Public Aquariums and Aquaculture

Across the globe, commercial aquaculture supplies nearly half of all fish-based food products (Perry et al). Historically, one of the primary sources for aquafeeds has been fishmeal sourced from capture fisheries (Naylor et al), putting pressure on vulnerable wild stocks. Efforts to replace fishmeal with high quality plant-derived protein sources (soy, pea protein, wheat, corn gluten) have reduced the amount of feeds based on marine raw materials, but are more costly than raw fish material.

Thus, the aquaculture industry has focused on ways of including some of the more cost-effective alternative sources of protein that will not only help to further replace fishmeal; but also substitute some of the expensive high-quality plant protein concentrates and provide more flexibility in feed formulations using a wider range of locally available raw materials. This will reduce costs, carbon footprint, and be more sustainable. If successful, this will improve aquaculture and local food availability.

Our solution looks to solve an issue that deals with dependence of a growing global food source on dwindling wild stocks and unsustainable raw materials that compete with human value chain.

Across the globe, commercial aquaculture supplies nearly half of all fish-based food products (Perry et al). Historically, one of the primary sources for aquafeeds has been fishmeal sourced from capture fisheries (Naylor et al), putting pressure on vulnerable wild stocks. Efforts to replace fishmeal with plant-derived protein sources have reduced the amount of feeds based on marine raw materials of animal origin to just 7% of the 65 million metric tons of aquafeeds produced annually. 

Although some progress with utilization of lower-quality plant protein has been made a number of concerns must be overcome including low palatability, imbalanced amino acid profile, or a presence of anti-nutritional factors responsible for inducing intestinal inflammation, to maintain acceptable growth rates and feed efficiency values at high fishmeal substitution levels. Thus, the aquaculture industry has focused on ways of including some of the more cost-effective alternative sources of protein that will help to further replace fishmeal and provide more flexibility in feed formulations using a wider range of locally available raw materials.

We will leverage existing resources within Shedd Aquarium to conduct a pilot study evaluating the effects of sustainable diets on rearing of silversides, Menidia beryllina. 

Silversides are a common and hardy aquarium food fish which tolerate a varied diet. Following the initial live feed period, larvae will be divided into three treatment groups. A control group will receive a typical diet, a second will receive insect meal-based diet and a third, plant protein-based feed formulated using cost-effective and high quality local protein sources (see Study Plan). All diets will be fed at restricted rates based on fish biomass and feeding activity.

At approximately 75 and 105 days post-hatch, fish will be harvested. All groups will be assessed for the following: final average growth, total body length, weight gain, and survival. In addition, dietary treatment groups will be analyzed in three ways. First, proximate analysis of protein, fat and ash content will be performed to measure nutritive value of the whole fish body. Second, a subsample of fish from each group will be dissected and subject to histology by veterinary pathologists to assess the health of the intestinal mucosa. Finally, gene expression of pro-inflammatory cytokines will be compared using quantitative PCR.

Populations who are dependent on fish as a food source will benefit from a stable, high protein and renewable food source. With access to a wider range of feed options that are not only sustainable but more cost-effective, the aquaculture industry will be better positioned for expansion to support a growing world population.

Providing data to support diets that are both environmentally and economically sustainable for aquaculture, and driving other aquariums to do the same, will promote the shift towards a low-impact food source for farmed fish.

Our solution is cross-disciplinary: by finding common ground between public aquariums and commercial aquaculture facilities, it uses existing resources in new ways. Moreover, the addition of DNA-based molecular techniques to routine chemistry and histology will provide genomic data that is normally accessible only through universities and research centers. Aliquots of DNA extracted from these samples will be stored for future experiments which could include measuring the expression of other genes relevant to nutrient extraction and/or surveillance for microbial pathogens.

Shedd Aquarium is home to a QuantStudio real-time PCR instrument which can detect and quantify nucleic acids. These include genes that are expressed during clinically significant events such as inflammation. This tool will allow us to answer critical questions about the impact of sustainable diets on fish health.

Real-time or quantitative PCR is a well-validated technique for comparing levels of gene expression between biological samples (Yusta et al, Schmittgen & Livak).

According to the Food and Agriculture Organization of the United Nations’ 2018 report (see references), the average annual increase in global food fish consumption over the past 50 years has not only outpaced population growth, but exceeded that of meat from all terrestrial animals combined. This increase in demand is not equally distributed across the globe; the same report showed people in developing countries have a higher share of fish protein in their diets than those in developed countries. The new information we will generate about the tolerance of feed fish for more sustainable diets, combined with greater public awareness of this important issue, will drive commercial facilities to consider alternatives to feeds based on fish protein. Moreover, successful demonstration of the role Shedd can play informing sustainable aquaculture will inspire other public aquariums to adopt this model, increasing the global footprint of our solution.

Currently, our solution is still in the scientific inquiry phase, but is building off prior studies we have conducted. We are working on a model that can be adapted once it can be effectively studied and implemented on high volume stock species, at which point the population it could serve is extremely far reaching in the hundreds of millions.

Our short-term goal is to continue to study the hypothesis in a new species of fish. In five years, we would like to have tested the hypothesis in widely available stock species to have a proof of large-scale concept.

Near-term barriers include experimental failure, e.g. silversides do not tolerate the alternative diets (low feed ingestion rate) as well as other species that have been previously studied.

Looking further out, the space and resources required to house fish for studies at the aquarium could be impacted by planned renovation and unforeseen acquisitions of new animals e.g. through confiscations.

A preliminary trial preceding the feeding experiment will be carried out to test ingestion rate in silversides of the same age. In case low feed intake is detected additional feed attractants will be added to experimental formulation to increase palatability of the feed. All treatment groups will also be evaluated at the conclusion of the larval and beginning of the juvenile stage. If mortalities exceed 10% the control diet will be re-instituted for a period of 4 weeks before resuming experimental diets during the grow-out phase.

Plans for aquarium renovation include construction of an offsite facility that includes tanks that could be repurposed for experimental systems in the event that onsite space is usurped.

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The solution team consists of six individuals. Four full-time Animal Health Team staff at Shedd Aquarium, one part-time Animal Health Team staff at Shedd, and one full-time staff at Southern Illinois University. 

Public aquariums are home to extensive fish-rearing expertise and have a shared interest in sustainable fish culture. Importantly, aquariums are also removed from economic drivers which can discourage commercial facilities from sharing innovations in practice. Testing strategies to improve fish tolerance of sustainable diets in a public aquarium setting will both inform commercial practice while advancing public and scientific understanding of sustainable food systems.    

Our team in particular has extensive experience in starting and running one of the first and only microbiome labs, in a public aquarium, in the country.

With researchers, water quality experts, pathology experts, veterinarians, and chemists on staff, our team has tackled major issues in both aquarium and wild settings.

Partnerships needed to complete the pilot study are currently in place. Merieux Silliker’s Crete, IL reference laboratory will perform proximate analysis to assess nutritive value of the silversides. Histological analysis of intestinal samples will be covered by Shedd's contract with the University of Illinois Zoological Pathology Program in the Department of Veterinary Medicine. 

Shedd’s dedicated Molecular and Microbial Ecology research group and in-house laboratory have both the tools and expertise necessary to perform the DNA extraction and PCR reactions needed to measure changes in expression of inflammatory cytokines and interpret the results.

For this project, Shedd is partnering with Southern Illinois University. We are working with SIU to develop, test and publish findings about the work we have done and will around this subject.

Partnerships needed to complete the pilot study are currently in place. Merieux Silliker’s Crete, IL reference laboratory will perform proximate analysis to assess nutritive value of the silversides. Histological analysis of intestinal samples will be covered by Shedd's contract with the University of Illinois Zoological Pathology Program in the Department of Veterinary Medicine.

Shedd Aquarium is the most visited paid attraction in the Chicagoland area with visitors from all over the globe. We function as a public aquarium, but provide learning and education, conservation, and scientific research opportunities that go well beyond our walls.

We provide learning and education opportunities that incorporate scientific advancement and STEM that includes hands-on scientific experiences. These programs train young people for a future in STEM through a variety of channels that includes work-study and internships.

Our Conservation team provides community-based stewardship and action opportunities to improve our local coastal lands and waterways.

Our Research team is in the field providing incredibly important scientific insights on a wide variety of subject including: invasive species, climate change impacts on coral, shark populations in the Bahamas, freshwater fish migrations, and more.

Shedd Aquarium, like most public aquariums, is so much more than what is seen in our collection, in our galleries, or even by our public. Shedd is an expansive institution of scientific learning and discovery that is making real impacts to our aquatic world each and every day. We are applying to Solve, because we feel we have a potential solution to a problem that impacts hundreds of millions of people. We want to illuminate the ways in which public aquariums can play a crucial role in solving issues like sustainable food practices and other important issues our world faces. We are leaders in the understanding of the aquatic world, and we wish to seek out opportunities which bring that work to forefront of society.

We are eager to find new opportunities to disseminate and apply our expertise in aquatic animal husbandry and molecular biology, extending the Aquarium’s impact beyond its four walls.

As one of the largest inland aquariums in the US, we maintain recirculating aquatic systems designed to replicate habitats from around the globe. These are home to 1,250+ species of marine and freshwater fishes, mammals and invertebrates. As such, we are in a unique position to answer questions about aquatic animal biology and the interplay between species and environments which are within our control. We also have high-confidence, long-term data sets that include clinical records of animal health and physicochemical properties of their habitats. We would like to grow our ability to share these resources in exchange for operational support. Past partnerships of this nature have ranged from validation of eDNA detection of non-native bighead carp species to providing researchers in human medicine with post-mortem samples of vertebral columns from sharks who, unlike humans, do not experience spinal degeneration as they age.