GCMD

Summary

Abstract: INDICATOR DEFINITION
A monthly clearance of marine debris from a westwards-facing beach on Macquarie Island.

TYPE OF INDICATOR
There are three types of indicators used in this report:
1.Describes the CONDITION of important elements of a system;
2.Show the extent of the major PRESSURES exerted on a system;
3.Determine RESPONSES to either condition or changes in the condition of a system.

This indicator is one of: CONDITION

RATIONALE FOR INDICATOR SELECTION
Accounts indicate that the quantity of litter in the world's oceans has been increasing over the years. Growing human populations, industrialisation and sea-traffic (especially fishing), make the Southern Ocean, one of the most remote of seas, susceptible to marine debris.

Regular recording of marine debris on a remote beach, such as Sandell Bay, gives information on changing patterns of human materials found at sea as debris (92% of marine debris at Sandell Bay is now of plastic material), the proportion due to fisheries activities, and the national sources of the material.

DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM
Spatial scale: A collection of all anthropogenic materials (marine debris) is made within the first week of each month from a defined 2km transect of beach at the head of Sandell Bay, Macquarie Island.

Frequency: Monthly collection, annual reporting.

Measurement technique: Objects greater than 1cm in length are collected. The high tide line is searched at or near diurnal high tide and masses of stranded seaweeds (principally Durvillea antarctica) are probed and turned to discover hidden items. The items are classified according to standard CCAMLR groupings and are also noted for these characteristics: size dimensions; mass; colour; recognisable plastic type (eg. polystyrene); markings that may indicate country of origin; and, if fragments, the nature of the original object of which they were once a part. Major wind direction and strength over the previous and current day and the occurrence and magnitude of pumice pieces stranded on the shore are also recorded. An estimate is made of pumice density as the number of pieces (greater than 1cm) found in three of 10m sub-transects taken at random along the high-tide line. A sample of 6 pumice pieces is taken each month.

The occurrence and description of any organisms (eg, goose barnacles) attached to any material in the debris collection is also noted. If fresh, such specimens are collected and stored in 90% alcohol and their presence noted on the survey sheet.

All debris items are removed from the beach and bagged and stored near the hut to await removal (usually once/year during change-over).

RESEARCH ISSUES
The long-term monitoring described above requires supplementary research to interpret the meaning of the monthly data in terms of what actually arrives and leaves the beach on smaller time scales such as a daily basis. Sandell Bay beach is a very active place where storm events can both dominate debris arrivals and departures. The relationship of weather to the monitoring signals is an important area to be investigated further. Another area of importance is the role of the beach as a zone of destruction and fragment size reduction for the plastics. It seems that the beach cobble zone can be very abrasive during storm events.

LINKS TO OTHER INDICATORS
SOE Indicator 27 - The annual population of Adélie penguins at colonies in the vicinity of Casey, Davis and Mawson and on Shirley Island and Whitney Point
SOE Indicator 28 - Standard demographic parameters for Adélie penguins at Mawson
SOE Indicator 29 - Breeding population of the Southern Giant Petrel at Heard Island, the McDonald Islands and within the AAT.
SOE Indicator 31 - Annual population estimates of Southern Elephant Seals at Macquarie Island
SOE Indicator 32 - Fecundity and pup growth in fur seal colonies on Macquarie Island
SOE Indicator 33 - Annual catch in tonnes of marine species harvested in Australian Antarctic and subantarctic waters
SOE Indicator 37 - Species and numbers of species killed, taken or interfered with or disturbed in the Antarctic and the sub-Antarctic for the purpose of scientific research