A group of Pacific Islanders joined an environmental protest blockading the Newcastle coal port on Friday, disrupting shipping traffic by paddling canoes across the harbour mouth.

Members of the Pacific Climate Warriors action group traveled from nations including the Marshall Islands, Fiji, Vanuatu, Tokelau, the Solomon Islands and Papua New Guinea to draw attention to the effects of climate change on their island nations, and to protest Australia’s continuing commitment to coal.

The Newcastle port is the world’s largest coal handling facility. An annual flotilla blockade has been held for several years, but this was the first time protesters were joined by the group from the Pacific Islands.

Fijian protester George Nacewa had earlier told Guardian Australia the effects of climate change were “really evident back at home with coastal erosion and in terms of sea-level rise”.

“To date there has been the relocation of two villages, they’ve moved further inland,” he said. “That’s Fiji alone, and the other Pacific islands are more affected because most of them are just atolls.”

“We lose our cultural identity and we lose our land, because we identify ourselves with the land and the ocean,” he said.

On Friday morning the 30 men and women were joined by a few hundred others on Horseshoe beach at Newcastle, as well as a police presence on land and water.

After a procession of several canoes shipped from Vanuatu, Fiji and other islands, and a Polynesian war dance, the traditional vessels took to the water. There were laughs and cheers from the crowd and police when two men tipped and then sank their canoe almost immediately. Then the leader of an outrigger canoe with “Tai Tokelau” painted on the side, shouted for others to “bring the kayaks” and dozens went in on their plastic watercraft.

“If we get to stop a coal ship, then all the better,” Nacewa told Guardian Australia after returning to shore. “But at the end of the day we are here to highlight the impact of climate change. All these islanders in their costumes – they live the realities of climate change.”

Milañ Loeak, from the Marshall Islands told Guardian Australia the climate warriors were joining the protest to tell people their stories in the hope more would join them in their fight.

“Just last week we had a king tide that affected some homes in the villages,” said the 26-year-old, adding that droughts and floodings were frequent.

Tiny coral atolls, the Marshall Islands are “especially” vulnerable to sea level rises, she said. “It’s something very personal to me, especially seeing it first hand and seeing family members and relatives and friends and their families have to leave their homes and find new places to stay.”

Kayakers were not permitted to go beyond yellow markers just a short distance offshore, but almost immediately a large number paddled past them into the middle of the waterway.

Within half an hour, the bulk carrier, Rhine, appeared, being pulled out of the port by tugs. Protesters quickly formed a blockade, hampered on one side by police boats. Police officers used boats to push the light watercraft back, and took jetskis around canoes to create wake and spray. The 225-metre vessel was delayed for a short time until police cleared the way.

One 47-year-old kayaker, Donna Bartlett, claimed a police officer on a jetski made contact with her bright orange kayak, knocking it against another and dislocating her finger. She said jetskis on either side of a group were sending protesters in opposite directions, causing chaos.

“The jetskis come, trying to get us unbalanced,” she said. “I’m scared today but I know the stakes.”

Zana Kobayashi, 25, from Newcastle, said she’d joined the protest because the federal government “doesn’t seem to be doing anything to address concerns [about climate change].”

Kobayashi, who was in a double kayak, said police on the water confiscated their paddles and towed them out of the way of the ship. When protesters began returning to shore, another officer towed them in. She said there were “a few aggressive characters” among the police officers.

Inspector Steve Laksa told Guardian Australia several people were detained and brought to shore, but none were facing charges. In going past the yellow markers, protesters “put other persons at risk and in danger”, Laksa said.

He was unaware of reports about police jetskis hitting Bartlett’s kayak, but said: “Police were on the waterway to ensure the safety of the protesters and persons on the waterway illegally, and were asking them and giving certain directions to move back to shore.

“The information I’ve been provided and what I’ve seen for myself is that the police have given directions to the protesters and set a line to the yellow markers.

“We were concerned there were a number of protesters with children that were entering into the waterway, in the path of a large ship. We had some serious concerns and had given directions for them to move back.”