Indicator: CO-32 Number of injuries to marine animals from marine debris

Data

Data on impacts of marine debris on marine animals are not available in any comprehensive form. However, preliminary reports suggest that high numbers of marine species are being harmed and killed by debris. Some species of marine turtles are thought to mistake plastic bags and other plastic items for prey. Other turtle species, especially hawksbills, eat encrusting organisms that grow on floating plastics and nets, and are likely to become ensnared when attempting to feed.

Based on available information, plastics dominate the debris found on beaches in northern Australia, generally comprising more than 50% and up to 90% of all items observed. While many materials in marine debris are persistent (such as glass, metals, foam, and even timber and cloth), plastic is of primary concern as it tends to be the most abundant debris type (by number and weight) found on beaches and in sediments, and it tends to have some of the most obvious impacts.

Source: National Oceans Office 2003, Finding solutions: derelict fishing Gear and other marine debris in northern Australia,, National Oceans Office, viewed 25 May 2006, http://www.oceans.gov.au/pdf/marine_debris_report.pdf.

Summary of fishing debris recorded from coastal surveys in northern Australia
Location	Total survey length/area	Total amount of debris recorded (items)	Total amount of debris recorded (weight)	Total fishing debris Recorded (items)	Total fishing debris Recorded (weight)	Fishing items as a proportion of total	Total derelict fishing nets recorded
Groote Eylandt NT	137km	1140	61 806	>812	55918	90%	812
Fog Bay NT	4km	596	n/k	107		18%
North-east Arnhem Land NT	100m	>727		>100		14%	33
Cape Arnhem NT	8.25km	7561	3880	2027	1040	27%	502
Cape Arnhem NT	8.25km	21 714	1974 (excluding nets)	6255	1040	29%	590
Cape Arnhem NT	8.25km	7443	1546	n/a	n/a	n/a	482
Groote Eylandt NT (8 mile and Salt Lake Beaches)	4.95km	1603	n/k	n/a	n/a	n/a	55
Groote Eylandt NT (South Point)	4.8km	2597	942	n/a	n/a	n/a	60
Elcho Island	3.25km	425	767	n/a	n/a	n/a	32

Source: Ilse Keissling 2003, Finding solutions:derelict fishing gear and other marine debris in Northern Australia, National Oceans Office, Table 4.

Finding Solutions: Derelict Fishing Gear and Other Marine Debris in Northern Australia (PDF - 8382 KB)

The discharge of garbage from ships is prohibited inside the territorial sea. If vessels need to discharge garbage, the material must be landed and disposed of under AQIS (or their authorised agents') supervision. General garbage has to be deep buried in landfills or autoclaved (usually the former). (Source: Email from AQIS, 21 April 2005.)

An estimate of the amount of debris generated by marine activities and vessels in Australia was done by the Australian and New Zealand Environment and Conservation Council (ANZECC) through the Marine Debris Status Review (ANZECC, 1996a). On the basis of the findings of this Review, it was estimated that across Australian waters each year:

around 13 800 tonnes of waste is generated aboard ships
around 2 400 tonnes of fishing gear is lost or discarded
only around 9 800 tonnes of debris is recovered over berths and disposal to landfills, so that up to 6 500 tonnes of waste per year is lost or discarded overboard.

Source: Ilse Keissling 2003, Finding solutions:derelict fishing gear and other marine debris in Northern Australia, National Oceans Office.

No data are collected that might indicate whether this quantity has increased or decreased in the last decade.

Some relevant data on actual marine debris impacts on marine animals can be obtained from the Queensland Parks and Wildlife Service Marine Wildlife Stranding Database.

Source: National Oceans Office 2003, Finding solutions: derelict fishing Gear and other marine debris in northern Australia, National Oceans Office, viewed 25 May 2006, http://www.oceans.gov.au/pdf/marine_debris_report.pdf.

Marine turtles stranded after ingesting or becoming entangled in marine debris
Year	Marine turtles
1999	39
2000	39
2001	36
2002	61

Source: Limpus, C. J.; Currie, K. J. & Haines, J. A. 2002, Marine wildlife stranding and mortality database annual report 2002: II. Cetacean and pinniped, Qld Environmental Protection Agency, viewed 8 Jun 2006, http://www.epa.qld.gov.au/publications/p01191aa.pdf/Marine_wildlife_stranding
_and_mortality_database_annual_report_2002_II_Cetacean_and_pinniped.pdf.

What the data mean

Harmful marine debris consists of garbage washed or blown from land into the sea, fishing gear abandoned by recreational and commercial fishers, and solid non-biodegradable floating materials (such as plastics) disposed of by ships at sea.

While garbage disposal inside Australian waters is prohibited, fishing gear such as abandoned fishing nets, articles lost overboard by accident, materials from shipwrecks, or materials dumped in the open sea, can cause injury and death to marine animals.

Derelict fishing gear has been identified as the type of marine debris most hazardous to marine species. Lost fishing gear and gear scraps have been shown to cause declines in populations of species such as northern fur seals, Australian sea lions and New Zealand fur seals. ‘Ghostfishing’ (the effect of lost and discarded fishing gear that continues to catch marine species indefinitely) has also been demonstrated to negatively affect commercial fishstocks, and result in catch rates approaching that of active gear. Coastal surveys of northern Australia record 262 or 543 kg of abandoned fishing nets

It appears that a significant proportion of marine turtles stranded on the Queensland coast are the victims of various types of marine debris. However, this cause of death and injury does not seem to have been disaggregated for other types of marine animals. The very small amount of data currently available is insufficient to suggest trends as yet.

Data Limitations

Surveys of quantities and type of marine debris may, over time, provide some indication of changes in the scale of the pressure of marine debris on marine animals but cannot represent more than a small proportion of the actual amount of marine debris. Nor can they show the actual impacts (in the form of death or injuries) of that pressure on marine animals.

The Marine Stranding and Mortality Database provides data on animals harmed by contact with marine debris but these are not comprehensive data.

To date, only turtles (no other marine animals) found in this state have been recorded.
Only turtles that are stranded on the Queensland coast are recorded - other States do not keep such a database.
Turtles that recover and survive, or are injured too far from the coast to be washed up, or are eaten rather than stranded, are not recorded.

Issues for which this is an indicator and why

Coasts and Oceans — Direct pressure of human activities on coasts and oceans - Direct pressure of shipping

Ships transport materials which, if left in the ocean, can impact on marine life. Number of injuries reported that are attributable to this cause are one indicator of the intensity of this pressure.