American Scientist

To the Editors:

Sam Muka’s commentary on aquariums (“Trashing the Tanks,” November–December) came with a misleading tagline on the magazine’s cover, “Aquariums misrepresent ocean pollution,” detracting from her reasoned argument. Educating visitors about the threats to marine life is a primary goal of all major aquariums, but introducing pollution into our exhibits, as implied by the title “Trashing the Tanks,” would be the wrong thing to do. It would harm the animals and go against government regulations and industry standards for animal care. Muka suggests pairing pristine with degraded habitats to provide shock value and to show what’s at stake. It’s a worthwhile idea, one that we and many aquariums have used, and we continually search for more effective ways to introduce solutions into our exhibits.

Most visitors come to aquariums to experience the beauty and diversity of marine life. Surveys by New Knowledge show that the public has greater trust in aquariums than in any other source of information about the ocean. This trust brings with it a responsibility that most aquariums take seriously. In addition to signage and video messages at exhibits, aquariums address pollution and solutions through diverse portfolios of programs.

An ocean untouched by humans has not been a reality since our species first evolved, and human dependence on the ocean will only increase in the future. Aquariums provide venues for people to imagine alternative ocean futures and how their actions will influence that future. Our new wing, Pacific Visions, opening in spring 2019, centers on this theme, and focuses on the species whose decisions are affecting all others: Homo sapiens.

Jerry R. Schubel
President and CEO Aquarium of the Pacific
Long Beach, CA

Dr. Muka responds:

As you highlight in your letter, aquariums are a trusted source for information about the ocean. But a 2007 report by the Association of Zoos and Aquariums (AZA) by Falk et al. states that visitors already have strong understandings of ecology and intense connections to the marine environment. The results of the study suggest that “Zoos and aquariums should spend more time on specific conservation and natural history messages. Most visitors are ready to be more engaged in advocacy efforts.” Aquariums have certainly heeded this advice in the past 11 years; you point to a variety of efforts, including increased signage and exhibits. My essay suggests that aquariums might push the envelope even further by incorporating those advocacy efforts directly into tank design.

My suggestion is that aquarists turn their craft toward developing new display techniques that speak directly to visitors who already understand and care about the ecology of the environments portrayed. Many tanks still contain realistic-looking corals constructed from human-made materials—so it isn’t unheard of that tank design could include synthetic, nonnatural objects. This approach doesn’t require that the tank be full of delicate animals—an empty tank full of trash can be startling and thought provoking. As stated in the article, public aquarists have spent the past 100 years developing techniques and technologies to tell stories about the natural environment. Dealing with the threat humans pose to the ocean and educating individuals about their role in those threats require expanding the concepts of tank design into new territory. I look forward to your new exhibit!

To the Editors:

Sam Muka’s article “Trashing the Tanks” propagates the most perniciously widespread and hard-to-eradicate falsehood about corals: that bleaching and mortality are due to acidification rather than a high temperature. Every article about ocean acidification shows photos of corals that were bleached by an excessively high temperature, despite the fact that acidification does not cause bleaching at all!

Most of the corals in the world have now already died from heat shock caused by excessively high temperatures resulting from global warming, as Ray Hayes, Peter Glynn, Ernest Williams, and I predicted would happen almost 30 years ago after the planet suddenly passed the high-temperature tipping point for global-scale mass coral bleaching in the 1980s. Acidification only dissolves skeletons of corals long after they have died from heat shock.

Reducing carbon dioxide (CO2) in time to prevent global warming–caused extinction of coral reef ecosystems automatically prevents later damage from acidification, but controlling CO2 in time to prevent acidification guarantees that global warming will kill them by heat stroke. Focusing CO2-control efforts to prevent ocean acidification instead of global warming is a scientifically irresponsible and politically dangerous red herring.

Thomas J. F. Goreau
President, Global Coral Reef Alliance
Cambridge, MA

Dr. Muka responds:

Thank you for the clarification. You are correct that coral bleaching is caused by the evacuation or death of photosynthetic organisms from coral structures. If those photosynthetic organisms don’t return, the polyps die and all that is left is a “bleached” shell. Ocean acidification does not cause bleaching, but instead causes the dissolution of the calcium structure that makes up the coral. Ocean acidification occurs in warming seas, but it is not the primary killer of corals, nor will it ever be. The ocean would already have to be too warm for the survival of coral polyps before it was acidic enough to result in direct coral death.

However, I’m unsure that the differentiation affects the way the public understands their role in climate change, broadly speaking. The steps that aquarium visitors would be told to take (contact representatives, reduce fossil fuel use, lower their carbon footprint) are the same because, hopefully, anything they are taught to do would decrease warming and, by default, acidification.