Australian-born Howarth grew up in New Zealand. She had only been to Muriwai once before and was surprised to find it had a gannet colony, she said.
She said was "totally blown away" by how stunning the spot was.
"The light was perfect, there was no one else around and there were birds everywhere -
there must have been thousands of them - so it was just great timing really," she said.
"It was just one of those moments when things came together perfectly. I didn't set out to capture the birds as I did not know they would even be there."
Howarth said New Zealanders are "so lucky to have access to these truly mind-blowing landscapes".
"They really do make amazing photographs."
Other winning shots on Junebug's list included waterfalls, a classic car and several shots of skinnydippers.
Junebug Weddings website editor Carrie Schwab said great engagement photos must capture the emotions of the moment but also show imagination.
"Engagement photography offers the photographer more time with their couple to get creative, whereas a wedding photographer may only have 30 minutes to take couple portraits on the actual wedding day.
"Wedding photography is truly an art form and we feel a lot of pride in showcasing these talented artists to couples all around the world."
