All kinds of creatures can be found at beaches. (ABC Sunshine Coast: Grace Nakamura)
From shark eggs to deep sea creatures, long-lost jewellery, and silver rat poison canisters — all sorts of strange things can wash up on our beaches.
As people flock to the coast over the school holidays, beachcombers are urged to use their common sense about whether something is harmless or hazardous.
Sunshine Coast resident Carol Finn was looking for shells on the beach with her grandson recently when she came across something she couldn't identify.
A marine biologist says the object is likely a zebra shark egg. (Supplied: Carol Finn)
"It's about 10 to 15 centimetres long, it's like a bubble, sort of a bronzy-brown colour, transparent when held up to the light," she said.
A post to a local community Facebook page had residents debating whether it was a seed pod or a shark egg — or if sharks even lay eggs at all.
Mrs Finn said the consensus was that it was a shark egg, often referred to as a "mermaid's purse" because of its shape.
Sunshine Coast resident Carol Finn walks along the beach to pick up rubbish and collect interesting things. (ABC Sunshine Coast: Grace Nakamura)
She said she had lived on the coast for 30 years and often collected interesting pieces from the shore for her grandson to take to daycare.
"I think it's just so important that kids who live around here realise how precious where we live is," Ms Finn said.
"The boys are really into collecting rubbish when they go along the beach.
"And when you collect rubbish, you also find other interesting things like beautiful shells and shark eggs."
Carol's grandsons love exploring rock pools for marine life. (ABC Sunshine Coast: Grace Nakamura)
Marine debris getting worse
Another beach find caused confusion when what looked like a robot vacuum washed ashore in Noosa.
Beachgoers were confused by what looked like a robot vacuum washed up on a beach near Noosa. (Supplied: Colin Jones)
Founder of the Australian Marine Debris Initiative Heidi Tate said it was actually a GPS buoy, used in commercial fishing.
"Each year from Cooktown to Cape York, we see about 300 washed up on the shoreline," she said.
Ms Tait said there was about 15 million tonnes of rubbish entering the ocean every year.
"The world's population keeps increasing therefore we keep using more stuff, our landfills keep getting full," she said.
"Plastics account for over 80 per cent of the rubbish on average that we find, and plastic never goes away."
Ms Tait said beachcombers could help by reporting their debris finds to the relevant organisations.
Penny Robertson has found couches, shoes, and even a pool table that has washed up on the shore. (Supplied: Penny Robertson)
Blue bottles and deep-sea creatures
Marine biologist Julian Pepperell said, while it was relatively safe to go beachcombing, there were a lot of bluebottle jellyfish to watch out for at this time of year.
Dr Pepperell said when it came to finding unusual marine life, it's best to take a photo and contact the Queensland Museum.
This unusual-looking object which washed up on Peregian Beach in 2017 is a porcupine fish swim bladder. (Supplied: Jess Yates)
This toothy creature found in Noosa is a starry pufferfish. (Supplied: Donna Sennett)
The discovery of this blue dragon nudibranch (or sea slug) sparked plenty of interest on Moffat Beach in 2019. (Supplied: Jason Cassidy)
A turtle bone was another interesting find on Shelly beach. (ABC News: Grace Nakamura)
"Sometimes deep-sea fish come in that die and get washed up like ribbon fish, oar fish," he said.
"That's always of a lot of interest if they're relatively rare."
Dr Pepperell said he once saw a 3-metre-long swordfish that had washed up on a beach near Noosa.
A nearly 3-metre-long swordfish washed up on a Queensland beach. (Supplied)
He said, as a rule of thumb, it was best to leave strange-looking creatures alone to "let nature take its course".
That is, unless it's dead, particularly weird, and small enough to fit in a freezer for the museum to collect.
Warning for 'poison canisters'
Not everything that washes up on the shore is safe to handle.
Since 2012, Australian emergency services have had dozens of reports of silver canisters washing up on beaches that contain a rat poison called aluminium phosphide.
Queensland Parks and Wildlife Service (QPWS) have an active alert for a number of beaches, including K'gari (Fraser Island), North Stradbroke Island, Bribie Island, and Moreton Island.
The canisters are likely to have come from an "unreported shipping cargo loss sometime before February 2012".
Toxic silver canisters have been washing up on Australian shores since 2012, mostly on the east coast. (Supplied: Australian Maritime Safety Authority)
If opened, the flammable gas inside has a "strong odour that can smell like garlic, rotting fish, or urine."
"Exposure can cause symptoms such as headaches, nausea, vomiting, difficulty breathing, dizziness, tightness of the chest, diarrhoea, fluid in the lungs, liver/kidney damage, and in severe cases death," the alert reads.
Authorities warn that these canisters should not be moved or opened and should be reported to triple-0.
Beach kids often grow up with a fascination for marine life. (ABC News: Grace Nakamura)
ABC Sunshine — local news in your inbox
Get our local newsletter, delivered free each WednesdayYour information is being handled in accordance with the ABC Privacy Collection Statement.