Testing deceased wildlife
There are some circumstances where DEW or other government agencies may investigate dead wildlife, including by submitting carcasses for necropsies and/or additional testing.
Algal bloom wildlife testing
Reports of dead marine wildlife to the Emergency Animal Disease Hotline (1800 675 888) are reviewed by scientists, including vets and ecologists, who use their expertise to decide if they require further investigation.
Investigations are conducted only where suitable fresh samples can be collected and either:
- There is a suspicion of an infectious disease of biosecurity or public health concern.
- It could contribute valuable information to understanding the effects of the algal bloom.
Not all carcasses or sick animals reported to the Emergency Animal Disease Hotline can be investigated or collected.
For example, carcasses that are too decayed when reported or are in an inaccessible location may not be investigated.
Where a carcass is not required for testing, the land manager, typically the local council, may remove it for disposal.
When a carcass is collected, the testing process involves undertaking a necropsy and collecting tissue samples for further testing.
Depending on the necropsy results, this could include:
- Histology – examination of tissues under a microscope
- Microbiology (culture) – testing of microscopic organisms in tissue
- Biotoxin/brevetoxin – testing for the presence of algal toxins in tissues
Summary of test results
Date collected | Location collected | Species | Notes | Link to full report |
|---|---|---|---|---|
15 July 2025 | Point Turton, Gulf St Vincent | White shark | No cause of death was identified. Examination (necropsy) found that the shark’s overall body condition was lean and heavily decomposed. The stomach was empty with no evidence of recent feeding. The liver to bodyweight ratio was normal, suggesting it was not malnourished. Brevetoxins were not detected in either liver or gill tissues above reporting limits. | |
30 June 2025 | Semaphore Beach, Gulf St Vincent | Common dolphin | The animal was found deceased on a suburban beach, which is not unusual. Laboratory examination (necropsy and histopathology) could not identify the cause of death. Laboratory testing for avian influenza was negative and there was no evidence of the presence of brevetoxins or other algal biotoxins. | |
30 June 2025 | Boomer Beach, Victor Harbor | Little penguin | There were liver flukes found in this animal which may have contributed to the bird being unwell. This is not an unusual finding in a wild little penguin. Laboratory testing for avian influenza and Newcastle disease was negative and there was no evidence of the presence of brevetoxins or other algal biotoxins. | 20250630-Little-Penguin-Boomer-Beach |
27 June 2025 | Port Broughton, Spencer Gulf | White shark | Physical symptoms (including inflamed gills) were consistent with a cause of death related to exposure to high levels of Karenia spp. No alternative cause of death was identified. Laboratory examination (necropsy) found that the shark’s overall body condition was good and the stomach was empty, with no evidence of recent feeding or stomach eversion. The liver to bodyweight ratio was normal, suggesting it was not malnourished. Negligible concentrations of brevetoxins were detected in the gill tissues; however these levels are considered too low to have had any significant impact on the shark’s health. | |
25 June 2025 | Emu Bay, Kangaroo Island | Little penguin | The cause of death in the penguin was trauma (injury) - likely from being hit by a car. The animal also had inflammation in the liver and kidney. Laboratory testing for avian influenza and Newcastle disease was negative and there was no evidence of the presence of brevetoxins or other algal biotoxins. | |
21 June 2025 | The Bluff, Victor Harbor | Little penguin | There was mild, multifocal (mild, in multiple places) medium- to long-term inflammation in the liver, which contributed to this animal’s illness. Laboratory testing for avian influenza and Newcastle disease was negative and there was no evidence of the presence of brevetoxins or other algal biotoxins. | |
30 May 2025 | Stansbury, Gulf St Vincent | White shark | No cause of death was identified. This shark was not able to be retrieved from its stranding location and was dissected in water. The shark was too decomposed to allow for soft tissue diagnosis, such as examining the gills. Negligible concentrations of brevetoxins were detected in the liver tissues; however these levels are considered too low to have had any significant impact on the shark’s health. | |
26 May 2025 | Brighton Beach, Gulf St Vincent | Long-nosed fur seal | The animal had hauled out (come to land) at an unusual place during a storm. The animal was very underweight and unwell and died while being anaesthetised. Laboratory examination found signs of long-term inflammation and infection in many body systems but could not identify the original cause of disease and weight loss. Laboratory testing for tuberculosis and avian influenza was negative and there was no evidence of the presence of brevetoxins or other algal biotoxins. | |
16 May 2025 | Sultana Point, Investigator Strait | White shark | No cause of death was identified. Examination (necropsy) found that the shark’s overall body condition was lean and the stomach was empty, with no evidence of recent feeding or stomach eversion. The liver to bodyweight ratio was low to normal, suggesting it was not malnourished. Due to the initiation of early decomposition, it was not possible to conduct a viable analysis of the gill tissues. Negligible concentrations of brevetoxins were detected in the gill tissues; however these levels are considered too low to have had any significant impact on the shark’s health. | |
13 May 2025 | Port Wakefield, Gulf St Vincent | White shark | No cause of death was identified. Laboratory examination (necropsy) found that the shark’s overall body condition was good and the stomach was empty, with no evidence of recent feeding or stomach eversion. The liver to bodyweight ratio was normal, suggesting it was not malnourished. Due to the initiation of early decomposition, it was not possible to conduct a viable analysis of the gill tissues. Negligible concentrations of brevetoxins were detected in the gill tissues; however these levels are considered too low to have had any significant impact on the shark’s health. | |
5 May 2025 | Henley Beach, Gulf St Vincent | White shark | Physical symptoms including gill damage, were consistent with a cause of death related to exposure to high levels of Karenia spp. No additional cause of death was identified. Laboratory examination (necropsy) found that the shark’s overall body condition was good and the stomach contents were minor and unidentifiable, without evidence of recently consumed prey. The liver was large and healthy, suggesting it was not malnourished. Negligible concentrations of brevetoxins were detected in the gill tissues; however, these levels are considered too low to have had any significant impact on the shark’s health. | |
2 May 2025 | Ardrossan, Gulf St Vincent | White shark | No cause of death was identified. Laboratory examination (necropsy) found that the shark’s overall body condition was lean, with the stomach everted. The liver was in the normal body to weight ratio range, suggesting it was not malnourished. Advanced decomposition prevented viable analysis of the gill tissues. Negligible concentrations of brevetoxins were detected in the liver tissues; however, these levels are considered too low to have had any significant impact on the shark’s health. | |
18 April 2025 | Port Willunga, Gulf St Vincent | White shark | No cause of death was identified. Laboratory examination (necropsy) found that the shark’s overall body condition was good, with a healthy liver, suggesting it was not malnourished. Thawed gill tissues were unable to be analysed. Negligible concentrations of brevetoxins were detected in the gill tissues; however these levels are considered too low to have had any significant impact on the shark’s health. | |
18 April 2025 | Port Moorowie, Investigator Strait | White shark | Physical symptoms, including gill damage, were consistent with a cause of death related to exposure to high levels of Karenia spp. The shark could not be retrieved from its stranding location and was dissected on the beach. As a result, a comprehensive necropsy was not conducted. The shark’s overall body condition was good, with a large liver and full stomach, suggesting it was not malnourished. Negligible concentrations of brevetoxins were detected in the liver and gill tissues; however these levels are considered too low to have had any significant impact on the shark’s health. | |
24 and 26 March 2025 | Tunkalilla Beach | Western grey kangaroos | Large numbers (approximately 70 out of 200) of western grey kangaroos were found with difficulty standing at Tunkalilla Beach. The sick kangaroos were all found close to the beach, which was affected by the algal bloom at the time. This was confirmed by detections of Karenia spp. in the ocean and adjacent creek. Several kangaroos were euthanised on welfare grounds, and 7 underwent further examination (necropsy and histopathology). Findings in 5 of the kangaroos were inconclusive, and findings in the other 2 kangaroos were consistent with Phalaris toxicity, which is considered to be the most likely cause of the symptoms. Phalaris toxicity is a well-known disease that affects livestock and wild animals (including kangaroos) and is caused by eating a type of pasture grass (Phalaris aquatica) that contains neurotoxins. The risk of Phalaris toxicity is highest with new grass growth, but it can occur at any time of year. Phalaris grass grows throughout South Australia. Brevetoxin was detected in both kangaroos tested and another algal biotoxin (PST) was also detected in one of the kangaroos. The low levels of brevetoxin and PST detected in this case are considered unlikely to have materially impacted on the health of the kangaroos. |
