Dying Coral

Thanks to everyone that has supported my coral rehabilitation efforts along the way! It has been an amazing journey – culminating in presenting at MACNA 2022! When I was asked to speak, I reflected on the last few years, where we were unable to meet in most capacities.  The theme for MACNA 2022:  Gathering and Growing, highlights the path forward for us as a community, but we need to translate that vision for gathering and growing corals as well.  This presentation focuses on what is preventing that growth and how to move forward.

Synopsis:  These are not your average, ordinary, everyday reefkeeping problems.  These corals are dying – for a reason.  Learn systematic troubleshooting techniques, unusual parasite identification, and potential treatment options through short case studies and copious photographs, all presented through the holistic lens of systems engineering.  Join us as we delve into rehabilitating corals, one polyp at a time.

Rough Transcript

This rough transcript is not exact, and it is still in work. Thanks for your patience while I add everything in.

Slide 1:

Good morning!  Before we get started, I’d like to thank all of the leadership, volunteers, sponsors, vendors, the other speakers, our hosts here at the convention center and partnering hotels, and of course, all of our attendees!  You all have truly pulled a remarkable event together. 

And, once I saw the event schedule, I got excited.  8am on a Saturday morning after a great reception?!  I knew I was going to have *the most* hardcore group of reefkeepers at MACNA!

As the slide says, I’m Nikki Bridges, and you can typically find me as “Reef’d Up” on various forums.  When I was asked to speak, I reflected on the last few years, where we were unable to meet in most capacities.  The theme for MACNA 2022:  Gathering and Growing highlights the path forward for us as a community, but we need to translate that vision for gathering and growing corals as well.  This presentation focuses on what is preventing that growth and how to move forward.

To help wake you all up a bit – I have a question.  Just raise your hands – don’t be shy.  Who has watched a coral die, despite all attempts to save it?  This presentation on coral triage and rehabilitation covers my approach.

Slide 2

As most of us are well aware, reef degradation is ongoing globally.  While our knowledge is rapidly increasing, it may not be sufficiently rapid.  Over the last forty years, there has only been an average of one coral disease described per year, and there are substantial gaps in the applicability of this research of native habitats to that of what we find in our aquariums.  These native habitats are complex systems that we try to replicate at home, which can help or hinder our success.  Aquarists have come up with some incredibly innovative treatments for various parasites, algae, and sick fish, but much of that information is insufficient for the scientific community – nor is it readily scalable.  As a hobby, we can help ourselves and the broader scientific community by progressing toward evidence-based modern medicine.

Slide 3

This presentation is based on well over 250 successful rehabilitations – these are just a sample of the before and after photos.  My rehabilitations have ranged from fish to corals to anemones to other invertebrates, but my specialty and the focus of this presentation is on coral rehabilitation.

Slide 4

We’ll walk through the most critical aspect, in my opinion, of rehabilitating corals in aquaria, some unique challenges, some pests and parasites that may be a bit uncommon, along with various diseases and syndromes I’ve encountered along the way.

Slide 5

Slide 6

For those of you that don’t know me, I’m an engineer by trade, and aquariums are my hobby.  I’m a military spouse and mom to two awesome kids (that you’ve probably already heard by now).  And for those of you that have had enough coffee and put it all together – you’re right – we move frequently, which means my aquariums do too.  In my infinite free time, I also scuba dive and love to volunteer with reef clean-ups and restoration. That being said, I’m not a photographer, doctor, vet, or really anyone qualified to give opinions.  This is just what has worked for me or what I’ve noticed.

Slide 7

After I put this presentation together, I realized I’m actually a daughter and grand-daughter of wildlife rehabilitators.  I grew up with all sorts of “normal” and not-so-normal pets, including a fox!  We always had aquariums too, so when I went off to college, I was thrilled when I found a “free” tank.  The expensive part was over!  HA!

Slide 8

After that, it was all history – so I have to thank my family for supporting my tinkering.  This was one of my old rescuing systems.  Unfortunately, being based in the Washington, DC area doesn’t allow such large working spaces.

Slide 9

So, while I may not have a medical background, I believe I can still contribute to the greater knowledge by my systems engineering approach, which anecdotally appears to work.  Just like in my professional life, corals live in a complex environment, where all of the interacting parts affect each other in novel ways.  We need to look at the biology, chemistry, and mechanical underpinnings of the systems to see the big picture.  Systems engineering brings the thought-processes to connect the pieces of the system throughout the life-cycle, across various biological functions, anatomical structure, and behavior.  With that interconnected knowledge, we can use tools to identify patterns, model to predict outcomes, determine how things went wrong and why.

Slide 10

As we go through this thought process, we have to start with assumptions.  Down in the corner is a Venn-Diagram (don’t worry, we’re going to start nice and easy with this 8am presentation).  Many problems in aquaria are multifactorial – something hosts an agent, but the environment has to also be conducive for the problem to manifest.  When a coral is dying, the environment is often the easiest to begin to control.  That’s where I start.  I remove the dying coral from its previous habitat and place it in an aquarium that I know is as ideal as possible.  From there, I work to minimize the host and agent interactions, thus minimizing this central area for issues to continue.

Slide 11

Slide 12

Whenever I can, I go searching for all corals that I can possibly help save.  Typically, I bring home a box of 10 to 20, all in various stages of dying.  Over the years, what I found is that categorizing them can have profound effects on their outcome.

Slide 13

Ultimately, I need to create a usable “diagnosis” – what is causing the coral to decline?  Typically, in industry, I see the “Root Cause Diagram” with a tree, but to me, this alga is more akin to how we need to think about coral health issues.  The signs are what we can physically observe at a surface level.  Tracing back the signs can help identify the problems, and at the root of problems may be one or more causes.

Slide 14

At the hobbyist level, with a batch of declining coral, I use signs to determine what I need to do.  This eye chart has worked for me, time and time again.  I start at the top, in the terminal range.  Corals here, in my experience, have essentially no chance at survival.  If the coral is not in that category, I move down to the Emergent category.  Corals with these signs need immediate, all-encompassing care to survive.  If the coral is not in that category, I move down to the urgent category.  Signs in this category mean that I need to move fast and provide a lot of resources, but the outcome is promising.  The last category is just the routine category, which is the easiest category to manage. 

Slide 15

Going back to the top of the flowchart is the Terminal section.  First, I look for tissue – I know, to some of you, that sounds like an insane first step.  But, sometimes, there is nothing left of the coral by the time I get home.  Next, I look for signs of fluorescence, and of course, the amount expected varies by coral species.  These corals were subjects of a literal bleach bath caused by an angry customer at a local fish store.  Unfortunately, these did not recover.  Next, I hope for more than 50% of a mouth.  This, too, varies by species and comorbidities.  If it had more than 50% of its mouth, I would look to see if the mouth was gaping, like shown in this coral.  And, finally, if the mouth is gaping, I look to see if there are mesenterial filaments present.  If the coral reaches this point in the diagram, I have never seen it recover.  I consider these terminal cases, where I should minimize my resources.  But, if the coral’s signs lead us away from a terminal case, we must next consider it as an emergent case.

Slide 16

Here, I consider if the coral has been exposed to improper chemicals, like in this case.  If not, then I worry about bare skeleton cases, but more on that in just a moment.  If the skeleton is not visible or is mostly ok, I look for any signs of a brown jelly substance, like in this bottom photo.  Going back to the visible skeleton, I worry less if the skeleton is covered in algae as that means the coral has been declining for some time.  If the damage looks new, I need to classify the signs by tissue loss speed and skeletal color:  is it green, white, or pink (and by pink, I don’t mean coralline algae).  These are all cases that I identify as Emergent – they need fast care with extensive treatment.  All of these corals, except the last, made a full recovery.

Slide 17

As an example, this Homophyllia coral did not meet the signs for the Terminal category, and to my knowledge was not exposed to improper chemicals.  However, its skeleton was showing with no signs of coralline or other macroalgae, and it looked like concrete.  The coloration was light green, which meant this was an Emergent case.  I trimmed the skeleton, removed obviously rotting tissue, dipped it according to my protocol (more on that in a moment), and used veterinary-grade tissue glue to help reattach the remaining healthy tissue to the skeleton.  Over the next 30-days, I monitored the coral daily in quarantine.  At that time, I determined the coral was on its way to recovery.  I trimmed the remaining skeleton, performed my dip routine again, and moved the coral to the grow-out phase.  The coral spent the next 30-days growing out before receiving its final set of dips, fragging, and then move to new homes.

Slide 18

If the coral has signs inconsistent with Terminal and Emergent, I move on to consider the Urgent category.  This area has challenging signs, but many of these signs also indicate that there is ample time available for treatment.  For instance, coral bleaching is a serious concern, but many corals can live for extensive periods – up to weeks – in this state.  If the coral isn’t bleached, I look at signs in the tissue for treatment clues.  Is the tissue clinging?  Is the coral’s mouth unresponsive?  If there’s slow tissue loss, is there a sign of pests or parasites?  Or, is there a sign of infection in the coral that doesn’t meet the signs of an emergent category?  If so, these signs warrant urgent treatment.  Note, that all of these corals survived, and I have all of them except the last, currently in my tank.  Let’s take a closer look at this coral, which I’ve had going on 12 years now, as an example.

Slide 19

The overall process for Urgent is similar to Emergent.  Here, the tissue had fair coloration, but the tissue was clinging to the skeleton.  Once again, I trimmed the skeleton, used my dip procedure, monitored for 30-days, grew-out for 30-days, then moved it into its permanent home.  The difference is in the details – the time to treat, dip procedure, and monitoring process were all less intensive in this Urgent case.

Slide 20

The last category is the Routine category.  Unfortunately, corals that look like this are typically destined for the live rock bin; however, these are some of the easiest corals to treat, in my opinion.  Mild bleaching, poor fragging, mild recession, coralline-covered skeletons, browning, a lack of polyp extension, slow tissue recession, and burnt tips are all signs that indicate the coral has a good chance of recovery in the proper environment.  Once again, all of these corals survived.

Slide 21

Now that we’re in the Routine category, we can go into more details with the basics of my process.  This coral had browning and mild recession with a coralline-covered skeleton.  Easy, right?  I started off with a more in-depth inspection, with both white light and UV light.  This helps me search for any evidence of pests and further assess the fluorescence health of the coral.  Next, I magnify my view, typically with a camera so I can thoroughly inspect the coral over time – preferably in a comfy chair!

Slide 22

Next, I remove as much excess skeleton or other substrate as possible to open up the skeleton for treatment, remove hidden pests and eggs, and allow the tissue to regrow more easily.  Of course, this all depends on the coral species – I do not perform this step on Fungia corals as a rule.  Typically I use my band saw and heavy duty toenail cutters.  I know some of you use bone cutters, but typically those are too large for my hands. Adapt and overcome!

Slide 23

At this point, it’s time for dipping.  I have a partially 3D-printed dip stirrer tank, and if you’re interested in making your own, you can find instructions on my website.  This stirrer helps get the treatment throughout the coral more gently and steadily than using a pipette, in my opinion.  Plus, it has a removable rack so that I minimize my own interaction with the dip solution.

Slide 24

For the most routine-of-routine cases, I use a three-dip process.  However, this process varies widely by coral species, signs, and triage category.  Typically I start with a hydrogen peroxide and tank water dip, and you can see the Pectinia coral in that dip here.  I then follow that dip by another that is specific to whatever I notice is going on.  Last, the Pectinia went into a CoralRx dip, used according to manufacturer instructions.

Slide 25

Initially, I thought the coral was declining due to poor water quality; however, during my daily monitoring sessions while the coral was in quarantine, I noticed something else was going on.  My triple dip process had failed.  I then had to re-evaluate the coral’s triage category and treatment plan.  It appeared that these pods – probably Ostracods – were possibly irritating the coral and causing it to decline in health.  Typically Ostracods are harmless, but this was definitely suspicious.  Without a better plan at the time, I decided to use a treatment plan to break the lifecycle over a series of dips.

Slide 26

Yes, this process was stressful to the coral, and initially, it looked terrible.  However, it was successful and necessary to properly treat the coral.  Once it was healthy and passed all quarantine inspections, it went to its permanent home.

Slide 27

Slide 28

As I’ve briefly mentioned, there are a lot of challenges to helping corals recover.  Corals are dying for a *reason,* and I have to ensure I take into consideration all factors – especially my personal safety.  The decaying tissue can wreak havoc with an aquarium, from both a nutrient and coral warfare perspective, which can increase the risk to other tank inhabitants.  Some tank inhabitants may try to clean up the decaying tissue, only to exacerbate the situation.  Some creatures try to have one last hurrah with a reproduction event – which can also affect the aquarium’s biological filter.  Sanitization and ensuring I had plenty of the proper treatments available was especially challenging during the pandemic, and it still isn’t easy on a good day!  Then, there are long-term growth issues; many of these corals can take years to finally achieve typical growth rates after a degraded period.

Slide 29

Going back to personal safety for a moment – I always try to avoid dying corals that I am unable to safety accommodate, especially if I have any open cuts on my hands.  I always wear my personal protective equipment, including this 3D-printed face shield that I made during COVID.  If you’re interested in making your own, the instructions are on my site.  Bottom line – this is a risky endeavor, so all precautions are required.

Slide 30

In addition to all the logistics and safety challenges, there are also substantial ethical considerations for my efforts.  Of course, the owner of a dying coral won’t want to take a loss, so the owner sells the coral.  If it’s purchased, then that reinforces the idea that severely damaged corals are acceptable, which in turn could incentivize substandard coral quality.  Additionally, I have to worry that this sort of presentation could inappropriately increase hobbyist confidence in their abilities to rehabilitate a damaged coral. 

Of course, a dying coral could potentially spread the problem to other corals, and this threatening situation has to be mitigated through multiple levels of quarantine, segregated tools, and prioritized cleanliness.

Similar to purchasing dying coral is the idea of flipping dying corals for a profit.  A hobbyist buys a discounted coral, gets it healthy, then resells it for a gain.  But, corals aren’t houses; they are living creatures that need proper care.  Profit optimization undermines that care.  My husband can definitely tell you that there isn’t a profit if the corals are getting the care they need.

Then, there’s the more philosophical consideration of having to determine what lives and dies.  I can tell you right now that if I had a choice between rescuing a crashing 75-gallon tank full of Xenia or taking in a single dying Scolymia, I’ll choose the Scolymia every time (and that’s not far from a hypothetical situation – I had a very similar situation once).  I have limited resources, so I do have to prioritize care.

Bottom line, please take away from this presentation that coral rehabilitation is for researching problems and saving corals.

Slide 31

Slide 32

Most of you are probably familiar with Acropora-Eating Flatworms, but I thought I’d share some other interesting worms and flukes I’ve found over the years.  If you’ll recall my intake procedure, where I mentioned using white light and UV or actinic, you can see the importance of that process here.  On your left, is an LPS flatworm under actinics, where it is mostly camouflaged.  On the right, the coral is under white light, where the flatworm is much more contrasted with the coral.

Slide 33

Once again, red bugs are fairly common, but I’ve also dealt with various spiders and gray bugs as well. 

Slide 34

Of course, I’ve found my fair share of various nuisance crabs. 

Slide 35

Then, there are various predatory nudibranchs.  Thankfully I don’t see these often.  I lumped the pyramid snails in here, as I’ve even taken in various invertebrates.  These are quite a pain to address, especially if you have small snails, as I found them even on Collonista and Stomatella snails.

Slide 36

So, as a hobbyist with limited samples, I model.  I modeled the life cycles of Acro-eating flatworms, red bugs, and Montipora-eating Nudibranchs.  I also attempted to model various coral growth rates so as to see how the food source would affect the pest population.  And then, I added various treatments that could be switched on and off.  Systems engineering can help fill the gaps.

Slide 37

Although I may be able to model pest interactions, I haven’t figured out how to handle boring sponges.  Thankfully, I rarely encounter these in my rescuing, but I have been unable to find sufficient information on treatment.  Here, in the top right, you can see these orange sponges growing up and out of a coral in the wild.  For those of you unfamiliar, these boring sponges essentially dissolve the host coral’s skeleton out from underneath it.  I took in a hammer coral that wasn’t doing well, and I found this spongy orangish mass inside the skeleton.  Here, on the left, you can see that the sponge has dissolved the coral’s skeleton, just leaving tiny pieces in the matrix.  Once I realized what was going on, I took a slice from the coral’s skeleton, along with a slice from a previously healthy hammer coral.  On the left, you can see the sponge has fully engulfed the skeleton.  Then, I bleached the piece so that I could see what was left, and a substantial portion of the skeleton was gone.  More interesting to me were the tunnels that the sponge had bored – you can see these in the center photos.

Slide 38

Slide 39

Moving into the diseases and syndromes section, you can see some of the corals I’ve brought back to full health that might’ve had bacterial-related bleaching.  Whenever I see corals that have this blotchy, uneven bleaching, I begin to suspect it is bacteria-related.  As I’ve mentioned, a lot of the problems we face in this hobby are multifactorial, so sometimes just moving the coral to a new environment may help.  With Vibrio, in particular, there are quite a few studies that suggest it becomes more of a problem with high nutrients and higher temperatures.  So, what could help these types of corals in the hobby?  We need ways at the hobbyist level to confirm the cause and be able to treat – with responsible antibiotic use, if necessary.

Slide 40

Similarly, Brown Jelly is potentially multifactorial.  I’ve personally dealt with it dozens of times, and it anecdotally seems to appear more often with higher temperatures and nutrient levels.  And, each time, there are large masses of ciliates.  Add in bacteria with some sort of relationship to the other factors, and this brown gelatinous mass appears, quickly leaving behind a bare, white coral skeleton. As far as I’m aware, Cipro is one of the most widely used antibiotics for this syndrome; however, I am concerned with the hobby creating antibiotic-resistant strains of bacteria.  We need more options and a better understanding of the cause.

Slide 41

While I’ve successfully dealt with brown jelly and bleached corals, my success rate falls dramatically over the next few slides.  I frequently encounter this pink skeletal staining in dying corals, and more often than not, I am unable to save the coral.  This staining is not coralline; it appears to be caused by the coral itself, possibly as part of a defense mechanism.  The causality and treatments are major gaps for me.

Slide 42

Although I’ve covered bleaching, I personally consider Trachyphyllia bleaching to be something else.  Compared to the previous bleached examples, typically I see Trachyphyllia retain their fluorescent pigments longer.  I’ve never managed to save one of these, so I would like to understand the causality.  I do wonder if the corals are executing a type of programmed cell death in response to a stressor, which just runs out of control and results in the entire coral’s death.  Again, I would love to see more information on this.

Slide 43

“Elegance Coral Syndrome” might be a bit more familiar, as it has been known in the hobby for decades.  While I’ve saved a few Elegance corals, I was unable to save this one despite a variety of attempted treatments. 

Slide 44

This is a problem I frequently encounter, and yet I have found no information on what could be occurring or what to do.  Certain bleached corals regain coloration in my care, but they turn a dull grayish blue.  Then, they slowly die.  I even saw something similar out in the Florida Keys while diving; the coral had bleached, recovered to a bluish gray hue, and then was starting to recede.  My only guess is that the zooxanthellae to repopulate the coral were unsuitable for sustaining the corals needs, so the corals eventually starved.  I still have this bottom coral, and it has lasted longer than most with regular feedings.

Slide 45

So, in conclusion, we can all make a difference with whatever backgrounds we have.  We all bring unique perspectives and experience to better our hobby.

Slide 46

Since death is a process, a systems engineering approach is uniquely situated to handle interventions through root cause identification, correlation of signs to usable diagnoses, and development of a systems-view of health and well-being.  As each hobbyist can contribute to the overall knowledge, systems engineering can help crowd-source that information and utilize tools to pull it all together.  With this sort of effort, we can develop better protocols for treating unhealthy corals and help transfer that information to efforts on the reefs.  As hobbyists, we can reduce our losses and contribute to the broader scientific community.

Thank you all for coming and sitting through a nerdy presentation at 8am on a Saturday morning.  We are short on time, so if you have in-depth questions that might lead to a longer discussion, let’s take those offline.  Are there any other questions?