According to the most extensive investigation of the tidal Thames, since it was deemed biologically dead in the 1950s, seahorses, eels, seals, and sharks live there.
However, scientists from the Zoological Society of London (ZSL), who carried out the research, warn that industrial runoff and sewage discharges are causing rising nitrate levels along the 95 miles of the tidal Thames. In addition, as a result of global warming, water levels and temperatures are also increasing.
According to the State of the Thames report, summer temperatures in the upper tidal Thames have increased by 0.19C each year on average since the turn of the century. The extent of plastic contamination in the tidal Thames, which runs from below Teddington to Shoeburyness, is also emphasized. Wet wipes, in addition to thousands of plastic bottles, are a significant hazard.
Since 2014, Barnes’s one mound of wet wipes has grown by 1.4 meters and now covers 1,000 square meters. “These items, many of which contain plastic,” according to the research, “physically modify the foreshore along the Thames by forming enormous mounds of material densely bonded together.”
According to the paper, the density of microplastics discovered in the Thames is 19.5 plastics per cubic meter, and microplastics move down the river at a rate of up to 94,000 pieces per second. The Thames’ natural ecosystem was assessed by ZSL using 17 different indicators.
It emphasized the importance of specific conservation measures, such as the Salt Fleet Flats reserve on the Thames’s southern bank near the river’s mouth. A variety of wading birds call the mudflats and saltmarsh habitat home, which was established in 2016. Seahorses and even sharks, such as tope, starry smooth-hound, and spurdog, can be found in the Thames.
There were roughly 900 harbor seals and 3,200 grey seals, according to the most recent count. There has been significant and continuous growth in both seal populations in the Thames estuary since the studies began in 2003.
However, fish populations have been declining since the 1990s, and conservation specialists say more research is needed to figure out why. The tidal Thames supports about 115 fish species, 92 bird species, and nearly 600 hectares of saltmarsh, an essential habitat for various wildlife.
“Estuaries are one of our neglected and threatened habitats,” Alison Debney, ZSL’s conservation program head for wetland ecosystem recovery, stated. They supply us with clean water, flood protection and serve as crucial breeding grounds for fish and other wildlife. The Thames estuary and its related’ blue carbon’ habitats are vital in our struggle to prevent climate change and build a healthy and resilient future for wildlife and people.
“This research has allowed us to take a closer look at how far the Thames has come since it was pronounced biologically dead, and in certain situations, establish baselines from which to build in the future.”
While dissolved oxygen and phosphorus levels have decreased during the 1990s, scientists have discovered a long-term increase in nitrate concentrations, which can severely impact water quality and be harmful to wildlife.
According to the Environment Agency, industrial and sewage effluent dumping into the water are sources of excessive nitrate levels. Furthermore, many substances of concern are not being checked regularly, potentially harming the fauna of the Thames.