NIWA conducted a survey to assess the scallop abundance within Block B in the interim AMA in Golden Bay. A random dredge survey (15 tows) was carried out to quantify relative abundance of scallops within Block B, AMA 1 on 27th March 2014, using two scaled-down commercial scallop dredges. Results showed that the scallop densities in 2014 were similar to previous surveys and did not indicate a substantial recovery of the fishery at the present time.

Tidal currents were measured by a month-long deployment of an ADCP seaward of the existing farm in Te Pangu over a neap-spring cycle. Results showed that while water flow was greater close to the mouth of Te Pangu, recirculation and eddies generated by adjacent headlands suggested there would be no significant advantages in moving net pens within the near vicinity once drag from the net pens was considered.

NIWA was contracted by Property and Land Management Services (PALMS) LTD to assess phytoplankton depletion due to the extension of marine farms 8431, 8432 and 8433 in East Bay, Port Underwood. This was achieved by running a hydrodynamic model over a period of 100 days (11 April to 20 July 2005) and was validated by the associated ADCP data. Results revealed that the overall depletion footprint was very similar to the existing-farms case, which was expected given the modest increase in the total effective number of mussels from the extension.

Water column monitoring at the end of Stage 1 for mussel farm MPE921 (Site 8572) in April and May 2011 estimated phytoplankton concentrations from fluorescence and chlorophyll a measurements.

To satisfy resource consent conditions for monitoring at 2 mussel farm sites in Pigeon Bay, Banks Peninsula, Pigeon Bay Aquaculture LTD commissioned NIWA to conduct a survey of the seabed beneath the 2 farm sites.Sampling for this project included a benthic grab, core samples and benthic dredge at sample sites established along 4 transects extending to the north, east, east(middle) and south of the farms. At each site, measurements and observations were performed to characterise key indicators of benthic effects including sediment grain size, sediment organic content, sediment smell and colour, depth of sediment, redox layer, infaunal community composition, epifaunal community composition, and shell drop. Results showed no evidence that the mussel farming activity had caused significant adverse impacts to the benthic habitat or communities beyond and beneath farm boundaries.

The Marlborough District council is developing the second generation of its resource management plan for the Pelorus Sounds area. This includes, amongst other things, the identification and protection of significant marine biological sites, and the development of marine farming provisions. Pelorus Sound is a key location for both significant sites and activities This project provides a historic context for understanding how the Pelorus has changed, and will assist in the development of environmental outcomes for seabed habitats of planning provision. This project uses the Compound Specific Stable Isotope (CSSI) method developed by NIWA scientist, Max Gibbs, that can identify and apportion, by land use on a catchment scale, the sources of soil contributing to the sediment at a location of an estuary (Gibbs 2008).

Just Mussels LTD engaged NIWA to complete a benthic survey and assessment as part of a coastal permit application for an extension to marine farm 8321, in Wilson Bay, Pelorus Sound. This assessment comprised side-scan-sonar swath mapping of sites to characterise seabed topography, photoquadrats of the seabed to ground-truth the side-scans, samples of epifauana, diver observations and core sampling. The report indicated that the proposed extension is not expected to cause any significant adverse ecological effects. The ecological effects of farming the proposed additional mollusc species are likely to be no greater than the effects of farming green mussels. Farming of the algal species (as proposed) is unlikely to have any significant ecological effects. The report identifies a dense population of burrowing shrimp (Upogebia hirtifrons) adjacent to the inshore boundary of the site. However, the report notes that there is unlikely to be any significant detrimental effect of the proposed extension to the shrimp burrow habitat.

Aquaculture Direct engaged NIWA to complete a benthic survey and ecological assessment as part of a coastal permit application for an extension to marine farm 8203, near Camel Point, at the entrance to Tennyson Inlet, Pelorus Sound. This assessment comprised side-scan-sonar swath mapping of sites to characterise seabed topography, photo-quadrats of the seabed to ground-truth the side-scans and sled samples. The report indicated that the proposed extension is not expected to cause any significant adverse ecological effects. The ecological effects of farming the proposed additional mollusc species are likely to be no greater than the effects of farming green mussels. Farming of the algal species (as proposed) is unlikely to have any significant ecological effects. Work was completed during May-July 2014.