelen, in 1913, systematically researched by René Jeannel in 1939 and then by the different entomologists that have followed (see Figure 5.38).

      The toponymy of the sub-Antarctic Îles Kerguelen and Îles Crozet (Delépine 1973) pays tribute to some of these pioneering scientists for invertebrate research: Lac Eaton, Péninsule Gauss, Cap Jeannel, Mont Moseley, Mont Etienne Peau, Port Perrier, Rivière Studer, Île Suhm, Bras Vanhöffen, Mont Werth and Mont Wyville Thomson are examples.

1.5. Current research on invertebrates

      The study of macroinvertebrates is the subject of the research program “Subanteco” supported by the “Institut Polaire Français Paul-Émile Victor” (IPEV). This program seeks to evaluate the impact of environmental changes and biological invasions on native communities and more generally, on the functioning of terrestrial ecosystems. This program is based on the long-term monitoring of changes in the distribution of native and introduced species and on experimental designs, in order to respond to three main questions: 1) how much are distribution patterns and community structure of terrestrial fauna and flora changing over time? 2) What are the effects of changing environments and multiple stresses on species physiological ecology? 3) What are the dynamics of invasive species, and how much are they affecting sub-Antarctic biodiversity? This makes it possible to better understand the adaptive responses of species to changes and to better understand the processes underlying biological invasions. It also helps decision-making for those responsible for the management and development of these areas.

      Figure 1.15. Portraits of some naturalists who worked on the invertebrate fauna of the Îles Kerguelen and the Îles Crozet

1.6. Nature reserve and access areas

      The southern French islands of Kerguelen, Crozet, Saint-Paul and Amsterdam were classified as a nature reserve in 2006. The management plan of the reserve defined zones of integral protection and areas of regulated access. No invertebrate species are protected, but significant steps have been taken to limit the introduction and spread of alien species. Eight zones on the Îles Kerguelen and four on Île de la Possession (Figure 1.16) are now subject to access authorization for scientific activities.

      Figure 1.16. Protected areas of the Îles Kerguelen and Île de la Possession (maps: Floran Hoarau)

1.7. The terrestrial macroinvertebrates

      Terrestrial macroinvertebrates are represented by seven classes: Clitellata, Gastropoda, Chilopoda, Arachnida, Malacostraca, Collembola and Insecta. The class of Malacostraca includes at least one species of woodlouse, and that of Chilopoda includes at least one centipede species. These two species, whose identification is uncertain, are not presented in this book. Likewise, Collembola and small invertebrates such as mites and tardigrades are not described in this book because we do not have sufficiently recent revisions. The following chapters therefore describe the earthworms, gastropods, spiders and insects currently present on both the Îles Kerguelen and Île de la Possession.

The native species described in the literature have almost all been found during the specific prospecting campaigns that have been carried out since the 2000s. This book therefore gives an account of our current state of knowledge. Similarly, the taxonomy used here takes into account the various revisions that have been published.

      In regards to introduced species, only established species have been included. Species seen very occasionally, but which have not succeeded in becoming established, are not considered to be part of the fauna of the two islands. An exception is made for some occasional Lepidoptera that arrive on the islands by natural migration routes. Most of the introduced species have been identified.

      For the taxonomic nomenclature, we have used the reference system published by the National Museum of Natural History in Paris¹. The identification criteria given here are relatively brief because an identification guide and keys have already been published (Hullé et al. 2018). The arrows on the illustrations of the species correspond to the identification criteria written in blue and italics in the “identification” paragraph. For more direct access to information, we have chosen to present families and species in alphabetical order within each order.

      As far as possible, we provide information on the distribution, identification and ecology of each species. The level of information concerning the distribution and biology of species depends on the knowledge we have of them through the literature and field observations reported by various scientists. It is appropriate to pay tribute here to the many people who have collected, identified and studied all of these species. It was not only specialists but also students and field assistants who contributed for a few days, weeks or months to the acquisition of this knowledge. In fact, the permanent scientific programs supported by the “Institut Polaire Français Paul-Émile Victor” (IPEV) make it possible each year to send researchers on summer campaigns and send young volunteers for a full year.

      The ability of introduced species to become invasive is a major concern for scientists and managers. In this book, the currently known distribution of each introduced species is given graphically in the form of a presence map. This is the minimum information we have today on the distribution of these species because not all areas have been explored, especially on the Îles Kerguelen which are large.

To complement the morphological approach, molecular characterization of native and introduced species has also been undertaken since 2016. Currently, 162 sequences (gene C01) have been deposited in the Barcode of Life Data System². This is the STIMT (Sub-Antarctic Terrestrial Invertebrate Molecular Taxonomy) project, which to date includes sequences from 28 native species and 17 introduced species belonging to the different orders present on the two islands.

      1 1 https://inpn.mnhn.fr/programme/referentiel-taxonomique-taxref.

      2 2 www.boldsystems.org.