Combined Hunter Underwater Group (CHUG) celebrated its 10th anniversary last weekend and the small group has been working hard to build our community's understanding of marine issues, increase involvement in citizen science projects and work in partnership with agencies and groups since.

The ultimate aim of the group is to deliver positive results for our marine bioregions, in particular the southern section of the Manning Shelf Bioregion from Myall Lakes to the Hunter River and includes the Port Stephens-Great Lakes Marine Park.

On reflection, our group has been proud to work with local divers, National Marine Science Centre and State Government to fan curiosity of what lies beneath the surface through the Sea Slug Census project.

To showcase the variety of nudibranchs seen locally and the enthusiasm of divers, snorkelers and rockpoolers to get involved in citizen science. The project has gained interest further afield with census' happening in other locations across the state and around Australia.

Not as photogenic is the work undertaken by CHUG to document the less palatable story: the conversations around community perceptions and understanding of where rubbish goes. Port Stephens and the ocean are downhill from everywhere. Whether it has been on the annual Clean Up Australia Day, held each March, or other marine debris survey activities, our volunteers have been disappointed at what has been found and collected underwater especially at the Nelson Bay breakwater.

Some rubbish has arrived through storm water drains and plumes of rubbish can be seen in relatively shallow depths just offshore, other pieces appear to have been blown overboard or thrown, out of sight for some, but not our volunteers. Some of the stranger items collected and recorded include an Elsa plastic figure found 'frozen' down six metres, credit cards, fishing tags identifying a commercial catch which had been packed interstate, and mobile phones.

Each underwater cleanup is time limited due to the tides, with an average of 2km of fishing line (a very tight football sized amount) removed after carefully unravelling from the soft corals and marine algae to minimise further damage.

In addition to fishing line around 8kg of plastic packaging items, consumer items such as cigarette butts, straws and plastic cups, bait bags and recreational fishing items. Over 10 years that is a total of 80kg of rubbish and 20km of fishing line: further than the distance from Shoal Bay to Soldiers Point.

CHUG encourages everyone to think about the impact of their actions on the local Nelson Bay community and our marine environment; to dispose of their food wrappers, fishing tackle and line in a bin or preferably take it home with them.

The longer your rubbish stays in the outdoors, or underwater, it breaks up into smaller pieces and can be ingested by fish, birds and marine turtles or cause entanglement.

These residents of the Port Stephens-Great Lakes Marine Park have a tough time surviving and reaching maturity without the added pressure of dealing with our plastic rubbish.

Margo Smith is the co-founder and chair of the Combined Hunter Underwater Group.

Beneath the Surface is an Examiner column exploring the Port's incredible marine park and its inhabitants, in collaboration with divers, marine scientists, photographers and eco groups.