Orca attacking coomon dolphins in False Bay

Transient Orcas
attack Dolphins
False Bay, Capetown,
South Africa
April 26, 2009
Photo by
David Hurwitz

April 26
It is very seldom that we encounter Orcas in False Bay (Cape Town, South Africa) & in the 11 years that I have been operating an ECO boat charter company in the bay, have only had a brief sighting of 2 animals about 10 years ago.
On Sunday 26 April 2009, I had the experience of my life as I spent 2 hours watching a pod of Orcas attacking a large school of Common Dolphins. My real bonus was capturing a photo of an Orca with a Dolphin in its mouth! (see above!) Best regards,
Dave Hurwitz, Simon's Town Boat Company, Cape Town, South Africa

REPORT - 26 April 2009-05-07
Weather Conditions:
Wind: 1 - 4 Kt SE, Sea Conditions: Calm
Weather: Light coastal fog
Observation period: 11:25 am to 12:45 pm
Account:
At 11:00 am, I received a call from Chris Fallows informing me that he had encountered a school of dolphins being hunted by a small pod of Orcas. His position at that time was indicated at 1.5 NM West of Seal Island.
I immediately grabbed my camera & proceeded out on vessel "Awesome" - an 8m semi rigid inflatable.
On arrival at 11:25 am (position: 4 Nm SW of Sea Island), I noted the following:
A school of Approx 800 Common Dolphins, approx 6 Orcas (one calf) & a small number a Cape Fur Seals.
The dolphins were moving in a SW direction at approx 6 Kts (feeding), with the pod of Orcas following on the surface about 150 metres behind them.
The Orcas were tracking them & progressively moving closer to the rear of the group. It appeared as if the Orcas were observing their feeding behaviour & waiting for just the right moment to close in. This was evident from the behaviour of the dolphins which appeared unaware of the potential danger & only reacted when the Orcas were right in amongst them.
At this stage the Orca pod split up and launched individual attacks - mostly approaching from just below the surface (dorsal fin visible most of the time) and in a few instances breached & descended on the dolphins. Throughout the predatory event, the Orcas remained at the rear of the school, perhaps seeking out a weaker animal. The dolphins remained as a group throughout the attacks & maintained a linear formation, rather than the semi circular to large oval feeding formation that I regularly see.
Even though I witnessed a number of successful predatory attacks, I did not notice any blood in the water or any Cape Gulls feeding on the surface as with GW Shark predations.
The duration of the event lasted no longer than 5 minutes & the Orcas moved off in a Westerly direction. The dolphins continued feeding as if nothing had happened (heading in the direction of Whittle Rock).
For the next 40 minutes the Orcas swam around in a relaxed manner in random directions, showing no interest in the dolphins whatsoever.
By 12:00 the distance between the 2 groups had extended to over 1 NM & the dolphins were approaching Whittle Rock.
. At about 12:10 there was a sudden change in the behaviour of the Orcas. They re- grouped & started moving in the direction of the dolphins - increasing their speed to about 8-10 Kts until they again reached a distance of 200 metres from the rear of the dolphins. Then exactly as per the first encounter, they maintained an approximately 150 metre tracking distance and moved in again for the second attack.
This took place at 12.28 and was virtually a carbon copy of the first - lasting about 5 minutes (off Whittle Rock).
It was during this event that just missed capturing a breach attack & took the picture of the surface predation (see above).
Interesting Observations:
~There were a total of 3 predatory events, all at 50 minute intervals.
~The Cape Fur Seals in the vicinity were happily swimming alongside & approaching the Orcas.
~The dolphins maintained a very narrow & linear formation when under attack.

Killer whales 'decimating harbour seal population'

The catastrophic decline of the common seal population in Scottish waters could be blamed partly on killer whales, marine biologists believe.


Numbers of the common seal, also known as harbour seals, are continuing to fall in Orkney, Shetland and Caithness – areas where the whales' predatory behaviour is increasing. One theory is that killer whales are moving south from Iceland and the Arctic to escape the effects of climate change.

The common seal population has falled by up to 50 per cent in the Firth of Tay and 25 per cent in Strathclyde. There are now up to 35,000 common seals in Scottish waters, compared with 50,000 in 2001. By contrast, there are about 164,000 grey seals – 44,000 more than was previously thought.

The Scottish Government's Special Committee on Seals report for 2008 found that competition for food from the more stable grey seal population might also be a significant factor in the decline in harbour seal numbers.

Professor Ian Boyd, director of the sea mammal research unit at St Andrews University, said the presence of killer whales was having an increasingly harmful effect on the species.

But Mark Simmonds, the director of science at the Whale and Dolphin Conservation Society, said the decline was much dar likely to be linked to the legalised shooting of seals to protect fish farms.

A report by the BBC's Countryfile programme this month suggested that up to 5,000 seals were killed off the Scottish coast each year to protect the lucrative salmon industry, as well as by netsmen and anglers.

Orcas spotted on the central coast

The killer whales have arrived on the central Oregon coast.

Orcas start showing up in spring on the central coast around April 15, lingering for approximately a month, until the middle of May. And as if right on schedule, a group of seven Orcas were spotted by the Whale Watch Center in Depoe Bay last week, on April 16.

Killer whales approach the area and patrol the central coast waters, looking for baby gray whales and maybe a few sea lions or seals to munch on. They are rarely seen in these waters, except at this time of year. And when it does happen, it's in the Depoe Bay and Newport areas, but they may be seen from Cascade Head all the way down to Florence and farther.

They are seen more often on the central coast because there are more officials that spend more time watching for them.

The killer whales are what are known as "transient" whales, meaning officials don't know where they come from. They're also more predatory, living off seals and baby gray whales.

Morris Grover, with the Whale Watch Center, says these are smaller and more shark-like in appearance than what are nicknamed the "friendly" killer whales, which visit here from the San Juan Islands and live on salmon.

Grover said orcas know that gray whales are migrating through the area, in mother/baby configurations. They know they can't take on a full-grown whale, so they go after the calves. Often, their technique involves some distracting of the mother, while others take out the baby whale.

Officials at the Whale Watch Center have seen them gobble up seals and sea lions in the waters of Depoe Bay.

Grover said the public's ability to spot Orcas or even gray whales is largely dependent on oceanic conditions, which haven't always been prime so far in April. "We know they're out there," he said. "But looking for whales blow on a day like today, with a lot of white caps, it's like camouflage for whales."

March viewing conditions were excellent. While April has had a few good days, they weren’t as numerous.

To catch sight of these killer whales, just like spotting any whale, Grover suggests patience, and head to a high vantage point. The Newport area has many of these, such as the lighthouse at Yaquina Head, Devils Punch Bowl and nearby at Cape Foulweather. The headquarters for the Whale Watch Spoken Here program is in Depoe Bay, at the seawall, and is another good spot for seeing them as well.

Grover said they sometimes can be seen coming into Yaquina Bay in Newport when they can't find baby whales, attracted by the proliferation of seals and sea lions in the bay. Some years, they have also been known to linger at the edges of the bay's jetties. One sighting in recent years was of a killer whale chasing a seal all the way through Yaquina Bay, almost as far east as Toledo.

"It's all food related," Grover said. "They come up here all the time. Basically, they will take the easiest prey."

A grim future for some killer whales

An oil spill off the U.S. coast 20 years ago still threatens marine life

In 1989, an oil tanker called the Exxon Valdez struck an underwater reef in Prince William Sound, a large body of water in southern Alaska. The ship dumped about 11 million gallons of crude oil into the freezing water, creating the largest spill in U.S. history — and a disaster for animals that lived in or near the water.



This 25-year-old AT-1 male (foreground) isn't as physically developed as he should be, says marine biologist Craig Matkin. Behind junior: mom.


Now, 20 years later, the area still has not fully recovered. At the time of the spill, two groups of orcas, or killer whales, were swimming in the area. One of these groups of whales appears to be headed for extinction, and the other is recovering more slowly than scientists had predicted.

The first group, called AT-1, wasn’t large to begin with: When the spill happened, the group had 22 whales. Nine of these whales died during the spill, and since then, no baby whales have been born in the group. The older males — who can live to be 60 — have been dying off. Now, only seven whales remain.

These orcas may look like and live in the same areas as other killer whales, but orcas in the AT-1 group are genetically different and communicate with a different set of sounds. They are transient orcas, which have larger home ranges than the other kind of killer whales, called resident orcas. Transient orcas eat mammals, such as harbor seals, sea lions, porpoises and other whales; resident orcas eat fish. These two types of killer whales don’t breed with each other.

Lingering effects from the oil spill are not the only threats to orcas. The whales are swimming in polluted waters, and scientists have found these pollutants in the whales’ blubber (or fat). These toxic substances may keep the whales from reproducing successfully. The pollution probably originated in plumes of air that wafted across the Pacific from China and Southeast Asia, says Craig Matkin, a marine mammal biologist who studies the whales.

“I don’t want to make it sound like the oil spill is solely responsible for [this group of whales’] decline,” Matkin says. “It just exacerbated an already bad situation.”

The other group of endangered whales eats fish and squid. These are resident killer whales, and their group is called AB. After the spill, 13 whales in this group died. Scientists predicted the population would recover — that is, return to its original size — within 12 years. But they were wrong. The whales that died were mostly females and juveniles. Now, 20 years later, scientists think the AB group of whales will not recover for another 10 years.

The oil spill also broke up the family structure of the whales. Groups of orcas live in matriarchal communities, where a female acts as the head of the family. The matriarch of the AB group apparently died in the oil spill, and afterward many whales left to join a different group.

When the AB group does eventually recover, it won’t be the same. And the AT-1 group may become extinct. Other scientists are finding that certain other major species affected by the oil-spill — like otters, clams, herring and certain birds — have also failed to fully recover. And in many cases, they’re surprised about why, 20 years after the spill, so many effects of the Exxon Valdez disaster still persist.




This male from the AT-1 population of transient orcas exhibits a curiously stunted, or small, dorsal fin.

Aman Sundher: How we’ve poisoned the killer whale

Many of us became familiar with the killer whale through various corny films, such as the Free Willy series, which often depict the whales being threatened by evil, oil-spilling businessmen or careless fishermen leaving their nets around. In reality, however, the status of the killer whale remains threatened due to a variety of factors which work in ways far more sinister than those of the aforementioned characters.

A new study published in Environmental Toxicology and Chemistry has revealed that the declines in the northern and southern populations of killer whales found along B.C.’s coast can be attributed to environmental contaminants known as persistent organic pollutants (POPs). These contaminants accumulate in salmon during their time at sea, and subsequently become integrated into the systems of killer whales, which primarily consume salmon. Despite having been regulated, major POPS such as DDTs (pesticide) and PCBs (found in electrical capacitor and transformer fluid) are found in the highest concentrations within analyzed killer whale tissue. This is because any remaining residues of DDTs and PCBs continue to enter the ocean via terrestrial runoff, a process by which rain combines with and carries contaminants into the ocean.

It is also important to note that while industrialized countries such as Canada and the USA have regulated the use of these POPs, with DDTs being banned 30 years ago, and PCBs being limited in their use, these practices have not been adopted universally. Many developing countries still continue to use these chemicals, which subsequently enter nearby bodies of water, eventually reaching the Pacific in less than five to eight days.

Meanwhile, another threat looms on the horizon: another type of POP called PBDE (found in flame retardants) has been found to cause endocrine disruption as well as liver and thyroid complications in other marine organisms such as seals and is postulated to have similar effects on the killer whale. This POP has been found in moderate concentrations in the tissues of southern resident whales and will likely increase as this contaminant is not yet regulated.

While a single salmon usually isn’t chock full of POPs, and isn’t in itself likely to poison a killer whale, because POPs characteristically remain within the fatty tissues of marine organisms over a lifetime of 50 to 70 years (as typical for a killer whale), the whale will eat enough salmon for significant levels of POPs to accumulate and effect its longevity. The effects of such elevated concentrations of contaminants include skeletal abnormalities, endocrine and immune system disruption, liver damage, as well as reproductive impairment.

These effects are especially apparent in newborn calves and the southern resident killer whales. Calves have been found with particularly high concentrations of POPs in their systems, as these are passed on to them from their mothers at birth, and continue to accumulate as they are nursed with contaminated milk. As a consequence, about 43 percent of calves die within their first six months. Southern resident whales, whose range extends to the waters of California, are particularly prone to having high levels of POPs because of their feeding behaviors.

Salmon in the southern waters carry higher amounts of POPs (southern waters being up to four times more contaminated than northern waters), and because these salmon have depleted fat stores, which they have used on their journey back to their streams, killer whales compensate for the lack of nutrition by consuming larger volumes. This has contributed to accelerated rates of decline for the southern residents which have decreased by 17 percent to 81 individuals since 1996 as compared to the northern residents which sit at 205 individuals, having declined 7 percent since 1997. It is estimated that it will take 30 years for the northern residents to recover from the effects of POPs, the southern residents closer to 60.

So what is being done about the dire situation of the killer whales? Currently, a Recovery Strategy for B.C. resident killer whales has been developed by the Canadian government, and an American strategy for southern resident whales is expected to be released soon as well. However, this can always remain a case of all talk and no action. The government seems to be particularly prone to this; for example, this strategy was due to have come out in 2006, but only made its debut this past March after a threat of legal action by Ecojustice, a nonprofit environmental law organization. It has been stipulated that this delay has been due to Canadian military interference, which did not want the critical habitat of the killer whale identified in the strategy, seeing as it uses it for military sonar testing. Military sonar has been widely found to be damaging to marine organisms, its high frequency being found to harm the sensory organs and disrupt communication.

Although the current strategy has identified critical habitat, the Department of Fisheries and Oceans has yet to formally declare protection of critical habitat of the killer whales under the Species at Risk Act. One can only wonder how long it will take for this strategy to even be implemented, and if, at that point, it will even be effective. As of today, the northern resident killer whales have a designated “threatened” status, while the smaller southern population has slipped to a more dire “endangered” status.

What this illustrates is that there is never a “quick fix” for environmental damage. That is, we can’t undo the effects of years of pesticide use and pollutant exposure overnight. In the meantime, the Earth and its wildlife continue to pay for our mistakes, or sometimes, more accurately, our carelessness. Due action has been, and continues to be, impeded by political and business interests—the unenforced Recovery Strategy and the nonexistence of any regulation to limit the serious threat of PBDEs illustrate that in many circumstances, the environment is not seen of high importance. It is quite disheartening to learn that this is still continuing, especially when we are just starting to feel the consequences of not caring for our planet.

Aman Sundher is a third-year biology student at Simon Fraser University.

Dead Orca Calf Washes up Near Monterey Bay

Last Sunday a report of an orca (more commonly known as a killer whale) found floating on the rocks near Monterey Bay came into The Marine Mammal Center. Due to weather conditions the carcass was inaccessible until Wednesday, April 8. When news that the orca would be towed to shore came in, the Center's lead veterinarian Dr. Frances Gulland and team along with a team from Moss Landing met at Moss Landing Marine Laboratories to perform a necropsy on the remains. The orca, although partially decomposed, was identified as a female calf weighing approximately 300 kg or about 660 lb. The cause of death remains unknown as does the pod/sub-species origination. While all orcas may bear the same black and white markings, there are actually three distinct sub-species of orcas. Transient orcas, known to swim as far as 250 miles a day travelling in groups of up to 7 individuals; eat other marine mammals and are commonly seen along the western coast. Offshore orcas typically travel in groups of 30-60 individuals, are rarely seen, and eat a diet consisting primarily of fish. Resident orcas, such as the southern (endangered) and northern residents, reside 9 months out of the year in the Pacific Northwest, but have been known to travel as far south as Monterey Bay in search of plentiful salmon runs. While this small calf is an orca, more identification studies will need to be conducted to see which pod she originated from. It is rare to find a dead orca because they typically sink, however, information gathered from the carcass could give whale researchers new insight into toxin levels and other useful information that could otherwise not be gathered. The Marine Mammal Center and other whale researchers hope to learn more about the cause of death and origin of this small calf.

Experts to study body of large killer whale that washed ashore in B.C.

Killer whale experts are taking advantage of a rare opportunity to study the body of a large, male orca.

The carcass washed up this week near Telegraph Cove, on the northeast side of Vancouver Island.

John Ford, with the Department of Fisheries, says it's a rare event and the first time they've been able to study a transient killer whale in decades.

Ford says the dead whale is one he first identified as a calf back in 1976 and called T-44.

A necropsy didn't determine the cause of death, but Ford says the whales only live about 30 years.

He says they'll do further studies on what was in the whale's stomach and contaminant levels in its tissue.