FINAL Wader Beach and Greenwich Bay litter analysis July 2015 · • Greenwich Bay has a higher more diverse visitor use. The area is popular with recreational anglers from the wider

Analysis of litter data collected from Wader Beach and Greenwich Bay

Dec 2014 to May 2015

Report by Port Phillip EcoCentre for

Friends of Williamstown Wetlands, June 2015

Analysis of litter data collected from Wader Beach and Greenwich Bay Dec 2014 to May 2015

Author: Neil Blake, Port Phillip EcoCentre 4

Contents: Introduction..................................................................................................................................5 Executive Summary.....................................................................................................................5 Description of study areas............................................................................................................7

Wader Beach............................................................................................................................7 Greenwich Bay.........................................................................................................................8

Differences between Wader Beach and Greenwich Bay .............................................................9 Wader Beach Quadrats ..............................................................................................................10

Wader Beach east quadrats ....................................................................................................10 Wader Beach middle quadrats ...............................................................................................11 Wader Beach west quadrats ...................................................................................................12

Greenwich Bay quadrats ............................................................................................................14 Similarities between the 2 study areas .......................................................................................16 Data collection method ..............................................................................................................17 Results........................................................................................................................................18 Major types of litter recorded in the total study.........................................................................18

Timing of data collection .......................................................................................................18 Significant differences between Wader Beach and Greenwich Bay data..............................18

Wader Beach Analysis...............................................................................................................19 Greenwich Bay Analysis............................................................................................................21

Comparison of Greenwich Bay ‘Low’ and ‘High’ (river bank) data.....................................21 Comparison of Greenwich Bay ‘control’ and ‘river bank’ data ............................................21

Westgate Park foreshore (Yarra bank) litter audits 2015...........................................................24 Factors influencing direction of travel of litter ..........................................................................24

Wind direction .......................................................................................................................24 Tidal currents .........................................................................................................................25

Tagged Litter report 1993 ..........................................................................................................26 Corio contribution to Wader beach? ..................................................................................26

Discussion ..................................................................................................................................27 Recommendations......................................................................................................................27 Appendix 1. Wader Beach data .................................................................................................28 Appendix 2. Greenwich Bay data ..............................................................................................29 Appendix 3. Westgate Park foreshore litter audits ....................................................................30 Appendix 4. Influence of air pressure on wind speed and direction (from Bureau of Meteorology)..............................................................................................................................30 Acknowledgements: This report was prepared for Friends of Williamstown Wetlands as a component of their ‘Wader Beach For Birds Not Litter’ project funded by Metropolitan Waste & Resource Recovery Group through the Cleaner Yarra River & Port Phillip Bay Litter Hotspots Program. Thanks go to Marilyn Olliff, Peter Smith, Ian Rae, Karen Manly, Sandra Thorn (Members of Friends of Williamstown Wetlands), Nick Olliff, David Speller (Jawbone Marine Sanctuary Care Group); Maria McGuane, Jill Hocking, Philippa Cursio, David Stubbs (Friends of Greenwich Bay). Spreadsheets prepared by Peter Smith and David Giles.



Introduction At Wader Beach 6 quadrats (4m X 4m) were audited at monthly intervals on 6 occasions by Friends of Williamstown Wetlands between December 2014 and May 2015. At Greenwich Bay 3 quadrats (4m X 4m) were audited at monthly intervals on 6 occasions by Friends of Greenwich Bay between December 2014 and May 2015. Raw data compiled by Peter Smith of Friends of Williamstown Wetlands was forwarded to Port Phillip EcoCentre for analysis with a view to identifying:

• The likely source of the litter (local or regional waterway catchment) • The influence of rainfall events and litter quantity • The influence on wind-generated wave action and tides

The following desktop research was conducted to provide regional context and inform interpretation of the current data collection:

• Additional litter data collected in March and April 2015 at Westgate Park riverbank (1.8km upstream of Greenwich Bay);

• Examination of findings of the 1993 Tagged Litter Study; • Examination of Port Phillip Bay tidal current directions.

Executive Summary Monthly audits of both study areas were conducted on the same day on 3 occasions, one day apart on 2 occasions, and one week apart on one occasion. The total of items collected (all quadrats and months combined) was 4,606.

Although representing only one third of the total quadrats the 3 quadrats at Greenwich Bay yielded 2,905 (63.07%) of the total litter items collected. 1,701 litter items (36.93%) were collected from the 6 quadrats at Wader Beach.

The number of litter items recorded at both study areas was markedly higher for the December to February audits compared to March to May audits. This may be due to seasonal variation in prevailing wind direction and human activity in catchments.

Comparative differences in major litter types represented at both sites include:

• ‘Plastic pieces’ represented 59.08% of items recorded at Wader Beach compared to 15.87% of Greenwich Bay

• ‘Fishing line’ represented 6.82% of the Greenwich Bay total whereas none was recorded at Wader Beach.

• Polystyrene pieces represented 25.03% of litter at Greenwich Bay compared to 5.64% of litter items at Wader Beach

• Plastic/cellophane/film/wrap represented 8.3% of litter at Greenwich Bay compared to 3.47% at Wader Beach

• Similar proportions of ‘Broken glass’ were recorded at Wader Beach (8.75%) and Greenwich Bay (8.3%).



Litter types that are likely to be from on-site or relatively local sources include:

• ‘fishing line’ and ‘fishing gear’ (counted as a separate items) respectively comprised 6.82% and 2% of all litter items at Greenwich Bay; and 0% and 0.76% at Wader Beach.

• ‘rope/twine’ was in negligible amounts at Greenwich Bay (0.07%) but recorded as 4.23% of the total at Wader Beach.

Distinct differences were found in the types of litter found in the 2 study areas, despite the fact that:

• The 2 areas are relatively close to each other (approximately 3km ‘as the crow flies’ and 8km by shoreline);

• the audits were predominantly conducted on the same day or within 24 hours of each other (indicating similar climatic conditions would have prevailed at the time of audits).

The above factors suggest that there limited (if any) exchange from the ‘Yarra mouth’ zone (Greenwich Bay) to the ‘West of Jawbone’ zone (Wader Beach). To test this hypothesis, the following investigations were conducted:

• a review of climate conditions (wind and rain) prevailing in the month prior to each survey;

• a review of tidal patterns; and • a review of the 1991-93 Tagged Litter Report1.

On the evidence found, it is concluded that much of the litter accumulating at Wader Beach originates from catchment sources to the west of Jawbone Marine Sanctuary.

1 Backyard to Bay Tagged Litter Report. 1993. Melbourne Parks & Waterways.



Description of study areas

Wader Beach Wader Beach is an important site for birds, in particular migratory waders that feed on the low tide flats during the summer and early autumn. The area adjacent to the beach is environmentally significant, with remnant saltmarsh right up to and in some cases on the beach. The beach is predominantly sand/gravel and small to medium sized rocks with a significant amount of washed up seagrass. The bay stretches for about 700 metres from the rocky outcrop of Jawbone in the east to the mouth of the Kororoit Creek and Paisley-Challis wetlands drain in the west.

Site selection and size Three locations along Wader Beach were selected to provide a wide coverage of this shallow, curved but otherwise fairly uniform bay. The sites were designated Wader Beach East, Wader Beach Middle and Wader Beach West. The distance between Wader Beach East and Wader Beach Middle is about 500 metres; the distance between Wader Beach Middle and Wader Beach West is about 90 metres. The sites chosen were adjacent to inter-tidal areas with relatively fewer rocks so that tidal deposits of litter to the beach were not significantly impeded by rocks. A pre-survey trial was conducted using 2x2, 4x4 and 8x8 quadrats. The 2x2 quadrats captured limited information with few classes of litter. The 8x8 quadrats captured about the same number of classes of litter as the 4x4 quadrats but at a greater volume, and so monitoring of 3 pairs of 4m x 4m quadrats was adopted as the most cost-effective method. At each location, two 4x4 metre sites were marked out. One site was located just above the mean high water level (the ‘low’ site) and the other a further 4 metres inland where the beach was slightly elevated by about 0.5 metres (the ‘high’ site). The high sites contain permanent coastal vegetation. At the Wader Beach Middle site, the high site was not directly behind the low site, being offset by a few metres due to the terrain. This site included a number of slabs of concrete from buildings that were at the site some 100 or more years ago (see photo on page 16).



Greenwich Bay The Greenwich Bay area on the western bank of the Yarra estuary is highly modified with the riverside being constructed of basalt boulders and ballast. The area is especially popular with recreational anglers and pedestrians and cyclists who use the path passing through the area. The car park also serves as an out-of-the-way place for people to socialise at night.

The Greenwich Bay study site consisted of one pair of ‘river bank’ quadrats with one on the waterline and one higher up on the river bank. An additional quadrat (marked with pegs) was located immediately west of the cycle path near the concrete wharf. This quadrat was located in an elevated position away from the river and served as a ‘control site’ representing litter generated on-site as opposed to possibly arriving via the river.



Differences between Wader Beach and Greenwich Bay The key differences between the 2 study areas are their orientation in relation to currents and wind driven waves; and different uses by people.

Notable differences between the two study areas that are relevant to litter types and volumes are:

• Wader Beach is located on the northern shores of Port Phillip Bay between Kororoit Creek and Jawbone Marine Sanctuary and receives litter items primarily borne on wind-driven waves. Note: the direction of prevailing west to south westerly currents and wave energy at Wader Beach is evidenced by the sandy seabed.

• Greenwich Bay is on the western side of the Yarra mouth and subject to influx

of litter from local users and from the wider Yarra catchment. Passage of container ships to and from the Port of Melbourne (upstream of Greenwich Bay) generates bow waves that push any litter in the river towards the shoreline.

• Wader Beach is a rocky inter-tidal coastline fringed by saltmarsh vegetation

which primarily attracts beach strollers from the neighbouring residences.

• Greenwich Bay has a higher more diverse visitor use. The area is popular with recreational anglers from the wider region, and a walking/cycle path crosses through the site.

• Pedestrian access to Wader Beach involves walking several hundred metres

from the nearest, relatively small car park.

• The Greenwich Bay riverbank is oriented generally in a north south direction; whereas the Wader beach shoreline is oriented west-north-west to east-south-east.

• Wader beach has a wide expanse of inter-tidal shallows and relatively gentle

sloping beach.

• The Greenwich Bay riverbank is constructed of large basalt boulders and has a narrow and relatively steep inter-tidal zone.

• The Greenwich Bay site has a large car park in close proximity which is visited

by people from the wider region.

• Wader Beach is located immediately east of the mouth Kororoit Creek and Paisley-Challis drain and thus receives litter from Melbourne’s western region.

• Greenwich Bay is in the Yarra estuary and thus receives litter from the greater

Melbourne area.



Wader Beach Quadrats

Wader Beach east quadrats Date: 28 November 2014 Photo title: 141128 WB East Altitude: 0 m above sea level Image Direction: 225 (magnetic) Latitude: 37° 51' 39.6" S Longitude: 144° 52' 26.4" E

141128 WB East

Date: 14 June 2015 Photo title: 150614 WB East Altitude: 0 m above sea level Image Direction: 202.5(magnetic) Latitude: 37° 51' 43.2" S Longitude: 144° 52' 26.4" E

150614 WB East

Date: 28 November 2014 Photo title 141128 WB East showing stakes Image Direction: 45 (True) Latitude: 37° 51' 39.6" S Longitude: 144° 52' 26.4" E Peg at bottom west corner of site. (lower site).



141128 WB East showing stakes

Wader Beach middle quadrats Date: 28/11/2014 Photo title: WB Middle Altitude: 0 m above sea level Image Direction: 202.5 Magnetic Latitude: 37° 51' 32.4" S Longitude: 144° 52' 12" E

Date: 14/06/2015 Photo title: WB Middle Altitude: 0 m above sea level Image Direction: 202.5 Magnetic Latitude: 37° 51' 32.4" S Longitude: 144° 52' 12" E

Date: 28/11/2014 Photo title: WB Middle – showing stakes Altitude: 0 m above sea level Image Direction: 202.5 Magnetic Latitude: 37° 51' 32.4" S Longitude: 144° 52' 12" E



Wader Beach west quadrats Date: 30 November 2014 Photo title: WB West – scab duty clean up Altitude: 0 m above sea level Image Direction: 202.5 Magnetic Latitude: 37° 51' 32.4" S Longitude: 144° 52' 8.4" E

A photo of WB West looking towards the Bay was not taken on 28 November 2014. This photo was taken on 30 November, 2 days after stakes were planted when Scab Duty did the initial clean up. Date: 14 June 2015 Photo title: WB West Altitude: 0 m above sea level Image Direction: 202.5 Magnetic Latitude: 37° 51' 32.4" S Longitude: 144° 52' 8.4" E

Date: 28 November 2014 Photo title: WB West showing stakes Altitude: 0 m above sea level Image Direction: 45 (True) Latitude: 37° 51' 32.4" S Longitude: 144° 52' 8.4" E



Wader beach west low quadrat

Wader Beach showing west-north-west to east-south-east orientation



Greenwich Bay quadrats

Greenwich Bay ‘Low’ quadrat

Greenwich Bay view from ‘Low’ to ‘High’ quadrat

Directional orientation between the Greenwich Bay quadrats RSL and RSH was approximately east-west.



Greenwich Bay ‘Control’ quadrat

Greenwich Bay on-site information



Similarities between the 2 study areas The Wader Beach middle site (WBM) is of comparable structure to the Greenwich Bay riverside quadrats in that their respective quadrats are separated by ‘mini-cliffs’ of approximately the same height. At Wader Beach the ‘mini-cliff’ consists of a concrete beam along the top of the beach, whereas at Greenwich Bay it consists of basalt rocks.

Wader beach mid low quadrat (note concrete beam at top of beach)

Wader Beach view to ‘Mid-High’ quadrat (with concrete beam in foreground)



Data collection method Litter Data was collected from quadrats at Wader Beach (6 quadrats) and Greenwich Bay (3 quadrats) on 6 occasions between December 2014 and May 2015. Surveys were conducted approximately at monthly intervals. Each 4x4 quadrat was marked out with wooden stakes at each corner. The stakes were approximately 30cm high and were sprayed with fluorescent orange paint for easy identification of the sites and to warn walkers of the stakes. For the shoreline at Greenwich Bay, paint was sprayed directly on the rocks as it was too rocky to insert stakes. Sampling times Monthly surveys were undertaken at both Wader beach and Greenwich Bay at approximately the same time each month. Surveys were conducted at Wader Beach during low/mid tide times to avoid disturbance to birds at the beach. Litter collection and data recording A data recording sheet was developed based on the litter sheets used by the Victorian Litter Action Alliance (www.litter.vic.gov.au), the Port Phillip Eco-Centre (www.ecocentre.com), and the Tangaroa Blue Marine Debris Initiative (http://www.tangaroablue.org) with some items added/removed following initial visual surveys at Wader Beach. Examples of Litter Survey Sheets are given in Appendix 2. For each survey a minimum of two volunteers were employed, one to record and one to count and bag all litter items from each site. At the end of each survey, the bags were carried out and disposed of in the Hobsons Bay refuse collection bins Counting litter items involved a ‘hands and knees’ approach to sift through the weed matts to find small items, especially small pieces of plastic. If any nurdles were seen, this was recorded on the data sheet, but a detailed survey of nurdles was not carried out. For each survey, the date and time of the litter collection was recorded. Additional data on wind speed and direction and time of high/low tides were recorded. Any exceptional strong winds and heavy rain events in the weeks preceding each survey were noted. Names of the monitors were noted and a safety sheet signed for insurance purposes.



Results

Major types of litter recorded in the total study The top 5 major litter types (76.08% of the combined total) was comprised of:

Plastic pieces: 1,466 31.83% Polystyrene pieces: 823 17.87% Plastic/cello/film/wrap: 614 13.33% Broken glass: 403 8.75% Fishing line: 198 4.3%

Timing of data collection Month Wader beach Greenwich bay December 21/12/14 14/12/15 January 19/1/15 18/1/15 February 22/2/15 22/2/15 March 23/3/15 22/3/15 April 19/4/15 19/4/15 May 17/5/15 17/5/15

Table 1. Collection sites and dates

As shown above, except for the month of December, data collection in all quadrats was conducted either on the same day (3 occasions) or within 24 hours (2 occasions). This relatively close coincidence of timing provides a good basis for comparing results in relation to climatic factors prevailing in the month prior to the survey.

Month Wader beach Greenwich bay December 352 20.69% 827 28.47% January 337 19.81% 566 19.48% February 386 22.69% 588 20.24% March 135 7.94% 325 11.19% April 270 15.87% 388 13.36% May 221 12.99% 211 7.26% Total all litter 1,701 100% 2,905 100%

Table 2. Percentages of site total litter by month

Significant differences between Wader Beach and Greenwich Bay data Litter collected at Wader Beach in the 3 months from December and February comprised 63.19% of the WB total; compared with 36.8% between March and May. Litter collected at Greenwich Bay in the 3 months from December and February comprised 68.19% of the GB total; compared with 31.81% between March and May. The most significant differences between the 2 areas are seen in the months of December and May. Greenwich Bay has a significantly higher percentage than Wader Beach in December and significantly lower percentage in May. These differences may be attributed to seasonally changing public usage patterns at Greenwich Bay and/or different prevailing climatic conditions (rainfall and wind direction) influencing the amount of waterborne litter stranded on shorelines. Influence of climatic conditions is discussed later in this report.



Wader Beach Analysis

Detail of Wader Beach data is shown in Appendix 1. The 6 quadrats audited 6 times at Wader Beach recorded 1,701 litter items. QUADRAT DEC JAN FEB MAR APR MAY AV EL 9.94% 8.01% 6.22% 3.70% 14.07% 8.60% 8.42 EH 36.93% 52.23% 76.68% 40.74% 33.33% 43.89% 47.30 ML 15.06% 7.42% 5.70% 26.67% 20.00% 17.19% 15.34 MH 11.65% 5.93% 2.59% 2.22% 18.15% 5.88% 7.70 WL 15.06% 7.42% 6.22% 20.74% 11.48% 2.71% 10.60 WH 11.36% 18.99% 2.59% 5.93% 2.96% 21.72% 10.59 Table 4. Percentage comparison of Wader Beach quadrats

In the ‘Eastern’ quadrats the significant majority of litter was in EH in all months. In the ‘Middle’ quadrats most litter was found in ML in all months. In the ‘Western’ quadrats ‘majority’ varied with WL in the majority in December, February, March and April; and in WH in January and May.

Wader Beach Litter Survey Total

Plastic pieces59%

Glass broken10%

Polystyrene piece6%

Rope / twine4%

Plastic straw3%

Other15%

Plastic / cello / film / wrap3%

Plastic pieces

Glass broken

Polystyrene piece

Rope / twine

Plastic / cello / film / wrap

Plastic straw

Other



Wader Beach 'Low' Quadrats Litter Analysis

plastic pieces32%

glass broken30%

plastic/ cello/ film/ wrap7%

rope/ twine3%

plastic bag3%

polystyrene pieces3%

Other22%

Wader Beach 'High' Quadrats Litter Analysis

plastic pieces71%


rope/ twine5%

plastic straw3%


plastic lid/ cont2% Other

10%



Greenwich Bay Analysis

Comparison of Greenwich Bay ‘Low’ and ‘High’ (river bank) data In the first 4 audits at Greenwich Bay the ‘Low’ quadrat has significantly less litter than the ‘High’ site, increasing to approximately the same in April and substantially more in May. The ‘Low’ quadrat at Wader Beach recorded marginally more litter than the ‘High’ quadrat in 5 audits and substantially more in April.

Comparison of Greenwich Bay ‘control’ and ‘river bank’ data The ‘control’ quadrat was located on the pedestrian/cycle path that passes along the western side of the concrete wharf. While winds could deliver lighter litter items from adjacent areas, due to the elevated location, high tides and storm surges would be unlikely to deposit litter directly onto this quadrat from the river. The total items collected from the ‘control site’ was 7.78% of all items collected from Greenwich Bay quadrats. Polystyrene pieces (the most common item overall at GB) was uncommon (0-4 pieces) in the ‘control site’ after the first audit found 31 pieces. Similar findings applied to the second and third most common items: plastic/cellophane and plastic pieces both of which were predominantly found in the ‘High’ quadrat. Broken glass (4th most common item at GB) was predominantly in the ‘Low’ river bank site (212 pieces) as was Fishing line (5th most common item at GB). Both of these items are likely to have originated from on-site, as opposed to arriving from the river. ‘Control’ site audits found 0-2 pieces of broken glass in most audits, However, the February and April audits recorded 7 and 8 pieces respectively. Due to the nature of broken glass, these may have resulted from only 2 instances of littering, but do pose a hazard in the environment. Detail of Greenwich Bay data is shown in Appendix 2. The 3 quadrats audited 6 times at Greenwich Bay recorded 2,905 litter items. QUADRAT DEC JAN FEB MAR APR MAY AV RSL 31.32% 24.38% 12.59% 32.92% 45.88% 61.61% 34.78 RSH 51.03% 71.02% 76.02% 60.92% 47.68% 37.91% 57.43 PSt 17.65% 4.59% 11.39% 6.15% 6.44% 0.47% 7.78 Table 3. Percentage comparison of Greenwich Bay quadrats

A significant majority of litter was recorded at RSH in months of December to March, with amounts in RSL and RSH almost equal in April; and a significant majority in RSL in May.



Geenwich Bay Litter Survey Total


plastic pieces16%

glass broken8%

fishing line7%

Other21%

Polystyrene piece26%

plastic bag3%

Polystyrene piece

plastic/ cello/ film/ wrap

plastic pieces

glass broken

fishing line

plastic bag

Other



Greenwich Bay 'High' Quadrat Litter Analysis


plastic pieces17%

park ticket4%

plastic bag4%

fishing line2%

Other10%


Greenwich Bay 'Low' Quadrat Litter Analysis

glass broken24%

fishing line19%

plastic pieces13%



fishing gear5%

Other25%



Westgate Park foreshore (Yarra bank) litter audits 2015 Friends of Westgate Park conducted 3 litter collection audits on the Yarra bank during March and April 2015. The Westgate audit area (approximately 1km of river bank to Lorimer St kerb) is 1.8 km upstream of the Greenwich Bay study site but on the opposite side of the river.

The audit on 29/4/14 was assisted by Tangaroa Blue, Port Phillip EcoCentre and Beach Patrol. The following data (all audits combined) is extracted from the Australian Marine Database Initiative. Detail of Westgate Park foreshore audits is shown in Appendix 3. As with Greenwich Bay polystyrene was the most common litter item.

Factors influencing direction of travel of litter Prevailing winds and the direction of tidal currents were investigated in order to determine if litter from the ‘Yarra mouth’ zone is likely to move towards the ‘West of Jawbone’ zone.

Wind direction In the southern hemisphere, winds generally flow in a clockwise direction around low pressure systems (and slightly inward); and anticlockwise (and slightly outward) around high pressure systems. Where isobars are closer together the wind will be stronger than in areas where they are further apart (see Appendix 4).

Prevailing winds associated with Port Phillip Bay vary seasonally. In broad terms prevailing winds during spring and summer are south to south westerly; whereas westerlies and northerlies prevail in the autumn winter seasons. Winds from the north-east to south-east of Melbourne are relatively rare primarily due to the Melbourne Eddy – a circulation pattern caused by the blocking of easterly and north-easterly winds by the Australian Alps – under stably stratified conditions2. The following chart accessed from the Bureau of Meteorology is a typical example of ‘High’ pressure systems in relation to ‘Low’ pressure systems passing from west to east across southern Australia in April and May. Winds associated with these systems are predominantly from south-westerly to north westerly.

2 Hall D.N. Port Phillip Bay Environment Study: Status Review. CSIRO. December 1992.



Tidal currents Charts showing ‘Ebb-tide’ and ‘Flood tide’ conditions show currents in the north of the Bay travelling from south-westerly, westerly, north-westerly to northerly. There are no east to west currents indicated on the charts.

Total Water Movement during Flood Tide calculated from Current Measurements and Mathematical Model simulations. Environmental Study of Port Phillip Bay 1968-1971

Total Water Movement during Ebb Tide calculated from Current Measurements and Mathematical Model simulations. Environmental Study of Port Phillip Bay 1968-1971



Tagged Litter report 1993 The ‘Tagged Litter Report’ conducted by Melbourne Parks and Waterways commenced in September 1991 with the release of 1,307 items of tagged litter into Melbourne’s drainage network. By August 1993 slightly less than half (629) of the tagged items had been retrieved from banks of urban waterways or bayside beaches. The study showed that litter from streets many kilometres inland can reach the Bay. Of the tagged items that reach the Bay, 80% were found on beaches within 2 km of the relevant drainage outlet.3 Of the 786 items released in the Yarra catchment more than half were found within the catchment and only 13 found in the Bay, none west of the Yarra mouth. Whereas: Of the 183 items released in drains in south-eastern suburbs of Metropolitan Melbourne (Port Melbourne to Mordialloc) only 6 were found within the catchment and 100 were found on bayside beaches. The findings of the Tagged Litter Study support the view that there is minimal exchange of litter from the Yarra mouth zone to west of Jawbone Sanctuary. Of the total of 1,240 tagged items launched in the Yarra and south-eastern suburban catchments 122 were found in the Bay. Only one was found on the western side of the bay (near Port Arlington).

Corio contribution to Wader beach?

The Tagged Litter Study concluded that there was little if aany exchange of litter from Corio Bay to northern Port Phillip Bay. 43 tagged litter items were launched to waterways feeding into the western end of Corio Bay. Of these, 9 were retrieved in waterways and 10 from beaches around Corio Bay. The most easterly location of the Corio Bay recoveries was at Point Lillias4 (around 50 km west-south-west of Wader Beach).

3 Backyard to Bay Tagged Litter Report. 1993. Melbourne Parks & Waterways. P.21 4 Backyard to Bay Tagged Litter Report. Melbourne parks & Waterways. Map 1. P.18



Discussion Due to their physical shape, the materials they are made of, and relative weight, different types of litter exhibit different degrees of ‘bouyancy’. The most lightweight litter types (such as polystyrene) that do not absorb water are the most buoyant. As such, they are generally found on the surface of water column where their direction of travel is strongly influenced by wind strength and direction. The significant difference in polystyrene pieces represented at Greenwich Bay (25.03% of GB litter) compared to Wader Beach (5.64% of WB litter) indicates that the majority of polystyrene enters the Bay from the catchments feeding to the Yarra mouth (Stony Creek, Maribyrnong and Yarra catchments). Due to tidal currents running clockwise around the top of the Bay and winds that vary seasonally from southerly to northerly almost all litter entering the Bay from the Yarra mouth is likely to travel generally southward or be washed up along north-eastern bay foreshores.

Recommendations Examine Hobsons Bay Council area drainage infrastructure maps to identify potential major sources of litter. Examine Wyndham Council area drainage infrastructure maps to identify potential major sources of litter. Conduct regular audits of identified litter hotspots in the region. Friends of Williamstown Wetlands and Hobsons Bay City Council participate in regular ‘Western Shorelines’ meetings convened by Melbourne Water. Investigate opportunities for HBCC and Wyndham City Council to engage other user groups in litter education reduction campaigns. Seek grants for continuing audits and analysis of litter quadrats at Wader Beach and Greenwich Bay. Continue to build relationships with other local groups who are interested in reducing single use plastics.



Appendix 1. Wader Beach data

Date Site

plastic

plastic

plastic

bait

plastic

plastic

plastic

rope/

plastic

6pack

polystyr

glass

cig.

nurdles

syringe

other

pieces

film/w

rap

bag

bag

bottle

lid

straw

twine

strap

holder

piece

broken

butt

pooled

21.12.14 EL 25 0 0 3 0 0 0 1 0 0 1 0 0 0 0 5

EH 104 0 0 0 2 1 3 6 0 0 1 0 0 0 0 13

ML 8 0 1 0 0 0 1 0 0 0 1 31 5 0 0 6

MH 21 0 0 0 0 0 0 1 0 0 16 0 0 0 0 3

WL 38 0 0 1 0 1 0 4 0 0 0 0 1 lots 0 8

WH 18 0 2 0 1 1 3 1 0 0 0 0 4 0 0 10 Month Total 214 0 3 4 3 3 7 13 0 0 19 31 10 0 45

19.1.15 EL 0 16 0 0 0 2 0 2 0 0 2 0 0 0 0 5

EH 122 5 3 0 4 4 11 12 0 0 5 0 2 0 0 8

ML 2 0 0 0 0 1 0 2 0 0 0 19 0 0 0 1

MH 4 2 0 0 0 1 0 2 0 0 9 0 0 0 0 2

WL 9 2 0 0 1 3 1 3 0 0 0 0 0 0 0 6

WH 31 5 2 0 0 6 7 8 0 0 0 0 0 mod. 0 5 Month Total 168 30 5 0 5 17 19 29 0 0 16 19 2 0 27

22.2.15 EL 12 1 1 0 1 0 0 3 2 0 1 0 0 lots 0 3

EH 244 0 1 3 5 3 5 12 0 1 5 0 3 0 0 14

ML 4 0 0 0 0 0 0 0 0 0 0 14 0 0 0 4

MH 6 0 0 0 0 0 0 0 0 0 3 0 0 lots 0 1

WL 0 10 1 1 8 0 1 0 0 0 0 0 2 0 0 1

WH 0 2 0 0 0 0 0 2 0 0 2 0 0 0 1 3 Month Total 266 13 3 4 14 3 6 17 2 1 11 14 5 1 26

23.3.15 EL 2 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0

EH 42 2 2 0 1 1 1 1 0 0 1 0 2 0 0 2

ML 3 1 2 0 0 1 1 1 0 0 1 23 0 0 0 3

MH 0 0 0 0 0 0 0 0 0 0 3 0 0 mod. 0 0

WL 18 1 4 0 0 2 1 1 0 0 0 0 1 0 0 0

WH 5 0 0 0 0 1 0 1 0 0 0 0 0 mod. 0 1

Month Total 70 4 10 1 1 5 3 4 0 0 5 23 3 0 6

19.4.15 EL 27 2 2 0 1 0 0 0 0 0 0 0 2 0 0 4

EH 79 2 0 0 1 1 2 1 0 0 3 0 1 mod. 0 0

ML 2 0 0 3 0 0 0 0 0 0 6 40 0 0 0 3

MH 22 0 0 0 0 0 0 0 0 0 26 0 0 mod. 0 1

WL 13 4 1 1 0 3 3 1 0 0 2 0 2 0 0 1

WH 3 0 1 0 0 0 0 0 0 0 0 0 0 lots 0 4 Month Total 146 8 4 4 2 4 5 2 0 0 37 40 5 0 13

17.05.15 EL 10 1 2 0 0 1 2 1 0 0 0 0 0 0 0 2



EH 78 3 1 0 0 1 0 4 0 0 3 0 3 0 0 4

ML 0 0 0 0 0 0 0 0 0 0 0 35 0 0 0 3

MH 10 0 0 0 0 0 0 0 0 0 3 0 0 few 0 0

WL 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2

WH 39 0 0 0 0 0 2 2 1 0 2 0 0 few 0 2 Month Total 141 4 3 0 0 2 4 7 1 0 8 35 3 0 11 Grand Total 1005 59 28 13 25 34 44 72 3 1 96 162 28 1 130

Appendix 2. Greenwich Bay data

Date Site

plastic

plast/cello

plastic

paper

plastic

plastic

plastic

rope/

plastic

6pack

polysty

polysty

park

glass

cig.

fish

fish

Other *

pieces

film/w

rap

bag

bottle

lid/cont

straw

twine

strap

holder

piece

cup

ticket

broken

butt

line

gear

14.12.14 RSL 45 43 8 0 3 9 9 0 5 0 18 9 4 25 7 45 11 24 RSH 46 134 21 12 4 5 7 0 7 0 101 9 34 6 3 12 13 8 PSt 31 38 6 32 1 4 2 0 8 0 3 0 0 2 3 1 0 15 Month Total 122 215 35 44 8 18 18 0 20 0 122 18 38 33 13 58 24 47 18.1.15 RSL 14 7 5 2 1 11 1 0 1 0 5 0 0 67 12 10 0 2 RSH 153 9 21 2 8 8 2 0 0 0 164 1 18 1 3 5 1 6 PSt 2 8 3 2 1 1 0 0 1 0 1 0 1 2 2 0 0 2 Month Total 169 24 29 6 10 20 3 0 2 0 170 1 19 70 17 15 1 10 22.2.15 RSL 8 6 4 3 0 1 3 0 4 0 2 0 0 18 9 13 0 3 RSH 30 179 3 0 0 3 1 1 1 0 209 2 14 0 0 1 0 3 PSt 4 5 1 9 2 0 1 0 0 0 0 1 0 7 31 0 0 6 Month Total 42 190 8 12 2 4 5 1 5 0 211 3 14 25 40 14 0 12 22.3.15 RSL 25 0 2 0 3 15 4 0 4 0 4 0 1 23 4 16 1 5 RSH 28 59 6 7 0 3 1 0 3 0 80 0 4 1 2 0 0 4 PSt 2 0 0 1 0 2 0 0 0 0 1 0 1 1 6 0 0 6 Month Total 55 59 8 8 3 20 5 0 7 0 85 0 6 25 12 16 1 15 19.4.15 RSL 21 2 3 1 1 0 2 0 3 0 37 0 0 29 7 37 26 9 RSH 20 43 5 1 1 2 2 0 1 0 82 0 2 1 1 11 0 13 PSt 3 1 0 2 1 0 0 0 0 0 2 0 0 8 0 2 0 6 Total 44 46 8 4 3 2 4 0 4 0 121 0 2 38 8 50 26 28 17.5.15 RSL 5 0 7 2 0 0 0 1 1 0 0 0 0 50 9 44 6 0 RSH 24 21 5 0 1 1 1 0 0 0 18 0 0 0 0 0 0 9 PSt 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 Month Total 29 21 12 2 1 1 1 1 1 0 18 0 0 50 9 45 6 14 Grand Total 461 555 100 76 27 65 36 2 39 0 727 22 79 241 99 198 58 18



Appendix 3. Westgate Park foreshore litter audits

Extracted from Australian Marine Debris Database http://www.tangaroablue.com/amdidb/reports.php Litter category Total Percentage Foam insulation & packaging (whole & remnant) 5,097 49.3% Fishing line (in metres) 1,272 12.3% Plastic film remnants (bits of plastic bag, wrap etc) 796 7.7% Lids and tops, pump spray, flow restrictors & similar 738 7.12% Plastic bits & pieces (hard & solid) 627 6.06% Plastic drink bottles (water, juice, milk, soft drink) 466 4.5% Paper & cardboard packaging 360 3.48% Aluminium cans 351 3.4% Plastic packaging (food wrap, packets, containers) 348 3.36% Foam cups, food packs & trays 281 2.72% 10,336

Appendix 4. Influence of air pressure on wind speed and direction (from Bureau of Meteorology) Pressure

Air pressure is probably the single most important weather element, because pressure variations drive the winds. Daily weather map sequences show a series of high pressure ('highs') and low pressure ('lows') systems moving across the continent. The lines on the map show variations in the pressure from place to place at a horizontal level, usually mean sea level. These 'isobar' lines ('iso' means equal) join places having the same atmospheric pressure.

Air movement and pressure systems Exactly how does air move in relation to these systems? Outside the tropics, the broadscale wind flow is closely related to the distribution of atmospheric pressure.

Some general rules are:

• In the southern hemisphere, winds flow clockwise around low pressure systems (and slightly inward) and anticlockwise (and slightly outward) around high pressure systems.

• Where isobars are closer together the wind will be stronger than in areas where they are further apart.

Inflowing air associated with a low pressure system results in convergence and ascent of air often resulting in deep cloud formations and rainfall. Conversely, outflowing air associated with a high pressure system results in divergence and descent of air and more stable weather.

Typical weather map.

How air moves in relation to pressure systems in the southern hemisphere.

Documents

FINAL Wader Beach and Greenwich Bay litter analysis July 2015 · • Greenwich Bay has a higher more diverse visitor use. The area is popular with recreational anglers from the wider