Reality check on New Zealand fur seal vs. penguin debate.
By Dr Jane McKenzie
21 February 2012
Published in an edited form in The Islander, 2012.03.01, under the title “Muddying waters”
Fur seal pelts were Australia’s first export industry and the early settlers capitalised on their value in China and Russia. Unlike most native species in this State, we are witnessing the population recovery of fur seals, which were almost eliminated by humans.
Instead of rejoicing at their recovery, certain sectors of the community have decided, based on little evidence and misinterpretation of scientific research, that increasing seal populations are the major cause of declining penguin populations, fish stocks and the poor recovery of the Australian sea lion population.
John Ayliffe and the shadow minister for fisheries have recently joined this group of ill-informed noisemakers by selectively quoting and misinterpreting the science on interactions between fur seals and penguins. Together, Ayliffe and the shadow minister have muddied and biased the debate on the impact of New Zealand fur seals on penguins and other marine species in South Australia.
In a letter to the editor “Penguin contradiction” (The Islander, 26/01/2012) Ayliffe quotes a statement from the 59th report of the Natural Resources Committee, tabled in the House of Assembly September 28, 2010 – “From examining the scats of individual seals the researchers concluded that adult male New Zealand fur seals were the main predators of little penguins“. Ayliffe uses this to imply that fur seals eat more penguins than any other known predator (including feral cats, dogs, rats, goannas, sharks, sea eagles, sea lions).
I am a co-author on the scientific study on the diet of fur seals on Kangaroo Island. The results of this study in no way indicate that male New Zealand fur seals are the “main predator” of little penguins and at no stage has any credible scientist made such a claim.
Ayliffe also quotes the report – “Evidence regarding predation of Little Penguins (and seabirds generally) by fur seals at the Cape Gantheaume colony“. Page et al (2005) studied a New Zealand fur seal breeding colony at Cape Gantheaume on Kangaroo Island in 2005, located in close proximity to a colony of Little Penguins that has since become extinct (Wiebkin 2011b, p43)”. Ayliffe wrongly suggests that fur seals and little penguin can not co-exist and he makes unsubstantiated jumps in logic that are dangerous and misleading. Penguins still nest adjacent to the seal colony at Cape Gantheaume, and there are plenty of examples of penguin populations co-existing with large populations of fur seals on Kangaroo Is and elsewhere around the State.
In an earlier article by Shauna Black, “Census shows penguin peril” (The Islander, 19/01/12), Mr Ayliffe is quoted as saying that “New Zealand fur seals do not eat penguins in New Zealand. In Australia it is becoming increasingly common and may indicate food shortage for seals. It may indicate a potential collapse of the marine ecosystem“. Of course, Ayliffe is wrong here too. My quick search of the scientific literature uncovered multiple studies that indicated that fur seals eat penguins in New Zealand. It seems quite clear that penguins are quite comfortably co-existing with their fury counterparts.
Why does the shadow minister ignore 10 years of scientific research by SARDI and Adelaide Uni on the interactions of fur seals with tuna and kingfish aquaculture as well as the rock lobster, sardine, garfish and mullet fisheries. These freely-available research reports all show that fur seals have negligible impacts on these industries. I urge both poorly informed members of the public and politicians who are entering into the debate to read all of the facts before they make giant leaps in logic, totally false statements, because their credibility will be shown for what it is.
Misquoting and fabricating facts only serves to muddy the debate, misdirect conservation investments and puts pressure on government departments to make knee-jerk management decisions. It does not promote the conservation of little penguins and other marine wildlife, nor does it assist in the sustainable management of wildlife-tourism and fisheries industries.
Dr Jane McKenzie
Marine Research Scientist
Adelaide
[On the same subject see also
Wilderness is no garden, and NZ fur seals are as “Australian” as the sea lions — Dr Bittar, 2012-02-05]
Some folk may wish to Google the following heading with particular reference to pages 300 & 301
After reading this anyone can determine who or what is credible.
Dietary resource partitioning among sympatric New Zealand and Australian fur seals
Brad Page1, 2,*, Jane McKenzie1, Simon D. Goldsworthy1, 2
May I quote from the Fifty Ninth report of the Natural Resources Committee, tabled in the House of Assembly 28th September 2011, page 10;
“Evidence regarding predation of Little
Penguins (and seabirds generally) by Fur Seals
Cape Gantheaume colony
Page et al (2005) studied a New Zealand fur seal breeding colony at Cape Gantheaume on Kangaroo Island in 2005, located in close proximity to a colony of Little Penguins that has since become extinct (Wiebkin 2011b, p43)”. and later in the document, “From examining the scats of individual seals the researchers concluded that adult male New Zealand Fur Seals were the main predators of Little Penguins.”
I provide the link to the article in question:
“Dietary resource partitioning among sympatric New Zealand and Australian fur seals“, Page et al. 2005
I can’t see where the authors are supposed to state “that adult male New Zealand Fur Seals were the main predators of Little Penguins”.
What they do report is that though little penguins constitute a part of the seals’ feed, the largest part of their diet consists in fish and cephalopods (squids, cuttlefish and octopuses).
Nothing, in my opinion, that could justify a call for a culling of seals.
Dr G. Bittar
I note that Simon Goldsworthy of SARDI is currently seeking funding to do some follow up studies about interaction between NZ Fur Seals and other SA PInnipeds and putative food sources, in particular fin-fish resources, including penned fish and ‘ecotourism’ species, Giant Cuttles and Little Penguins. I f the researtch goes ahead, it may give us more objective evidence to base public opinion on. I would certainly welcome hard evidence as opposed to anacdotal, subjective evidence and sumise.
Like Dr Bittar, I do not hold that a cull of fur seals can be justified. My reasoning is that since the fur seals live in the ocean which has no boundaries, others would simply move in to take the place of those culled. Perhaps that is over-simplistic – I’m not a scientist, just an occasional penguin tour guide.
I would however refer everyone to “What is causing the decline of little penguins (Eudyptula minor) on Granite Island, South Australia?” published by SARDI in July 2007. They show (page 32) that Little Penguin in the second most common item in the Fur Seals’ diet.
That there is a decline in penguin numbers is irrefutable – surely what we need is more investigation into what is causing the decline.
The nz fur seal is having a significant affect on the commercial fishery in the coorong. Professional fisherman are loosing the battle against the predators that are destroying valuable equipment when they rip mulloway and mullet from the nets.
We cull our national emblem when it impacts farmers, yet for some reason protect these animals that aren’t even native to Australia.
This notion that “non-natives” should be exterminated is a very primitive obsession in human history. It’s been ongoing with its symmetrical obsession, that “natives” must be exterminated – be they humans, animals or plants. Following WWII, any talk of exterminating specific groups of humans finally came to be frowned upon by most people. But the mindset was still there, deep in…
Starting in the 1960s, this on-going obsession, which was discouraged where it concerned humans, came to be re-encouraged where it concerned animals and plants, in the guise of environmental concerns. This “politically corrected” murderous mindframe originated in the USA and Australia.
But a change of victims does not make a wrong less nasty and more ethical, only more acceptable socially and more convenient politically.
That’s why I personally disagree with any talk that “non-natives” only deserve death. I find this attitude repulsive. I also find it dangerous, because there’s not much needed to extend hatred for a category of animals to hatred for a category of humans.
That being said, what makes you believe that “nz fur seals… aren’t even native to Australia”? They lived between the SE Australia and New-Zealnd coasts before any human beings settled them.
If it’s the “NZ” tag, note they could have been called just as well “SE Australia fur seals” — but then, I presume there’d be people like you in New-Zealand arguing that they should be exterminated because they’d be Aussie, not Kiwi!
It’s reasonable for fishermen to argue about defending and preserving their source of living, but they should not use dubious moral or scientific arguments.