Anti-Aquarium activists in Hawaii are using a new tactic in 2015, alleging that the collection and handling of reef fishes for the aquarium trade amounts to “cruel treatment”—but does this stand up to facts gathered by marine scientists?

The Data behind Defining “Cruel Treatment” & “Substantial Injury” in Aquarium Fisheries

By Ret Talbot

Five aquarium fishery-related bills will be heard Wednesday by the House Committee on Ocean, Marine Resources and Hawaiian Affairs, including HB 883. While the two so-called “ban bills” on Wednesday’s agenda (HB 606 and HB 873) are fairly easy to understand–they would both close Hawaii’s aquarium fishery based on claims of unsustainability–HB 883 is somewhat more complicated, and, as such, may need some explanation.

People interested in submitting testimony for the public hearing should do so before 8 am HST February 9, 2015 (Tuesday). The instructions for submitting testimony may be found at the bottom of this article.

On the surface, HB 883 may appear a good bill for Hawaii’s fishes, as it calls for prohibiting the sale of aquarium fishes subjected to “substantial injury” or “cruel treatment” during harvest, holding or transport. While this may seem an obvious bill to support, the Bill itself defines many common practices in the aquarium fishery as “cruel treatment” or as leading to “substantial injury.” While anti-aquarium fishery activists contend the practices outlined in the Bill are responsible for the majority of post-harvest mortality, fishers, aquarium trade experts and the best available science claim many of these same practices are actually in the fishes’ best interest. Critics of the Bill argue that if HB 883 passes, parts of the new law could actually increase post-harvest mortality, while other parts could unnecessarily make harvesting fishes for the aquarium trade cost-prohibitive. Some contend the Bill is actually little more than a non-data based effort to close the fishery.

Substantial Injury & Cruel Treatment – Definitions

According to the Bill, the purpose of HB 883 is “to increase survivability and prohibit the cruel and unethical treatment of Hawaii’s marine life when taken for sale as pet animals, and uphold Hawaii’s values of respect for local marine life.” HB 883 specifically seeks to achieve these objectives by prohibiting the sale of fishes “taken under an aquarium fish permit…that has been subjected to substantial injury or cruel treatment.” As such, the definitions of “substantial injury” and “cruel treatment” are central.

“Substantial injury” is defined in the Bill as “bodily injury that creates a substantial risk of death or that causes serious, permanent disfigurement, or protracted loss or impairment of the function of any bodily member or organ.”

“Cruel Treatment” is defined as “behavior that may result in substantial injury to the aquarium fish or aquatic life, including but not limited to:

  1. Surfacing at a rate resulting in physical damage to the body tissue;
  2. Piercing or deflating the swim bladder;
  3. Cutting the fin or spine;
  4. Withholding food for more than twenty-four hours; or
  5. Holding fish or aquatic life in less than one gallon of water, per each specimen, within any container.”

The objective of the Bill is therefore really twofold: “to increase survivability” and to “prohibit cruel and unethical treatment.” The former can be viewed within the context of what is known–what the data and the best available science show regarding whether or not the practices in question actually lead to increased mortality or not. This article will focus on that data and how the best available science can inform the legislative process. The latter, the question of what is “cruel” and what should be deemed as “unethical” is a much broader question that is significantly harder to address. Legislating ethics is generally considered to be problematic on multiple fronts.


Advocates of HB 883 contend that outlawing certain practices that are common in the aquarium fishery and trade would lead to lower post-harvest mortality. The first two specific practices the Bill would outlaw have to do with bringing fishes up from depth. When fishes, like SCUBA divers, come to the surface too quickly, injury and even death may occur secondary to a change in ambient pressure. A fish that is not given time to properly acclimate to the changing pressure (i.e., decompress) may experience an increase in swim bladder gasses that can result in both external and internal trauma known as barotrauma.

While barotrauma is considered less of a concern in food fisheries because, in most cases, survivability is not economically necessary, in fisheries where the survivability of the fish is valued, barotrauma is a very real concern. When it comes to aquarium fisheries, catch-and-release recreational fisheries, live food fisheries, and bycatch in food fisheries, minimizing trauma is critical to a fish’s long-term survival. Quite a bit of research has been done on barotrauma in fishes, but very little of it has focused on reef fishes being brought up from the most common depths at which most aquarium fishes are harvested.

The obvious signs of barotrauma may include an inability to swim properly because of an over-inflated swim bladder (positive buoyancy), bulging eyes (exophthalmia) and intestinal protrusion. Even if a fish recovers from these external signs of barotrauma, or shows no signs of trauma at all, studies show nonlethal internal injuries such as ruptured swim bladder, internal bleeding, damaged organs surrounding the swim bladder and other trauma associated with gasses leaked from the swim bladder can persist for extended periods. It is believed that these nonlethal injuries can indeed lead to post-harvest mortality the fisher may never witness.

Venting and Decompression

Common methods used by fishers to mitigate barotrauma include venting and decompression. In Hawaii, venting–sometimes called “pinning” or “fizzing”–involves puncturing the swim bladder of the fish with a hypodermic needle to release accumulated gasses. In other parts of the world where the value of fishes at the point of harvest is less, venting may be performed with any available sharp object ranging from a modified fishing hook to the spine of another fish.

Decompression is similar to what divers do–coming up to the surface at a rate that gives the body time to acclimate to the difference in pressure. In Hawaii, it is common for fishes to be held at one or more decompression stops, although practices vary based on diver, species of fish and other factors. In general terms, venting is quicker and therefore less expensive. In fact, some argue that properly decompressing fishes is prohibitively time-consuming. Fishers in Hawaii and elsewhere commonly use a combination of venting and decompression when harvesting aquarium fishes, and they argue there are no long-term effects that cause post-harvest mortality.

If HB 883 passes, the sale of vented aquarium fishes would become illegal. Presumably the sale of aquarium fishes brought to the surface by decompression would be legal but only if there was no “bodily injury that creates a substantial risk of death or that causes serious, permanent disfigurement, or protracted loss or impairment of the function of any bodily member or organ.”

New Data Published on Venting and Decompression

As already mentioned, few data exist regarding barotrauma associated with bringing shallower water reef fishes to the surface. A group of researchers recently set out to better understand whether or not delayed mortality caused by sublethal injuries was in fact a significant cause of post-harvest mortality in aquarium fishes. Their paper “The effects of venting and decompression on Yellow Tang (Zebrasoma flavescens) in the ornamental aquarium fish trade” was recently published in the journal PeerJ.

According to Dr. Brian Tissot, one of the co-authors on the paper, the impetus for the study was a trip to Maui in 2010 and a long discussion Dr. Tissot had with anti-aquarium fishery activists Robert Wintner and Rene Umberger. “They expressed major concern at that time of the effects of ‘fizzing’ and felt that it was responsible for causing most of the aquarium fish mortality,” says Tissot, pointing out that Wintner and Umberger often pegged post-harvest mortality at greater than 90%. “Even though Todd Stevenson has shown that was not the case in his 2011 paper it didn’t address venting directly.”

When Emily Munday, who is the lead author on the paper, started graduate school at Washington State University, Dr. Tissot discussed with her the idea of looking more closely at venting, and Munday took it in on for her MS thesis. The work, which was funded through the NOAA Coral Reef Conservation Program, was undertaken during the summers of 2011 and 2012.

At the outset, the researchers predicted that fishes collected for the aquarium trade suffer the same sort of undetected sublethal injuries as food fishes do. What they wanted to know is if these sublethal injuries, if they exist, lead to mortality further along the supply chain. Answering this question is central to HB 883, for if it is the case that common practices in the fishery lead to post harvest mortality, then making the sale of fishes harvested in such a manner illegal would indeed increase survivability.

No Morality in Yellow Tangs Subjected to Standard Collection Practices

Munday et al found that “the methods commonly used in this fishery (ascent without decompression stops, or ascent with one decompression stop, followed by venting) resulted in no immediate or delayed mortality.” In the study, only fish subjected to ascent without decompression stops and no venting suffered mortality. Beyond outright mortality, the researchers used histopathology to detect any signs of inflammation, organ damage or infection caused by venting. “Wound healing with no evidence of ongoing necrosis or inflammation, as seen in these fish, indicates that the venting procedure does not pose a significant threat to fish survival post-collection, nor does it cause significant sublethal effects.”

“[T]he project clearly showed that there was no morality in Yellow Tangs subjected to standard collection practices–fast ascent and venting–from normal collection depths of 25-40 feet,” even after being held for 3 weeks,” says Tissot. “Moreover the histology showed no long-term tissue damage from the needle…. The only mortality observed was in animals brought quickly to the surface that were not vented.” That mortality was 6%.

The second part of Munday’s study, which has yet to be published, looked at fish collected from the reef and holding practices in a collector’s facility in West Hawaii. “It is more holistic then the venting work as it includes their normal handling procedures and eventually shipping to the mainland,” says Tissot. That study showed that the practices of the Hawaii fish exporters did not cause any mortality in Yellow Tangs received by the researcher and held for the duration of the six month study.

Munday’s study is not a comprehensive study on the practices of venting and decompression in the Hawaii aquarium fishery, as it only looked at one species collected in the 15-18 meter depth range. The researchers caution that fishes collected from different depths may yield different results. They also point out that different species may react differently to the venting and decompression. Nonetheless, the data do show that rapid ascent and/or venting does not contribute noticeably to post-harvest mortality in the most frequently harvested aquarium fish in Hawaii. The study also suggests HB 883 should, at the very least, be amended to not define fast ascent and/or venting as “cruel treatment” if that phrase is defined as “behavior that may result in substantial injury to the aquarium fish or aquatic life, including but not limited to 1) Surfacing at a rate resulting in physical damage to the body tissue, or 2) Piercing or deflating the swim bladder.”

“Though animal rights groups in Hawaii criticize venting, we did not find that it caused mortality or sublethal injuries in Yellow Tang. Banning venting may increase mortality rates if fishers implemented ascent without decompression. While opponents of venting have suggested that slow decompression be used instead, the time required to properly decompress these fish is economically prohibitive and impractical for fishers to implement.”

Is Clipping Cruel?

Another common practice in the Hawaii aquarium fishery is clipping spines on fishes that have extremely sharp spines on their fins or tail. HB 883 would prohibit the sale of fish with clipped spines, as the practice is, according to the Bill, “cruel treatment” that may result in substantial injury to fish. While anti-aquarium trade and animal rights activists argue the practice is unethical, fishers and aquarium fishery experts argue it is necessary to insure that some fishes do not puncture the bag in which they are being shipped. “This does not harm the fish, and the spines soon grow back,” says one fisherman, summing up the general consensus of those familiar with the practice. “It is no different than cutting your toenails or trimming your hair.”

There are no published reports or scientific studies readily found that support the proposed ban on the sale of fishes with clipped fins. If data exists to contradict the experience of fishers and those in the trade who liken the practice to cutting one’s toenails, it has yet to be presented despite the fact that this same bill has been presented in various forms over the past five years at both the county and state level.

Purging Fishes Prior to Transport

The practice of not feeding fishes prior to transport is based in the best available science and is considered a best practice. The purpose for withholding food before transport is so that ammonia doesn’t build up in the shipping water. Many organizations, including the Food and Agriculture Organization (FAO) of the United Nations and Hawaii Sea Grant, recommend withholding food long enough to void the stomach and intestine as a best practice. The reason is that, as part of the metabolic process, fish excrete ammonia after being fed. If fish are fed too close to the time of shipping, ammonia can accumulate to lethal levels very quickly during transport. As the New England Aquarium, a science-based leader in ocean research and conservation, stated in testimony regarding a 2011 version of this bill, “This portion for the proposed bill is paramount to suggesting it is inhuman to withhold food and water from a dog or cat prior to any veterinary procedures.”

Arbitrary and Capricious?

The fifth and final practice HB 883 specifically addresses is the holding of “fish or aquatic life in less than one gallon of water, per each specimen, within any container.” Again, there are no readily available, published scientific studies supporting the proposed one-gallon per each “aquarium life” standard specified in the Bill. Marine aquarium trade exporters, research institutions that ship fishes and other live animal shipping experts say that in some cases, shipping in a gallon of water is insufficient, while in other cases it is over the top. They argue the one-gallon minimum is, in the absence of any data, “arbitrary and capricious.”

Around a half a million fishes are shipped from Hawaii to the mainland annually, and these shipments consistently have some of the lowest shipping mortalities in the industry according to importers. Many importers report less than 1% mortality on Hawaii shipments, indicating that current water volumes and shipping densities are not contributing significantly to post-harvest mortality as the Bill’s supporters contend. As Dr. Andrew Rossiter of the Waikiki Aquarium pointed out in testimony last fall against a similar bill at the county council level, “it is hard to imagine why [a report supporting the one-gallon minimum] would be needed when the existing shipping system is clearly already almost perfect.”

Sticking to the Data 

While HB 883 portends to have animal welfare at its center, in reality, there is little if any science supporting it when it comes to the practices it specifically mentions. When it comes to the ethical argument, there is a lot more grey area and opportunity for debate. Many of the Bill’s advocates believe keeping wild-harvested fishes in an aquarium is ethically repugnant in the same way that other animal rights activists argue against a variety of commonly accepted practices in the complex relationship between humans and animals. The Legislature is a difficult place to have this discussion, and, as stated earlier, legislating ethics is generally problematic. As such, it seems prudent to focus on what the data show, and the data appear to clearly support opposing HB 883.

As reported today in West Hawaii Today, HB 883 is one of a bevy of animal welfare bills before the Hawaii State Legislature this year. Most were drafted by lawyers for the Humane Society of the United States (HSUS), and the HSUS’s senior director for state affairs in Hawaii is quoted as calling the bills “common-sense” measures.

Submitting Testimony

To submit testimony for HB 883, use the blue “Submit Testimony” link on this page:

In addition to HB 883, the House Committee on Ocean, Marine Resources and Hawaiian Affairs will also hear public testimony on HB 873, HB 606, HB 511 and HB 483. More about those bills can be found here.


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