AUSTRALIAN 192 BIRD WATCHER AUSTRALIAN BIRD WATCHER 2000, 18, 192-198 The Effects of an Oil Spill at Apollo Bay, Victoria, on Little Penguins Eudyptula minor in May 1990

by R. JESSOP1 and P. Du GUESCLINZ 1 Phillip Island Nature Park, P.O. Box 97, Cowes, Victoria 3922 2 Department ofNatttral Resources and Environment, 83 Gellibrand Street, Colac, Victoria 3250

Summary On 21 May 1990, an oil spill was observed off the southern Victorian coast, between Cape Otway and Lome. The first oiled Little Penguin Eudyptula minor came ashore the following day. Overall, 327 oiled birds of six species, including 318 Little Penguins, were recovered. The percentage of Penguins rehabilitated and released from Apollo Bay was 38. 7%. This is considered low, and was attributable to a number of factors, which are discussed.

Introduction Little Penguins Eudyptula minor breed on the coastal Australian mainland and offshore islands, south from Broughton Island, New South Wales, to Carnac Island, near Perth, Western Australia (Marchant & Higgins 1990). In Victoria, the western coast is an important area for both breeding and feeding (Harris & Norman 1981, Dann et al. 1992). Breeding colonies occur in the Port Campbell National Park (4000 pairs; P. Du Guesclin pers. obs.), on Lady Julia Percy Island (2000 pairs; Harris & Norman 1981) and Middle Island (1000 pairs; Penguin Study Group unpubl. data). Penguins from other parts of Bass Strait, including Phillip Island, feed along the western coast of Victoria at some times of the year (Reilly & Cullen 1979, Dann et al. 1992). Oiled plumage was the most common cause of Little Penguins being admitted to the rehabilitation facilities at the Phillip Island Nature Park (PINP) between 1984 and 1992 (D'Arnore & Jessop 1995). Sixty-one Little Penguins were admitted following an unidentified oil spill in 1985- 86, and 112 after a spill near Apollo Bay in May 1990. The latter was the greatest number of Little Penguins to be rehabilitated after being oiled until the Iron Baron oil spill off Tasmania in 1995, when 2000 live oiled Penguins were recovered (Holdsworth & Bryant 1995). Some oiled birds are received at PINP throughout the year, but they are more common in winter (PINP unpubl. data).

Study area and methods On 21 May 1990, a slick of crude oil was reported 6.5 km off Blanket Bay (38°49'S, 143o35'E), between Cape Otway and Lome, Victoria. The size of the slick was estimated to be 16 km long and 100m wide. The following morning, an aerial survey by the Port of Melbourne Authority and searches using a boat failed to locate the spill (Du Guesclin 1992). Later that day, at 1630 h, the first live oiled Little Penguin was washed ashore at Apollo Bay.

Search effort On the evening of 22 May, staff from the Department of Natural Resources and Environment (NRE), Colac Re~ion, commenced searches for oiled wildlife along the coastline between Skenes Creek (38°43 S, 143°43'E) and Shelly Beach, near Cape Otway (38o52'S, 143o31'E) (Figure 1). The search area was divided into sectors to ensure a search as thorough as possible, to prevent duplication of effort and to enable continuous monitoring of 'hot VOL. 18 (5) MARCH2000 Oiled Penguins, Apollo Bay, Vic. 193

50

Lome fort Campbell Wye River 41 Apollo Bay 78 2 / Cape Otway 39'

142" 30 143" 30 144' 30 145' Figure 1. Locations where live oiled Little Penguins from the Apollo Bay oil spill were found. spots'. Searches were later extended eastwards to Anglesea (38°25'S,144°1l'E) and westwards to Warrnambool (38°23'S, 142°29'E); however, not all of the coastline was covered. Intensive searches, from dawn to dusk, were made over the next three days and then tapered off, finally ceasing after eight days, when no further oiled birds were located (Du Guesclin 1992). Specific searches were made at the Port Campbell colony to capture oiled birds as they returned to their burrows at night. Corpses were counted by NRE personnel and either buried, if the location was remote, or returned to Apollo Bay. Live birds were taken to the Apollo Bay Higher Elementary School for initial treatment, and later transported to PINP for long-term care. Staff from PINP, and NRE, Port Phillip Region, and members of the public conducted searches along the coastline between Phillip Island and Point Nepean; dead and live birds were retrieved. Live birds from the Mornington Peninsula were sent directly to PINP for rehabilitation. Little Penguins found near Warrnambool (NRE, Portland Region) were rehabilitated at a wildlife shelter near Warrnambool, while those found near Torquay (NRE, Geelong Region) went to a wildlife shelter in Torquay.

Rehabilitation techniques In the initial stages of the spill, oiled Penguins at the Apollo Bay rehabilitation centre were cleaned by untrained and unsupervised personnel using non-standard techniques, such as toothbrushing with soap, which resulted in substantial feather damage. After four days, RJ went to Apollo Bay and initiated procedures that had been in place at PINP for some time (Jessop & Healy 1997). A roster for cleaning, feeding and weighing Penguins was implemented with the help of NRE staff and volunteers. When the birds' health had been stabilised, they were transferred to PINP to complete their rehabilitation. Birds were considered stable when they had been rehydrated, could stand without the aid of their flippers, and did not regurgitate their food. They were considered suitable for release when they had attainded a weight of 1 kg and their down feathers were dry after swimming in a pool for at least one hour.

Results

Bird species affected A total of 327 oiled birds of six species was recovered. Of these, 318 (97%) were Little Penguins (166 live and 152 dead). Dead, oiled Great Cormorants AUSTRALIAN 194 JESSOP & Du GUESCLIN BIRD WATCHER

40 Ill c: 35 :I Olc: 30 C1l a.. 25 C1l E 20 :.J...... 0 15 C1l .Q 10 E 5 z:I 0 21 23 25 27 29 31 2 4 6 8 10 Date - May/June1990

Figure 2. Number ofoiled Little Penguins admitted to the rehabilitation facility at Apollo Bay each day following the oil spill on 21 May 1990.

Phalacrocorax carbo (3), Pied Cormorants P. varius (2), Fairy Prions Pachyptila turtur (2) and a Pacific Gull Larus pacificus were also found. An oiled Common Diving-Petrel Pelecanoides urinatrix was captured, but died before treatment could be administered. Tracks suggested that foxes also took an unknown number of oil-affected birds from the shoreline. Other species, such as Silver Gulls Larus novaehollandiae, Double-banded Plovers Charadrius bicinctus and Red-capped Plovers C. ruficapillus were also observed with various degrees of oiling but could not be caught.

Distribution and origin of oiled Penguins A total of 17 dead oiled Little Penguins was found near Warrnambool, four at Lome, 126 between Port Campbell and Wye River and five at Phillip Island. Live oiled birds were also found in these areas (Figure 1). Two of the oiled Little Penguins recovered from the Port Campbell (London Bridge) colony had been banded; one was 13 years old, and the other at least six; both were banded at London Bridge.

Arrival and condition of live oiled Penguins at Apollo Bay Little Penguins arrived at the rehabilitation centre at Apollo Bay over a period of 20 days, with the majority being found 3- 5 days after the spill (Figure 2). The degree of oiling of each bird was not systematically recorded. However, most birds brought to the rehabilitation centre at Apollo Bay were completely covered in oil, with no white plumage visible. Nine birds which were caught when coming ashore at the Port Campbell colony were only lightly oiled, with some patches of their plumage unaffected. VOL. 18 (5) MARCH2000 Oiled Penguins, Apollo Bay, Vic. 195

Little Penguin waiting to have oil cleaned from feathers. Protective poncho prevents preening and ingestion of oil. Plate 55 Photo: R.E. Jessop

Age was determined by plumage characteristics and measurements (Marchant & Higgins 1990). The majority of birds found were adults (75 % ), and the remainder were first-year birds. Of the adults, 46 were female, 38 male and 16 were not sexed. There was no significant difference in the survival (Table 1) or weight on arrival of Penguins caught during the early phases of the spill (22-24 May) and those arriving afterwards.

Survival of oiled Penguins after rehabilitation Of the 318 oiled Penguins recovered, 152 had died at sea and were washed ashore. Only 38.7% of the 142live Penguins sent to the Apollo Bay centre were banded and released; the remainder died before or during treatment and

Table 1

Survival of Little Penguins arriving at the Apollo Bay rehabilitation centre before and after 24 May 1990. Birds recovered at Torquay and Warrnambool are not included as their arrival dates are unknown.

Arrival date Penguins which died Penguins which survived Total

Number % Number % Number % On or before 24 May 49 61 31 39 80 56 After24May 38 61 24 39 62 44 Total 87 61 55 39 142 100 AUSTRALIAN 196 JESSOP & Du GUESCLIN BIRD WATCHER rehabilitation. Thirty birds died at the rehabilitation centre at Apollo Bay, and 112 were transferred to facilities at Phillip Island. Most mortalities occurred within the first 12 days. The mean stay for birds that died was 7.7 ± 10.6 days. For birds that were released, time spent in captivity ranged from 50-297 days (mean = 157 ± 48 days) depending on the time taken to attain waterproofylumage and reach a weight of at least 1 kg. Although not statistically significant, birds which were lighter appeared less likely to survive. The mean weight, on arrival, of those Penguins that died before or during treatment was 742 ± 137 g (range 520-1140g); for those that survived it was 812 ± 170 g (range 685-1240g).

Recoveries A total of 58 Penguins was released after rehabilitation. The birds were released at the Penguin Parade on Phillip Island, which is 200 km from Port Campbell by sea. Three of the Penguins released have been recovered: one was found dead at a nest at the Twelve Apostles, Port Campbell National Park, 2.5 years later; another again became oiled and died at the Bay of Fires, north of St Helens, Tasmania ( 41 o24'S, 148°18'E), two months after release; and the third was found dead on Hazards Beach, Freycinet Peninsula, Tasmania ( 42oll'S, 148o17'E), six months after release.

Discussion Even with relatively small oil spills, the interaction between birds and oil can last for many days. Oiled Penguins have a strong tendency to leave the water (Erasmus et al. 1981, Culik et al. 1991), and oiled Little Penguins observed at PINP have often come ashore during the day (R. Jessop pers. obs). Repeated beach patrols throughout the day are therefore necessary to ensure that affected wildlife is found. After the Iron Baron spill off Tasmania in 1995, oiled Little Penguins were retrieved from Ninth Island, other offshore islands and the northern coastline at Low Head for at least three weeks (M. Holdsworth pers. comm.). As time passed birds were found farther away from the centre of the spill. Penguins beach-cast east of the 1990 Apollo Bay spill were presumably trying to return to Phillip Island, St Kilda or other colonies farther east. Birds may have been assisted by an easterly-flowing current. Gibbs (1992) found that, although the surface currents along the western coast of Victoria flow in an easterly direction during winter (June-September), in summer, weak currents flow in variable directions. Radio-tracking and banding studies have shown that Little Penguins from Phillip Island travel as far west as Kangaroo Island in South Australia (~ei lly & Cullen 1979, Dann et al. 1992, Collins et al. 1999). The Little Penguin colonies closest to the 1990 spill were at Port Campbell (some 60 km to the west) and Phillip Island (180 km to the east). Birds from Phillip Island in their first or second year would have been foraging in the vicinity of the spill (Dann et al. 1992, Collins et al. 1999), but the majority (75%) of oiled birds found were adults. From breeding statistics at Phillip Island, in the previous breeding season 7200 chicks could have fledged, of which 2000 were banded (PINP unpubl. data). Although some of these would have died in their first months at sea, the proportion of banded birds could be at least 25% of the Phillip Island first-year birds. As only two banded Penguins were found at Apollo Bay, VOL. 18 (5) MARCH2000 Oiled Penguins, Apollo Bay, Vic. 197 however, most of the oiled Penguins were probably local in origin. Beach-cast Penguins found at Port Campbell in the past have included birds from Five Islands, N.S.W; Gabo Island, Phillip Island and Portland in Victoria; the Furneaux Group, Tasmania; and Troubridge Island in South Australia (Reilly & Cullen 1982, P Du Guesclin unpubl. data). Birds living in this colony have originated from Phillip Island and Warrnambool, Victoria; Bruny Island, Tasmania; Troubridge Island; and Five Islands (Reilly & Cullen 1982). The total number of birds affected cannot be easily quantified, as birds washed ashore would represent only a small proportion of those that died. Most oiled Penguins presumably die in the water, and their bodies then either drift off-shore, sink or are eaten before reaching the shore, or wash up on inaccessible shorelines. Those washed ashore could be buried by wave action or scavenged by foxes or other predators, such as Pacific Gulls Lams pacificus, before being found. After the Exxon Valdez incident in Prince William Sound, Alaska, in March 1989, it was estimated that only 10- 30% of oiled birds washed ashore (Piatt eta!. 1990). If 318 Little Penguins represented only 10-30% of the total, then the total number oiled may have been 1060-3180. Little Penguins generally respond well to treatment for oiled plumage. Evidence for this comes from the survival of adults weighing as little as 640 g (i.e. approximately 50% of the mean adult weight of Penguins recorded at the Penguin Parade at the same time). However, the percentage of Penguins released after this spill (37.8%) was poor in comparison with PINP records over the last five years, which range from 67% (10/15 birds oiled in 1996-97) to 88% (102/116 birds oiled in 1994-95) (PINP unpubl. data). The poor rehabilitation for birds from the Apollo Bay spill was attributable to a number of factors, particularly the degree of oiling, the amount of oil ingested and the low weights of birds arriving at the treatment centre. Inappropriate cleaning techniques used by well­ intentioned but inexperienced and unsupervised volunteers at the initial treatment centre may also have been a contributing factor. Considerable variation has been found in the response to cleaning of different species of birds, with release ranging from 0-95% (Kerley & Erasmus 1986). Sixty-five percent of Jackass Penguins Spheniscus demersus were released over an eight-year period, but this rose to 95 % if birds were obtained soon after oiling (Randall et a!. 1980); the percentage depended on the type of oil and the length of time since oiling. In Tasmania, 95% of Little Penguins collected after the Iron Baron oil spill were released (Holdsworth & Bryant 1995). The low weight of Penguins arriving at the Apollo Bay rehabilitation centre probably reflected the time of year (lowest weights are recorded in winter, Dann eta!. 1992), and the time interval between the oil spill and the Penguins reaching shore. Oiled Penguins swim more slowly, have increased (50% higher) heart and metabolic rates and increased (73% higher) energetic cost of swimming than unoiled penguins (Culik eta!. 1991).

Acknowledgements We would like to thank students and members of staff at the Apollo Bay Higher Elementary school, members of the public, NRE staff and PINP staff who assisted with the capture and rehabilitation of penguins at Apollo Bay and Phillip Island. We also thank Mike Cullen and Peter Dann for commenting on a draft of this manuscript, and Pauline Reilly and Mark Holdsworth who refereed the text. AUSTRALIAN 198 JESSOP & Du GUESCLIN BIRD WATCHER

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