A comprehensive mussel spat questionnaire, which will be used to survey mussel spat collectors and harvesters in Kaitaia and the Marlborough Sounds region. These surveys will be conducted through personal and telephone interviews, as well as online questionnaires, distributed and promoted through email. The aim of this work is to gauge and utilise the knowledge, opinions and experiences of people that have been or are involved in mussel spat aquaculture to direct and focus areas of potential future research at NIWA.

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.

The Stock Exclusion Low Slope Land 2020 layer identifies areas of "low slope land" as defined in the Resource Management (Stock Exclusion) Regulations 2020. The layer shows the land parcels, or part parcels, defined as low slope land. These areas have a mean slope is less than or equal to 10 degrees. Parcels with a parcel intent of "ROAD" are excluded. Areas of lakes, ponds, settlements and urban parkland, as defined in Land Cover Database 5, are also excluded. Areas of low-slope grassland and annual cropland within high-slope parcels are also included in the Stock Exclusion Low Slope Land extent.

NIWA reviewed an assessment of environmental impacts of salmon farms at Te Pangu Bay, Tory Channel (U090841) and Clay Point, Tory Channel (U060926), prepared by the Cawthron Institute for The New Zealand King Salmon Co Ltd (NZKS), and proposed variations to the Environmental Quality Management System (EQMS) for the farms.

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.

The feasibility of shifting the consent area for marine farm 8049 in Oyster Bay, Queen Charlotte Sound to deeper water was assessed in this report. Sampling of the new site and nearby reef was conducted using a remote-operated camera (ROV) to attain photographs and video transects, as well as an acoustic dropper current profiler (ADCP) to measure currents in the ocean. Mathematical modelling was also incorporated (DEPOMOD modelling). Results showed that depths were suitable for the development of a finfish farm, and the farm would be beyond any significant depositional footprint if established. Although greater production was likely to result in enrichment effects to the benthic communities which may result in a replacement of existing benthic species by opportunistic species.

Plant and Food Research engaged NIWA to design and implement a survey programme to monitor the effects of an experimental fish feeding operation on the benthic environment in Nelson Haven, to satisfy resource consent requirements. This was conducted to assess whether the feeding programme would adversely affect the local benthic environment, the survey focussed on measuring key indicators of organic enrichment. To do this, a range of sediment physicochemical parameters were characterised using benthic cores and sledding methods. Parameters included: sediment grain size, sediment organic content, sediment colour and smell, and redox potential of surficial sediment,and also biotic features including: the composition of animal communities living upon and within the sediments, and the distribution and abundance of macroalgae. This report describes the survey undertaken 8 months after the commencement of the fish feeding activity. Benthic and sediment data from 7 sites have been processed, checked, analysed, and summarised in the client report. Previous reports in this time series are: Brown, S. N. (2014a). Wildfish 2030: Benthic Monitoring Baseline Survey. Report prepared for Plant and Food Research Ltd. NIWA Client Report No. NEL2014-013. 18 p. Brown, S. N. (2014b). Wildfish 2030: Benthic Monitoring Survey – First post baseline survey. Report prepared for Plant and Food Research Ltd. NIWA Client Report No. NEL2014-021.18 p.

To satisfy resource consent conditions at a mussel farm site near Beacon Rock and Blind Bay, Banks Peninsula, Sanford LTD commissioned NIWA to conduct a benthic monitoring survey. Sampling for this project included a benthic grab and benthic sled to obtain samples to describe sediment physicochemical characteristics, and benthic assemblages at sample sites established along transects extending to the northwest, north and east of the farm block.

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.