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Request for information on "soaked" seabirds


Dear colleagues

In collaboration with Patrick O'Hara at Environment Canada, I would like to collate records, photographs and incidental observations of the effect of fish oil on seabirds - specifically, contamination of plumage resulting in loss of waterproofing.

In 2001 I wrote a short article in Bird Numbers on the incidence of "soaked" Cape gannets observed at Ichaboe Island, Namibia. It is speculated that foraging on fish offal dumped at sea causes contamination of the birds' feathers by fish oil. The birds became waterlogged and unable to fly until their plumage dried (depending on the extent of the contamination), but became soaked again when entering the water. Rapid loss of body condition resulted and many soaked birds were seen dead.

I would like to collate information on the following:

  • birds becoming contaminated with fish oil (observations at sea, captive/rehabilitating birds)
  • loss of waterproofing not attributable to petrogenic oils (birds looking wet, but not obviously oiled)
  • flying birds having difficulty taking off from water, especially in calm conditions
  • flying birds swimming to shore, as opposed to flying
  • sticky contamination on feathers, with a fishy smell
  • albatross/petrel regurgitation - effect on feathers
  • any other relevant information, records, photographs or insight

Any information that could contribute to our understanding of this phenomenon would be appreciated.

Comments ( 7 )

Kees (C.J.) Camphuysen

Kees (C.J.) Camphuysen

Hi Michelle,

How sure are you about your fish oil? Please check for example:

we have had loads of soaked (drowned) seabirds, Black-throated divers, in a similar disaster in the German Bight some years ago, which had nothing to do with oiling but everything with phytoplankton. Nothing to be seen in the feathers. Do check if there is traces of fish oil on your birds!

Kees Camphuysen

Monte Merrick

HI MIchelle,

On the California Coast fish-oiled seabirds have been a serious problem. I can connect you to some of the internet-based amterial Bird Ally X has ( We have a dozens of good photographs. Last summer we treated over 250 birds, mostly California Brown pelican, releasing approx 80%.

Feel free to contact me to discuss in more detail.

Thanks and take care, monte

Edward Abraham

Edward Abraham

This isn't relevant to fish oil, but there was an article in today's Guardian about seabirds being killed by a having there feathers contaminated with a sticky substance. According to the article "scientists at Plymouth university concluded it was most likely a form used as an additive in lubricating oil".

John Paterson

Hi Michelle I am wondering if demersal trawlers were the culprit. I would rather suspect midwater trawl factory vessels with a fish reduction plant on board. The oil they produce is a sticky yellow substance with a strong fish smell, the smell might become diluted with soaking. I have found birds in Walvis bay close to the fish processing plants covered in thick sticky yellow oil which was really smelly. During many hours of observations from trawlers I have never seen any fish oil slick or signs of oiling of gannets or other birds by fish oil around Namibian demersal trawlers.

I had some correspondence with Jesica Kemper and Anton Wolfaardt around this Namibian oiling and the possibility of mascerating discards before dumping overboard. It seems likely that reduction plants on factory ships were to blame with the illegal dumping of fish oil

John Paterson.

Michael Ziccardi

Hi Michelle-

In addition to the above info from Monte on this year's fish-oiled BRPE issues, another great example of this is a spill response the OWCN managed in Oct-97 in Monterey Bay caused by a sardine boat dumping a rancid load of packed fish while transiting the bay. We collected 480 live birds that had significant feather fouling due to the weathered fish/vegetable oil from the cargo. Primary species affected included COLO, WEGR, and SUSC. Release percentage was very low for us because the tacky composition of the contaminant could not be washed from feathers easily - much worse than standard weathered petroleum. Additionally, Salmonella infection was present in the species - very likely from the dumped fish. I am happy to provide further info if desired.

Mike Ziccardi

Laird Henkel

This US Federal Register notice has a bit of information on effects of fish oil (and other non-petroleum oils) on birds:

-Laird Henkel

Michelle Bradshaw (née du Toit)

Michelle Bradshaw (née du Toit)

Thanks for continued feedback and additional info! I will follow up on each comment.

  • Michelle