Displaying items by tag: killer whales
Flame retardants, pesticides and other pollutants are among the toxic ingredients found in four killer whales stranded on the Irish coastline, according to a new study writes Lorna Siggins
Blubber samples analysed by scientists from Galway-Mayo Institute of Technology (GMIT) and the Marine Institute showed that the marine mammals concentrate persistent pollutants to “very high levels”.
The samples were taken from three killer whales stranded in Galway, Mayo and Waterford between 2010 and 2017 - one of which was pregnant with a near term foetus that was also sampled.
The study showed bio-accumulation of 16 polychlorinated biphenyls (PCBs), seven brominated flame retardants and 19 organochlorine pesticides, according to results published in the Marine Pollution Bulletin.
Concentrations of PCBs in one killer whale, stranded at Doohoma, Co Mayo, exceeded the suggested toxicity threshold of 17mg/kg, the authors state.
GMIT PhD student and senior author Moira Schlingermann noted that “although these concentrations are high, these results are relatively low from a global perspective, particularly in comparison to the highly contaminated transient killer whales from coasts along the north-east Pacific Ocean”.
“These contaminants are known as legacy pollutants as they were produced decades ago but still persist in our marine waters,” she said.
“ We are also interested in “emerging” pollutants, new chemicals that have only recently been designed and released into our environment and for which we do not know their effects,”she said.
“Persistent pollutants continue to be of major concern for marine apex predators such as killer whales and it is vital that they are continually monitored and reported in order to add to the knowledge of pollutants across the entire range of this species,” she said.
Dr Philip White of GMIT supervised much of the work with Dr Brendan McHugh from the Marine Institute and it was conducted at the institute laboratories in Oranmore, Co Galway.
“We have to do everything we can to prevent these substances from entering the marine environment"
Dr Simon Berrow, co-supervisor at GMIT and Irish Whale and Dolphin Group chief executive had warned of the “dire future” facing killer whales last year.
“The build-up of persistent pollutants and their effects on these animals reproduction are undoubtedly the biggest long term threat they and species of dolphin and porpoise face in our oceans,” Dr Berrow said.
“We have to do everything we can to prevent these substances from entering the marine environment and the food chain, because once in it, they will be almost impossible to remove,” he said.
This work was conducted under a GMIT RISE studentship, which was part-funded by the IWDG.
For access to the publication in the Marine Pollution Bulletin visit:
#MarineWildlife - Video posted on social media over the weekend of two killer whales spotted off the Co Dublin coast has gone viral.
Trawlerman James Mac Cluskey used his phone to record a few seconds’ glimpse of the pair of male orcas, which came close to his boat some 8km off Rockabill on Saturday afternoon (17 November).
According to the Irish Whale and Dolphin Group (IWDG), it’s the second sighting of the largest species in the dolphin family off the East Coast in recent weeks, with another fisherman reporting an encounter some 22km off Skerries on 30 October.
And it’s believed the duo may be part of the Scottish West Coast Community Group, a unique orca pod long under threat of extinction owning to not having produced any calves for years.
Earlier this year, whales from this group were identified feeding off the Blasket Islands in Co Kerry, showing just how far their range extends.
#MarineWildlife - The RV Celtic Voyager departed the Port of Cork yesterday (Wednesday 24 October) for ‘Operation Orca’, a 12-day survey of an offshore killer whale community associated with the Northeast Atlantic mackerel fishery.
A team of marine scientists from University College Cork is on board the research vessel that’s headed to waters east of the Orkneys, to study the orcas that feed on mackerel between October and February each year.
“This is the first time a dedicated research vessel will be heading up to study these killer whales and we are hopeful to come back with a lot of data,” said PhD researcher and chief scientist Róisín Pinfield in her introductory blog for the survey.
“We will have cameras, GoPros, drones, underwater hydrophones collecting acoustic data so we can hear the killer whales and a RIB so we can get in close if weather conditions allow. Time to pray to the weather gods to keep the storms away!”
The [email protected] blog will be regularly updated by the Celtic Voyager team once they reach the fishing grounds and begin their survey, which runs till Sunday 4 November.
The prognosis for killer whales in Europe is dire, according to the Irish Whale and Dolphin Group.
There was great excitement and media interest in the sighting of killer whales off West Kerry over a month ago. The IWDG has identified them as what is known as the Scottish West Coast Community of killer whales. It has recorded them previously in Irish waters, from County Antrim, to Cork and from Co Kerry to Mayo.
But that group of whales may soon become extinct and that is a warning over the way in which marine waters are being abused as a sink for human waste. The warning has been given by the Chief Scientific Officer of the Irish Whale and Dolphin Group, Dr.Simon Berrow, speaking to Tom MacSweeney on his THIS ISLAND NATION radio programme. Listen to the clip below.
“Killer whale sightings in any Irish waters are rare events, and they seem to be getting rarer,” said Pádraig Wholley of the Irish Whale and Dolphin Group, whose member Nick Massett photographed the orcas in Dingle Bay on Monday 5 March.
Both are members of the genetically distinctive Scottish West Coast Community Group, which commonly feeds in the Hebridean Islands but has previously been found as far as Lough Swilly and Scotland’s east coast, likely in search of food.
“Colleagues from the Hebridean Whale & Dolphin Trust can confirm that John Coe was seen exactly seven days [previously] in Scottish waters … which tells us a lot about the movements of this highly mobile apex predator,” said Wholley.
The Scottish West Coast Community Group has been feared to be on the ‘brink of extinction’ for many years. In January 2016 the pod lost a female member, Lulu, due to what was at first thought to be entanglement with fishing gear but was later blamed on PCB pollution.
Local fisherman Pete Flannery landed what was the first giant squid recorded in Irish waters for 22 years in mid May, as previously reported on Afloat.ie.
But amazingly, he had repeated the feat this month while trawling in the same area, on the Porcupine Bank west of Dingle.
Before this year, only five of the enormous cephalopods had been found in Irish waters since records began in 1673.
What’s more, two of those squid were landed by Flannery’s own father Michael back in 1995.
“I'll probably have to catch a third now so that I can have bragging rights,” Flannery told RTÉ News, which has more on the story HERE.
Elsewhere, a Galway man recorded video of a killer whale carcass washed up on the shore near Roundstone in Connemara.
Independent.ie reports that the orca sighting was confirmed by the Irish Whale and Dolphin Group, whose Mick O’Connell said the species is “neither common nor very rare [but] you wouldn’t see then very often.”
Ireland’s North Coast is a regular haunt for an “evolutionary significant” pod of killer whales that has been under threat for years due to its lack of young.
#MarineWildlife - "High pollution levels" could be to blame for the failure of Ireland's only resident killer whale pod to produce any calves.
As reported two years ago on Afloat.ie, the well-known orca pod often seen between Scotland and Ireland has been judged to be on the 'brink of extinction', with its conservation status described as "critical".
Since then the pod's number has dwindled from nine adults to just seven, with no juveniles recorded in the 30 years the so-called Scottish West Coast Community has been monitored by researchers.
One reason for that, posits Dr Simon Berrow of the Irish Whale and Dolphin Group (IWDG), could be "high pollution levels" in the food chain which may have rendered them infertile.
“If you’re moving all around Europe and living a long time, you get a lot of contaminants from fish over time,” he told the Irish Mirror.
That's a theory backed up by evidence of pollutants detected in whale carcasses beached around Ireland in recent years.
Far from the ferocious beasts of horror tales, Ireland's killer whales are considered among the gentle giants in the marine wildlife world - with one recently the recipient of a shark bite on his tail fluke.
Marine scientists have long been interested in the group for their genetic distinctness from other orcas in the north Atlantic, bearing closer relation to their Antarctic cousins.
It's believed that the orca duo may be part of a bigger pod that was feeding off West Cork at the time.
And they seem to be happy finding their own food, unlike their counterparts in the Southern Ocean who have taken to nabbing fishermen's catches.
According to the Guardian, killer whales off the Crozet Islands between Africa and Antarctica have learned to grab Patagonian tooth fish off longlines since a fishery was established there some 20 years ago.
Now scientists say they've found a link between this near constant supply of food and the orcas' reproductive rates. In other words, more fish means more, and healthier, killer whale calves.
The orca, known as John Doe, is one of the familiar pod of killer whales that's commonly seen off the west of Scotland but has also been spotted in Donegal and off the east Scottish coast near Aberdeen.
Marine scientists have long been interested in the group because of its genetic distinctness from other killer whales in the north Atlantic – with studies showing they bear closer relation to orcas found in Antarctic waters.
And this latest discovery is troubling in light of the group's already precarious status, with no calves recorded among them since experts began to study them two decades ago.
The Hebridean Whale and Dolphin Trust (HWDT) said it could not "realistically speculate" on what species of shark may have been to blame for the bite.
But one it most certainly isn't is the plankton-hungry basking shark, a species that's seen a drastic fall in numbers locally over the past year, according to the Irish Examiner.
Sightings of the ocean's second largest fish – after the similarly harmless whale shark – have dwindled by a third on 2013 figures, which the HWDT says is part of a trend.
However, experts have moved to quell any concerns over the health of the marine species, as they may simply have moved to offshore waters – or below the surface – in search of greater supplies of their favourite foodstuff.
Basking sharks may be seen less often, but there's another shark species in the oceans that even the experts know very little about – and one of them was just landed in the Philippines.
The Washington Post has more on the 'mysterious' megamouth shark, a prehistoric looking beast that was only discovered by science in 1976 and has been sighted just 64 times since then.
Scientists still have no idea of the size of their population or in what oceans they're concentrated, and this find may reveal little more - but it might tell us something new about their plankton-based diet and their unique physiology.
After being spotted earlier this month in Kerry coastal waters, Clet – the French cetacean interloper first seen in West Cork – was thought to be headed towards Fungie's usual haunt around Dingle.
But in recent days he's been spotted off Inis Oírr in the Aran Islands, frolicking with another recent resident of that island.
Sandy is perhaps better known to Afloat.ie readers as Dusty, the Doolin dolphin that was the subject of much controversy last summer after a number of aggressive acts against swimmers, one of whom was hospitalised with serious injuries.
And now with Clet's arrival, it seems these two dolphins with bad reputations have made the perfect couple, with the Irish Whale and Dolphin Group saying Clet has "hit it right off" with Sandy.
Still, the IWDG has reiterated its warning to swimmers and other water users to stay clear of the pair based on their track record.
In other cetacean news, the Irish Examiner reports on a rare sighting of killer whales off the south-west coast recently.
The seven-strong orca pod was spotted in the Atlantic near the Porcupine Seablight by researchers on the IWDG's Cetaceans of the Frontier Survey cruise on board the RV Celtic Explorer.
Joe.ie has images of the killer whales, which are common to North Atlantic waters but rarely trouble Irish shores; the last significant sighting here was a different orca family in Lough Swilly visiting from Scotland, and believed to be on the 'brink of extinction'.
Elsewhere, BBC News has footage of a large dolphin pod swimming close to the shore in Portrush on the North Coast, in what's described as a "very unusual" occurrence.
And here's a link to last night's RTE television programme on basking sharks.