Natural Resources Wales is reassuring visitors to some North Wales beaches that bright orange-coloured water is not pollution.
It says it's a type of seasonal marine algae.
Officers have been testing the water at Penmaenmawr beach and have identified the early signs of an algal bloom.
There are reports Reports that the orange colour is visible at Llandudno and may also be present on other beaches in North Wales.
The Noctiluca marine algae, also known as Sea Sparkle, is common across the Welsh coastline during this time of year, and is a naturally occurring phenomenon.
The orange colour can be even more pronounced at night as it appears to glow in the dark.
The iOS version of a new beaches app will be launched later this morning in Kenfig, with the Android versions also available to download in a few weeks.
– Emyr Roberts, Chief Executive of Natural Resources Wales
The app will help highlight some of the excellent recreational opportunities that are available for people in Wales and the visitors who come to explore. The Wales Coast Path showcases the diversity of the landscape and habitats of Wales, from the urban environments to the vast countryside, linking up our nation."
In many parts of Wales, it's been the sort of day when you might have thought about heading to the beach.
Soon you'll be able to take advantage of a new app available from today which tells you all you need to know about the beach you may be heading to.
Carl Edwards reports.
A new app is being launched today with the aim of making discovering Wales' beaches easier. The app - along with its accompanying website - has been developed by environmental charity Keep Wales Tidy.
The website contains detailed information on 150 beaches including how to get there; the awards they hold and the facilities available. In addition, the app holds information on the route and gradient of the Wales Coast Path; live weather links and tide timetables.
The launch of the new app and website will take place in Kenfig later this morning and will be available to download shortly afterwards.
Heavy rain and flooding in Wales last summer is being blamed for the drop in the number of beaches which have excellent water quality, according to the latest Good Beach Guide.
The annual results released by the Marine Conservation Society (MCS) today show that the number of beaches found as having excellent water quality has fallen from 153 in 2012 to 98 this year.
Beaches which failed to meet bathing water standards included Rhyl in Denbighshire, Criccieth in Gwynedd and Ogmore Slip in the Vale of Glamorgan.
The MCS said, "Relentless rain and flooding in many parts of the country led to an increase in the amount of bacteria and viruses ending up in our bathing waters.
"This type of pollution can originate from a variety of sources such as agricultural and urban run-off, storm waters, misconnected plumbing, septic tanks and dog faeces.
"Sewage and animal waste is full of viruses and bacteria and most water users won’t be aware that this type of pollution can increase the chance of them going home with an ear, nose or throat infection, or even gastroenteritis."
To see whether your local beach passed the test visit the Good Beach Guide website here.