New research finds that the shrimp-like creatures on the southern coast of England have 70 percent less sperm than the least polluted sites elsewhere in the world The research also discovered that the number of individuals living in the survey area is six times less per square meter than those who live In cleaner water.
The discovery was published today at Aquatic Toxicology, Reflects similar results in other creatures, including humans. A leading research scientist at the University of Portsmouth believes pollutants may be responsible, which this latest research has highlighted.
Professor Alex Ford, a professor of biology at the University of Portsmouth, says: “We usually study the effect of chemicals on species after water treatment. The shrimp we tested are often in untreated water. The study site suffers from water storms, which are likely to become more common with Climate change. This means that creatures can be exposed to many different pollutants through sewage, historical landfills and old chemicals such as those found in anti-slip paints. There is a direct relationship between the rate of heavy rainfall and the levels of untreated wastewater. ”
Professor Ford describes the shrimp as “the canary in the mine” – worried that the shrimp’s plight is only the tip of the iceberg in terms of fertility problems for male creatures, both small and large.
“Some male fertility problems are thought to be related to pollution,” said Professor Ford. “It may not be the same pollutants, but all the chemicals are released into the environment. It is not being stopped, and most importantly, the effects are not being properly monitored or understood.”
Historically, most male fertility research has focused on vertebrate species. Very little is known about the effects of pollution on the fertility of invertebrates, particularly those amphibians at the bottom of the food chain.
A decade ago, University of Portsmouth scientists noticed very few shrimp with very few sperm in nearby Port Langston. Surprised by this result, they decided to observe the animals for the next ten years.
When Marina Tenorio Botelho, a PhD student at the University of Portsmouth, was unable to continue her lab-based research due to COVID restrictions, she was tasked with digging into data on contract statistics. Their routine study revealed the disturbing fact that these animals had consistently low sperm counts similar to those in artificially polluted areas.
Professor Ford explains that other marine creatures are also suffering: “We know that pollutants affect male fertility levels of all species. Killer whales around our coasts are contaminated with many pollutants that some cannot reproduce. Recent studies * have also indicated that porpoises are contaminated with industrial compounds. Highly toxic, known as polychlorinated biphenyls (PCBs), they undergo smaller tests. “
Researchers at the University of Portsmouth believe this new study feeds into broader studies of male fertility. Professor Ford says: “Researchers have been studying the global decline in sperm count in humans over the past 50 years. Research * has shown * that in some countries, a boy born today will have half the sperm count of his grandfather, and there are concerns that boys are dangerously close to Infertility.
Marina Tenorio Botelho’s research also showed that female shrimp produced fewer eggs and appeared at lower densities in the same waters. Because because of the poor ability of male shrimp to fertilize females, the females, in turn, have fewer eggs. Scientists are concerned that this could lead to a population collapse in the area, which could have an effect on the rest of the food chain. Eating less food ultimately means fewer birds and fish in the area.
* Williams, RS, Curnick, DJ, Brownlow, A., Barber, JL, Barnett, J., Davison, NJ, Deaville, R., Ten Doeschate, M., Perkins, M., Jepson, PD, Jobling, S . 2021. PCBs are associated with reduced testicular weights in porpoises (Phocoena phocoena). International environmentPp. 106303.