Top of the South Marine Biosecurity Partnership
Protecting the Top of the South from marine invaders


One of the goals of the Top of the South (TOS) Marine Biosecurity Partnership is to slow the spread of marine pests in the Top of the South Island. A focus of the work is on recreational boats at marina berths and on moorings. These types of vessels can easily accumulate marine pests in their hull biofouling and are the main ‘pathway’ by which pests established in and around port areas are spread into the region.

Since the summer of 2015/16, we have conducted regional in-water surveys of recreational boats to check for marine pests and assess levels of boat fouling, and checked for pests on adjacent structures like swing moorings. We also talk to boaters about the importance of keeping their hull clean, and collect basic data on their hull maintenance practices. These web pages provide a summary of the survey work and key findings.

Layout of web pages

You will see five tabs in the bar at the top of the page. These will take you to the detailed information from the surveys.

Each of the tabs provides key information relevant to the surveys, including:

Methods: summary of survey methods used, target marine pests and Level of Fouling assessment.

Key findings: provides a summary of the key findings from the latest summer survey, with a comparison to earlier years.

Explore data: enables visualisation of the survey results in the form of maps and graphs. In the top right navigation bar you can switch between views of the data for the entire TOS, or separately for each subregion (Tasman, Nelson, Marlborough). The sliding bar allows you to filter the data to time periods of interest. Hovering over map symbols and chart data shows additional information and clicking on their legend entries will show/hide layers. Static outputs and their data can be exported using the top left buttons on the maps (, ) and top right menu buttons on the charts ().


For feedback on web page content and ideas for improvement, please email us at