A range of threats are present to penguins, some can affect all penguin species whereas others are species or location specific. In the Falkland Islands there are few detrimental threats on land. Tourisms, egg collecting without licences and disturbance by researchers are some of the man made threats. Predation of eggs and chicks by skuas and striated caracaras and disease outbreaks are natural threats. Because penguins spend huge periods of their lives at sea, some of the more problematic threats, and those out of our control, are in the marine environment.

Commercial Fishing

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Falkland Islands fishery patrol boat. The Falkland Islands Government spends £6m per annum on fisheries protection and research.

Large-scale commercial fishing takes place in Falkland Island waters. It is the mainstay of the Falkland Islands economy with the fishing licence annual income generating about £12m - £15m for the Falkland Islands Government. Further information on the fishery can be found at www.falklands.gov.fk/fisheries.

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Squid fishing vessel (jigger). Squid are caught at night, attracted by rows of very bright lights, which line each side of the vessel.

The main target species are principally squid (Illex and Loligo), and to a lesser extent, finfish including Rock cod, Blue Whiting and Hoki. There are two long-lining vessels, which catch Patagonian toothfish. During the penguin breeding season (November – February) the fishery is closed.

For further information on the jigging fleet seabird interaction see report: Observations of high sea jigging vessels from a Falkland Islands Fishery Patrol Vessel. (513kb PDF). December 2005.

The key concern for penguin survival is that there may be competition for the same species with the commercial fishery. This could reduce the birds’ food supply, and lead to a decline in the population. To investigate and monitor this issue Falklands Conservation, at the request of and with the support of the Falkland Islands Government, have since 1987 undertaken annual monitoring of penguin populations including diet studies and breeding success rates.

Of all Falkland penguins, the Rockhopper penguin has suffered the greatest decline in population over the past century. Recent studies undertaken by Falklands Conservation show that their diet consists of a mix of Euphausia lucens and E. vallentini and juvenile fish (non-commercial). In one of the 3 years of the study only 15% of the diet was juvenile Loligo gahi (squid). Limited data collected in the early 1980's suggests that the prey taken by Rockhoppers was much as it is today. Therefore, commercial species appear to play a negligible role in their diet. It appears that the mortality of Rockhopper penguins cannot be blamed on competition with the fishing industry in Falkland waters.

For Gentoo penguins the story is a little different. Their main prey is lobster krill and rock-cods, with about 25% squid, in particular Loligo gahi of a size that does overlap with the fishery. However, Gentoo penguins generally are not declining and their breeding success rate, which may fluctuate from year to year, does not relate to fishing activity.

Part of the Falklands fishing trawler fleet in Stanley Harbour

 

Loligo_gahiLoligo gahi

Magellanic penguins do rely on Loligo gahi for about 50% of their diet. They do not appear to be able to digest Lobster krill due to the hard carapace (Gentoos can because they carry stones in their stomachs). In 2002 when numbers of Loligo were very low, Magellanic penguins suffered an almost total breeding failure.

As there is very little data on penguin diet in the Falkland Islands before large-scale commercial licenced fishing was introduced it is difficult to prove that fishing has affected their diet. However, studies have now shown that there is no direct detrimental effect on the penguins in terms of competition for prey. If overfishing of relevant species occurs in future, Magellanic penguins would be the first to suffer.

Further information on the diet of Falkland penguins is available to subscribers of Polar Biology (www.springer.com/uk/home) (search Journals for Polar Biology) entitled:
Winter diet and foraging range of gentoo penguins (Pygoscelis papua) from Kidney Cove, Falkland Islands by Andrea Clausen and Klemens Putz. Ref: Polar Biology (2003) 26: 32-40.
and
What is out there: diversity in feeding of gentoo penguins (Pygoscelis papua) around the Falkland Islands (Southwest Atlantic) by Andrea P. Clausen, Alexander I. Arkhipkin, Vladimir V. Laptikhovsky and Nic Huin. Ref: Polar Biology (August 2005) 28, Number 9: 653-662.

For diet analysis: Falkland Island Seabird Monitoring Programme Annual Report 2001/2002 by Dr Andrea Clausen. Falklands Conservation. September 2002.

Climate and Oceanographic Change

The Falkland Islands’ penguin population crashes of 1985-6 and 2002 appear to be the result of changes in ocean temperatures by around 2°C, resulting in massive reductions in the availability of prey species. This is further backed up by the fact that the ommastraphid squid Illex argentinus was dispersed over the Patagonian shelf and absent from Falkland waters in these years.

A study by Dr Ian Keymer, commissioned by Falklands Conservation to investigate the 1985-86 mortality, found that Rockhopper penguins in particular suffered from a lack of krill, an important food for them in the breeding season. The mortality coincided mainly with the birds’ post-breeding moult at a time when they are especially susceptible to starvation. It seems possible that the shortage of krill was a sequel to the 1982-83 El Nino Southern Oscillation in the Pacific. This may have adversely affected the krill and other organisms in the food chain by raising water temperature in some off-shore currents where normally these penguins appear to feed.

The reasons for these oceanographic events are largely unknown. A warmer climate may cause the Antarctic ice shelf to melt and colder waters feeding into the Falklands Current could ultimately result in these anomalies.

Further background information is provided in the report summary: A stable isotopic investigation into the causes of decline in a sub-Antarctic predator, the rockhopper penguin Eudyptes chrysocome. (59kb PDF)

Disease

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An infected penguin suffering from avian pox virus in 2006. Photo: Kevin Schafer.

On remote islands such as the Falklands the introduction of exotic diseases can have catastrophic effects. In 2002 veterinarians from the Wildlife Conservation Society (www.wcs.org) of New York, who own Grand and Steeple Jason Islands, took blood samples from black-browed albatross and gentoo penguins and tested these for a wide range of avian diseases. It was found that unlike seabird populations on the coasts of South America, the Falkland Island populations had no antibodies and thus no resistance to the tested diseases. This means that birds may suffer heavily if or when diseases are introduced. Serious outbreaks have occurred in other sub-Antarctic islands notably avian cholera on Amsterdam Island and South Georgia, and avian diphtheria in New Zealand.

In 2006 over 500 gentoo penguins in five separate colonies died on West Falkland from a mystery illness. The virus did not reach East Falkland. The penguins appeared weak and had wart-like lesions predominantly on their feet, flippers and around their eyes and beaks. The illness affected both chicks and adults. Falklands Conservation urgently investigated the outbreak with the result that an avian pox virus was found to be the cause (not connected to bird flu). The report Outbreak of Avian Pox Virus in Gentoo Penguins in the Falklands (134kb PDF) (February 2006) fully describes this event and its implications.

Marine Algal Blooms

Marine/Harmful Algal Blooms (sometimes called ‘red tides’) are highly toxic to birds. They are caused by dinoflagellates, microscopic red phytoplankton which ‘blooms’ under certain conditions covering extensive areas of the sea. These tiny toxic plants are fed on by larger animals, which concentrate the poisonous toxins in their tissues. When eaten by a larger predator, such as a penguin, it can be fatal. Red tide algal blooms have led to temporary closure of several shellfisheries along the Patagonian coast in the Santa Cruz and Chubut provinces.

Between November 2002 and February 2003 many thousand Falkland penguins were poisoned (along with prions, gulls, cormorants, albatross and steamer ducks) by a ‘red tide’ event.


The red algal bloom was observed by a pilot in the west of the Islands, over Queen Charlotte Bay. January 2003.

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Dead Gentoo penguin at Fox Bay, West Falkland. Photo: Kevin Schafer.

Some birds were found floating dead in the sea, others showed signs of paralysis followed by death within a day of arrival on land. Islanders reported large numbers of Gentoos coming ashore in a crippled state, unable to walk or even hold themselves upright. The Manageress of Port Howard Lodge Jackie Jennings, said, ‘It is very disturbing, penguins are literally lying on the beach and dying, surrounded by swarms of scavenging gulls’. The picture on New Island was no brighter. The large Gentoo colony at the North End of New Island normally holds 5,500 breeding pairs of penguins. Eye-witness Kevin Schafer reported that there were "only a few hundred birds on eggs left – and that these were being picked off very quickly by great flocks of skuas and caracaras."

Following an investigation by Falklands Conservation with analysis of tissue and stomach samples from penguins and analysis of water samples, the toxins which caused these deaths were found to be dinoflagellates Alexandrium tamarense and A. catenella.