Find out more about the Top End’s extraordinary coasts and lifestyle, amazing desert country, and the success of Fish River Station.
Gamba Grass
The extensive savanna woodlands of Australia’s Northern Territory are prime habitat for an array of native wildlife and a place of beauty and solitude for locals and visitors alike. But the region faces a severe threat: the spread of gamba grass, an invasive species that is fuelling intense bushfires and destroying natural habitats in the north of the territory, known locally as the Top End.
Gamba grass, native to African savannas, was introduced to the Top End in 1942 to feed cattle. But it wasn’t until the early 1980s that it was planted on a large scale to feed a growing number of livestock. The Territory Government initially hailed the grass as a huge success, but soon the invasive plant’s dangers came to light, and by the late 1990s it was clear that gamba grass proved a major threat.
This highly invasive weed destroys and replaces savanna woodlands and has the potential to spread across millions of hectares of Northern Australia. Working with partners to prevent the spread of gamba forms part of Pew’s efforts to secure a sustainable future for people and nature in Outback Australia.
Our Goals
Following consultation with local stakeholders and experts, Pew has identified five priorities for action: increasing investment in community outreach; maintaining support for private landholders to manage the weed; improving gamba management on public land, including national parks; enhancing compliance and enforcement; and fostering collaboration between key agencies and stakeholders.
Pew works with local partners through the Gamba Grass Roots alliance in advocating for strong policy commitments from the Northern Territory Government to ensure that landholders are supported and equipped to manage gamba infestations and reduce the subsequent risk to properties and nature.
Top End sea life
The waters of the Top End and the Gulf of Carpentaria are rich in tropical marine life and support the vibrant outdoors way of life in the Northern Territory. The shallow warm waters of the Timor Sea, stretching from the border with Western Australia across to Queensland’s Cape York in the east, are among the last thriving tropical marine systems remaining on the planet.
Indigenous sea ranger groups are active throughout the region. Drawing on traditional knowledge, contemporary science and their increasing legal rights, Traditional Owners and rangers visit sacred sites, track sea life, report illegal fishing and remove ‘ghost nets’ (discarded fishing nets) while maintaining and renewing cultural connections to their sea country.
The waters west of Darwin provide a haven for threatened sea turtles, which feed around submerged reefs and nest on nearby beaches. East of Darwin, underwater pinnacles off the Coburg Peninsula rise dramatically from the sea floor, attracting and supporting light-loving marine life.
On the edge of the continental shelf rise, cooler, deeper ocean waters provide feeding grounds for whale sharks and predatory fish. Closer to shore, these islands dotting the Arnhem shelf are fringed by colourful reefs and clear waters, creating a refuge for large fish such as snapper, emperor and grouper.
Farther east, in the Gulf of Carpentaria, sea grass meadows off Groote Eylandt and Limmen Bight are a hot spot for vulnerable dugong and rare snubfin dolphins. The soft sea floor of the central Gulf is home to an abundance of heart urchins, which cycle nutrients through the interconnected food web.
The monsoonal rivers flowing into the southern Gulf remain largely free from dams and large-scale water extraction, making the region unique around the world. Free-flowing wild rivers bring a flood of nutrients and fresh water each wet season, supporting high levels of phytoplankton, sea plants that produce the oxygen we breathe.
Our Goals
Pew works with partner organisations the Environment Centre NT and the Australian Marine Conservation Society through the Keep Top End Coasts Healthy alliance, safeguarding the extraordinary marine life through establishing a sensible balance of marine parks.
In 2020, the Limmen Bight Marine Park was declared by the Northern Territory Government — the first in the Northern Territory in more than 30 years. Located at the mouth of the Roper River in the Gulf of Carpentaria, Limmen Bight is an extraordinarily productive marine ecosystem, fueled by three big river systems that push vast amounts of nutrients into the sea.
Properly managed marine parks give ocean waters the best chance of remaining healthy and sustaining natural populations of sea life. As is the case with national parks on land, there are different types of marine parks. Carefully situated sanctuary areas provide the highest level of protection.
Keeping Territory Rivers flowing
The Territory has some of the most special rivers remaining in Australia and in the world. Rivers such as the Daly and Roper underpin one of the most important economic and cultural pursuits – the Top End fishing experience.
Northern Australia is characterised by a distinct seasonality, with relatively high and largely reliable rainfall occurring in the short summer wet season. The wet season is a time of renewal; of very rapid growth in grass and the greening of vegetation; of flower, seed, and fruit production; of streams, rivers, and wetlands filling; of resource abundance and breeding for many animal species, particularly wetland species such as crocodiles, waterbirds, turtles, many fish, and frogs.
Seasonality is the primary driver of ecological processes in large tropical rivers. Most of the annual flow occurs within a three-month period, followed by a long period of little or no flow. Regular seasonal overbank flooding, occurring when it is warm, drives great bursts of productivity. During the dry season, surface water becomes restricted to a few permanent or semipermanent water holes and streams.
However, recent improvements in the productivity and pest resistance of key crops—such as large-scale cotton—are increasingly serious risks to rivers and natural landscapes.
Our Goals
Pew is working with landholders, Traditional Owners, tourist operators and local communities to secure long term protection for iconic, high conservation value rivers in the Northern Territory.