Pressures on the marine park

Over the last 170 years...
Species on the brink
Habitats in need of help

What we do on the land, along the shore and on or in the water can affect the diverse and fragile ecosystem of Moreton Bay Marine Park.

Moreton Bay has existed for thousands of years. Only very recently has human impact started to take its toll.

European settlement commenced in 1824 with the first penal settlement at Redcliffe. Significant alterations to coastal wetlands, seagrass and mangroves began almost immediately with major foreshore work less than ten years later. Queensland's first major industry was based on whaling. Ever since, human settlement has continued to impact on the area now covered by Moreton Bay Marine Park.

The population of south-east Queensland is booming - every year another 50,000 residents arrive ¹. This growth means the marine park is not in as good a shape as it once was because of coastal developments, land-based pollution, fishing and simply from overuse.

Nowadays the water isn't as clean, the coral and seagrass beds aren't as extensive, and some marine animals and birds aren't as common as they once were.

Some significant species are having trouble adapting to these changing conditions, and while once plentiful, are now rare or threatened. These trends are worrying indications of what may happen to other species and habitats in Moreton Bay Marine Park.

However, with careful management the marine park's unique species and habitats can demonstrate remarkable recoveries if given some breathing space. A great example of this is the once decimated humpback whale population that now supports a thriving eco-tourism industry in Moreton Bay Marine Park.

Over the last 170 years...

Moreton Bay has become one of the most intensively fished areas along the entire Queensland coastline. It now accounts for one third of the state's recreational fishing effort, even though it has just three percent of the coastline ².
Toxic lyngbya blooms are becoming more frequent, blamed on excessive nutrient loads in waters ³.
Reclamation of tidal land for port, industry and residential development has led to removal of mangroves, seagrass and salt marshes ⁴.
The number of turtle and dugong killed by boat strike has increased in southern Moreton Bay Marine Park with 80 percent of known dugong strikes occurring in this area since 2000 ⁵.
Increasing boat traffic is disturbing dugong from their critical feeding areas on the Moreton Banks, even in "Go Slow" areas.
A number of fisheries in Moreton Bay have resource concerns including being vulnerable to overfishing and habitat modification to key fish habitats, for example the mud crab fishery, prawn fishery and snapper fishery ⁶.
Two thirds of the original vegetation has been cleared from south-east Queensland, resulting in increasing nutrients and sediment pouring into Moreton Bay ⁷.
Every major river system entering Moreton Bay Marine Park has high sediment loads and high nutrient concentrations that are affecting the health of the marine park ⁸.
Migratory shorebirds are being disturbed more frequently by dogs, boats and vehicles, and are under increasing threat along all of their international migration paths.
Significant loss of seagrasses has occurred in localised areas due to increased murkiness of water ⁹.

Species on the brink

Marine turtles

Six of the seven species of marine turtles in the world are found in Moreton Bay Marine Park. All six species are threatened.
The loggerhead turtle population has declined by 50 percent since the 1970s and the Queensland population of the loggerhead turtle is facing local extinction ¹⁰.
Approximately 200 reports are received each year of sick, injured or dead turtles in Moreton Bay Marine Park.
In 2005, approximately 40 turtles were found dead in Moreton Bay Marine Park with injuries consistent with boat strike ¹¹.
The average size of nesting female green turtles has been reducing over the last 25 years, meaning they are producing fewer eggs.

Grey nurse sharks

The species was almost wiped out by the 1960s because of targeted spearing and fishing.
Fewer than 500 grey nurse sharks remain along the entire east coast of Australia.
Grey nurse sharks could be extinct within 40 years without further protection.

Dugong

Approximately 600 - 800 dugong remain of a pre-European settlement population numbering in the tens of thousands.
Half of all dugong boat strike incidents along the Queensland coast occur in Moreton Bay Marine Park ¹².
88 percent of the 41 reported dugong deaths in Queensland in 2004 were related to human activities. In 2005, it was 84 percent of 40 reported deaths ¹³.
Dugong depend on healthy seagrass beds and an adult eats over 30kg of seagrass per day.
Moreton Bay Marine Park remains the only place in the world where turtle and dugong populations live in such close proximity to a capital city.

Habitats in need of help

Seagrass meadows are a nursery habitat, providing food and shelter for many juvenile species of fish and crustaceans. Since 1987, large areas of seagrass have been lost from Moreton Bay. Approximately 2000ha of seagrasses have disappeared from southern Deception Bay over the last 100 years ¹⁴.
Moreton Bay Marine Park has eight species of mangroves that provide a critical habitat for juvenile fish and other species. Mangroves trap sediment and reduce erosion by stabilising coastlines and riverbanks. Mangroves continue to be impacted by coastal development with losses of over 200ha between 1947 and 1997 ¹⁵.
Between 1974 and 2002, 3051ha of saltmarsh were lost from Moreton Bay. The remaining area is less than half that in 1974 when saltmarsh and saltpans occupied 5573ha or 27 percent of the total tidal wetland area ¹⁶.
Coral bleaching has been observed at inshore sites in Moreton Bay Marine Park. Coral grows on hard substrates and provides habitat for hundreds of other species. In 2002, 55 percent of corals at Shag Rock and 35 percent of corals at Flat Rock were bleached ¹⁷. Cover and diversity of corals around Green and St Helena islands are at historical lows.