Shipping in Torres Strait
The Torres Strait lies to the north and north-east of Cape York and separates Australia and Papua New Guinea. It is about 90 nautical miles wide and 150 miles long. A characteristic feature of Torres Strait is large expanses of shallow seas that support productive coastal marine ecosystems, including abundant seagrass/algal meadows and coral reefs. The region has a rich maritime history and there are strong cultural, social, economic and spiritual links between Torres Strait Island people and their sea country, which are governed by their distinct “Ailan Kastom” (Island Custom). A plethora of recreational and commercial vessels operate within or transit Torres Strait. They unite the island communities and are a key transport mechanism for all kinds of goods and services. While shipping offers many benefits to the Torres Strait there are also associated risks, especially in event of an accident. These include threats to water quality, biodiversity and ecosystem health, physical or chemical damage from groundings and the introduction of pests.
Community Shipping
For indigenous communities travel and work in small vessels is a part of life. Fishing, hunting for dugong and turtle and commercial industries such as pearling, crayfish, prawns and trepang are all marine based. Boats are the main means of transport between islands and often voyages of more than 80 nautical miles (nm) are undertaken in all kinds of weather. Whereas the main concern with shipping in transit is threats to the marine environment, the main concern for indigenous communities is preventing injury and loss of life at sea. The Torres Strait Marine Safety Program is an inititive to make boating and marine industries safer in Torres Strait. It distributes practical information like boating safety and fuel requirements sticker for boats, and organises the delivery of education and licensing.
Improving access to information about weather is another aspect of increasing boating safety for local communities. Torres Strait islanders can contribute to a web-based knowledge product that aims to capture Aboriginal and Torres Strait Islander interactions with, and knowledge of, weather and climate. Access to real-time weather is gradually improving, although away from Thursday Island and the mainland, only Poruma Island has regular wind speed reporting.
Commercial Shipping
Transits of large commercial vessels through Torres Strait was identified as the highest risk to the marine environment [1], because of the high volume of traffic, the proximity to the islands and reefs and because the channel is complicated to navigate, being shallow with complex tidal streams and currents.[2]. The high risks of navigation has resulted in a long history of shipping incidents. There have been 14 groundings of bulk carriers and cargo vessels since 1970 recorded by AMSA, and historically, hundreds of shipwrecks (Shipwreck encyclopedia URL). Torres Strait became a Particularly Sensitive Sea Area (PSSA) in 2005 in recognition of the need for special protection for the region. As a result the pilotage and mandatory reporting (REEFVTS) systems on the Great Barrier Reef were extended to Torres Strait.
Shipping traffic in the Torres Strait over a 3 month period as measured by the Automatic Identification System (AIS) maintained by the Australia Maritime Safety Authority. This shows generally larger vessels (for which AIS mandatory) and some smaller vessels.
Due to the cultural significance of marine resources and their importance as a source of food and income, prevention of shipping incidents is considered by the island communities as the highest priority regarding strategic planning of shipping activities. An extensive network of aids to aid in navigation including buoys, lights, sector lights, racons and day marks and a marine Differential GPS exist. Where warranted, real-time transmitting tide gauges and a current meter provide information for under keel clearance management [1]. REEFVTS is available to enable the monitoring of shipping traffic with systems that can automatically identify ships that stray from the channel. Ships are monitored as they enter Australian waters and any ship without a pilot on board is tracked with survellience aircraft [1].
While improved regulation of shipping within Torres Strait has reduced the risk of a major accident, there are still risks of a grounding or collision. The second largest ship-source oil spill in Australian waters occurred in 1970 when the Ocean Grandeur, a bulk oil carrier with a pilot on board hit an uncharted rock. (AMSA shipping incidents). Between 1000 and 4000 tonnes of crude oil was released, as compared to almost 40000 tonnes from the Exxon Valdez accident off Alaska in 1989. The absence of a co-ordinated response plan after the Ocean Grandeur spill led to the National Plan, a strategy for responding to oil and chemical accidents at sea.
Oil spill response planning is organised according the amount of oil spilt. Spills of less than 10 tonnes are dealt with resources sourced locally from industry and/or state authorities, whereas larger spills initiate regional or national assistance and resources. Maritime Safety Queensland co-ordinates the response to ship-sourced oil spills in Torres Strait according to REEFPLAN and TORRESPLAN. Having high response capacity relies on access to equipment and trained personnel. The nearest stockpile of oil spill equipment controlled by AMSA is in Townsville. Training includes simulated scenarios initiated by AMSA biennially. In Torres Strait an AMSA exercise in 2002 simulated the collision of a bulk carrier and an oil tanker in the Great North East Channel. A report followed with recommendations to increase training and education for Torres Strait residents. There are still questions as to the adequacy of TORRESPLAN in the event of a major spill especially in the outer islands [1].
Marine pests are another source of risk to the marine environment in Torres Strait associated with shipping. Organisms discharged from ballast water and those transported from biofouling, the adhesion of organisms to a ship’s hull, are the main source of marine pests known in the tropics [3]. Marine pests that have the potential to establish in the Torres Strait region include species of mussels, barnacles, seaweeds, crabs and worms (see is it a pest?) Historically, invasive species found in the tropics have mostly been fouling organisms with economic rather than severe ecological consequences (Neil, 2005). Organisms found in ballast water, on the other hand can cause disease in the marine environment and in humans. Discharge of ballast water is regulated within Australian waters and typically commercial vessels exchange their ballast water at sea before entering the coastal zone. A baseline survey in the port of Thursday Island in 2004 did not detect any invasive marine pests or harmful micro-organisms (Stafford et al, 2006), however Torres Strait is considered a high risk area, particularly as discharge of ballast water is common to manage vessel stability in the shallow channels and around landings. The top three vessel types identified as potential sources of marine pests were commercial fishing boats, dredges and offshore support vessels [3].
While considerable resources have been directed to improve the safety of people and the environment the complexity of shipping in Torres Strait dictates that a process of continuous improvement is needed. There are inherent risks associated with forecast increases in traffic connected with plans for port expansions in Queensland and Papua New Guinea (PNG), and with trends towards increased vessel size and globalisation of trade. Generating economic opportunity within the region needs to supported by increasing the reliability and sustainability of marine industry.
References
1. Waterhouse J, Brodie J, Wolanski E, Petus C, Higham W (2013) Hazard assessment for water quality threats to Torres Strait marine waters and ecosystems. TropWater, James Cook University.
2. Queensland Transport and the Great Barrier Reef Marine Park Authority (2000) Oil Spill Risk Assessment for the Coastal Waters of Queensland and the Great Barrier Reef Marine Park. Department of Transport (Queensland), 65pp.
3. Neil, K.M., Hilliard, R., Clark, P. and Russell, B.C. (2005) A Situation and Gaps Analysis of IMS, Vectors, Nodes and Management Arrangements for the Northern Planning Area. An independent report by CRC Reef, URS Perth and the MAGNT for National Oceans Office Branch of the Department of Environment and Heritage. 177 pp.
4. Stafford, H., Neil, K.M., and Chalmers, S.J. (2006) Port of Thursday Island – Baseline Survey for Introduced Marine Pests. Final Report of the March 2004 Port-Wide Field Survey. CRC Torres Strait and Queensland Department of Primary Industries and Fisheries, 46pp.