Where Do Orcas Find Drinking Water? (How Many Fish Do Orcas Need; Part Three)

Orcas are beautifully adapted to life in the marine environment, but unlike fish, they are not able to meet their water needs by drinking seawater. Sources of fresh water are limited to coastal river inputs and subsurface springs, and although it is unknown at this point to what degree orcas or other whales can utilize those sources, they are certainly not able to rely upon them. So, how do orcas survive without fresh water?

Whales and dolphins have undergone some adaptations to cope with the marine environment- their kidneys are able to remove some of the excess salt that is inevitably swallowed, and their rubbery skin presents a good barrier which helps keep salt out. But there are really only two known ways that the fish eating orcas can get water; one is through the fish and squid they consume, and the other is by using their fat stores.

All vertebrate animals maintain their bodies at about the same salinity, which is a quarter to a third of the salinity of the ocean – so when the orcas can find enough fish, presumably they don’t need any other source of water. When fish become scarce though, the whales use their own blubber for energy, and one byproduct of breaking down their fat is water, at least enough to get by.

Like any other system that uses energy, there is a net loss when the whales don’t have enough to eat – in other words, there is loss both in storing the fat and then using those reserves later to provide sustenance and water. For the orcas, any shortage of fish is also a shortage of water, leaving them in a doubly precarious situation if the shortages extend for any great period of time.

Research on baleen whales indicates that those animals may need 30% more krill (which is saltier than fish) than previously thought when the problem of salt balance is taken into account. Even though orcas are completely different animals from the baleen whales, it does stand to reason that their need to obtain water from fish may drive both the type and the quantity of salmon needed to provide them with both water and nourishment.

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J40 catches a salmon off False Bay, September 8, 2008 (CWR photo by Astrid van Ginneken)

“Water, water everywhere, nor any drop to to drink”. (From Rime of the Ancient Mariner by S. Coleridge)

A Swim With Orcas

As we continue to study the issues confronting the survival of our local endangered resident orcas, I thought it would be good to take a break, and enter their world for a bit. The first video is not long, and is a pleasure to watch.

The comments that follow it relay the experiences of two hardy souls who dove with the orcas in Norway, and the last video, while a bit long, shows the orcas feeding on herring and gives a sense of what it is like to dive with the whales in those semi-arctic winter conditions.

Love at first sight: We dove into the water immediately. At first I saw nothing, but the squeaking and clicking noises grabbed my attention. There ­ out of the blue ­ came the biggest killer whale I had ever seen!
Sure, I know everything looks enlarged under water, but I am pretty sure this male was well over six meters. He was passing just eight meters below me when suddenly he looked up at me, took a U-turn and swam back towards me.
I followed his motions and as if in a ballet we moved in unison for a little while. This slow dance must have fascinated my new friend, for suddenly he turned and came swimming right at me, his head slightly skewed to the side with a wondering, intelligent look. Our eyes met. I was transfixed, time and place disappearing, unable to move. I was not aware of it, but in the boat they had heard my screaming through the snorkel. At the time the orca was just three meters away, and I remember thinking “Oh no, he will collide with me!” followed by a thrilling “Oh yes…!”
Just as suddenly he turned away and disappeared into the deep sea.

It is horrible. They are silent, vast, beautiful, perfect. The first one glides directly below, much, much closer than I’d ever imagined, close enough that if I weren’t pulling my elbows in, tucking my knees up, and generally trying to deny my own existence, I could actually reach down and touch a fin. Two, three more glide silently below, then another, but this time, instead of swimming past, the killer whale angles up, as if about to charge, tilts to one side and stops, a single, disembodied eye staring straight at my face, probably no more than six feet from my frozen being. I actually cannot look into its eye, and gaze meekly instead somewhere around its fin. And then it goes. I am not sorry.

So why put yourself through it? There’s no simple answer. Three more times we get back in with the killer whales, and each time there is that same slightly horrifying moment of truth. And yet, there’s also something intoxicating, delicious – it’s like teetering atop the world’s highest rollercoaster, surrendered, delirious, alive.

How Many Fish Do The Orcas Need? (Part Two)

Adult orcas need to consume a mind boggling 193,211 to 286,331 calories per day to meet their requirements – a figure derived by measuring the needs of captive orcas (but because those whales are forced into an inactive couch-potato lifestyle, the scientists add adjustments for the considerably more active wild orcas). Onto this figure is added the estimated amount of indigestible matter present in fish. Given all the guesswork involved in determining the caloric requirement for an orca, these figures may seem overly precise – but scientists minimize the magnitude of error by not rounding the numbers off.

How many fish does it take to meet those needs? Well, this is where it gets sticky, because the calorie values vary among the different salmon species. Using this calorie calculator, I determined that if the orcas were eating only salmon fillets, it would take about 355 lbs of Chinook, 530 lbs of chum, 398 lbs of coho, 380 lb of sockeye, or 547 lbs of pink salmon daily to feed an active adult male orca. If the salmon were solid muscle, that translates to 14 (25 lb) Chinooks, 41 (12 lb) chums, 44 (9 lb) cohos, 54 (7 lb) sockeye, and a whopping 109 (5 lb) pink salmon.

However, orcas are able to eat salmon whole, and can digest most of the bones, fins etc, because they have a three-chambered stomach. The first chamber is a muscular widening at the base of the throat, and here the salmon is mashed and ground before it is passed to the acidic stomach. Shells and pebbles have been found in the first chamber and are believed to aid in grinding the fish. By time the orcas are done digesting there is not much matter left to excrete.

I have yet to determine how many calories are present in the eyes, bones and organs etc, but I checked a fish processing site and learned that a fish over 100 lbs will yield 50% of its body weight in fillets, while smaller fish only yield 30 to 40% by commercial methods.

Therefore, depending upon the calories available to the orcas in the 50% to 70% that we humans consider the waste by-product of fish, the actual number of salmon required for them will vary considerably. Assuming for a minute that the whole fish has the same number of calories as its muscle tissue, the math becomes pretty simple: 3.5 (100 lb) or 17.5 (20 lb) Chinooks are equivalent…until you factor in the increased hunting effort needed to catch all those smaller fish.

Another complication is that the nutritional status of salmon alters over time (particularly sodium, potassium, and lipid content) as the salmon undergo the changes needed for them to adapt to different conditions and meet their own dietary needs.

The minimum number of Chinook salmon, using all the optimized figures presented here is 17.5 per orca per day – young animals will require less, nursing females more. With the present number of southern resident orcas at 87, that is 1522.5 (20 lb) Chinooks daily, which is approximately 45,675 per month, or 548,100 per year.

To insure that the orcas actually catch what they need, two to more than three times the number of fish must be set aside, bringing the number to 1 million to 1.6 million for the bottom line. Using the accepted effort rate of 3.2, the number becomes about 1.75 million Chinook salmon – and this is assuming that all of the salmon are uniform in calories and nutrients, and that the whole fish contains the same calories as the flesh, minus the 15% to 20% already accounted for in the basic caloric needs.

It seems like a lot of fish, but by making a generous allowance for the orcas, more salmon will survive to reproduce, creating a greater abundance for us all.

And Baby (Orca) Makes 5!

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New calf J46 swimming with J28 (photo by Mark Malleson)

Another beautiful baby orca has joined J pod’s clan, raising the number of whales in the southern resident orca community to 87.

There is something incredibly heartwarming to see pictures of this baby’s tiny dorsal fin snuggled in among the large dorsals of its family members – even his/her uncle, J44, who was born earlier this year seems big by comparison – I think the arrival of this little one brings a hopeful note at the close of the season.

This is the time of year that the resident orcas begin to spend more and more time away from the inland waterways of the Salish Sea and more time off the coast and points unknown. However, the less frequent observations of orcas during the winter are extremely valuable, and the researchers remain ready to jump in their boats during all but the worst conditions, all winter long.

So they will be keeping a close eye out for the new calf’s orange countenance and tiny fin.

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New calf J46’s family tree.

Because orca families are centered around lifelong mother calf bonds, their family trees are referred to as ‘matrilines’. The new calf’s mom is most likely J28, whose own mother produced J44 this year, technically J46’s uncle.

Not that it matters to the calves, I imagine they will just be happy to play together like young animals everywhere. And the rest of us are just happy to see the new little peach colored face out there among the black and white.

How Many Fish Do The Orcas Need?

The single most important thing that needs to be done in order to ensure that the orca families of J, K, and L pods continue to thrive in our inland waterways is to provide them with adequate food. And for these whales, that means salmon, and lots of it. Whale biologists have been sounding this alarm for years:

Linking killer whale survival and prey abundance: food limitation in the oceans’ apex predator?
John K. B. Ford, Graeme M. Ellis, Peter F. Olesiuk, and Kenneth C. Balcomb

“Here we show, using 25 years of demographic data from two populations of fish-eating killer whales in the northeastern Pacific Ocean, that population trends are driven largely by changes in survival, and that survival rates are strongly correlated with the availability of their principal prey species, Chinook salmon (Oncorhynchus tshawytscha). Our results suggest that, although these killer whales may consume a variety of fish species, they are highly specialized and dependent on this single salmonid species to an extent that it is a limiting factor in their population dynamics. Other ecologically specialized killer whale populations may be similarly constrained to a narrow range of prey species by culturally inherited foraging strategies, and thus are limited in their ability to adapt rapidly to changing prey availability.”

Estimates vary, and there are some variations in culture between our southern resident orcas and their cousins to the north, but decades of research shows that both populations prefer Chinook salmon, followed by Chum and Coho. Sockeye and Pink salmon are not often consumed even when present in large numbers.
This preference is so strong that it may drive the whales to follow the preferred salmon to a new location, or the orcas may actually starve if sufficient fish can’t be found, and/or new hunting strategies in a new location can’t be learned in time.

The crucial question then is: how many Chinook salmon do our southern resident orcas need to flourish in their home waters? What will it take to ensure that little J-45 and the other calves grow up to have offspring of their own, and that our own children and grandchildren have the opportunity to enjoy the presence of these magnificent whales? What if this orca population is driven to extinction right about the time we learn how crucial their role is in the ecology of the inland waters, or how these intelligent animals communicate with each other?

No one wants that to happen, and scientists and government agencies have pretty much got the “peddle to the metal” in trying to get the situation fixed. The problem, of course is that there can be a huge disconnect between how quickly the government moves on issues versus the immediacy of the problems they are trying to address.

Adding complexity to the situation is that as yet scientists can’t provide definitive answers to the questions that government officials pose – no one knows for sure how many Chinook salmon the whales need to thrive (more on this topic soon), or where the whales go and exactly what they eat when they are not in their summer inland range. So everybody takes their best guess, then budget constraints and special interest groups push for the adoption of the smaller figures, which range from 221,000 to 1.76 million Chinooks for the whales each year.

But… wild salmon is a favorite diet item for people too. Its health benefits are legend, it is tasty, and salmon is as much a part of Pacific Northwest culture as are the iconic orcas. It only makes sense to err on the side of caution and to use the higher estimates when deciding what actions need to be put in place to restore the salmon populations, and quickly.

Next, some clues as to why the orcas have such a strong preference for Chinook salmon, and a closer look at the status of those salmon populations-

Timeline: Salmon, Dams, and Orcas

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Calf J 45 with his family (Photo by Ken Balcomb)

Four generations of orcas, spanning nearly 100 years in age, live and forage together for increasingly difficult to find Chinook salmon. These are the “J2s”, one of the southern resident orcas’ most easily recognized and often seen family groups, and I have chosen them to illustrate how the orcas have been impacted by the construction of dams over the last century.

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J2, matriarch of her family.

Witness to the most change, the matriarch of the family J2 is nearly 100 years old (previous post). When she was born, around 1911, there were no dams on the Columbia River, and only three on the upper Snake River. (Although those dams either blocked salmon runs, or had inadequate provisions for the fish, they were located in the upper reaches of the river in Idaho leaving much of the river free running.) Construction had begun on one of the Elwha Dams.

About this time, up to 30 million salmon and steelhead would return in any given year to the Snake and Columbia Rivers, and an estimated 400,000 to the Elwha.

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J12 (J2’s daughter)

Around 1935, J2 gave birth to a daughter, J12. By then, two more dams had been built on the upper reaches of the Snake River, and construction had begun on two dams on the Columbia River. Two dams were in place on the Elwha, blocking salmon from most of their natal habitat.

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J1, believed to be J2’s son.

When the familiar male orca J1 was born around 1951, the sixth dam had been built on the Snake River, a third was started on the Columbia. Work was completed on the Bonneville and Grand Coulee Dams, completely blocking upriver passage of salmon.

By then, the average size of Chinook salmon that were caught was nearly half that of early records.

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J14 (J2’s granddaughter)

In 1974, J2’s granddaughter J14 was born (her mother was J12, who died in 1996). By the time she was born, the number of dams had increased dramatically: there were 12 dams on the Columbia and 14 on the Snake River. ( See Hydroelectric Dams on the Columbia River).

From Save Our Wild Salmon’s website: “Wild Snake River fall chinook populations have plummeted by more than 90% and now teeter below their recovery target of 3,000. Since 1975 when the eight dams (four on the lower Columbia River and four on the lower Snake River) were completed, return rates have only rarely exceeded the 2 percent salmon survival minimum.

The returns to the Elwha are equally bleak – down to roughly 4,000 fish, or 1% {this is a corrected figure from original post} of the original estimated salmon population.

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J45, great-grandson of the matriarch J2

This year, J2’s great-grandson was born, and presently there are 14 dams on the Columbia, 14 (10 major) on the Snake, and 2 on the Elwha Rivers. Although it is impossible to know the actual abundance of salmon 100 years ago when his great-grandmother J2 was born, the waterways where she and her family hunt now contain an estimated 10% – 50% of the fish available to her at her birth.

But there has been another change in the years between the births of J2 and her great-grandson J45, a change that is equally monumental to the massive dams that impede the progress of salmon up river; where once we believed that the ocean would provide us with endless bounty we now know that those beliefs have led to destruction on a massive scale.

And we’re doing something about it. The two dams that are scheduled to be breached next year on the Elwha signify how very far we have come in understanding the adjustments that we need to make to insure that there are salmon available for us, as well as for the orcas, well into the future.

“River of Renewal”- Salmon, Dams, Orcas, and You (Introduction)

The other night I just happened to catch on the PBS station KCTS the second half of an excellent documentary about the Klamath River, called “River of Renewal”. I found the part that I watched to be coherent and insightful, and regret that I missed the first half. Although the Klamath River runs through Oregon/California, the film covers the same issues we face here in Washington as we consider removal of dams in the Snake/Columbia river basin.

The restoration of salmon populations is a large and complicated issue, and to help all of us keep track of information I’ve added two special sections to the link bar (to the right) which refer directly to previous posts; one section concerns the basic biology of orcas, the second covers salmon issues. By doing this, I can continue to write about interesting but not necessarily salmon related things that might come up, yet still keep a continuity of the main subjects going.

So, starting with the questions that must occur to everyone when we begin to talk about taking down dams and saving fish: what will we lose and what will we gain by taking such drastic measures?

The following video addresses those questions, and although it is about the California/Oregon Klamath River, it exemplifies the issues that concerned farmers, commercial fisheries, Indian tribes, and a utility company in the consideration of removing four dams, a situation that parallels that of the Snake/Columbia river basin.

These conflicts were recently resolved, and the dams are scheduled to be breached in 2020 – although even that may be too far in the future to arrest the downward trend of those salmon populations. But it shows that disparate interests can come together, and why it is so desperately necessary for us to do so.

Two dams are also scheduled to come down here in Washington on the Elwha River, and due to money allocated by this administration’s stimulus package, demolition and restoration will begin in 2010. It is a momentous undertaking, and thanks to individuals who had both the foresight and fortitude to see this project completed, we may be able to see the salmon populations of those rivers rebound in our lifetime:

As we delve into this subject of restoring salmon populations and what it might require of us to accomplish this, please keep in mind that we are writing from the viewpoint of establishing a food supply for the orcas, and will focus this discussion on their preferred salmon species.

And as always, it is helpful to set aside bias and, as stated in “River of Renewal”; “Find our common roots, do what we can to fix the world”

Vote For Orcas and Salmon – No on I-1033

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Photo by Stewart Macintyre

From The Nature Conservancy:

“Initiative 1033, or I-1033, is a statewide measure headed for the November ballot. This measure could have a devastating effect on Washington’s precious landscapes. I-1033 threatens to undermine the quality of our air and water and the natural treasures that we, as conservationists, hold dear.

Locking in “The Worst of Times”
I-1033 would limit the growth in revenue each year for state, county and city general funds through an arbitrary formula based on inflation and population growth. At face value, it may sound reasonable – but the impact of this radical proposal is anything but reasonable.

Because of today’s poor economic conditions, spending for natural resources in Washington has already been cut severely. I-1033 would permanently lock in place those dramatically low funding levels for conservation and the environment at both the state and local levels. It would also make it nearly impossible to restore funding to earlier, higher levels, even when economic times improve. The result of I-1033 would be more cuts to conservation and environmental projects.

Unintended consequences for Washington’s natural heritage
In the campaign, you’ll likely hear a great deal about this measure’s damaging effects on education, health care and Washington’s economy–all are very real issues. We also want you to know what this initiative would do to Washington’s natural areas:

* It will lead to more park closures, as parks agencies are forced to cut costs.
* It will lead to reduced quality of air and water, as dollars to enforce important rules protecting our rivers, lakes, streams and Puget Sound will be harder to come by.
* It will lead to reduced conservation of natural areas and open space around the state, with fewer funds to protect important fish and wildlife habitat and working farmlands, as well as less money to care for the places we treasure.

Learning from the past
Colorado voters passed a similar measure several years ago, so we know a lot about what the passage of I-1033 would mean. It led to deep cuts in funding for state parks, public schools and children’s health care. It did so much damage that, in 2005, Coloradans voted to suspend the law altogether.

Taking a stand

The Nature Conservancy doesn’t often weigh in on ballot measures. But after much deliberation, we have joined the No on I-1033 Campaign, a broad-based coalition of conservation groups, business leaders, labor organizations, senior groups and others opposed to I-1033. By supporting the No on I-1033 Campaign, we’re underscoring our commitment to our life-affirming mission and to our collective responsibility as citizens and conservationists.

We hope you’ll join the Conservancy–and a growing community of people committed to the quality of life and the environment in Washington–by standing up for the future of our state and saying No to Initiative 1033. Our choices today will shape our lives and landscapes of tomorrow. We can help to ensure a future that includes clean water, working farms, intact forests and vibrant wild lands.” [From The Nature Conservancy]

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Calf L112 with its mother L86 (Photo by Dave Ellifrit)

Please consider the four new orca calves when you cast your vote.