麻豆传媒

PLANNING a trip to the beach? If you are holidaying in the UK, remember to cast a keen eye over the seaweed lying around. What you see could help monitor the impact of climate change on marine life.

Seaweed, including kelp forests, is a key component of marine ecosystems globally. The sea around the UK alone is home to more than 600 species. However, they are threatened by rising sea temperatures, ocean acidification and increases in non-native species.

鈥淲e know that 30 per cent of kelp around the world is changing, has been lost or is threatened,鈥� says , a seaweed researcher at the Natural History Museum in London.

By participating in this year鈥檚 Big Seaweed Search, you can help scientists like Brodie investigate how seaweed species around the UK are changing as oceans acidify and sea temperatures rise. Get started by visiting bigseaweedsearch.org.

The Big Seaweed Search team recommends that you begin your search an hour before low tide because this is both the safest time for amateur beach scientists and the best time to spot seaweed.

Select a 5-metre-wide strip that runs from the top of the shore to the sea. Starting at the bottom of this strip with your back to the sea, photograph the area to show the conditions when you did the survey. Then, walking away from the sea, explore your strip, photographing and noting details of any of 14 target species you come across.

You can identify these species using the guide on the survey website. When you have finished, submit your findings and upload your photos to the website (or you can send them in the post).

Information collected by volunteers through the Big Seaweed Search and similar research projects shows that the proportion of non-native seaweed species is increasing, says Brodie. In the UK, the figure has risen from 6 to 7 per cent over the past five years. 鈥淲e know that the number of alien species is increasing, so we鈥檙e curious to see where people are finding them,鈥� she says.

Noticing the absence or scarcity of species is important, too, says Brodie, because identifying threatened species helps guide conservation efforts.

If you don鈥檛 have access to a coastline or you live outside the UK, you can take part in other marine science without even leaving your home. The project asks volunteers to browse satellite images online to spot giant kelp forests. This helps scientists who are studying how these forests change over time.

Alternatively, if you enjoy playing games, you can download NASA鈥檚 game on your smartphone or tablet and score points as you help the agency to classify coral reefs.

For other projects visit聽newscientist.com/maker.