How is sewage and farming waste affecting underwater life?
The shore crab is one of the creatures that lives in seagrass meadows
- Published
New research shows that sewage and agricultural pollution - which is pollution caused by farming - is having an "alarming" knock-on impact for animals living along Britain's coastline.
Scientists found that in underwater seagrass meadows where there was lots of sewage, fertilisers and manure, there were far less small invertebrates like crabs, shrimps and snails.
Project Seagrass, which carried out the research with Swansea University found there were also less varieties of the species, too.
Dr Benjamin Jones from Project Seagrass said: "People don't want to swim in seas polluted by sewage... but this is one of the first studies of its kind...to show an impact on the animals too."
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What are seagrass meadows?
Seagrasses are flowering plants that live in shallow, sheltered areas of the coast.
Growing closely together they form underwater meadows.
They help fight climate change by absorbing a lot of carbon dioxide and are considered incredibly important habitats.
Dr Benjamin explained that, if seagrass meadows are forests, then the "invertebrates are basically insects that help it function".
Dr Benjamin Jones diving in a seagrass meadow
What is the waste doing to the water?
Sewage, fertilisers and manures from farms, and wastewater can all increase certain nutrient levels in rivers and estuaries.
These extra nutrients can lead to the growth of algae, which impacts seagrass beds by smothering them and blocking out the sunlight - which they need to grow.
This also takes a lot of oxygen from the water. The researchers found that in areas where there was lots of nitrogen, there were fewer animals and less variety in species.
The research focused on 12 areas around the UK coastline.
Dr Richard Unsworth from Swansea University says the findings are "quite alarming", because the reduced numbers and types of living things in the sea then impacts the amount of food there is for fish and birds.
Dr Jones added that looking after the wildlife in the seas needs to begin with tackling what is being washed off the land.
He said: "If we want to protect the marine environment we need to look towards the land... that's a conversation that's very rarely had."
