Episode 4: Dr. Melissa DellaTorre, Pacific Hybreed - Unveiling the Mysteries of Oyster Origins

Unveiling the Mysteries of Oyster Origins with Dr. Melissa Delatorre

In this episode of OYSTER-ology, host Kevin Cox is joined by Dr. Melissa DellaTore, CEO of Pacific Hybreed, to delve into the very front end of oyster development and breeding. This is where it all begins, with the development of oyster "seed" for oyster hatcheries and farms all over the world. Dr. DellaTorre highlights the complexities and innovations in oyster breeding and aquaculture today and the many challenges that it presents. In this episode, she shares her insights on genetic testing, selective breeding, and the development of resilient shellfish, including the significance of triploid oysters and biosecurity practices. The conversation expands to her unique career path, including her academic achievements, athletic pursuits, and dedication to oyster research, particularly against diseases like Pacific Oyster Mortality Syndrome (POMS). They also explore the challenges and rewards of oyster farming in diverse environments like Hawaii and the Pacific Northwest, as well as environmental threats, the nutritional needs of oysters, and potential aquaculture expansions. The episode combines scientific depth with personal anecdotes, painting a comprehensive picture of the current state and future of oyster breeding and development.

00:00 Introduction to OYSTER-ology
01:02 Meet Dr. Melissa Dellatore
03:03 Pacific Hybreed: Breeding Stronger Shellfish
04:00 Understanding Hybreed Vigor
04:54 Challenges in Oyster Breeding
07:48 Melissa's Journey into Aquaculture
13:11 Oyster Life Cycle and Breeding Techniques
15:48 Triploids and Biosecurity
20:01 Warm Water vs. Cold Water Oysters
26:17 Oyster Diseases and Resilience
29:54 Future of Sustainable Aquaculture
30:57 Global Oyster Species and Pacific Oyster Dominance
31:57 Challenges of Crossbreeding and Biocontamination
32:55 Oyster Aquaculture and Restoration Efforts
33:37 Triploids and Ocean Acidification
34:47 Threats to Oysters and Survival Rates
36:22 Pacific Hybreed's Facilities and Operations
37:26 Algae Production and Hatchery Practices
41:49 Shipping and Expansion Plans
48:21 Water Quality Issues and Solutions
55:53 Team Dynamics and Daily Operations
58:41 Conclusion and Future Prospects

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Transcript

Episode 4: Dr. Melissa Dellatorre, Pacific Hybreed

Melissa: [00:00:00] In our laboratory conditions, we make everything as perfect as can be. You know, we give them all the best flow rates and water conditions as we know. And still, it's 2 percent of the fertilized eggs make it through metamorphosis on a good run. Like a good typical run. 

Kevin: Welcome to Oysterology, a podcast all about the wide world of oysters, aquaculture, and everything from spat to shuck. I'm your host, Kevin Cox. When most of us think of oysters, we picture ragged shells sticking out of the water along a shoreline, or a platter of perfectly shucked oysters glistening on a bed of ice.

But do we ever think of where oysters come from? If a baby oyster could ask its mommy where it came from, I know, it's ridiculous, because oysters don't have brains, they can't talk, they never even meet their parents, and they're, well, oysters. [00:01:00] But if they could, what do you think the answer would be? To address that question, I have not a talking oyster mommy, but rather my guest, Dr. Melissa Dellatore. Dr. Dellatore is the Chief Executive Officer of Pacific Hybreed. A commercial shellfish breeding outfit in the Pacific Northwest and Hawaii, whose mission is to improve the health and resilience of shellfish through careful breeding and genetics. She earned her doctorate in marine biology and in biological oceanography from the University of Southern California. And also has a Master's in Environmental Toxicology from NYU and a BA in Neuroscience from Bowdoin College. Yeah, she's one of those really smart scientists who dedicates her time to figuring out how to develop and better breed stronger, more resilient shellfish through genetic testing and really hard science.

Oh yeah, and although she's so humble and soft spoken, she's a total badass. Who when she's [00:02:00] not studying, breeding, or caring for millions of microscopic baby shellfish, or teaching, or lecturing, or publishing scholarly works, or doing, you know, CEO business stuff, she relaxes by competing in the Kona Ironman World Championships. swims, scuba dives, dirt bikes, spearfishes, and volunteers for Habitat for Humanity. And she's graciously made time to help us better understand the early life cycle and challenges of oysters and where they come from. So put on your thinking caps and lean into your stereo microscopes to learn about Hybreed vigor, biosecurity, oyster inbreeding, oyster herpes, the tiny food that microscopic oysters eat, gametes, poms. And even sturgeons in New York with my guest, Dr. Melissa Della Torre. 

Hi Melissa, it is so great to have you on Oysterology.

Melissa: Thank you. It's fun to get the chance to talk again. 

Kevin: Where in Hawaii are [00:03:00] you right now? 

Melissa: I'm in Kona on the big island. 

Kevin: Okay. So you are currently the chief executive officer of Pacific Hybreed and Pacific Hybreed is a Pacific Northwest company that's focused mainly in commercial shellfish breeding programs to benefit the kind of the West coast aquaculture world.

Exactly. So, 

Kevin: um, what I'd like to do is hear a little bit about. Pacific Hybreed first, just so we kind of understand the context of what you do. And then I want to hear more about you, but tell me a little bit about Pacific Hybreed. 

Melissa: Yeah. So the company was started by our two founders, professors, Joth Davis and Dennis Hedgecock.

And they've had, you know, decades of experience, both as far as Joth and his being a farm owner and Dennis coming from, all his genetic research in shellfish. So the two of them came together and founded Pacific Hybreed back in 2014, uh, based on the concept of Hybreed [00:04:00] vigor. What is Hybreed 

Kevin: vigor?

Melissa: , it's a concept that's been used a lot in the agriculture industry with plants such as corn. So it's a series of inbreeding and then Hybreedizing to improve yields and performance of, of the animals. 

Kevin: So you're taking different strains or species of shellfish , and breeding them together to create something new and stronger?

Melissa: Yep. Yeah. And so we start that just from wild populations. So to start the process, we just pick one male and one female, um, just natural wild animals coming from Washington. And we'll mate those to produce So they're all siblings with the same parents. So we're not genetically modifying the organisms, but we're finding natural resilience that's just seen in oysters and then pulling out those resilient genes through crossbreeding. 

So you 

Kevin: just kind of take a walk on the edge of a water somewhere where there's some wild oysters growing and look and say, [00:05:00] those look pretty good. Let's give those a try. 

Melissa: Yeah. And then the real work comes from genotyping them and doing that genetic genotyping.

Yeah. process to map, um, which ones should be paired with each other. Um, and that's one thing that sets our company apart from other programs that are doing selective breeding, which is where you would just choose the two, you know, biggest, best looking animals and mate those together. And that's usually, um, works really well for specific traits or where the genetic variance is additive.

where then the offspring would have the average performance between those two parents. But what, um, our founders have found is that oysters actually have a lot of non additive genetic variants. So their performance is due to a combination of genes. And that's where crossbreeding and Hybreedizing, um, can then improve the offspring's yields and performance and factors of interest.

So that they perform better than either [00:06:00] of their two parents individually. 

Kevin: Now when you say performance, what kind of things do you mean for the oysters? 

Melissa: Yeah, so the top things that we're looking at right now are survival and growth. Uh, and that's one thing that we're planning to customize for this, for the farmer.

So based on what the farms are interested in, like for instance, in Alaska, uh, fast growth is a huge thing for them, um, because the colder waters, the animals grow more slowly. But in Mexico, our partners there, since water's warm and they have plenty of food. They can actually grow too fast there where they then get bigger than the harvesting size too quickly. So for them, it's more disease resilience and survival. So through our program, we're hoping to build the perfect oyster for Whatever the farms are looking 

Kevin: for. These are Pacific oysters, I assume. Is that right? 

Melissa: Yep. 

Kevin: So you're taking the same kind of oyster and just through breeding it the way [00:07:00] you're doing, you're making one that will thrive in the cold Alaskan waters and one that will slow down and thrive in the warm waters of Mexico or somewhere like that.

Melissa: Yep. Yeah. So, so far we've created like 200 different genetic lines. I'm starting at the generation zero. Yep. And so we're just then, um, field testing them at different sites along the Pacific coast right now to see what we can pull out to see which families do better in the warm, which do better in the cold.

And then we also are looking to then do the research on those lines to figure out. What genes are responsible for that. So then we can streamline our breeding program and not need to field tests, you know, across the whole world. 

Kevin: It's incredible. I would love to hear your background and how you got into this sort of thing.

Uh, tell me a little bit about your background. 

Melissa: Yeah, my background was, so [00:08:00] I first got into aquaculture actually when I was 14, I started working at a local seafood shack in my hometown. Um, didn't know anything about genetics or physiology at that point, but enjoyed eating fried clams and scallops. 

Kevin: Where was your hometown?

Melissa: In Scarborough, Maine. 

Kevin: Oh wow, you've really, you've kind of gone as far away from there as you can go and still be in the United States. Yes. 

Yeah. 

Kevin: Okay, so you were a 14 year old kid in Maine, chowing down on shellfish, and then what happened? 

Melissa: Yeah, so, and then I went to college, uh, and studied neuroscience, actually.

I thought I wanted to be a neurosurgeon, but then every summer when I was looking to apply for different science internships, I found myself a lot more drawn to the environmental ones. And ended up doing a summer out on Catalina Island studying oyster larvae in a hatchery there at the Wrigley Marine Science Center. [00:09:00] And had such fond memories there, um, decided to go back there for my PhD. 

Kevin: So you went out there, was that for your master's originally or for your undergrad? 

Melissa: Yeah, for an undergrad summer internship. 

Kevin: That sounds like a pretty nice internship, being on Catalina Island, dealing with oysters.

Especially if you're coming from Maine. I did look at your, , your background a little bit. And I also noticed that in addition to your unbelievable academics , and science and genetics and all of those things, you also, Uh, let's see, you were varsity cross country, varsity triathlon, you're a certified diver.

You were in, is it the world championships for Ironman triathlon ? Tell me just for a second about that. 

Melissa: Yeah. So that, um, came up, so moving to Kona, um, which actually was kind of a, uh, you know, bit of a gamble for me. Like I'd never been to Hawaii, didn't know anyone here, didn't have a place to live, didn't really know [00:10:00] what I was gonna be doing. , but got here and loved it. And so Hawaii is actually where Ironman first , started, originated, so, uh, quickly got into running, biking, and swimming. I'd always been running. I, like, I'd always done those things as a hobby, but Why 

Kevin: did you go out to Hawaii in the first place, ? One 

Melissa: of my co advisors for my PhD was, um, Dennis Hedgecock, who was one of the founders of Pacific Hybreed. And then additionally, a post doc in our lab, Francis Pan, was doing a lot of the genetics work for Pacific Hybreed. So, as I was wrapping up my PhD, um, it got offered to me that they needed, um, some people to work in the hatchery in Kona. Wow. So that sounded like a fun opportunity. 

Kevin: So when you were there you got, you continued with triathlon sort of things?

Melissa: Yep. Yeah. Um, since I didn't know anyone here, I pretty much just joined all the clubs. So they have a run [00:11:00] club, a bike club, a swim club, a dive club. , so just jumped straight into, um, all the activities here to see what Hawaii was all about. Got, got pretty hooked on the triathlon 

Kevin: thing. So, you're a badass is basically what I'm hearing here.

I mean, with your, with your science and your business acumen and all of these other things, it's pretty fascinating. You have a pretty interesting background, so was it when you got to Hawaii that you discovered Pacific Hybreed, or how did that whole relationship come about? 

Melissa: Yeah, so I had known about it, , one of my, so I, Started at USC Mm-Hmm.

in 2016 Mm-Hmm. . And worked pretty closely. My lab worked pretty closely with Dennis Hedgecock in his lab, so we could combine the physiology with the genetics. Right. And get kind of the whole picture of nature and nurture with the larvae. So I had been tuned into, , Pacific Hybreed, , since that [00:12:00] time. 

Kevin: And at some point before that you were involved, I think maybe it was in your, master's , you were involved with sturgeons. 

Melissa: Yeah, that was, uh, that was my master's that I did at New York University. So, the Sturgeon, um, so in the Hudson River, it's, uh, It's a super fun site for PCBs, polychlorinated biphenyls.

Kevin: Nasty things like that, right? 

Melissa: Yeah. . So, and the surgeon in particular, they were getting curved spines and they were getting um, these, you know, different diseases due to that. So my project there was actually the first kind of, um, biopsy. Bit of genetics I got into is looking at the molecular mechanisms and gene expression of different drivers for that.

Kevin: When I think of sturgeons, I think of caviar, basically. , isn't that where caviar? Yeah, caviar comes from that, but probably not the same kind that you were dealing with, right? 

Melissa: Yeah. So [00:13:00] we come, you wouldn't want the caviar from the sturgeon, but yeah. But I did work with the larvae, so it was I saw a lot of sturgeon eggs..

Kevin: So, let's get back to oysters for a minute. Can you describe what is the, kind of the early life cycle of an oyster from, I guess, the hatching standpoint or maybe even before? 

Melissa: Yeah. So, the life cycle of the oyster starts with, um, conditioning the adults. So, , we try to mimic the natural conditions to get them ready to spawn. So we'll slowly ramp up the temperature. We'll ramp up the food, um, make the conditions good for spawning. And then the oysters will start releasing their gametes. So, um, that will mate for our breeding program. We want just one male and one female to mate together. And so once those fertilized. , you can see the first, uh, under a microscope, you can see that first polar body, the first cell division happened in [00:14:00] about a half an hour.

And then within less than 48 hours, um, they've already developed their shells and they spend their first few weeks actually as free swimming plankton in the water column. So they grow from, you know, about a hundred microns in size, like a tenth of a millimeter, and then up until about 300 microns when they're ready to go through metamorphosis and set. And that's based on, you know, food availability and temperature, the timeline for that. 

Kevin: So you're talking about initially things that you can really only see under a microscope. You can't see them in the water at all. They're so small. 

Melissa: Yep, exactly. 

Kevin: Oysters can change their sex, and I don't know what impact that has on, on trying to separate, you know, find the right male and the right female and breed them the way you described.

How do you deal with that? 

Melissa: Yeah, yep. So usually, so they're protandric. So usually they'll start as males, and then they'll turn into females later in life. [00:15:00] And every once in a while you get a hermaphrodite that has both eggs and sperm. Um, and so there are a couple of ways we can do that to try to see what their sex are before we spawn them. And one of those methods is just drilling a little hole in them and then sticking in a pipette tip and then taking a small sample so we can see if they're male or female. And the oysters actually then can rebuild shell over that hole. So year to year, um, they recover from that. Yeah. And then the other method that we use is Epsom salt.

So if you put them in a Epsom bath, they'll start to open up their shell a little bit, just enough for you to, again, just get a little pipette in there and see whether they're ripe and whether they're a male or female. 

Kevin: That's unbelievable. . The only genetics that I've ever really heard much about when it comes to oysters is the distinction between the number of Chromosomes and there's the [00:16:00] diploids and the triploids and that sort of thing Can you explain a little bit about what that is and how that's different from what you guys are doing?

Melissa: Yeah Yep, so and ultimately we're hoping to combine that triploidy with hybrids But yeah the the Triploids are preferred in a lot of instances, because you can induce triploidy, um, so basically giving the animals a third chromosome, and that makes them sterile. So there's a lot of advantages, and then They, for one, they don't then reproduce with the natural population. So there's a biosecurity to that. You don't have the populations mixing between the wild natural populations and the ones that farmers are growing in cages for aquaculture. 

Kevin: Okay Biosecurity can mean a number of different things in the oyster world. Often people think of it as meaning the security and safety of eating oysters. For example, keeping them cold after they're harvested. So Vibrio and other diseases and bacteria. Turia don't [00:17:00] develop and make you sick. But what Melissa is talking about here is biosecurity of the population of an oyster. And what that really means is you don't want to introduce foreign bacteria or germs, or even foreign oysters into an existing population. This is one of the reasons why in many places, including Washington state, for example, when you can go publicly and harvest oysters, you have to shuck them on the beach where you found them. And you have to return the shells to that beach. You can't take them away, shuck them later and dump the shells off on some other beach or somewhere else because there are different pathogens which could infiltrate the existing population, which is foreign. And create, , a kill off or something like that. So that's what biosecurity means in this instance. 

Melissa: Uh, then also because the animals are sterile, so usually diploid, regular diploid oysters in the summer use all their energy [00:18:00] to convert into gamete so they can. And then after they spawn their body is completely emaciated Like you wouldn't be able to harvest that oyster because it has no like meat or body to it So by producing triploids Because they're not using that energy for reproduction.

They have a lot more energy to then use for growth So triploids are often faster growers However, there are studies now showing some farms have a lot of triploid mortality Hmm And it seems to be more prevalent in warmer waters, like the triploids, for some reason, are more susceptible to mass die offs, and sometimes that's happening right before harvest, which is super frustrating for the farms, of course.

So, that is one thing that, yeah, we're trying to solve. There's two methods to make triploidy. One is to chemically induce it, um, when the eggs get fertilized. And then the other is to spawn a diploid with a [00:19:00] tetraploid. And so, the research avenues we're looking at is Creating better tetraploid stocks that can be used to then make better performing triploids.

So then you have the normal wild oyster, I guess it would be naturally a diploid, right? 

Yep. 

Kevin: And so then if you want triploids, you have to make a tetraploid first. 

Melissa: There's two methods. So you could either make a tetraploid first, and basically when you chemically induce it, there's a really high chance of death.

So the more kind of surefire way to get a good triploid spawn is to mate a diploid with the tetraploid, because then you know that they're going to be a hundred percent triploids. Versus if you chemically induce the triploids just straight away without going through tetraploids, you, it's, there's more room for failure.

Kevin: So then when you get a triploid, what you're saying is they appear, at least in some cases, to not thrive as well in [00:20:00] warmer waters. Are you working to develop oysters that are more tolerant or resistant to warm temperatures versus cold? Yeah, 

Melissa: yeah, that's exactly what one of our goals is to do. 

Kevin: How do you do something?

I mean, how do you even Figure out what to try. 

Melissa: Yeah. So we kind of have two approaches to it. And one being just putting all those lines out there. So one of our field testing sites is in Baja, Mexico, where the water stays warm all year round. So we have different genetic lines out there. Uh, and under those conditions and just looking to see which ones do best.

Um, but then from the other side of it is looking to see, you know, from the genetic and physiological functioning level, what makes them do better. And so a lot of our previous work at USC has been on that and like the energy supply and demand. And looking mostly at the larval stage, but then also looking to see how the larval stage [00:21:00] then translates into juveniles and adults to, to make sure that the ones that do best in warm water as larvae are also the ones that do best in warm water as juveniles and adults.

Kevin: I hear people talking about the difference between warm water and cold water oysters and cold water oysters, and sometimes you hear people give oysters from the Gulf of Mexico a bad rap because the water's so warm that they are afraid to eat them raw. But I'm hearing you talk about oysters in Baja, Mexico , and maybe even warmer climates. So what's the story on the whole warm water risks that people seem to be afraid of?

Melissa: Yeah. So a warm water is definitely, a bigger breeding ground for virus and disease. So that may be part of it. One of our studies with the larvae is like, so as you warm up the water, rates of everything increase, right? So, , feeding rates increase, respiration rates increase, [00:22:00] synthesis rates increase, like all these functions within the organism are increasing and they take up energy.

So one of our previous studies has shown that as temperature warms up overall, you have this difference in energy supply and demand where the oyster's larvae need more energy or they're using energy at a greater rate than they're making it, which then presents a problem. But one thing that we found with all these different genetic families is there are a few families that actually become more efficient in the warmer water and they'll increase their energy producing rate faster than they increase their energy using rates. And so it's those families that we think that can perform really well in warm water. 

Kevin: It's so amazing to me. How you're able to, monitor and study different oysters in these kind of conditions and to distinguish between the ones that are producing more energy or just performing differently. Do [00:23:00] you do that all in Hawaii? How do you test these different conditions? 

Melissa: Yeah. So when we test, we'll test them in a laboratory. And so, yeah, you just need water baths at different temperatures. , and that's one advantage that Hawaii has. Um, so Hawaii, for us so far at Pacific Hybreed, has mostly just been a breeding site, where we grow a bunch of different families, and we haven't done too much of the physiology work in Hawaii. But Hawaii does offer a lot of benefits for that, because we have surface water, and then we also have deep sea water. So we can make any temperature we want just by turning a valve without needing to use a valve. heaters and chillers. 

Kevin: And then the nutrients in the water are probably different though than in the waters where you hopefully will have these oysters thrive.

Melissa: Yeah, so that, and that's one challenge in Hawaii because the water is so clear, like all the nutrients are as far as like what the oysters eat being algae, is they only get what we can grow at our own scale. So, for [00:24:00] instance, in Washington, like when there's natural algae blooms throughout the summer, the animals will grow a lot faster there, but in Hawaii with the warm water. We can grow them year round with the food that we can make. 

Kevin: Are there different kind of algaes that grow in different areas so that if you have oysters that you're breeding in Hawaii and they're used to one kind of nutrient or algae and then they go somewhere else where it's different, does that have much effect on them?

Melissa: Yeah, there's a lot of uncertainty on what kind of effect that has. In the hatchery, the practice is pretty standard. Um, there's one like small algae called isocrysis. It's like tiny cells that the oysters are able to start feeding on when they're just two days old. Uh, and then as they get bigger, you can start to add in different species like diatoms and bigger species of algae that are more nutritious, but they need to kind of develop to that right size before they can start eating them.

Kevin: Okay. Real quick sidebar here. Isocrisis is a type of algae. It's commonly used to feed oysters and [00:25:00] it's usually used to enrich zooplankton before feeding oysters, , in their larval stage. So it's really, really tiny. Then there's also diatoms, which oysters love to eat. And that's a micro algae that's just floating around in the ocean. But that doesn't mean they're not important. They take carbon dioxide and convert it to oxygen. And somewhere between 20 and 50 percent of the oxygen produced on the entire planet each year come from diatoms. They're a single celled organism and they're interesting little cell walls are made of a type of silica, giving it a sparkling colorization, which is why many scientists often refer to them loosely as living opals or jewels of the sea. 

 Now I've heard that during the really cold winters, they don't feed much, they don't grow much, they just kind of go dormant. And they just sort of sit there, living off the fat of their meat inside their shell. 

Melissa: They're such hardy animals, like, they can survive so long without food, like, they can survive [00:26:00] without water, you know, they'll just close up their shell for days, so.

Kevin: I wish I could do that. So if you take an oyster and you put it in a warm water climate, like in Mexico, where there's more nutrients in the water year round. They just grow faster, typically? 

Melissa: Typically, yeah. 

Kevin: One of the things that I hear a lot of people talking about, and I guess it's different in different regions of the world, are the diseases in the water.

And there are a few of them. Can you tell me a little bit about the diseases that seem to most threaten oysters? 

Melissa: Yeah, one of the biggest diseases that we're interested in right now is Poms, uh, It's also caused by a variant of the herpes virus, and it's a huge threat to production, I think, worldwide.

Quick 

Kevin: sidebar here, Melissa mentioned POMS, which is a Pacific Oyster Mortality Syndrome. , this affects, , Pacific oysters, and it's caused by a virus called the O,S H V one micro variant. This is important because Poms causes rapid death and high mortality rates in farm [00:27:00] Pacific oysters up to a hundred percent within days of being detected. So it's a nasty thing. 

Melissa: Um, and that's one of the reasons also that we chose Hawaii as a breeding site, because it's so far removed from other land masses that it's less likely to transmit, or like, it's less likely that the virus comes to Hawaii. , 

Kevin: does Poms come from landmasses or where does it originate?

Melissa: I'm not sure where it originated from, but it's been very prevalent in France and then also in Australia, New Zealand, uh, and those areas have actually created a resilient strain of oysters or oysters that are resilient to the herpes virus. Um, but the problem is we can't import those oysters, right?

Because they're grown in areas that have the virus. So, um, there's no way like in Washington State would ever allow any oysters to come from France or Australia, New Zealand because they have the virus there. So, we're working to create our own resilient [00:28:00] strains, um, so that we can have our own safe strains, but know that they're also resilient when the virus does make its way up the coast.

And that's when one of our, um, one of our big successes this year is we do, um, we have been field testing in an area that has a less virulent strain of the herpes virus. And most of the families that we put out there, we had, I think, a 14 percent survival across all families. But we found two families that had a super high survival, like 70 80 percent survival.

And then afterwards when we, um, genotyped those families and got them sampled for the viral load, all of the other families had that herpes virus that we, that we found in those families, but those two with the best survival rate didn't have any viral load. So that was one of our biggest accomplishments is finding a resilient strain in that area further.

Kevin: Wow. So then when you find a resilient strain like those two, those are the two you're going to focus [00:29:00] on in terms of further development, I guess, right? 

Melissa: For that farm. Yep. 

Kevin: Yeah. Does it vary between farms in the same geographic areas? For example, in the Pacific Northwest, there's a lot of different waters and estuaries and nutrients, but for the most part, it's the same general region.

Do you have different performance standards by the same oysters that you breed in those different areas? 

Melissa: Yeah. So that was, that was the other big accomplishment we had this summer when we field tested at. Four different sites all in Washington state. But yeah, like you said, they all had different, you know, different types of algae, different currents, different temperatures.

And we found that the top five, about the top five families were the top five in all of those sites. So it does seem to be that there are generalist families that. Do better in that area, regardless of the other variables going on in that area. Now, 

Kevin: this work that you're doing at Pacific Hybreed, who are you doing it for?

Are you doing it for [00:30:00] your own oyster operations or for others? What's your plan for that? 

Melissa: Yeah. So the plan is to like enhance, you know, sustainable aquaculture, find a sustainable food source globally. So we're trying to, you know, produce better oysters for. Uh, starting with the Pacific Northwest and the farmers that we know here in the area.

But, yeah, hoping to expand by geography and also by species. So last year we started this breeding program using the same process with Manila clams. And we hope to keep adding new species. Um, we've been starting to work with other universities and governments on different species across the states. 

Kevin: So is the physiology between clams and oysters sufficiently similar that you can kind of do some of the same work with both clams?

Species. 

Melissa: Yeah, as far as, yeah, the concept of Hybreed vigor and using a cross breeding approach, it will translate across species. 

Kevin: Now you mentioned the five species [00:31:00] of oysters in the United States or in the Pacific Northwest. Um, but there are many more species of oysters around the world, I believe. Is that right?

Melissa: Yeah. And that's one reason why we started with the Pacific oyster. Because the Pacific oyster is found on every continent except Antarctica. So it's the number one grown oyster species in the world. So even just using the Pacific oyster, there's tons of room for expansion. 

Kevin: And then hopefully you could take that, the learnings that you get from that and apply it to other species in different parts of the world.

Melissa: Exactly. 

Kevin: And how would that work? Would you sell, , brood stock or seed or something to other oyster farms around the world? 

Melissa: Yeah. So there's a bit of a permitting process involved that we're still getting a hang of the regulations and things that will be required in order for us to ship. seed or brood stock to those other areas.

Kevin: I guess the cross breeding [00:32:00] or biocontamination between different oyster species is a problem. I know that some years ago when there was, a huge mortality experience in the East coast, they considered introducing Pacific oysters to the East coast. And for reasons I don't fully understand, hopefully I'll find somebody who can explain it one day.

It was decided that that wasn't going to happen. It wasn't a good idea because of the cross contamination. Is that something you have to deal with when you're dealing with a specific species and introducing it somewhere else? 

Melissa: Yeah, I think we will definitely stay away from introducing a species where it's not already present.

I think, yeah, there, there's definitely a risk for unintentional consequences and that species could become invasive and then outperform the native species. In that area, which can be problematic. So yeah, we definitely wouldn't be introducing a species to an area where it's not already there. 

Kevin: So if I understand the history of oyster aquaculture or just oysters in [00:33:00] general, at least in the Pacific Northwest, that kind of already happened years and years ago, because originally there was just the Olympia oyster.

And then the Pacific, was it the Pacific oyster that was introduced? 

Yep. 

Kevin: And now I, it's, now it's the big kahuna, so to speak. But Olympias are still growing wild, 

Melissa: yeah, and there's a, um, the Puget Sound Restoration Fund. There's some organizations that are, , trying to help bring, bring back those populations of Olympias.

Kevin: And, um, and then what about the, the various Japanese, strains of oysters like the Kumamoto's and those, , how does that, uh, Impact the work you're doing. 

Melissa: Yeah. So we hope to start crossbreeding those species as well. That's one thing where the triploids can be really important because if you put triploid animals out there for aquaculture, they don't spawn. So they're not going to then start producing populations in the, in the wild or in the environment or crossbreeding with other oyster species or anything like that. 

Kevin: So, triploids would then be [00:34:00] used for oyster aquaculture, where there's actually farming of oysters as opposed to shellfish restoration in the wild or something like that, and that's one way of controlling it by not allowing them to reproduce because they're triploids, you're not going to have that kind of invasion.

I often hear people talking about the negative impacts on shellfish from ocean acidification. And the rising levels of acid , and changes in pH balances in our different seas . Do you deal much with that sort of issue? 

Melissa: Yeah, so that's one, uh, we're working on actually grant research proposals to be able to get more into that. , and we don't have any, you know, results to share from that yet, but it's definitely a big area for research. And something that we look forward to hopefully collaborating on . 

Kevin: What are the principal threats to oysters in the water these days? I mean, you mentioned POMS. What other kind of diseases or threats exist that are really large scale? 

Melissa: I think the big [00:35:00] ones, is temperature, ocean acidification, and disease.

And it's interesting because even in the wild, so oysters are, have a type three, , survival. So less than 1 percent of them are going to survive. So even in the hatchery when, In our laboratory conditions, we make everything as perfect as can be, you know, we purify the water as much as we can, we grow algae, you know, sterilize the algae as much as we can, um, give them all the best flow rates and water conditions as we know, and still it's 2 percent of the fertilized eggs make it through metamorphosis on a good run.

Like a good typical run. And then in the wilds, like you have all these other factors of like larvae dispersing into areas that are uninhabitable. You have predation, you know, starvation if there's a lack of food. So there are chances there are less than one percent. And a lot of that's thought to be due to genetic [00:36:00] inviolability.

Kevin: So you have to produce a hell of a lot of Larvae or little baby oysters just to have a normal average survival rate. Do you ever feel bad when they die? Like, Oh, we just lost a million oysters. Yeah. 

Melissa: It's the worst feeling, especially when you've been putting all your time and effort into growing them every day.

And then, yeah, and then they just die. So, 

Kevin: so I'm trying to picture your facilities in Hawaii, where you do this. Can you describe a little bit about what it's like at Pacific Hybreed? 

Melissa: Yeah. So our goal is. It's to grow a bunch of family lines. So we start all of these single male, female pair matings, and then they each need their own individual tank.

So we have a shipping container that fits 50, 50 liter tanks. And each of those tanks then has an algae line and airline and a, uh, a water line. And then they each have like a banjo [00:37:00] screen on them. So, um, and then every other day we'll siphon out the water in all those tanks and condense them onto, um, a small mesh screen, put them into a little beaker, um, count them, photograph them, put them back.

Um, and so that's, that's the gist of our operations is like growing a lot of different families in a lot of small tanks. And then the other half of it is algae production. So we grow three different types of algae species at every level from a Petri dish to a flask to like a bigger jug and then, um, into bags and tanks.

Kevin: How do you grow algae? I mean, algae, you start out with little individual cells and just develop them. Yeah, 

Melissa: they grow with light. So we'll add the nutrients that they need and then just let them reproduce in the light. 

Kevin: So the algae growth is critical because that's what you're feeding to the, the oysters.

So without the algae, you can't, you [00:38:00] can't do anything, I guess. Right. 

Melissa: Exactly. Yeah. 

Kevin: And does, do you develop your own strains, for algae, or do you modify algae to best benefit the oysters or anything like that? 

Melissa: Yeah, we've tried. Um, not really. We've tried in the past doing different experiments with different algae species and different food concentrations and things like that.

But we're using Pretty much the standard hatchery practices that have been around for decades, , growing the same species. We order fresh stalks from, , a lab in Bigelow about once a year just to, in case, you know, over time some contaminant starts to come into our algae or vibrio or things like that.

So we usually start with fresh stalks at least once a year. I 

Kevin: thought cleaning my goldfish bowl was a lot of work. Uh, you're like Cleaning these 50 liter tanks on a regular basis and carefully preserving everything and then counting them. How do you count them? Is it under a microscope? 

Melissa: Yeah. Yep. So [00:39:00] we'll count them volumetrically. So we'll, we'll put them into a small volume, like let's say a hundred mils of a beaker, and then we'll take out like 30 microliters and count how many are in that 30 microliters and then just multiply it out to get an average of how many would be in the whole hundred mils.

Kevin: So then once you've counted them and you're growing them and they're starting to get a little bit bigger, which is still incredibly tiny, how, how large do you grow them before you send them somewhere else? 

Melissa: Yeah, so we'll grow them, , up until once they get retained on about a 250 micron mesh screen.

You'll start to see, um, they get a little dark eye spot on the shell, and then they'll grow, , a foot. So we'll call them petty villagers at that time, and then that, when that foot starts to come out and, like, crawl around, it's looking for a substrate to set on. , and so then at that point, we'll set them either by adding culture, which are like these really teeny pieces of crushed up [00:40:00] oyster shell, uh, or they also, you can chemically induce them to set with the chemical epinephrine.

Uh, and so once they set or go through metamorphosis at that point, they're sessile. So they stop moving and they look like. The same oyster that you would eat, but only like half a millimeter in shell length. So, , then we usually grow them. Yeah. So we can grow them pretty much to any size. Until the farmers want to buy them. So most farms will start to put the seed out at their farms around three millimeters. 

Kevin: Three millimeters, how would you describe how big three millimeters? 

Melissa: Yeah, I feel like quinoa is actually a common analogy that I've heard. It's like when you pick up, it's like, Oh, they look like little quinoa.

Kevin: So the culture that they attach to must be , just tiny, right? 

Melissa: Yeah, usually about the same size. So the 250 microns is the same size as them at that time. 

Kevin: [00:41:00] And does that give you the ability to have just one oyster attached to one piece of culch? 

Melissa: Yeah, that's the idea. I see. 

Kevin: I guess the purpose of all of this is for growing individual oysters for half shell use or something like that. As opposed to growing reefs of oysters. So yeah, 

Melissa: mostly for the sales. I think the farms would prefer to have singles, 

Kevin: singles. Right. So it's that brief period of time when the tiny baby oyster has a little foot that it's kind of a freewheeling easygoing oyster that's moving around and the rest of its life after that, it's not able to move at all.

What happens to the foot? 

Melissa: , so that's what sends out this elastic kind of thing that gets it to stick on something. 

Kevin: So it's kind of still there holding it there forever. 

Melissa: Yeah, I think. 

Kevin: So when you ship these little tiny baby oysters, how do you ship them? 

Melissa: Yeah. So we'll rinse them, , onto whatever size screen they'll [00:42:00] fit onto.

And then we dip them in a bleach bath for about an hour for at least an hour, , just to kill anything that they have on their shells. And that's what makes them safe then to ship to other areas. And then we'll wrap them up in wet, damp paper towels with ice packs. And just send them off and use priority overnight shipping so that they can get where they need to go as soon as possible.

Um, but yeah, they'll stay out of water for a couple days during that time. 

Kevin: And you ship them back? All over the place at this point, right? 

Melissa: Yeah, we'll ship them. Yeah from Alaska down to Mexico. We've got a current oysters in place along with Hawaii 

Kevin: Do you have any plans other than hopefully adding kumamotos into your work to, , produce this for oysters, like eastern oysters on the east coast of the United States or other places in the world where the species are different?

Melissa: Yeah, we hope to do [00:43:00] that as well. And we're working with some collaborators for the eastern oyster and some other things in the works. 

Kevin: They say, only eat oysters with months that have an R in them. , is that because of the The gamites and the, , the breeding period that you talked about before?

Melissa: Yeah, since they naturally spawn like May through August, the months without the R's, that's when it's more risky to eat them because you could either be getting a mouthful of their gametes, or if they just spawned, then their bodies are going to be really emaciated and not have much mass to them. 

Kevin: So if you get an oyster that's filled with gametes and you get it, you know, in July or something like that, that's gonna, is that gonna be what people often say is kind of a creamy oyster as opposed to, a nice shiny lump of meat? 

Melissa: Yeah, it could be. I think I haven't eaten enough oysters to be to know for sure, but I imagine that could be the case.

Kevin: , okay. Do you like to [00:44:00] eat oysters? 

Melissa: Yeah, I'll eat a few of them. I actually, , my favorite oysters are, , grilled or fried. 

Kevin: That's interesting. Is that just because you feel a little guilty eating the live guys, , since you've worked so hard to help them thrive? 

Melissa: What 

Kevin: kind of expansion plans do you have in terms of growth?

Is is the company's plan to be the number one leader , of oyster seed around the world? Or what's your kind of long term goal? 

Melissa: Yeah, that's the goal. , and it takes like through our breeding program, it takes us four generations to get to our final, superior product. So we're not yet market ready.

We're just testing different hybrids, doing more on the research side of things and figuring out, what the best combos for cross breeding will be and how that differs in different areas. 

But 

Melissa: starting next year is when we'll be able to really. , crank out the better performing hybrids. So we hope to continue growing from there.

Kevin: That's cool. So how long is a [00:45:00] generation?

Melissa: it depends on a lot of factors and obviously the species too. For the Pacific oysters, , it can be anywhere from one to three years. For us, it's been, yeah, about a year and a half. 

Kevin: So, does that mean to say that you will actually hold on to some of your oysters until they're fully grown, full adult oysters, to monitor their performance all the way through their life cycle?

Yeah, absolutely. 

Melissa: Yep. . So yeah, we definitely want to get their performance data on first summer and second summer. And, actually, so the hybrids that we're using now were produced back in, 2015. Really? So oysters will live, 25 or more years. So, , , we can keep respawning the same ones year after year. So we hope to have a genetic repository of all our different genetic lines. So we'll definitely need to, find a big place to keep all those lines going as we continue. 

Kevin: Right now you kind of have like a little oyster zoo going on [00:46:00] there, it sounds like.

Melissa: Yep. 

Kevin: And how big, how big is your facility in Hawaii? 

Melissa: So we have three shipping containers. , and then we've got. land space with, uh, with a bunch of large tanks for algae growing. So it's about 5, 000 square feet, so it's quite small. Um, we have room to grow, but that's the other part of our breeding program is like right now there's still so much uncertainty as far as what causes variability and growth.

So we'll start 50 different genetic families at the same time from broodstock that grew up in the same conditions. Keep the families all the same with the same food, same temperature, same flow rates, same number of larvae per tank. And some families grow really fast and some families grow really slow.

And some have really high survival and some completely die off. So once we figure out the reasoning behind that, um, and we learn what factors to look for, we can really make our [00:47:00] program more efficient and not have to waste time growing all these families Just to learn that they're not good performers

Kevin: you hear about with some mammals , that too much inbreeding within the same family can be a negative thing for the overall population of the animal. Is that something that is an issue with oysters or other shellfish? 

Melissa: Yeah, that's a huge issue. Um, and that's, yeah, it actually can happen really quickly with oysters too. We've done some work that's shown that inbreeding depression can be seen after just the first generation of mating siblings together.

And I think that's why a lot of, farms or hatcheries that do selective breeding, if they choose the two biggest and best oysters, their offspring can actually be really horrible because if those two adults were Related to each other then you can start to get that inbreeding depression And since we know that only one percent of oysters survive in the wild like they are very likely to be related to [00:48:00] each other so that's something that we're definitely cognizant of and Our program actually inbreeds them for one generation before we crossbreed them As part of the process of hybrid vigor.

Kevin: What are the biggest challenges that you guys are facing right now at Pacific Hybreed and how are you dealing with them? 

Melissa: Yeah, a huge challenge for us, has been water quality issues. and it's caused a lot of larval mortality for us. Actually, in our facility in Washington, um, they started having water quality issues a couple years ago and found that it was due to the pipelines.

So now, for our larval runs there, um, they have a truck with a water trailer and go down to the dock, fill up water off the dock, and use that water, and it grows really well for larvae. And then last year, Kona started having water quality issues. and we tried the same [00:49:00] thing, you know, just using water straight from the ocean, but unfortunately, That hasn't worked for us in Kona, so we're still working through a lot of different water treatments, taking measurements, um, sending a bunch of samples off to different places to test for different things and trying to figure out what the problem is.

Kevin: So if you're not getting water from the ocean and using that, what do you start with? I guess it needs to be completely sterile, no, you know, chemicals or anything in it. You can't just get it out of the sink, right? 

Melissa: Right. Yeah. So it usually gets pumped from the ocean and it goes through a series of sand filters and then cartridge filters and sock filters.

So ultimately we filter, for the larval stage when they're more vulnerable and susceptible to different things. all the seawater goes through a filter of 0. 

35 

Melissa: microns and it gets UV treated. and that's sort of standard hatchery practice to do that. Um, and then we [00:50:00] also put it through, charcoal, activated carbon filter.

And, we add different additives like EDTA and, calcium carbonate just give them everything that they should need to grow and try and take out everything that's not good for them. 

Kevin: The more you tell me, the more, um, complex. I see what you're doing is because you're not just doing the research and the development with the oysters. You're also in the algae and food production business and also in the water conditioning business before you even get started with the actual purpose of being there, which is the oysters themselves. Are you only doing this work in Hawaii or are you also doing anything in the Pacific Northwest?

Melissa: We also have a hatchery site at the NOAA facility in Manchester, Washington. So right now that's our productive site where all the breeding work is actually being done as well. 

Kevin: How many people do you have in Hawaii [00:51:00] working on all of this? 

Melissa: Just two of us right now. 

Kevin: Just two of you? You can't, just two of you are doing all of 

Melissa: that?

So we've gone through a lot of struggles. You know, we've had a lot of challenges in the last year. So our staff has been, Climbing up and down. So it's a little bit unfortunate right now, since the water's not working for us. 

it's been one of our big challenges. 

Kevin: It must be difficult because you can't just get anybody off the street who's interested in oysters. You need somebody who really has the kind of background in education, genetics, and that sort of thing. do you. much with other universities or institutions to try and find people who can help you? 

Melissa: Yeah, definitely. There's a lot of initiatives in Hawaii and getting people interested in aquaculture.

I 

Kevin: would imagine that the Hawaii connection might be appealing to some people as well. If they have the background and it's like, Hmm, and Hawaii, I could do that for a while. But like any job, there's Certain aspects of it, which suck. So what's, what [00:52:00] sucks in your work? What's, what's the thing you like least about what?

Melissa: Yeah. So one of the hardest things I think is how you can't schedule it. So it's like the animals are ruling the schedule, so you can't really plan, things outside of work or when you have larvae going, it's like they need to be fed and cared for every day. So it doesn't matter if it's a weekend or a holiday.

Um, you can try to like. Spawn them on a certain day to get them through metamorphosis at a certain time, but then despite your conditioning It's like they just decide not to spawn or they have some prolonged larval phase And they're not ready to move to the next stage when they should be So that's one thing 

Kevin: those pesky kids 

Melissa: And then you put your best effort into like caring for them, making sure everything's perfect.

You know, you spend all of these hours every day and then you come in and they just died overnight. And so it's like, oh, all that wasted time and effort, like doing all the work [00:53:00] for that many days just to have them die. 

Kevin: I can't imagine the feeling that you must have when you walk in there. How do you know when they're dead?

Melissa: So you very much obviously know when they're dead when they have an empty shell. So usually when you like, but you have to look at them under the microscope scope first. So like while you're draining the tank and you see them collecting on the screen, you're like, oh yeah, they're good. But then when you actually look, like take a sample and look at them under the microscope, um, you'll see like just clear transparent shells and you'll know that they're, that they're dead.

But sometimes it's slower than that. It's like they'll just stop eating or stop growing and they'll die slowly over time. Um, And like, you want to be hopeful. You're like, Oh, it's still got some color to it. Like the lighting's just wrong, but then you realize they're, they're dead. 

Kevin: So if you see some that are not doing well and they're still alive, but they're suffering, is there anything you can do? Do you add more food or what do you do to try and keep them going? [00:54:00] 

Melissa: Yeah. Yep. So that's exactly. So we'll try and like, um, just spray filter out or like every once in a while you'll get some, some things growing in the tanks that aren't the algae or like you'll get little ciliates or things. And those you can try to like spray them out.

The other thing is like once a few oysters die, that then create like a breeding ground for more bacteria and other things to start to flourish. Okay. So, like, just taking care of, like, when you start to see some that are dead, you try to screen out that population and maybe only keep the biggest ones of that family so that you're sure, like, those big ones are nice and healthy and they'll keep growing and you don't want to keep those smaller dead ones mixed in because then they'll just create bad water for the rest of the tank.

Kevin: So when you look under the microscope after walking in in that morning when you think they're all doing great, and then you see the empty shells, then you have to try and figure out how to [00:55:00] separate the good from the bad. And that's done through screening just based on size primarily?

Melissa: Yep, usually that's the best approach, yeah. I 

Kevin: can understand why that would be a hard part of the job and probably very demoralizing as well after all your work. What's, what's brings you the most joy or sense of satisfaction in doing what you do? 

Melissa: favorite thing about the work is the mission is like coming from studying, you know, specific physiological responses or molecular pathways for the sake of discovering new things about developmental biology was interesting. But what I really love now is like working for a company that's using that information to apply it. To, a bigger, uh, mission like, you know, solving world hunger and food security and resilience to climate change and, like, important problems that people can't walk away from. And my other favorite thing about the work is the team that we have.

Um, we're just a small adaptable team [00:56:00] and things have rarely gone according to plan for us. Um, but everyone always just finds a way to be resourceful and get things done. Um, like whether it's the animals or the water or the plumbing or the equipment, something's always going wrong. And I feel our team just really doesn't let it faze them and just keeps going.

Comes up with implementing some solution that gets us by and keeps the program going forward. So that's really, really fun to be part of. So 

Kevin: in addition to the two of you in Hawaii, you have more people back in the Pacific Northwest. How many people do you have there? Yeah, 

Melissa: so there's two people in Washington that run the hatchery there.

And then also, Francis Phan, who's our geneticist, he's based in Los Angeles. And he's, our chief science officer. Does all of our grant applications and studies and all of that as well. 

Kevin: Right, because in addition to doing your daily work like you've described it, as the CEO of this business, you're also handling, I [00:57:00] assume, the business side of things and funding and grant applications and that sort of thing. 

Do you ever get the opportunity to enjoy, swimming in the ocean in Hawaii and getting out there and enjoying the beauty of that place? 

Melissa: Yeah, I think that's why I love living in Hawaii is because you're right there on the ocean all the time. Also, like, I, yeah, so I wake up, you know, by 5 a. m. every morning to do an hour or two of something fun before work and still start the day. Start the day and have a full day because we're right here on the ocean It's so easy to go fishing for an hour go snorkeling for an hour And it doesn't eat into your workday, 

Kevin: so a day in the life for you as you get up at 5 you do some some me time things and then you head Into the office, which is basically where the containers are,And then Once you get there, what do you do? 

Melissa: Yeah, it's a mix of a bit of everything. 

and it depends on the season [00:58:00] and the week and the day even. So some days are more focused on the hatchery work and growing the algae. And if we have animals going, doing all that larval maintenance, but then yeah, there's of course like our fundraising, our accounting and financing and working on grant proposals and analyzing data from our field trials.

It's always different 

Kevin: when I think of oyster farming. You know, getting on the skiff, going out, getting muddy, getting wet, flipping cages, that sort of thing. But you're on the front end of all of this. I mean, it's all starting with you and the work you and Pacific Hybreed are doing. That's kind of the, the very beginning of the whole story, 

 Andjust from hearing the little that you've told us the devil is in the details and the science behind It is extraordinary. So thank you so much for joining me and Keep growing oyster babies

Well, that's it for this [00:59:00] episode of OYSTER-ology. Thanks to my guest, Dr. Melissa Delatorre. As always shownotes can be found on this episode's page. And if you enjoyed it, please rate or review it on whatever podcast platform you listen on. I'm your host, Kevin Cox. Join me next week. When we pry open the shell of another interesting OYSTER-ology topic.