Our Lucky Star

When Animal Caretaker Katie Malmberg got the radio call, she knew something was a little different.

“A guest handed me something at the tide pool. I think you should see it”. The message told her to expect something odd, but she was not prepared for what she saw.



It was a sea star! A small mottled star, Evasterias, found by the guest on a sidewalk near Pacific Science Center. By itself, that was surprising and disturbing, but the bigger mystery was, it did not appear to be from our tide pool touch tank.

Animal Care keeps photos of all our sea stars, a practice we began when we first became concerned with Sea Star Wasting Disorder. We want to know which individual animal we are talking about in case anything happens to one of them.

As far as we can surmise, this star was not taken out of the tide pool and later dropped on the sidewalk by an absent-minded guest. Instead we believe, it may have been lifted from the beach by an overly ambitious gull. Sea stars are not a large portion of the diet of gulls, but a quick Internet search for images of “gulls eating starfish” reveals that they do sometimes try and the stars are hard to swallow. Perhaps our star was grabbed and carried by its captor to a safe feeling place, where the bird intended to finish swallowing it. Or it turned out to be too big. Or perhaps a more tempting morsel appeared and the gull flew off, leaving the stranded star to dry up in the sun.

Lucky for the star, someone found it.

The star is currently in our quarantine area. Between the trauma of being transported in such a way, and the chances of it succumbing to wasting disorder, its prognosis is still guarded. And though its fate is still up in the air, at least it is now back in the water.


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The Truth About Animal Care

Earlier this year, we posted a story about our high hopes for the observation beehive. Although the beehive performed brilliantly all summer and well into fall, the population became too low to expect it to carry over into spring. As the Animal Care Department sat down to discuss this, and to think about how to present the saga, a larger story emerged.



BEES

An observation beehive is a very long way from the original life of a honeybee, native to southern Europe and North Africa. Bees evolved in warm, dry climates with lots of sunshine. Beekeepers have explored and mastered techniques for maintaining bees in situations vastly different from their natural habitat. But they have also inadvertently exposed them to chemicals and pathogens that did not exist in their place of origin. The price of transporting animals out of their natural habitat is the constant struggle to create a viable alternative.

But what about our other exhibit animals? How does captivity increase or diminish their chances of long, comfortable lives?

BUTTERFLIES

The residents of our Tropical Butterfly House come to us as pupae, so they have already lived longer than most butterflies would in the wild. In nature, butterflies produce far more eggs than will live to maturity. Predators, hunger, and disease can reduce the caterpillar population from dozens to just a few pupae. Therefore, few adults live long enough to reproduce. Butterfly farming tilts the odds in favor of the young surviving to adulthood.

Once our butterflies mature and fly around, they face fewer predators or weather hazards than they would in the wild. Sure, there are dangers but our Tropical Butterfly House is pretty safe. Our horticulture team provides ample nectar sources, and there’s fruit for those who prefer it. We choose species that don’t migrate, so their instincts to fly away are not thwarted. Our butterflies do not get to reproduce, but instead they serve as ambassadors for butterflies in the wild. They build good will and interest in preserving wild places for generations of insects to come.

NAKED MOLE RATS

So what about our naked mole rats? Our colony surely has less space than it might in the wild. This is where our Animal Care staff’s commitment to enrichment is critical. Naked mole rats are the most active, dynamic animals we exhibit. Their need to be busy leads to stress related health problems if we don’t challenge them. By constantly changing their surroundings and introducing food in novel ways, we keep them learning and moving. And we entertain our guests and ourselves.

The mole rats show no sign of being bothered by the sounds outside their chambers. They generate a fair amount of their own noise through chewing, and seem oblivious to other sounds. The daily maintenance from Animal Care staff is probably a mild stressor, but remember, not all stress is bad. It keeps animals engaged and busy.

No one knows how long naked mole rats live in the wild, but most sources agree that they live much longer in captivity and if their social needs are met, their quality of life is excellent.

SNAKES

Our boa constrictors are harder to keep active. As they reach their middle years, many snakes naturally become more sedentary, and ours are surely no exception. When you watch a snake presentation at our Live Science Stage, you are participating in an important part of the snake’s wellbeing and care: Exercise. Being handled is one of the best exercises these animals can get.

AXOLOTLS

The axolotls are a sad example of animals whose best chance of survival is in captivity. Introduced species, habitat loss, and human hunting critically endanger their natural relatives.

Axolotls have very specific water quality needs, but once those are met, they need (and want) less enrichment than many animals. Their natural place in the ecosystem is at the top of their food chain, with abundant resources and little novelty. Axolotls show stress very readily, so as long as they are healthy we have a good indication that their quality of life is good.

TIDE POOL ANIMALS

The tide pool animals live in a much-compressed version of their natural habitat. Our deep and shallow ends do not replicate the diverse ecosystems of Puget Sound. And we don’t have waves! Life in the open water is both more dangerous and more varied than what we can provide. At low tide, shore life is exposed to predation from gulls, crows, eagles, and shore birds pecking and grabbing them. Surely, they can withstand careful fingers!

What our tide pool animals really need is lots of love in the form of caring for their habitat. If our tide pool animals help create the bond that encourages that care, we think that’s a good use of their time.

This article is a long way of explaining that the animals in our care at Pacific Science Center teach us all about the bigger world and hopefully how to maintain it.
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Gifts from the MaST Center

Guests who were around at Pacific Science Center’s Salt Water Tide Pool at noon Friday got the wonderful experience of meeting a bevy of new creatures.

Staff and volunteers from Highline Community College’s MaST (Marine Science and Technology) Center led by Kaddee Lawrence, with expert information from Rus Higley, hand delivered a group of exciting Puget Sound organisms. These new residents are for us to share with anyone who wants to learn more about the diversity of our regional shoreline.

In addition to bringing an infusion of bright color, the animals are an assorted mix of species. Best of all, they are a mix of non-aggressive animals that will not try to eat each other.

Many of the sea stars in our collection are Pisaster species, among the most predacious of all creatures in the intertidal zone. Yet, we love how durable they are, and how happily they eat readily available shellfish. With the new sea star species, we hope to have animals that are easily cared for and unlikely to eat other members of the exhibit. If these sea stars do well, the folks at MaST have offered to help us replace our current Pisaster population with these less hungry brethren. We will then plan a second round of new animals to include chitons, limpets and other animals that easily get eaten. Already our exhibit is more diverse by the addition of:

2 - Red sea urchins (Strongylocentrotus franciscanus)
1 - Purple sea urchin (Strongylocentrotus purpuratus)
1 - California sea cucumber (Parastichopus californicus)
1 - Kelp crab (Pugettia productus)
2 - Vermillion sea star (Mediaster aequalis)
2 - Blood stars (Henricia leviuscula)
1 - Mottled star (Evasterias troscheli)
1 - Sun star (Solaster dawsoni)
25 - Plumose anemone (tiny)(Metridium sp)
2 - Swimming anemone (Stomphia coccinea)

We can’t say “thank you” enough to the scientists at MaST. However, if you find yourself down in Des Moines, at Redondo Beach on a Saturday morning, stop by and thank them for us! The program hosts a weekly open aquarium, where the public meets their animals and their wonderful staff and volunteers. This is a great way to extend your knowledge of marine life.


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Our Latest Tide Pool Collecting Trip

Last week Cari Garand, Adrian Eng, and Portia Riedel went on a tide pool collection trip at The Cove in Normandy Park outside of Seattle.

Here’s what they collected:



Moonsnail egg cases
Mussels
Hermit Crabs
Mossy/Hairy Chitons
Kelp Crabs
Mottled Sea Stars
Ochre Star


Shaggy Mouse Nudibranch
Shells with barnacles
Misc. Juvenile Crab
Plumose Anemones


Brooding Anemones (and their brood)
Aggregating Anemones


Spotted Aglajas
Isopod
Sand dollar
Heart cockle


We expect to keep the sea stars, anemones and hermit crabs for months or years to come. But snail egg cases are fragile and will probably only last a few days before breaking apart. To see our new collection in all its glory, hurry down!
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Tide Pool Bully

What has five arms, wears leather, and is deadly (to sea anemones)?



When we first got our leather star (Dermasterias imbricate) we were impressed by its textured good looks and willingness to slide up into the handling area for inquiring hands to touch it. Although these echinoderms are known to eat sea anemones, we hoped that with ample food, it might suppress its predatory urges. But over time, a series of mysterious casualties were taking place in the tide pool. Sea anemones were disappearing or becoming damaged, with no evidence of human mishandling. Whatever other circumstances, the leather star was always lurking near the scene of the devastation. Animal Caretaker Cari Garand was able to put together the clues, and recommended we deal swiftly with the rogue sea star.


But now we ran into a problem. Pacific Science Center’s tide pool touch tank is considered a terminal facility. This means the department of Fish and Wildlife had determined that our animals couldn’t be returned to the sea. Because we feed our tide pool seafood from other regions, our animals could harbor shellfish virus or other pathogens, harmless to humans but that would make them more of a menace to beach wildlife than our leather star already was to our anemones.


Without the option of release in the wild, a tough decision lay before us. We could let the leather star go on destroying our anemone population, or we could destroy the leather star. Or was there a third way? While we worked out a plan, we removed the star from the exhibit area and isolated it in our filtration vat. Here, it could be fed and looked after without having access to our exhibit animals. Cari contacted Tim Carpenter, at Seattle Aquarium. He graciously agreed to accept the star, and provide a habitat where it would fit in better. All the paperwork was arranged, and on Oct. 25, Tim's assistant, Katie, completed the transfer.


The star had outgrown our little tide pool. We hope he finds it is better to be a small “fish” in a bigger pond.

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Late Summer Tide Pool Collecting

This weekend, Cari Garand and Wendy Hanson did an end of summer tide pool collecting trip, along with volunteer John Aurelius who generously lets Pacific Science Center collect from his beach at Indianola.



Trained beach naturalists, Cari and Wendy collected carefully, taking only organisms allowed on our permit, and leaving animals as they found them if they could not be used in our tide pool exhibit.


Here are the animals that Cari and Wendy brought back:

Hermit crabs: 15

Mottled Star: smaller ones, 4

Shrimp: 2 very little

Limpets: no large ones, but many small ones came in attached to other animals

Painted Anemone: 1

Aggregating Anemone: 4 mostly came attached to stuff

Moon Snail Egg Cases: 3

Barnacle covered rocks: 10

Chitons: 3, 2 bigger mossy or possibly hairy ones and one small lined

Snails: 8

In addition to the animals we might expect from a collection, our team spotted a bunch of the coolest looking items we’ve seen! The gelatinous, finger like objects are squid egg cases, and you can actually see the baby squids floating around inside the case.


Of course, Cari and Wendy wished they could bring some of these cases back, but knew that our system would not support such large, free swimming predators as mature squids. So the cases stayed on the beach.


Cari and Wendy used their professional experience to assess which animals would work best in our Puget Sound Salt Water Tide Pool. But being professional does not mean the collectors didn’t feel the wonder and excitement of being on a beach.


We encourage everyone to visit one of our local beaches, and spend time getting to know Puget Sound better. Bring your camera; you never know what amazing pictures may be out there.

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The Very Hungry Nudibranch

Last Thursday, guests and staff were treated to a rare sighting of the Puget Sound Tide Pool model’s one and only shaggy mouse nudibranch (Aeolidia papillosa). This marine slug grazes on the tentacles of sea anemones. Having eaten the tentacles, it stores their stinging cells in its own body, rendering it toxic to predators. The shaggy looking growths on its back, which earned it its name, actually contain these stinging cells.



An unexpected stowaway from our most recent tide pooling expedition, the shaggy mouse is often hard to find. Unlike many home loving tide pool animals, it does not predictably return to a few favorite haunts. Since it is also small, flexible, and sandy in color, it tends to disappear for days or weeks only to suddenly appear in a new part of the exhibit.


In Pacific Science Center’s Life Sciences department, we must constantly remind ourselves not to anthropomorphize. Sometimes are easier than others. As the fluffy little nudibranch crawled between the arms of a purple sea star, it was all we could do not to think the star was petting it.


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Everything – and the kitchen sink!

The water in our Salt Water Tide Pool tends to change a bit in clarity over the course of a week. On days where we have a lot of visitors, the water gets cloudier. When attendance is low, the water tends to clear up a bit. But recently, regardless of attendance, the water has just been cloudy – even murky. Our ammonia, pH and other tests were within healthy range and the animals were thriving. But guests had difficulty seeing the animals. The purpose of our exhibit is to educate and create a sense of wonder and stewardship, and our touch tank was not meeting this need. We needed to fix it, on a shoestring budget, but how?


There are four types of filtration – biological, chemical, physical and mechanical. Our tide pool uses all of them. To create a more robust and successful filtration system, we knew we would need to make sure we were fully utilizing each of these types of filtration.


Biological filters use bacteria to break down wastes excreted by animals into less toxic products. In our tide pool, we use “bio balls” which provide extensive surface area and for the growth of good bacteria. Our water quality measurements were good, so we had adequate biological filtration.

Chemical filtration uses carbon to removes toxins and impurities from water by binding them to material that can then be removed and disposed of. If it’s overused, it also captures trace minerals needed for a healthy system. Using chemical filtration alone is not an option.


Our protein skimmer uses physical filtration. When protein is mixed in water, it forms bubbles. It’s like a meringue made of sea scum instead of egg whites. B y capturing and discarding the foam, you remove the unwanted protein from the water. But protein does not causing cloudiness, so adding more physical filtration would not solve our problem.

Mechanical filtration captures loose particles in water, using some kind of straining material. We had been using filter canisters made of a fine metal mesh, as well as felt-like filter fabric. However, water was leaving these filters as cloudy as it went in. The mechanical filtration appeared to be the weak link.


Our first step was to identify the most efficient medium for mechanical filtration for our size of tank We knew that crushed coral would function as both a mechanical and biological filter, and this seemed like the ideal option. This main issue with coral was its weight. It is pretty heavy when it comes in bulk, and with our current vats, it would be difficult to keep the coral from getting into the filters, and nearly impossible to remove it when we needed to. So how to you suspend 100 pounds of crushed coral inside a 500-gallon vat and still maintain relative accessibility? The answer came to Animal Caretaker Dan Warner while he was washing dishes: A sink!


We retrofitted a slop sink with added drainage holes. Then we sealed netting to the bottom to keep the coral in place. Water flows from the tide pool and into this sink full of coral which now provides our main source of filtration. Then it drains from the sink into the vat, where it’s pumped back out into the tide pool again.


But the fun doesn’t stop there. To provide even greater mechanical filtration, we started using hula hoops buoyed by water noodles! They now support felt filter media that lies above the sink to and captures the largest bits of junk, such as uneaten food, hair, and spines shed by sea urchins.

And as Dan says, “Bob’s your uncle!” We have the filter of our dreams for a fraction of what it would cost to buy a new one.


Does it work? The BEFORE picture is typical of our system mid-week, when attendance is brisk but not heavy. The AFTER picture was taken after the very busy “Polar Science Weekend”, and shows that even on one of our busiest days, the coral is up to the task.



Thanks to Lead Animal Caretaker Brianna Todd for the photographs to this story.
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Sea Urchins in the Spotlight!

Monday morning (January 31) Life Sciences Manager Sarah Moore and Lead Animal Caretaker Brianna Todd will feature our newest tide pool residents, green sea urchins, on "New Day Northwest." The KING 5 local news show begins at 11AM. Tune in!




Pacific Science Center's segment will discuss these and other delicate animals and how they fit into our fragile ecosystem. Our green sea urchins are a gift from Highline Community College's aquarium at Redondo beach.

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Leave them alone. They’re trying to clone!

Although they are animals, sea anemones are as lovely as the flower they are named after. Their colors range from red through orange, white, and green, some are even marbled in two tones. Tentacles fringe the perimeter, in the center is the orifice, or mouth. Sea anemones belong to the phylum Cnidaria. Because this group of animals lack a two-ended digestive tract, the mouth also functions as their anus.

At Pacific Science Center's Puget Sound Salt Water Tide Pool, we encourage you to touch the tentacles, which are used to sense and manipulate food and to defend the animal. We ask you not to touch the orifice! And now that you know what it is for, you probably don’t want to.



Sea anemones are normally round. But recently we have had a large number of anemones become elongated in one direction and narrow in the other. They look for all the world like rubber bands being stretched out tight.

These are one type of anemone, Anthopleura elegantissima, the aggregating anemone. While anemones can reproduce sexually by releasing free-swimming gametes into the water, many types also reproduce asexually. In the case of the aggregating anemone, the animals clone themselves. The stretched out individuals are part way through the process. Their two ends will each become a fully functional animal. The area in the middle thins until it eventually disconnects, freeing two daughter organisms.


Clonal groups of these anemones will often populate a large rock or flat area on a beach. When two groups meet, they use special stinging cells to battle each other. Don’t worry! None of the anemones in our exhibit is known to have a sting that can be felt by humans.


So when you see an anemone in the midst of cloning, please show it a little extra care. Cloning is fascinating, but it is also risky and costly of the animal’s resources. Choose another anemone – a round one – to touch. Though in a different way than we are used to, it is reproducing, and needs an extra bit of privacy.
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How to Make a Sound

Pacific Science Center’s Puget Sound Salt Water Tide Pool is designed to look like a natural habitat, but behind the scenes it functions very much like any other aquarium. In this case, a salt water system.

Each week, we remove a portion of the water from our Puget Sound Tide Pool model and replace it with 100 gallons of new, clean saltwater. Because we don’t have ready access to Puget Sound water, we use a commercially purchased synthetic salt: brand name- Instant Ocean. Really! When this synthetic salt is mixed with the appropriate amount of water and other additives, it becomes chemically comparable to the water found in Puget Sound. In our tide pool, we aim for a salinity of about 3.2%.


First, we add a measured quantity of salt to our new mix water. We then mix the salt into the water overnight, using a pump dedicated to circulate the water. This also allows the water to release any chlorine as a gas that might be in the water.


Each time we do a full water change, we test the newly mixed salt water and the water in our exhibit using a hydrometer, which measures the specific gravity of the water. A hydrometer measures how dense a liquid is compared to water at a certain temperature. Because water can dissolve solids without changing volume, the more solids that are dissolved in water, the more dense the solution becomes.

In our case, nearly all the solids in our water are salts. So our hydrometer measurement is a pretty good indicator of how much salt is in the water.

Once we know the specific gravity of our tide pool water, we can convert to salinity – in fact our hydrometer converts for us. Salinity measures the parts per thousand of salts in the water. In our case, the water is about 3.2% salt – a bit less than the ocean because 11 rivers feed fresh water into Puget Sound estuary.

If the ambient temperature is very hot, we can lose water from the tide pool simply due to evaporation. When this happens, the water becomes too salty and we need to add less saline water to dilute it. Our system rarely experiences this. We do suffer from salt creep, a situation where salt crystallizes out of the water. If that happens in the pipes, it gives us quite a headache because the water circulation slows down.


Operating the tide pool, or any aquarium, is a great opportunity to brush up on math and chemistry lessons from high school. Math helps us calculate the amount of salt needed to bring a given volume of water to a certain salinity; chemistry helps us understand when and how to add buffer and how the nitrogen cycle allows wastes to be broken down. These skills are integral to maintaining a fully functional aquarium - just as important as knowing the names and life cycles of the animals we care for.

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