Extreme Survival

Te Kopia red spring

Red pigmented spring at Te Kopia - the colour is due to microoganisms and precipitated iron. Photo Credit: Matthew Stott.

Geothermal habitats often generally have low biodiversity. There are limited types of species but they can be in a high abundance. The plant, animal and microbial species have evolved characteristics to help them survive in geothermal conditions.

Special characteristics of life in geothermal areas include smaller sizes and slower growth rates compared to their non-geothermal counterparts. Some plants have shallower roots and only intermittently flower.

Microorganisms have had to invent new ways of doing things too. For example, thermophilic microorganisms utilise temperature stable enzymes to carry out metabolic functions. Likewise extremophilic microorganisms often synthesise unusual fats to ensure the integrity of their cell membranes to these extreme conditions.

Resilience to Change

These geothermal communities need to be resilient to changing environmental conditions. Hot springs, geysers, mud pots, and fumaroles are dynamic surface features that are sensitive to any changes in their underground water supply.

Post hydrothermal eruption

Landscape immediately following a hydrothermal eruption at Ngatamariki. Photo Credit: Bruce Mountain.

Geothermal features are easily affected by natural events such as earthquakes and landslides. Man-made impacts also include the development of geothermal power stations and drilling of geothermal bores for domestic and commercial heating. This can all result in natural changes to temperature, water levels and chemistry.

Threats

Development of geothermal fields, land use change and pest invasion have already had an impact on existing geothermal environments. Extraction of geothermal energy for power generation and heating uses have affected surface activity, changed soil and hot spring temperatures, and resulted in ground subsidence.

Some flora and fauna that do not require the thermal features for their survival, but have learnt to adapt to thermal areas, have become threats to the unique geothermal species. Additionally, some imported warm-water aquarium species have been released into the environment and now thrive only in warmer geothermal waters, competing with indigenous fauna and flora for resources. Blackberry (Rubus fruticosus agg.) is a major problem in some areas, as is buddleia (Buddleja davidii), wild introduced conifers and some exotic grasses. Animal stock and people can trample vegetation when areas are not fenced.

Field sampling

Monitoring geothermal environments is an important part of sustainable resource. Photo Credit: GNS Science.

Protection of Geothermal Areas

Geothermal areas are often protected because the geothermal features, fauna and flora are rare and easily damaged. Five geothermal areas, White Island (Whakaari), Rotorua, Waimangu, Waiotapu and Tongariro, are considered to be of international significance and preservation takes precedence over development in these areas. Management of geothermal systems aims to balance development activities with the protection of highly-valued surface features and ecosystems.