The summer business can help each family in Quang Nam Province earn 2,200 USD.

It’s algae time for fishers in Quang Nam Province in central Viet Nam between May and July. They paddle out in search of sargassum, a type of brown seaweed found in tropical oceans that can be used to make surgical thread, adhesive, fertilizer and pesticide, as well as alcoholic drinks.

The algae can be found at depths of one to seven meters about a kilometer off the coast.

Locals say you need to be fit and strong to dive for algae. The men tie themselves to metal blocks weighing around five kilograms to stay underwater.

A tube to supply oxygen to a diver.

As a man sends the algae up, his wife collects it in a coracle.

Each family can collect between 200-300 kilograms a day and earn more than 50 million VND (2,200 $) from the season, the same as Viet Nam's average annual income for 2016.

The algae is laid out to dry after it is harvested. Dealers also hire workers to clean sand and other trash from the algae, which earns them 200,000 VND a day.

Locals say dealers pay them 5,500 VND per kilo of algae, which will then be sold in China.

(Source: VnExpress International)