The major area of concern for these stakeholders was the potential for ships using the jetty to strike whales and other mammals, as well as upsetting the seasonal migratory resting activities of mother and calf humpback whales in the Gulf.
Protect Ningaloo has run newspaper advertisements depicting a ship striking a whale, in opposition to GGL. Some other stakeholders have expressed concern at the impact an expanded campaign of this type would have on the project’s chances of being approved by government.
Protect Ningaloo’s messaging has recently changed to incorporate the theme, “Save Exmouth Gulf,” describing economic activity within the Gulf as threatening the Gulf’s role as the Ningaloo Reef’s nursery.
However, despite the above, several other stakeholders have identified opportunities for life below water to be enhanced by the project. These opportunities are explained in more detail below.
In its August 2021 report into the Potential Cumulative Impacts of Proposed Activities and Developments on the Environmental, Social and Cultural Values of Exmouth Gulf, the Environmental Protection Authority (EPA) noted that, “a long history of development has contributed to considerable environmental change,” in the Gulf, with, “pastoralism, defence and commercial fishing activities predating the establishment of the Exmouth township and continuing through the present”.
However, in addition to acknowledging a lack of ecological data generally for the Gulf, the EPA noted that, “relatively little information (was) available that provides insights into how these historical activities have impacted on the values of the Gulf”.
The Exmouth Gulf, Ningaloo Marine Park and Muiron Islands Marine Management Area are currently highly navigated waters, according to Automated Identification System (AIS) data recorded by Spire Maritime in 2020.
AIS broadcasts voyage related information, including ship location, speed, course, heading, rate of turn, destination and estimated arrival time, as well as static information, like a ship’s name, type and size.
Despite the high volume of existing commercial traffic, the EPA (above) described humpback whale values as being in “very good condition” in the Exmouth Gulf. Further, GGL could find no evidence of historical whale strikes by commercial vessels in the Gulf or surrounding areas.
However, without a jetty or similar marine infrastructure available, many of the commercial vessels navigating the Exmouth Gulf are forced to anchor in the Gulf or use dynamic positioning to maintain a position.
AIS data recorded between June 2016 and October 2020, revealed a cumulative impact on 299,439m2 of seabed in the Gulf, an area equivalent to the size of 42 soccer fields, based on 169 anchoring events recorded for a period of more than 24 hours. Given 24 hours is likely the time required for a full circle of swing, only these anchoring events were used to calculate the impact on the seabed.
The seabed environments affected by intense usage appeared to be mainly composed of sand and shells, however some vessels were anchored in coral reef areas. On average, the accounted vessels were more than 75m long, which produce more significant damage to seabed habitats than smaller boats, as they have larger anchors and chains.
However, it is worth noting that the AIS data revealed a total of 32,000 anchoring or dynamic positioning events of less than 24 hours during the 2016-20 period. This points to both a much higher impact on seabed habitats from anchoring, as well as the potential for impacts on marine life from dynamic positioning approaches.
It is also worth noting that, the absence of alternative marine infrastructure means that the Australian Defence Force is forced to offload up to 13 million litres of fuel for use at Learmonth at its Point Murat jetty, which is located inside the Ningaloo Marine Park, with this representing a significant and existing risk to life below water in the region.
In 2020, the International Union for Conservation of Nature (IUCN) found in its Conservation Outlook Assessment for the Ningaloo Reef that climate change posed the greatest threat to the long-term conservation of the reef. Increased tourism visitation and recreational use were identified as existing major threats. Future urban and industry development would need to be considered for potential future threats.
AIS data collected by Squire Maritime for 2020 revealed a highly trafficked marine environment for the Exmouth Gulf, Ningaloo Marine Park and Muiron Islands, with the above map tracking commercial vessel movements for that year, and table representing the type of vessels recorded as a percentage of commercial traffic.
