Dr. Jacob Allgeier, professor of Ecology and Evolutionary Biology at the University of Michigan, employs a unique tool in his research on the impacts of climate change on coastal ecosystems: fish urine. He and the researchers in his Coastal Ecology and Conservation Lab use fish urine and artificial reefs to study aquatic ecosystem conservation and food insecurity.
Allgeier said his research aims to lay the groundwork for future solutions in conserving coastal ecosystems, such as coral reefs and seagrass, which are under increased threat from factors associated with climate change and habitat encroachment.
“(Coral reefs, seagrass beds and mangroves) are disappearing at rates faster than pretty much any other system,” Allgeier said. “The rates of change are faster than any systems except maybe the Arctic, so they’re vastly threatened by climate change, development, fishing pressure, nutrient pollution.”
Allgeier said his lab focuses on methods of introducing necessary nutrients into these deficient ecosystems, landing on fish urine as a solution. Allgeier said fish are productive members of nutrient-poor coastal ecosystems and their urine can be used to provide vital support to coral and seagrass.
“In these ecosystems, essentially the fish and the other invertebrates, they are providing the fertilizer through their excretion, through their waste products,” Allgeier said. “Those waste products, largely fish pee, literally fertilize the ecosystems and allow them to be as productive as they are.”
In addition to researching the benefits of fish urine, Allgeier said his lab also works on the creation and development of artificial reefs.
“We construct the seagrass beds, and what happens is fish aggregate around the reef in high densities, and the pee nutrients really fertilize that local area from high density,” Allgeier said. “And that in turn enhances or jacks up the primary production, the seagrass around the reef, which provides more food and habitat for invertebrates, which provides more food for fish.”
The research will further the lab’s understanding on how the amount of fish in a local area affects the primary production — the creation of new organic matter by living organisms — of an ecosystem. Increases in the number of fish affect the primary production, invertebrates and the fish themselves, improving the overall health of the ecosystem.
Allgeier said coral reef conservation has positive effects on coastal communities which rely on the reef ecosystems. One focus of the research is using artificial reefs as tools to increase the productivity of fisheries, which would decrease food insecurity within local coastal communities. Currently, according to Allgeier, the population rates of tropical coastal communities which rely on fish are growing, leading to a decrease in food security due to overfishing. By placing artificial reefs on beds of seagrass, fish will fertilize the seagrass, which in turn will provide greater food and security to rebuild the fish population.
Rackham student Bridget Shayka, who also works in Allgeier’s lab, said it’s very important to ensure the artificial reefs used by the lab are placed in shallow areas available to coastal communities for two reasons.
“One is that seagrass also needs a lot of light, so it grows in shallow coastal areas,” Shayka said. “Plus we actually want the coastal communities to be able to access the benefits of these reefs. … We’re increasing the fish and invertebrate populations near the coast where the coastal communities can actually take advantage of that.”
Allgeier described how their research is working to develop a mathematical model which would help local communities sustainably fish by using the artificial reefs to alternate where they fish, allowing populations to replenish and decreasing food insecurity.
“So what we’re doing is we’re building mathematical models that allow us to be able to predict outcomes,” Allgeier said. “So say we want to build 20 reefs here (and) 20 reefs (there), the local communities can fish these reefs, but don’t fish these reefs, over 10 years that’ll increase the number of fish available to the people by X or Y.”
Alongside the development of a mathematical model, Allgeier’s lab has already established artificial reefs in Haiti, the Bahamas and the Dominican Republic to observe the research as it’s developing. These pre-existing reefs will allow the researchers to input confirmed data into the mathematical model and ensure that it works as intended.
Allgeier’s artificial reefs use items such as cinder blocks, which rest on beds of preexisting seagrass. LSA sophomore Shreyaan Seth, who works in Allgeier’s lab, said this specific form of preserving coastal ecosystems is something that has not been done before.
“It’s not something that’s been explored a lot, Jake is a little bit of a trailblazer here in the artificial reef field,” Seth said. “Because what I’ve heard people have done with artificial reefs before has just been planting coral and stuff like that, but his research is more about replicating the functionality versus planting coral which can be quite expensive and quite fragile.”
Shayka said the use of seagrass helps Allgeier’s reefs make an impact on climate change through carbon sequestration, which is the process of capturing and storing carbon in vegetation such as seagrass.
“(Seagrass) can store carbon at really high rates,” Shayka said. “This is partly due to their ability to trap sediment and bury it underground, which builds up carbon stock in the sediment.”
Allgeier said he takes issue with how some researchers deploy artificial reefs into the oceans.
“I actually have a lot of issues and a lot of concerns about the extent to which we are just willy-nilly throwing stuff overboard and calling it an artificial reef,” Allgeier said. “I think we need to be really calculated about this. Instead we’re just creating more trash essentially into the ocean.”
Shayka said there are numerous advantages of Allgeier’s model of placing artificial reefs within seagrass bed.
“If you just put an artificial reef in a sandy area, even if the fish come, when they’re peeing, they’re peeing on sand, instead of seagrass,” Shayka said. “Seagrass are habitats that house all of these organisms as well. … When you put down an artificial reef there, and you increase production, there are organisms, there are seagrass, there are (invertebrates) there to have increased production. You’re not just creating a structure for the fish to come to, you’re actually increasing production in the system.”
According to Seth, this overall increase in production acts as a cycle wherein the seagrass provides habitats for invertebrates, who provide food for fish, who further fertilize more seagrass with their pee.
Allgeier said while the development of his form of artificial reefs can result in increases in management and research potential, the implementation of artificial reef management should be managed by local communities.
“We ask questions, and we use their local knowledge to base what we do, and then the goal is that (the artificial reefs are) their reef,” Allgeier said. “They’re not mine, and so as we do this we also bring education into the process and help them understand the underpinning mechanisms of how these things work and try to really explain what’s going on, but the management is theirs.”
LSA junior Sean Richards, who works in Allgeier’s lab and takes a class with Allgeier, said the research is highly relevant to students on campus.
“Fisheries make up a ton of what we consume, and … people want to move away from those pasture farm products,” Richards said. “They’ll typically want to move towards a pescatarian diet. And so that actually puts additional stress upon these fisheries, typically in the tropics, and so if you aren’t doing the research to conserve these environments then you’re gonna lose a lot of that income, that food. You won’t have as much fish to eat.”
Daily News Contributor Joshua Nicholson can be reached at joshuni@umich.edu.