A Delicate Balance – Parks Australia
+3 A Delicate Balance – Parks Australia
A Delicate Balance – Parks Australia
A Delicate Balance – Parks Australia
A Delicate Balance – Parks Australia
A delicate balance: Celebrating the importance of species that
maintain a healthy ecosystem on Norfolk Island
In the intricate web of nature, every species contributes to the delicate balance of an ecosystem. Norfolk Island boasts a rich variety of terrestrial flora and fauna surrounded by an equally diverse marine environment. Even today, scientists are still making discoveries of new species at Norfolk Island, including a recently discovered palm-bug that lives exclusively on Norfolk, and an endemic coral found only in the waters surrounding the island.
This year marks the 250th anniversary of Cook’s landing on Norfolk Island. Since then, this island has undergone significant ecological change. Extensive land clearing and the introduction of invasive plant and animal species have greatly impacted the terrestrial ecosystem. This change in land use has also had an impact on the marine environment, increasing nutrient and sediments which enter the waters around the island, including the lagoon at Emily and Slaughter bays.
The Norfolk Island National Park, and Norfolk Marine Park are a refuge for many native species. However, certain species can play a particularly vital role in maintaining this equilibrium.
On land, one of these species is the famous Norfolk Island pine, which grows densely in the Norfolk Island National Park and is a critical contributor to the island’s ecological health. While in the ocean, the often overlooked echinoderms inhabiting the Norfolk Marine Park have a vital role to play in keeping our reefs healthy.
The Norfolk Island pine
The Norfolk Island pine (Araucaria heterophylla) stands as a symbol of Norfolk’s natural splendour, but its significance extends beyond mere aesthetics. This evergreen giant is a linchpin in supporting the forest ecosystem. By casting a towering canopy, the pines provide vital shade for an array of understory plants to grow, such as docks (Asplenium australasicum), merytas (Meryta latifolia or M. angustifolia), and a huge variety of ferns.
Within the Norfolk Island National Park, these towering pines also play host to a variety of orchids, providing a support system for these delicate epiphytes to thrive. Their branches offer sanctuary to nesting white terns and songbirds, contributing to the island’s avian diversity. Moreover, the Norfolk Island pine plays a pivotal role in supporting the island’s green parrot, providing both shelter and an occasional food source.
Beyond this, the substantial wood volume of Norfolk Island pines, when decomposed, becomes a valuable resource for fungi and other insects, contributing to the intricate web of nutrient recycling. And their capacity for carbon capture stands as a significant factor in mitigating the impacts of climate change, underscoring their importance in the broader environmental context.
Echinoderms: Sea Urchins and Sea Cucumbers
In the waters surrounding the island within the Norfolk Marine Park a different set of species takes centre stage – the echinoderms. Echinoderms are a group of marine invertebrates with endoskeletons (internal skeletons). Globally, there are around 7000 echinoderm species, with sea urchins and sea cucumbers being most common on the coral reefs encircling Norfolk Island. Sometimes termed the “lawnmowers of the sea”, echinoderms play a vital role by grazing on algae.
When in balance, some algae growing on the reefs is natural and even beneficial for our coral reef, providing food to fish and other marine animals. However, algae growth can become out of control when certain nutrients, especially nitrogen and phosphorus, become abundant. Due to the ongoing entry of nutrients into Emily and Slaughter Bays, there’s been a significant increase in algal growth on Norfolk Island’s reef.
Too much algae growth on the reef can smother existing corals and prevent new corals from settling. By grazing algae off the reef, echinoderms play an important role in maintaining the balance between coral and algae growth and create space for corals to settle and grow. In this way, these marine organisms contribute significantly to maintaining the delicate balance of the coral reef ecosystem and help foster a diverse underwater landscape.
Putting in protective measures
The Norfolk Island pine, with its towering presence on land, and the echinoderms, silently toiling beneath the waves, illustrate the crucial role seemingly ordinary organisms can have on the health and vitality of an ecosystem. Recently, protective measures have been put in place to protect these species and the greater ecosystem.
Within the Norfolk Island National Park, boot scrub stations have been installed at all major track entrances. These are designed to help prevent the spread of a plant-killing pathogen called Phytophthora, commonly called root rot or die-back. Sadly, Phytophthora has been found to be particularly damaging for Araucarias, such as the iconic Norfolk Island Pine.
Additionally, in 2023, in response to algae overgrowth resulting from continuing storm and groundwater pollution, the Director of National Parks issued a special determination preventing the take of any species from Emily and Slaughter Bays, and of any echinoderms from Cemetery Bay.
These measures provide greater protection for these two specific groups of organisms, allowing them to continue their role in supporting a functioning and healthy ecosystem.
But while the Norfolk Island National Park and Norfolk Marine Park help protect Norfolk’s spectacular island paradise, we are all stewards of our environment, and the responsibility to protect the species that safeguard Norfolk Island’s unique ecosystem lies with all of us. Whether you are hiking in the park, or snorkelling in the bays, please remember these rules, designed to protect the incredible ecosystem around you.
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Image Credit: Copyright Norfolk Island National Park – Supplied
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Article content disclaimer: Article first published in Discover Norfolk, Volume 07 Issue 01, 2024. Please note that details of specific travel, accommodation and touring options may be outdated. References to people, places and businesses, including operating days and times may be have changed. References to Government structure and Government businesses/entities may no longer be applicable. Please check directly with businesses and/or Government websites directly rather than relying on any information contained in this article before you make travel arrangements.
