Rich Ross

Eight is a lot of legs, David

Skeptical Reefkeeping 11- Ethics of Animal Selection

In our hobby, there tends to be mostly a super market approach to purchasing animals – you go to a store and select the animal you want from an array of holding tanks containing animals waiting for a new home. While such a selection seems great, it also creates an environment that may engender impulse buys rather than considered choices, makes us feel that instant gratification is the norm, as well as making us feel that somehow, for various reasons, any animal is worth a try in any tank. As people who say we love the reefs, and the animals that live on them, perhaps we should spend more time considering, and getting others to consider, which animals are appropriate for which tanks and which reefers. In Skeptical Reefkeeping 7 we took a general look at ethics and how they relate to our hobby. In this installment, we’ll look at some of the “how”s and “why”s we choose animals for our tanks, why we might think all aquarists are on the same page, and some ideas about how we might make more informed choices regarding the creatures that we put in our glass boxes.
New fish are always exciting, but are more exciting when forethought is put into the fish before purchase. Photo of a recent shipment from Live Aquaria by Rich Ross.
A Brief Reminder to Set the Scene

Skepticism is a method, not a position. It can be defined as a method of intellectual caution and suspended judgment. As a Skeptical Reefkeeper, you decide what is best for you, your animals, and your wallet based upon critical thinking, not just because you heard someone else say it. The goal of this series of articles is not to provide you with reef recipes or to tell you which ideas are flat out wrong or which products really do what they say they do or which claims or which expert to believe. The goal is to help you make those kinds of determinations for yourself while developing your saltwater expertise in the face of sometimes overwhelming, conflicting advice.

Who Should Get What, When? Everyone seems to agree that a brand new hobbyist shouldn’t purchase deep water fish, cephalopods, or non photosynthetic corals for their first tank, or that someone with a 50 gallon tank shouldn’t get a Blacktip reef shark, Giant Pacific Octopus or a Goliath Grouper. Besides obvious examples like those above (1), there is a huge grey area around what animals keepers should purchase and in which conditions it is appropriate to keep them in. Is it ok to keep a small tang in a small tank with the intention to transfer it to a larger tank when it gets bigger? How many fish is too many fish for a certain sized tank? No one has ever seen this fish before I better buy it before anyone else does! This situation is further complicated by the idea that there is a steep learning curve to keeping animals in glass boxes during that learning curve mistakes are made, and animals are lost. As a keeper’s experience goes up, they often start trying to keep more and more ”difficult” animals, and still there is a learning curve, and animals are lost – even to the best aquarist on the planet with the most resources. How do we cope with that idea?
(more…)

Why Point-of-Origin Matters

By Rich Ross and Ret Talbot
From Reefs Magazine

Most marine aquarium hobbyists purchase animals for their tanks without much thought to those animals’ origins. This is understandable since most local fish stores and online retailers don’t make that kind of information easily available to customers. Point-of-origin does matter, however, because not all animals are collected sustainably and not all fishers are treated equitably.

Local divers in Solomon Islands harvest aquarium fishes and corals in what is generally considered a sustainable fishery. In part, sustainability is insured through limited cargo space for exports and long-standing traditions of resource ownership/rights. Photo by Ret Talbot.
 

The marine aquarium hobby and its practices are increasingly scrutinized by anti-aquarium trade activists and environmental advocacy groups, wildlife managers concerned about invasive species introductions and legislators interested in pleasing constituents. A sustainable and equitable trade is a defensible trade; the status quo is not. More important than defense, however, we argue that purchasers of wild animals have a responsibility to know where their animals originate, how they are collected and handled, and what the trade’s effects are on reefs and reef-side communities. It seems that aquarists have a responsibility to treat the animals collected from the wild as the precious commodities they are instead of curios traded for pennies on the dollar.

If you know where your animals originate, you often have a better idea of howthey were collected and treated through the chain of custody. This should be important to every aquarist because a poorly treated animal is less likely to live or thrive. 

(more…)

Skeptical Reefkeeping 10 – The Power of Anecdote

From ReefsMagazine

by Richard Ross

In the last nine installments of Skeptical Reefkeeping we have looked at varied topics from phosphate to marketing to fallacious lines of reasoning to communication. One of the through lines all along has been the idea of anecdote, and generally, why it isn’t to be trusted. In this installment of Skeptical Reefkeeping, we are going to take another look at anecdote, try to understand why we are dependent upon anecdote in our hobby, and discuss some of its power and how to make it more useful. 

A Brief Reminder to Set the Scene

Skepticism is a method, not a position. It can be defined as a method of intellectual caution and suspended judgment. As a Skeptical Reefkeeper, you decide what is best for you, your animals, and your wallet based upon critical thinking, not just because you heard someone else say it. The goal of this series of articles is not to provide you with reef recipes or to tell you which ideas are flat out wrong or which products really do what they say they do or which claims or which expert to believe. The goal is to help you make those kinds of determinations for yourself while developing your saltwater expertise in the face of sometimes overwhelming, conflicting advice.

These two Dr. Seuss fish have not yet jumped out of their tank, but that doesn’t seem like a reason to jump to the conclusion that these fish aren’t jumpers.

These two Dr. Seuss fish have not yet jumped out of their tank, but that doesn’t seem like a reason to jump to the conclusion that these fish aren’t jumpers.


What is Anecdote Anyway?

From Skeptical Reefkeeping – Are you sure that that thing is true, or did someone just tell it to you? (1) Merriam-Webster defines anecdote as “a usually short narrative of an interesting, amusing, or biographical incident.” More hardcore, Ron Shimek says, “Anecdote is unsubstantiated or unverified observation generally made by an unqualified observer who often really doesn’t know what they are looking at.” Essentially, an anecdote is someone telling you what they think happened. The problem with most anecdotes, besides the observation and conclusion being suspect, is how quickly, with no real support, they can be converted to facts. This conversion can have a real and detrimental cost in both animal’s lives and your money.

(more…)

Skeptical Reefkeeping 9: Test Kits, Chasing Numbers and Phosphate

From Reefs Magazine

by Rich Ross and Chris Jury

The Editors Note: In Skeptical Reefkeeping IX, Rich Ross is joined by our old friend Chris Jury as they try to come to terms with the “impossible” yet confirmed PO4 readings in Rich’s gorgeous reef. The analysis is thorough, thought- provoking, grounded in science and suggestive of a far more complex picture regarding PO4 and its role in our aquariums.

There are many standard parameters in the reefkeeping world that aquarists strive to match in their home reefs – water quality, light spectrum and intensity, and water flow, just to name a few. Rarely do we stop to think where these standard parameters come from, and even more rarely do we consider calling into question the utility of these parameters. This can lead to aquarists ‘chasing numbers’; tweaking water parameters to hit a standard goal. Often times, people think that hitting a magic number will inherently result in a better, healthier tank. In the past few years, dealing with phosphate in saltwater aquariums has become one of the most talked about ‘must control at all costs’ parameter, and in this installment of Skeptical Reefkeeping, we will look at some evidence which calls into question the reliability of testing, the generally accepted target phosphate concentration, and general control of phosphate in reef aquariums.

Rich’s 150 gallon display, on a 300 gallon system, is running a phosphate level of 1.24 ppm, a level at 24.8 times higher than the often recommended .05 ppm. Photo by Richard Ross.
A Brief Reminder to Set the Scene

Skepticism is a method, not a position. Officially, it can be defined as a method of intellectual caution and suspended judgment. As a Skeptical Reefkeeper, you decide what is best for you, your animals, and your wallet based upon critical thinking: not just because you heard someone else say it. The goal of this series of articles is not to provide you with reef recipes or to tell you which ideas are flat out wrong or which products really do what they say they do or which claims or which expert to believe – the goal is to help you make those kinds of determinations for yourself while developing your saltwater expertise in the face of sometimes overwhelming, conflicting advice.

Some think that controlling phosphate is the key to making your reef not look like this eutrophic mess. The truth may be more complicated. (c) Wolcott Henry 2005/Marine Photobank.

Chasing Numbers

Sometimes reefkeepers fall into the trap of ‘chasing numbers’ – trying to adjust water quality to reach a goldilocks zone. A major problem with this approach is that it requires an aquarist to make nearly constant alterations to water quality based on small derivations from the standard parameter ‘set point’; often these alteration are performed manually by the addition of buffers, additives and potions. With such a high maintenance methodology, sooner or later something tends to go wrong – such as an accidental overdose of some chemical to the aquarium, which then leads to a cascade of far more serious problems. However, precise control over many water quality parameters in an aquarium is both unnecessary and impossible given the inherent imprecision associated with normal, hobbyist test kits. For instance, it makes little sense to spend time and money trying to lower your phosphate reading from 0.06 to 0.05 ppm, partly because the effective difference between the two numbers is so small, but more importantly, chasing numbers can be problematic because of the inherent limitations in testing methodology; it is quite possible that the 0.05 and the 0.06 ppm results could come from water samples with literally the same phosphate concentration. .

The test kits that are available to the home aquarist, and other testing methodologies for that matter, have inherent limitations in both their accuracy and precision, and are only as reliable as the techniques used by the person running the test. It makes a big difference to the result if you measure water levels in the test kit vials from the base of the meniscus or from the top of the meniscus. It makes a big difference if you measure the amount of reagent in the dosing syringe from the top of the plunger or the bottom of the plunger. It makes a big difference as to when you determine the titration end point. During a titration, do you assume that you’ve reached the end point when you see the testing sample change color? Start to change color? Stabilize to the changed color? It makes a big difference to the test results that the tests are run using the same techniques every time, as small changes in methodology can substantially impact the final test result. There are many variables in testing your water, so be methodical and follow the test kit instructions as closely as possible, and do all your testing the same way every time to minimize artifacts and procedural errors.

Joe Yaillo's 20,000 gallon reef tank at the Long Island Aquarium and Exhibition Center is arguably one of the most successful reef tanks in the world. Joe says "I am very happy if I can keep it {phosphate level} at .12 ppm. Photo by Richard Ross.
Joe Yaillo’s 20,000 gallon reef tank at the Long Island Aquarium and Exhibition Center is arguably one of the most successful reef tanks in the world. Joe says “I am very happy if I can keep it {phosphate level} at .12 ppm. Photo by Richard Ross.

Precision and Accuracy

Even when great care is taken by the person using the test kit, there are inherent limitations to any and every testing methodology, and many of our test kits are simply not as accurate or precise as we might assume them to be. Let’s first consider what is meant by the terms ‘precision’ and ‘accuracy’. Precision is defined as how reproducible results of one test are relative to others. That is, if we test the same water using the same test kit, do we get about the same number every time, or do we get a wide range of variation each time we use the kit? Accuracy is defined as how close we come to the true value with our test kit. Using a realistic aquarium example, we could imagine some sea water which has a magnesium concentration of exactly 1300 ppm. Let’s say we use a test kit to determine the magnesium concentration of this sea water three times and we get values of 1150, 1160, 1145 ppm. The test kit is fairly precise, but it’s not very accurate since the average of these three values is 1152 ppm, which is not very close to the true value of 1300 ppm. Conversely, if we get values of 1100, 1250, 1500 ppm, the average of these three gives us 1283 ppm, which is close to the true value of 1300 ppm, so the kit is relatively accurate, but not very precise. Ideally, we want our test kits to be both as accurate and precise as possible.

This reef tank at the Steinhart Aquarium runs a phosphate level of .1 ppm, twice the generally recommended level, but it doesn't seem to be hurting. The corals are robust and strong. Photo by Richard Ross.
This reef tank at the Steinhart Aquarium runs a phosphate level of .1 ppm, twice the generally recommended level, but it doesn’t seem to be hurting. The corals are robust and strong. Photo by Richard Ross.

Given the inherent uncertainties of our test kits, and a degree of variation from the user, most hobbyist grade test kits will have an uncertainty (i.e., a likely range of error) on the order of at least 5-10% of the value being measured, and much higher in some situations. If we were to measure the magnesium concentration of sea water which has a true concentration of 1300 ppm using a good-quality hobbyist grade kit we could easily get values ranging from 1200-1400 ppm during any individual titration (i.e., an error of 7.7%, or ±3.8% around the average). Of course, the magnesium concentration isn’t really changing in the sea water as we take samples to run titrations. Instead, we are getting variation in our test results because of the uncertainty of the test kit. If we factor in user error, this uncertainty could become far more significant. For example, what might happen if a person were to slightly but consistently add too little water to the test kit vial? Instead of getting an average magnesium concentration of 1300 ppm, with a range of 1200-1400 ppm for individual tests, they might end up with an average of only 1100 ppm with a range of 1000-1200 ppm. An aquarist might target 1300 ppm Mg2+ in their aquarium—close to natural sea water—and, if they are chasing numbers, start to make adjustments if the magnesium concentration deviates by more than 50 ppm. Hence, this person could end up making very frequent, small adjustments to their aquarium, driving himself or herself crazy, and eventually make some sort of major mistake which negatively affects his or her tank not because these adjustments were needed, but simply because this person was putting too much confidence in the numbers they were getting from their test kits.

Look for Trends, not Specifics

Make no mistake, it is often both useful and necessary to measure a variety of the water quality parameters in an aquarium using test kits. However, problems can arise if we fail to recognize that these test kits report only approximate values for these parameters, and those approximate values inherently come with a degree of error, including random variation. Going back to our magnesium concentration example above: an aquarist might obtain magnesium concentrations with their test kit of 1380, 1230, 1300 ppm in successive weeks and wonder why there has been so much variation in their tank when, in reality, the magnesium concentration was stable at 1300 ppm the entire three week period. In this case the apparent variation from week to week is an artifact, not real. Conversely, a person might get values of 1300, 1280, 1320 ppm in successive weeks and conclude the magnesium concentration has been relatively stable in the tank, when in reality the concentration slowly dropped from 1330 to 1270 ppm over these three weeks. In both cases, the true range of variation (or lack thereof) is simply too small to accurately detect by running a few tests.

A top down of Joe Yaliio's stunning reef tank. None of the corals in this tank seem to be impacted determinately by a phosphate level of more that double the standard recommended levels. Photo by Richard Ross.
A top down of Joe Yaliio’s stunning reef tank. None of the corals in this tank seem to be impacted determinately by a phosphate level of more that double the standard recommended levels. Photo by Richard Ross.

If you run a water test for phosphate level twice with the same water, it is unlikely you are going to get the exact same result both times. First you might get 0.05 ppm, second you might get 0.06 ppm – so which one can you trust? Some reefkeepers will retest a water sample if they initially get a result that they don’t like, and will keep testing until they get one they do like. However, the flipside is often not true – people tend not to retest a sample when they get an initial reading that they do like. This is called conformation bias, looking for the result you already want, and it is a pitfall to avoid because the result has been chosen rather than determined.

Be careful about thinking your test results are overly accurate or precise – instead use them to look at general trends and to obtain rough estimates of the parameters of interest instead of trying to nail numbers. Something to try at home – run the same water sample three or four different times being sure to use the same techniques you really use when you test your water (e.g., don’t stop a titration early or extend it beyond the end point to match the results you got in your previous test) and see what results you get.

This softie tank at the Steinhart Aquarium has a phosphate level of .218 ppm and isn’t overgrown with algae. Photo by Richard Ross.

0.05 ppm, the Magic Number for Phosphate

People have been shooting for 0.05 ppm or less as a level to keep their tank phosphate concentration, and this number is often cited as the concentration on natural coral reefs. Interestingly, the reality is that the PO43- * of natural seawater varies significantly on coral reefs in different locations. The worry has become that with PO43- levels above 0.05 ppm, algae will take over an aquarium, stony corals will become weak and brittle and will grow slowly, and that if your phosphate levels are high, your reef is in mortal danger. Over the past 5-10 years we have seen an explosion in the amount of phosphate removing methodologies, but what is unclear is if spending time and money battling phosphate inherently results in a better reef?

What is Natural?

On natural coral reefs, the phosphate concentration can vary substantially from location to location depending on several factors. For most coral reefs the typical phosphate concentration is on the order of 0.05-0.3 µM (micromolar—the unit of measure normally used in the sciences), or about 0.005-0.03 ppm (Kleypas et al., 1999; Szmant, 2002), which is in the same neighborhood as what is usually recommended for reef tanks. Using a hobbyist grade test kit, this level of phosphate would produce only a faint hint of blue in the test vial – or no hint at all, depending on one’s eyesight. However, values which are both much lower and much higher can be observed naturally on some coral reefs.

Corals and algae on coral reefs rapidly take up phosphate from the ambient sea water as it is available. In fact, it’s been shown that coral reefs tend to suck up phosphate as fast as it is physically possible to do so (Falter et al., 2004). In places like the barrier reef flat in Kāne‘ohe Bay, Hawai‘i—which is a very wide reef flat at about 1.5 miles (2.4 km) across—the reef is able to suck phosphate out of the water so effectively, it creates “ultra-oligotrophic” conditions as sea water passes over it (M. Atkinson, pers. comm.). Here it is not unusual to find phosphate concentrations at the very lower limit of scientific detection—on the order of 0.005-0.01 µM, or 0.0005-0.001 ppm. This is a much lower phosphate concentration than can possibly be detected using hobbyist grade test kits. In fact, it would take 10-50 times this concentration just to start getting a faint hint of blue in the test vial of a hobbyist grade kit. It is possible to achieve phosphate concentrations this low in a reef aquarium (Wiedenmann et al., 2013), but it’s impossible to detect the concentration much below 0.03 ppm using a hobbyist grade kit.

Common reef keeping wisdom says that high phosphate will make your reef into an algae farm, but is that really true? Photo by Paul Dyer.
Common reef keeping wisdom says that high phosphate will make your reef into an algae farm, but is that really true? Photo by Paul Dyer.

Now let’s consider the other side of the coin: phosphate concentrations on naturally high-nutrient reefs. Most high-nutrient coral reefs occur in areas of upwelling, especially those in the Eastern Tropical Pacific, the Central Pacific, near the equator, the Arabian Sea, and a few other locations. Deep, oceanic water is naturally much higher in nutrients than most surface sea water. When there is upwelling in nature it delivers a large supply of nutrients (including phosphate) into shallow water. On these reefs a typical phosphate concentration might be on the order of 0.3-0.5 µM, or about 0.03-0.05 ppm, but phosphate concentration can occasionally reach values of 0.9 µM (0.09 ppm) and even as high as 1.5 µM (0.15 ppm) for short periods of time (Szmant, 2002). These aren’t necessarily what we would consider “high” phosphate concentrations in an aquarium, but nonetheless they are at or above the typically recommended limit for phosphate in a reef aquarium. One might initially assume that these reefs should be in very poor condition, choked by algae, yet some of them are among the healthiest in the world. This good health is likely at least partly related to the fact that these reefs are very remote and receive few direct, human impacts (Sandin et al., 2008).

Elevated Phosphate on Wild Coral Reefs: An Emerging Picture

Make no mistake, one of the most effective ways to damage or destroy a coral reef in nature is to dump a bunch of nutrients on in, including phosphate. The classic example of the effects of nutrient enrichment on coral reefs comes from Kāne‘ohe Bay, Hawai‘i (reviewed by Hunter and Evans, 1995). Following World War II the population of Kāne‘ohe, HI and areas surrounding Kāne‘ohe Bay increased from just a few thousand people to tens of thousands (currently ~35,000 people in Kāne‘ohe town, with several thousand more in nearby areas). Along with this population increase came rapid development of the watersheds feeding into the Bay. Following WWII and until the late 1970’s, the sewage from Kāne‘ohe and from the nearby Marine Corps Base Hawai‘i was dumped directly into southern Kāne‘ohe Bay. Over the course of a few decades the reefs in the southern part of the Bay were severely damaged. On the order of 90-99% of the coral that lived there prior to WWII simply died off and was replaced by various filter-feeding and deposit-feeding invertebrates and algae. In the central part of the Bay, further from the sewage input, the reefs became severely overgrown by the bubble algae Dictyosphaeria cavernosa, which choked out and grew right over the corals. It was only in the northern portion of the Bay, several miles away from the sewage input and better flushed by the open ocean, that the reefs remained relatively healthy. Due to growing concerns of the impacts of sewage input, the sewage outfalls were moved from the Bay to deep, offshore water in 1978/79. Over the following 30 years the reefs showed a dramatic level of recovery. Slowly but surely, the algae and invertebrates which had smothered the corals and occupied space began to die out and the corals regrew and successfully reproduced. Today, more than 40 years after the sewage diversion, the coral cover (that is, the portion of the reefs covered by live coral) has increased from as little as 1-2% in the 1970’s to 50-90% on many of these reefs, which is similar to coral cover in the little-impacted northern part of the Bay. There are other examples of the negative effects of nutrient enrichment on coral reefs, but this is perhaps the clearest. Adding a lot of extra nutrients (including phosphate) to the reefs nearly killed them. Removing those stressors allowed the reefs to recover, though not all coral reefs impacted by excess nutrients have been so lucky.

Wild reefs can be very resilient to high nutrient loads, provided that they don't last for too long. What effect does this rusting construction equipment have on near by corals? I can be hard to tell given other impacts in the area. Photo by Richard Ross.
Wild reefs can be very resilient to high nutrient loads, provided that they don’t last for too long. What effect does this rusting construction equipment have on near by corals? I can be hard to tell given other impacts in the area. Photo by Richard Ross.

Prior to the sewage diversion, the phosphate concentration averaged across Kāne‘ohe Bay was about 0.3 µM, or about 0.03 ppm, but reached about 0.9 µM or 0.09 ppm in the heavily-impacted southern part of the Bay. Following the diversion the Bay-wide average phosphate concentration dropped to about 0.1 µM, or about 0.01 ppm, and a maximum of about 0.2 µM, or about 0.02 ppm. This is remarkable in the context of the phosphate concentrations observed on other coral reefs. During the period of sewage discharge to the Bay phosphate concentrations rose to levels observed on naturally high-nutrient reefs, and the reefs in the Bay were devastated. Following the diversion phosphate concentrations dropped to levels typical on most coral reefs, and the reefs in the Bay began to recover. Hence, it appears that absolute phosphate concentration is only one piece of the puzzle and the context in which a particular concentration occurs is also very important.

Now consider the case of the recently reported “black reefs” (Kelly et al., 2012). The Line Islands straddle the equator, due south of Hawai‘i. Due to equatorial upwelling, many of these reefs fall into the category of high-nutrient reefs, yet the more remote of these reefs are very healthy. At Kingman Atoll, Millennium Reef, and Tabuaeran Island there are some old ship wrecks. Within the vicinity of the wrecks the reefs have been utterly transformed. Rather than dense, healthy corals the reefs are covered by cyanobacteria, other algae, and detritus. Many of the corals that remain in these areas are diseased, and dying. The equatorial upwelling zone is one of the so-called high nutrient, low chlorophyll regions of the ocean. That is, you’d expect there to be a lot more algal growth in this region because of the elevated nutrients than what is actually observed. What has been shown convincingly is that many of these regions have relatively modest amounts of algae because there is insufficient available iron, which is a critical micronutrient. Hence, the algae in these regions can’t grow overly fast in spite of the high nutrients, including phosphate, because there is not enough iron. What are these wrecked ships made of? Bingo, you guessed it: iron.

Water’s edge/pier overlooking the Hawaii institute of marine biology on Coconut Island, in Kaneohe Bay. Photo by Chris Jury.

It appears that elevated nutrients, including phosphate, are not a problem for the reefs, as long as algal growth and disease-causing microbes are limited by some other factor—in this case, the availability of iron. When the iron limitation is alleviated the reefs respond to the high nutrients in much the same way as those in Kāne‘ohe Bay: the corals die and other organisms take over. The emerging picture on natural coral reefs is that excessive nutrient enrichment can severely damage a reef, but the effects depend on the context in which that enrichment occurs. What is safe for one coral reef could be enough to destroy another. The negative effects can also be largely indirect. That is, it is not necessarily clear from observations of whole coral reefs whether elevated nutrients (including phosphate) directly harm corals, but they can certainly be killed off if algae and microbes go bananas from excessive nutrient availability.

Elevated Phosphate and Corals: Do We Know What We Think We Know?

Looking at the anecdoteal reports available, we might think that tanks with high phosphate will be algae gardens and that SPS corals kept in such tanks will become so fragile that they will turn to chalk dust at the slightest touch. Some people say that their algae problems went away when they lowered the phosphate level in their aquarium, however, many of these tanks are also young and could easily be working through one of the many cycles that captive reefs experience. It may be the case that the algae issues would have resolved themselves without the phosphate level changes. In this case, however, we have more than just anecdote to work with.

Early studies of the effects of nutrient enrichment (including phosphate enrichment) on corals generally found that increased nutrient supply led to reduced coral growth rates. A number of hypotheses were generated to explain why, with mixed levels of support. For phosphate in particular, it is known that phosphate ions can interact with calcium carbonate crystals in such a way that they disrupt the structure of the growing crystal, and are said to “poison” the surface. Some hypothesized that elevated phosphate concentration could reduce coral growth rates by poisoning crystal growth as the corals worked to form their skeletons, and at least some of the early work in this area appeared to be consistent with the hypothesis.

Are your corals doomed to look like this declining patch of wild reef due to high phosphate levels? Maybe, maybe not. Photo by Richard Ross.
Are your corals doomed to look like this declining patch of wild reef due to high phosphate levels? Maybe, maybe not. Photo by Richard Ross.

In the mid-1990’s the ENCORE project (Effects of Nutrient enrichment on COral REefs) was conducted on the Great Barrier Reef (Koop et al., 2001). This experiment consisted of dosing concentrated solutions of ammonium and phosphate salts to coral microatolls at low tide over a 2 year timeframe, and assessing a large variety of responses by the various reef organisms. A variety of subtle, negative impacts were found under nutrient enrichment, but many response variables did not respond in the ways which were expected. In particular, under phosphate enrichment several coral species experienced higher growth rates. Hmmm… Skeletal micro-density also tended to increase slightly at branch tips for Acropora longicyanthis under phosphate enrichment, though bulk skeletal density tended to decreases slightly. Hmmm… Based on earlier work, and based on what we thought we knew about the effects of phosphate on coral growth, these results were not at all what was expected.

Two other recent studies have really begun to blow the lid off of what we thought we knew about the effects of elevated phosphate on corals. Godinot et al. (2011) examined the effects of phosphate concentration (0.00, 0.05, and 0.25 ppm) on growth and various physiological responses of the coralStylophora pistillata. Similarly, Dunn et al. (2012) examined the effects of phosphate enrichment (0.09, 0.2, and 0.5 ppm) on the coral Acropora muricata. Both of these studies were performed in aquaria where at least some of the negative, indirect effects of nutrient enrichment which can occur on a real coral reef, such as algal overgrowth, could be minimized. Surprisingly, in both studies the corals grew fastest at the highest phosphate concentrations tested (0.25 and 0.5 ppm, respectively). In fact, the rate of coral growth for both species increased linearly with the phosphate concentration. At least for A. muricata, skeletal density was also lowest for the rapidly-growing corals in the high phosphate concentration, though reduced skeletal density during periods of rapid growth is common for many corals. Hence, these corals were growing fastest and appeared to be “happier” at phosphate concentrations on the order of 5-10x greater than the commonly recommended upper limit for reef tanks, or about 10-50x the phosphate concentration typically observed on most coral reefs.

Algae may not be all bad. The bubble algae is being used by some clownfish as a nesting site. Photo by Barry Geller.
Algae may not be all bad. The bubble algae is being used by some clownfish as a nesting site. Photo by Barry Geller.

On a natural coral reef it is almost impossible to achieve nutrient concentrations this high without also turning the reef into a swamp, choked by algae and full of detritus. However, in captivity it is possible to have higher phosphate concentrations than typically occur in nature while at the same time preventing algal overgrowth and many of the other negative, indirect effects of elevated nutrients on corals. Under these elevated phosphate conditions, but in the absence of indirect stressors, at least some corals (and probably most of them) grow faster and perform “better” than they do under low phosphate conditions.

Go ahead and say it with us: ho…ly…crap.

Case in Point

Rich’s tank, pictured at the beginning of this article is running a PO43- between 0.9 and 1.26 ppm at least for the last year.** Phosphate levels in this tank have been tested with a Hanna Checker, Salifert Phosphate test kit, Red Sea Phosphate test kit, and Aquarium Water Testing services. Water from this tank has also been tested at the Steinhart Aquarium in the California Academy of Sciences using the Hach ascorbic acid molybdate method. All testing methodologies produced results that were well within the same ballpark, with multiple tests performed over the last year. Concentrations of between 0.9 and 1.26 ppm are a whole lot higher than the hobby go to number for PO43- 0.05 ppm but clearly the corals are not suffering and algae has not taken over the system. We would expect at least some annoying algae growth at those levels, but there has been nothing significant. It may be that herbivores are effectively grazing the algae before it becomes a problem. It may be the case that low iron concentrations are limiting the growth of algae. It may be the dense coral cover is out competing the algae for real estate to grow on. It also may be something else entirely.

How much time and money are you going to invest in lowering your phosphate level? Is it needed and worth it? Photo by Richard Ross.

What we do know is the corals in this tank are healthy and growing, and experimenting to find out the details might have a detrimental effect on the system. For instance, if we start adding iron to the tank and the algae blooms, all the coral might get wiped out, and Rich is not sure he wants to take that risk. It might be the case that the corals would do just as well or better if the phosphate level of the system were lowered, though the studies discussed above suggests they might actually do worse. The bigger question becomes ‘how much time, effort and money is worth spending to bring the phosphate level down?’ Some options on the table include Granular Ferric Oxide, which can be expensive, Lanthanum Chloride, which can be expensive, or perhaps an algae turf scrubber which may turn out to be affordable over time. At some point some phosphate reducing methodology may be attempted, but as the old saying goes, if it ain’t broke don’t fix it. Since corals are doing just fine in spite of, or perhaps because of the high phosphate concentrations, Rich may just leave it as it is.

What We Are and Aren’t Saying

One of the things we are saying that it is important to understand is that the reality of water chemistry testing comes with inherent uncertainty, and that chasing numbers can be detrimental and not effective. Constantly tweaking water parameters can be detrimental to aquarium life, as well as costly.

In no way are we saying that everyone should run out and run reefs at high PO43- levels. We are simply not sure what is going on in these reefs with higher than ‘normal’ PO43- levels and any methodological changes need more understanding and support before they can be recommended. What we are saying is how wonderful it is that observations from aquairsts can make us take a long hard look at what we previously accepted as ‘figured out’. It may turn out that higher PO43- levels are not much of a big deal at all, or it may turn out that we will come to understand some previously unknown process in aquariums. Only time will tell, and it sure seems fantastic to be part of a living, breathing, changing scientific effort where skeptical thinking informs all sides of the process.

Notes:

* We can hear the confusion over the internets – “what the heck is PO43- ? Why not just write PO4? And while we are at it, what is the difference between organic and inorganic phosphate?”. These are great questions that are outside the scope of this article, however, Randy Holmes-Farley has written extensively about phosphate, and this article is a great place to starthttp://reefkeeping.com/issues/2006-09/rhf/

** The system has been set up for over 10 years, and you can read about some of the system details here: http://reefhobbyistmagazine.com/arch…3/pages/18.htm .

References:

Kleypas, JA, McManus, JW, Meñez, LAB.1999. Environmental limits to coral reef development: Where do we draw the line? American Zoologist. 39:146-159.

Szmant, A. 2001. Nutrient enrichment on coral reefs: Is it a major cause of coral reef decline? Estuaries. 25:743-766.

Falter, JL, Atkinson, MJ, Merrifield, MA. 2004. Mass-transfer limitation of nutrient uptake by a wave-dominated reef flat community. Limnology and Oeanography. 49:1820-1831.

Wiedenmann, J, D’Angelo, C, Smith, EG, Hunt, AN, Legiret, F-E, Postle, AD, Achterberg, EP. 2013. Nutrient enrichment can increase the susceptibility of reef corals to bleaching. Nature Climate Change. 3:160-164.

Sandin SA, Smith JE, DeMartini EE, Dinsdale EA, Donner SD, et al. (2008) Baselines and Degradation of Coral Reefs in the Northern Line Islands. PLoS ONE 3(2): e1548. doi:10.1371/journal.pone.0001548

Hunter, CL, Evans, CW. 1995. Coral reefs in Kaneohe Bay, Hawaii: Two centuries of Western influence and two decades of data. Bulletin of Marine Science. 57:501-515.

Kelly, LW, et al. 2012. Black reefs: iron-induced phase shifts on coral reefs. The ISMI Journal. 6:638-649.

Koop, K, et al. 2001. ENCORE: The effect of nutrient enrichment on coral reefs. Synthesis of results and conclusions. Marine Pollution Bulletin. 42:91-120.

Godinot, C, Ferrier-Pagès, C, Grover, R. 2011. Journal of Experimental Marine Biology and Ecology. 409:200-207.

Dunn, JG, Sammarco, PW, LaFleur Jr., G. 2012. Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach. Journal of Experimental Marine Biology and Ecology. 411:34-44

Skeptical Reefkeeping Part 8: Animal Origins, Some Proposed Definitions

From Reefs Magazine
Richard Ross and Kevin Erickson

There are many terms in the marine aquarium hobby that are used in multiple ways by different people, which can cause a great deal of confusion. This is especially true as it pertains to the origins and sustainability of animals – it is possible to purchase an animal thinking you know its background, lineage, where it comes from and how it was raised/collected, only to find out that you and the person you bought it from have a different understanding of what certain terms actually mean. Normally, as discussed in Skeptical Reefkeeping III, we would advise people to be aware of the different ways various people and businesses use or misuse terms, and to ask clarifying questions before you risk animals lives or your hard earned money. However, during the February 2012 MASNA Live panel discussion regarding, “Tank Bred vs Captive Raised” (Erickson, 2012), it became clear that there exist a suite of terms concerning the background and origin of marine aquarium organisms that are ambiguous. Even worse, there has yet to be any real effort to try to standardize these terms. If this situation is allowed to continue, the confusion and misuse, whether intentional or not, will continue, and skeptical reefkeepers will continue to shake their heads and say ‘I wish someone would do something about this.’ So, what follows is our attempt to take action.

Designer clownfish are nearly all captive bred and as such are good for beginning hobbyists because wild reefs are not impacted by the learning curve. Photo by Sanjay Joshi..
Designer clownfish are nearly all captive bred and as such are good for beginning hobbyists because wild reefs are not impacted by the learning curve. Photo by Sanjay Joshi.

 

We have touched on this topic in the past, but in this installment of Skeptical Reefkeeping, we are going to explore some of these definitions as well as offer streamlined versions of terms which we think will help get everyone on the same page, avoid confusion, and help the hobby and industry communicate more easily and accurately about the animals in our care. 

A Brief Reminder to Set the Scene Skepticism is a method, not a position. Officially, it can be defined as a method of intellectual caution and suspended judgment. As a Skeptical Reefkeeper, you decide what is best for you, your animals, and your wallet based upon critical thinking: not just because you heard someone else say it. The goal of this series of articles is not to provide you with reef recipes or to tell you which ideas are flat out wrong or which products really do what they say they do or which claims or which expert to believe – the goal is to help you make those kinds of determinations for yourself while developing your saltwater expertise in the face of sometimes overwhelming conflicting advice. 

Our Goal and Process One thing that became clear during the MASNA Live panel discussion is that people have different ideas of how these terms should be defined, and trying to get a group of reefkeepers to agree on this kind of terminology is a bit like wanting people to agree on the best way to run a reef tank. We hope that the definitions offered below will at least reflect the underlying ideas of many different people. Our goal in this endeavor is to keep the definitions of terms simple and free of jargon, so that they are meaningful and easy to understand. Our hope is that anyone involved in any level of reefkeeping (or for that matter anyone not involved in reefkeeping) can easily understand what the terms actually and practically mean. Long, involved definitions are not only cumbersome, but seem to foster misuse and loopholes – which is exactly what we want to get away from. 

Captive bred Crested Oyster Gobies at home aquarium size, bred at the University of Florida. Photo by Matt Wittenrich.
Captive bred Crested Oyster Gobies at home aquarium size, bred at the University of Florida. Photo by Matt Wittenrich.

That said, in some cases it is important to have some ambiguity. Words like ‘grown’, ‘visible’, and ‘recently’ are useful because they avoid any kind of restrictive timeline which might be impossible or impractical to track or enforce. The term ‘captive-conditioned’ is a good example of this. In an effort to make the terms more consistent, we use the term ‘organism’ instead of a specific like ‘fish’ or ‘coral’ or ‘plant’ which allows for one set of terms instead of several for each class of creature. T

he Definitions:Wild Collected / Caught / Harvested

Organisms collected from the wild.

  This is one of the most straightforward terms, and there doesn’t seem to be any contention regarding its definition or use. The organism is taken directly from the wild and put in an aquarium. Such organisms may need conditioning to aquarium life and aquarium feeds, and should be quarantined, observed, and treated, if necessary, before being added to any existing population to avoid spreading infection and parasites. This currently seems to refer to the bulk of the animals in our hobby (Rhyne et al., 2012). 

A fish collector in Kwajalein prepares to wild harvest some fish for the aquarium trade. Such collectors work hard and dive deep so that we can have a steady supply of quality animals for our aquariums. Photo by Richard Ross.
A fish collector in Kwajalein prepares to wild harvest some fish for the aquarium trade. Such collectors work hard and dive deep so that we can have a steady supply of quality animals for our aquariums. Photo by Richard Ross.

Tank Raised / Captive Raised

Eggs or pre-settlement larvae collected in the wild, then grown or raised in tanks in facilities on land.

  This term refers to life stages of wild collected organisms that are generally not yet ready for aquarium life due to difficulty keeping them through the early, fragile stages of development. These organisms may be collected before they would normally settle (recruitment) out of the water column and become more like adult organisms. Some estimate that there is almost 55% mortality of new recruits; so removing organisms from the wild before this life stage to raise them in tanks may not impact wild populations in any meaningful way (Almany GR, Webster, 2005). Organisms removed after recruitment have a greater impact on wild populations; such animals, though they may be considered juveniles, should be considered Wild Collected / caught / harvested. Benefits of tank raised organisms include conditioning to aquarium life and foods, as well as having little or no impact on wild, adult breeding populations. Even though these animals have spent some time in captivity, they should be quarantined, observed, and treated, if necessary, before being added to any existing population to avoid spreading infection and parasites. Tank

Conditioned / Captive Conditioned

Wild collected organisms kept in tanks, conditioned to eat commercial aquarium foods, and accustomed to tank conditions.

  This appears to be the most easily misused of our terms. Often, organisms are labeled as being tank / captive conditioned when they still haven’t acclimated to captivity, or when they have only been in aquaria for a limited amount of time, which doesn’t provide the benefits of captive conditioning. Organisms that have been properly captive conditioned provide a host of benefits over wild caught animals. Besides being accustomed to aquarium life and foods, these animals have often gone through a quarantine and treatment regimen resulting in healthy animals with good body weight. Still, it is recommended that these animals be quarantined by their owners to further staunch any possible spread of disease. 

This baby H. zosterae is captive bred. It was born after its parents were observed spawning after months of being captive conditioned. Had it been born just after the adults were wild collected, it would be tank raised instead of captive bred. Photo by Richard Ross.
This baby H. zosterae is captive bred. It was born after its parents were observed spawning after months of being captive conditioned. Had it been born just after the adults were wild collected, it would be tank raised instead of captive bred. Photo by Richard Ross.

It is important to note that a tank raised organism is a tank conditioned organism but a tank conditioned organism is not necessarily a tank raised organism. This distinction can be confusing and could be used to mislead consumers. 

Tank Bred / Captive Bred

Organisms that were spawned and raised in tanks / captivity in facilities on land.

  These organisms were not born in the wild, but instead were born in aquaria, or emerged from their parents in aquaria. They are accustomed to commercial food, are well acclimated to life in artificial environments, and typically are well suited for life in your tank simply because they have never lived in any other environment. It is recommended that these animals be quarantined by to further stop any possible spread of disease. 

Developmental progress of Crested Oyster Gobies captive bred at the University of Florida. Research like this really highlights the difference between what goes into a true captive bred animal. Photo by Matt Wittenrich.
Developmental progress of Crested Oyster Gobies captive bred at the University of Florida. Research like this really highlights the difference between what goes into a true captive bred animal. Photo by Matt Wittenrich.

Tank Bred / Captive Bred organisms are often thought to be the holy grail of animal acquisition as they have virtually no direct impact on wild populations. However, it is important to realize that in the bigger picture, wild collected organisms serve an important role in preserving wild habitats by giving local peoples an economic incentive to care for those environments. 

February 2012 MASNA Live episode: LSMAC, New BOD, "Tank Bred" panel, & Ret Talbot. Image care of MASNA.
February 2012 MASNA Live episode: LSMAC, New BOD, “Tank Bred” panel, & Ret Talbot. Image care of MASNA.

Maricultured / Aquacultured / Farmed / Cultured / Pen Raised / Net Raised

Catch-all phrases for organisms ‘grown on purpose.’

  We have lumped all these together because the differences between the terms don’t seem to matter practically. Sure there may be technical differences between the terms, but the overarching similarity they all share is that the organisms were grown on purpose. All of these organisms should be quarantined and treated if necessary before introduction to captive populations to prevent the transmission of disease or parasites. 

A technician at a Tongan Coral Farm places coral in concrete troughs for the long process of grow out. Such systems use pumped, unfiltered ocean water which is one of the factors that leads us to lump Maricultured / Aquacultured / Farmed / Cultured / Pen Raised / Net Raised organisms together in one category. Photo by Richard Ross.
A technician at a Tongan Coral Farm places coral in concrete troughs for the long process of grow out. Such systems use pumped, unfiltered ocean water which is one of the factors that leads us to lump Maricultured / Aquacultured / Farmed / Cultured / Pen Raised / Net Raised organisms together in one category. Photo by Richard Ross.

Coral-centric Terms:Freshly Fragged

Recently cut fragments of organisms.

  Freshly Fragged organisms can be either wild collected or Captive grown. Freshly Fragged organisms may not do well due to stress from fragmentation and gluing. This practice has sometimes been referred to derogatorily as ‘chop shopping’ – wild colonies are chopped up, glued down and sold to customers who often believe that the corals have been in captivity for a significant amount of time. Both wild and captive grown freshly fragged organisms may suffer from the stress of fragmentation and gluing, while wild collected freshly fragged organisms have that stress compounded by the move from wild conditions to captive conditions. It is recommended that these organisms be quarantined and treated if necessary before being added to established systems. It is often possible to tell if a fragment has been freshly fragged by looking for exposed skeleton from where the coral was cut, or by the lack of encrustation onto the substrate to which the coral is glued. 

Freshly fragging of a wild collected coral with a hammer and large flathead screw driver. Photo by Kevin Erickson.
Freshly fragging of a wild collected coral with a hammer and large flathead screw driver. Photo by Kevin Erickson.

Healed Frags

Wild fragments of organisms that are fully healed prior to sale.

  These organisms, wild collected or not, are fragmented, but are allowed to stabilize, recover and grow resulting in corals that seem to adapt better to having their environment changed when they are moved to a new system. Though these organisms appear healthy, it is still important to quarantine and treat if necessary to prevent the spread of any coral diseases or parasites. 

Are these corals freshly fragged or healed? Only careful inspection of their attachment points for encrusting new growth will reveal the truth. Photo by Richard Ross.
Are these corals freshly fragged or healed? Only careful inspection of their attachment points for encrusting new growth will reveal the truth. Photo by Richard Ross.

Captive Grown

Organisms which contain no tissue / skeleton that was collected from the wild.

  These are typically frags of new growth from captive colonies (frags of frags) whose original origin was from the wild. These corals typically do very well as they have been conditioned to tank life for a long time. And, as with every other definition in this article, these organisms should be quarantined and treated if necessary before being added to an established system. 

Quarantined (QT) 

You might also notice that the idea of quarantine is discussed in many of the definitions above. We could have had one general paragraph about quarantine, but we feel the issue is important enough to mention it over and over again. A common thought in the hobby is that captive bred or tank raised organisms are somehow disease or parasite free, but this is a dangerous viewpoint to embrace, and, like most ‘easy’ and erroneous beliefs in this complicated hobby, it can cost lives and money. It is possible for animals kept en masse even in the cleanest of holding facilities to harbor unseen diseases and parasites despite the best efforts to eradicate them…and shipping stress caused by even the gentlest and most thoughtful shipping practices negatively impacts the organism’s immune system which makes it susceptible to diseases and pests. Even dormant and previously unseen pests and diseases carried by healthy-seeming organisms can manifest as a result of shipping stress. The short version of all of this: Regardless of where your animals come from, quarantine, and treatment if necessary, is mandatory before releasing organisms into their new home. 

Quarantine is important. This QT system at the Steinhart Aquarium is used for larger shipments of reef fish where all incoming fish are given a 30 day minimum QT regardless of their source. The rock island helps calm fish quickly and induces naturalistic behaviors making observation to determine if any treatment is needed much easier. QT set ups need not be this involved. Photo by Richard Ross.
Quarantine is important. This QT system at the Steinhart Aquarium is used for larger shipments of reef fish where all incoming fish are given a 30 day minimum QT regardless of their source. The rock island helps calm fish quickly and induces naturalistic behaviors making observation to determine if any treatment is needed much easier. QT set ups need not be this involved. Photo by Richard Ross.

When are these Definitions Useful? 

These definitions come into play when obtaining, selling or trading organisms, whether in person or online. Standardized terminology helps ensures that you are buying what you are truly after and that you will be as successful as possible. Keep the skeptical method of thinking in mind when observing and inspecting the organisms and do not be afraid to ask questions. Ask yourself, “What would Scooby-Doo ask?” Are the organisms really tank conditioned? What evidence supports that idea? If so, what types of food does it eat and is your tank appropriate for that particular organism at that stage in its acclimation to life in captivity? I

n Conclusion Remember, the goal of these articles is to help you make the useful decisions for yourself while developing your saltwater expertise in the face of sometimes overwhelmingly conflicting advice. By understanding these definitions yourself and confirming common definitions when speaking about organisms in captivity, we can work towards a set of universally accepted definitions. Remember, your animal’s lives and your money are at stake, be as informed as possible. It is important to note that we are not so full of ourselves as to think that we have nailed these definitions, and that everyone will agree on them. We will be happy if this discussion moves all of us towards universal definitions, whichever those end up being. Special Thanks to Ret Talbot, Tal Sweet, Andrew Rhyne, Jim Adelberg, Dale Pritchard, Matt Carberry, Chris Turnier, Matt Pedersen, Dan Navin, and Adam Youngblood for the discussion, both MASNA Live and personal communication, that inspired this article.

References Erickson, KP. 2012. LSMAC, New BOD, “Tank Bred” panel, & Ret Talbot. MASNA Live, February 29 (audio recording: MP3).

 Rhyne AL, Tlusty MF, Schofield PJ, Kaufman L, Morris JA Jr, Bruckner AW. (2012) Revealing the appetite of the marine aquarium fish trade: the volume and biodiversity of fish imported into the United States.

PLoS ONE 7:e35808–e35808. doi: 10.1371/journal.pone.0035808 Almany GR, Webster MS (2005) The predation gauntlet: early post-settlement mortality in reef fishes.

Coral Reefs 25:19–22. doi: 10.1007/s00338-005-0044-y Coral Reefs
March 2006, Volume 25, Issue 1, pp 19-22 

Possible Continued Reading 

Snyder, Noel F.R.; Derrickson, Scott R., Beissinger, Steven R., Wiley, James W., Smith, Thomas B., Toone, William D., Miller, Brian (1 April 1996). “Limitations of Captive Breeding in Endangered Species Recovery”. Conservation Biology 10 (2): 338–348. doi:10.1046/j.1523-1739.1996.10020338.x 

http://www.reefs.com/blog/2012/02/24…f-tank-raised/

http://en.wikipedia.org/wiki/Ex-situ_conservation

http://www.reefs.org/forums/topic140891.html

http://reefbuilders.com/2012/03/14/c…moorish-idols/

http://www.bluezooaquatics.com/resources.asp?show=431

CEPHALOPOD BREEDING