Scientists are on a quest to better understand the watershed of St. Thomas by cataloging the species of spineless creatures that dwell in it.
Last month, Drs. Christopher Rogers from the University of Kansas and Edwin Cruz-Rivera of the University of the Virgin Islands published a paper detailing the discovery of a new species of clam shrimp found in the Herman E. Moore Golf Course at UVI.
“The project that led to the discovery of this little shrimp was aimed at establishing baselines relating to groups of animals that you would find in the water with the conditions of that water,” said Cruz-Rivera.
“When we first started, one thing that became really clear is, we don’t know anything,” he said. Much of the existing scientific literature had been published by scientists who stumbled across their findings while on vacation, according to Rogers.
“It is amazing how many new records of species we have for the Virgin Islands,” said Rogers. “And with the clam shrimp out now, we’ve got more coming.”
He said there is a long precedent for using creatures and critters as indicators for habitat health and functionality dating back to the Clean Water Act of 1972, which set rules and regulations governing water pollution in the U.S.
“This has never been done in the Virgin Islands,” said Rogers, despite the fact that the mandates in the Clean Water Act apply to all U.S. territories and protectorates. Many of the regulatory requirements for data collected for the Clean Water Act are based on insect populations, but “tropical islands have very few insects,” he said.
Initially, researchers proposed looking at fish as a way to monitor water quality, but they found examining fish in this environment isn’t as revealing as studying their spineless cohabitants.
“The problem with fish is, you want to know the quality of water in this section right here,” said Rogers. “Some of these fish are living for decades or more and they could have just swam in from someplace that’s a lot cleaner or a lot more polluted, because they’re so old, the condition of these fish could be the result of conditions somewhere else.”
An invertebrate, however, is more indicative of its environment.
“Because they’ve got such a short lifespan, because they don’t travel so far from where their eggs were laid, they’re much more sensitive to perturbations in the system,” said Rogers.
In addition to living fast, dying young, and being void of wanderlust, invertebrates offer an extreme amount of biodiversity.
“Depending where you are in North America you could be getting up to 400, 500 different species of invertebrates,” said Rogers. “Because of the many species, and each species has its own range of ecological tolerances, you’ve got a lot more indicators to look at.”
So far, Rogers and Cruz-Rivera have recorded 130 species of invertebrates found in St. Thomas, “some of which are being found in places that nobody would ever even think of looking into,” said Cruz-Rivera, citing an invertebrate species found in the depression of tire tracks left in some mud.
Identifying their findings is no easy task, the researchers say. Much of their work is done using direct comparisons, which means looking at samples from collections around the world and comparing them to their specimens to identify the species. “I’ve borrowed samples from our museum of natural history here [University of Kansas]; I’ve borrowed from the Smithsonian; I’ve borrowed from Harvard,” said Rogers.
The world of invertebrates encompasses such a vast amount of individually unique creatures that Rogers and Cruz-Rivera have had to call upon experts from specialized fields to help identify some of their records.
“If you talk to the worm people [the people who study worms,] that group is so diverse, they don’t say they specialize in worms, they say that they specialize on a specific family,” said Cruz-Rivera.
“So sending it to Expert A may be completely useless because your specimen has nothing to do with the family he studies.”
Rogers and Cruz-Rivera’s project is still ongoing, and in the future they hope to recruit locals to help collect samples as a way to engage the community and get people excited and educated about what’s going on in the local watershed. “We can only do so much,” said Cruz-Rivera.
“We often don’t pay attention to the small things, and by that we end up thinking they’re not important, but if you look at the role these small things play in the environment and we eliminate them we could end up impairing really important things,” he said.