ABSTRACT The physical behaviour of estuaries controls the transport of substances from freshwater to the ocean. We conducted the first investigation of salinity distribution and its response to spring-neap tides and freshwater flow rates in the Waitemata Estuary, and estimated several estuarine parameters. Four surveys were conducted: two surveys were conducted in summer during spring-tide, low flow

ABSTRACT The Motueka catchment is a major river system in the South Island, New Zealand, typically considered to be of ‘good water quality’. The catchment has high metal inputs originating from a mineral belt in the headwaters. This study investigated the induction of metallothionein (MT) in the common bully, Gobiomorphus cotidianus, to assess exposure to trace metal contamination in the Motueka River

ABSTRACT Mysidae are widely distributed in aquatic ecosystems and form a large proportion of the hyperbenthic biomass in estuaries. The seasonality, spatial distribution and reproductive biology of the two hyperbenthic mysid species, Tenagomysis chiltoni and Tenagomysis novaezealandiae, were studied in an open estuary. Sampling was conducted bi-monthly at night between February 2008 and April 2009

ABSTRACT The identification and subsequent protection of suitable breeding habitat for little penguins (Eudyptula minor) is restricted by data deficiency across large stretches of the species range. For example, presence/absence data is lacking for much of the Canterbury coast, mainland New Zealand. In October 2019, a Protected Species Detection Dog was used to conduct the first comprehensive survey

ABSTRACT A literature review on longevity of New Zealand deep-sea fishes provided life history parameter estimates for 17 bony and five cartilaginous species. Preliminary age estimates for a further nine deep-sea bony fishes were made from otolith zone counts and included results from a pilot analysis of radiocarbon age estimates from the otoliths of three of the species. Radiocarbon age estimates

ABSTRACT We measured δ15N, δ13C, and percent carbon (C) and nitrogen (N) on foot and remaining soft tissue of the two native freshwater mussel species Echyridella aucklandica and E. menziesii (Hyriidae: Unionida) from three Waikato, northern New Zealand, streams to investigate differences among sites, sexes and species. Mean differences in δ15N and δ13C between foot and remaining soft tissue (mainly

ABSTRACT Ponds are increasingly being constructed to enhance amenity values in human-dominated lowland landscapes, but little is known of design features that influence macroinvertebrates which can provide important food resources for fish and waterbirds. We quantified pond characteristics, sampled benthic and water-column macroinvertebrates in winter, and related abundance, biomass and community composition

ABSTRACT Age compositions from eight blue cod (Parapercis colias) subpopulations off the South Island of New Zealand were compared to investigate recruitment patterns temporally and spatially. Findings indicate (1) recruitment is highly variable between years, (2) subpopulations closer to each other have similar age compositions, and (3) strong and weak recruitment events are linked and the key processes

Stream biofilms play an important ecological role in the supply of energy and organic matter to aquatic food webs. Bacterial community composition in stream biofilms is shaped by biotic interactions as well as physicochemical conditions which vary across space and time. However, knowledge of the relative importance of spatial versus temporal factors for microbial community composition is lacking. Here

Phosphorus (P) release from sediments accumulating since catchment deforestation, has been linked to algal blooms which have occurred in Lake Wairewa (Canterbury, NZ) for over a century. However, the mechanisms controlling this internal P loading are poorly understood. To address this issue, we investigated sediment P fractions, P release, dissolved oxygen (DO) and pH at the sediment–water interface

Wetland restoration or re-establishment is a common conservation goal, and the ability of a wetland community to recover from events such as drought are key to its long-term success. At the mouth of the Waiau River in Southland, New Zealand, a series of wetland ponds have been created by diverting water from the river. A period of particularly low river flows resulted in the wetland drying out entirely

Lakes are ‘hotspots’ for greenhouse gas (GHG) emissions, primarily carbon dioxide (CO2) and methane (CH4). Understanding the processes regulating GHG emissions from lakes, and their temporal variability, is essential for more accurately quantifying the role of lakes in global GHG cycles. In this study, we identified the processes that affect CO2 and CH4 concentrations in a small (0.3 km2) eutrophic

Vibrio parahaemolyticus and Vibrio vulnificus can be found in oysters in coastal environments. Vibrio vulnificus can induce life-threatening illness when ingested with oysters, while V. parahaemolyticus usually causes self-limiting gastroenteritis. This study investigated correlations between concentrations of these Vibrio species in Pacific oysters from eight New Zealand coastal regions (2008–2017)

Biomarkers in receptor species can be used to assess and monitor ecosystem health. This study aimed to develop mRNA biomarkers in the New Zealand triplefin Forsterygion capito and validate their induction in response to common estuarine contaminants. The targeted genes were cytochrome P450 1A (cyp1a), metallothionein (mt), vitellogenin (vtg), and cytochrome P450 aromatase (cyp19b). Fish were treated

(2020). Preface: land-use impacts on aquatic ecosystems - tribute to John Quinn. New Zealand Journal of Marine and Freshwater Research: Vol. 54, Special issue: Land-use impacts on aquatic ecosystems: evidence and solutions —Tribute to John Quinn, pp. 305-307.

Degradation of aquatic ecosystems by fine sediment is a global environmental problem, and damages reflect particle properties as well as mass concentration. We studied sediment-related water quality (SRWQ) of small streams in hill-country near Whatawhata, NZ, that have been monitored since 1995. In 2001, an integrated catchment management (ICM) plan was implemented in the Mangaotama (originally sheep-beef)

National assessments have highlighted that urban streams have some of the poorest water quality in New Zealand, yet there has been no analysis focussing on these streams. In this study we defined urban streams as >15% catchment urban land cover and used monitoring data to assess several indicators of water quality including dissolved metals, nutrients, bacteria and the macroinvertebrate community index

Environmental sustainability and the long-term wellbeing of Māori (the indigenous people of New Zealand) are interdependent and degradation of landscapes risks the progressive degradation of Māori wellbeing. The present study developed an analysis framework based on Ki Uta Ki Tai (holistic-mountains to the sea- management philosophy advocated by Ngāi Tahu) for exploring relationships between landcover

Understanding temporal patterns in restored environments is important for identifying potential barriers to recovery and improved management of degraded habitats. In this paper, we use temporal beta diversity analyses to compare invertebrate community recovery trajectories in three restored agricultural stream sites under different integrated catchment plans, a native forest reference site, and two

There is concern about the deteriorating nutrient status of aquatic receiving environments in New Zealand. We estimated the amount by which current nitrogen (N) concentrations and loads exceed criteria in rivers, lakes and estuaries nationally. Criteria corresponded to national ‘bottom-line’ (i.e. minimal) environmental objectives set by government policy. Three metrics were evaluated: (1) degree of

ABSTRACT We present hindcasts of currents in Cook Strait from a baroclinic, tide-resolving ocean model. Three hindcasts are run, forced respectively at the lateral boundaries with data from the Bluelink Reanalysis (BRAN), the global Hybrid Coordinate Ocean Model (HYCOM) and a New Zealand Shelf Seas baroclinic hindcast (NZROMS). The hindcast forced by BRAN is evaluated against measured currents at locations

Stream-lake networks include multiple transition zones between lake-like and river-like conditions. This study analysed environmental features, macroinvertebrate assemblages (MIB) and functional feeding groups in outlet, inlet and tributary streams (i.e. streams other than the main stem) of a stream-lake network in Chilean Andean lakes, to verify if lake outlets reflect an ecotone condition. Permutational

Ctenophora are important components of marine ecosystems. However, the South-western Atlantic and Sub Antarctic region are still one of the least studied region in the world. We report the species composition and spatial distribution of Ctenophora and reviewed the studies performed in this region. New data obtained between 1910 and 2019, encompassing an area of c. 7 million km2 (32–60°S, 34–70°W) were

Three independent annual surveys with some spatial–temporal overlap were amalgamated to describe the population dynamics of the New Zealand intertidal cockle (Austrovenus stutchburyi) at Lews Bay, Whangateau Harbour from 1997–2018. After more than a decade of relative stability there was a dramatic decline in the biomass (from 7.4 to 1.8 kg wet weight m−2), density (1049 to 409 individuals m−2) and

There is currently little understanding regarding storm surge in New Zealand, particularly in the southern region. To date, there has been no attempt to establish the frequency and magnitude of storm surge using observed sea level data on the open coast. The aim of this study is to examine the nature of storm surge in southern New Zealand and explore the influence of the Southern Annular Mode (SAM)

Blue mussels, Mytilus galloprovincialis, are a widespread and ecologically important species in New Zealand coastal ecosystems, yet, there is limited information on the seasonality and variability in reproduction among populations. The reproductive cycle of M. galloprovincialis was studied monthly over 1-year in two southern New Zealand populations (Aramoana (45.7787°S, 170.7037°E) and Timaru (44.3905°S

The ability of different broodstock generations to provision lipids to their gametes is often overlooked in aquacultured freshwater fish. In this study we investigated the ability of two generations (F1 & F2) of Giant Kokopu (Galaxias argenteus) to provision fatty acids into their eggs. Here we show that eggs of captive-bred females (F2) displayed different relative fatty acid concentrations compared

The New Zealand aquaculture industry is based primarily on the production of Greenshell™ mussels, Chinook salmon and Pacific oysters. The industry is primed for development and is anticipating increasing its export earnings to NZ$3 billion by 2035. To achieve this target and retain its ‘clean and green’ image, the industry must be able to demonstrate that its practices are sustainable. Integrated multi-trophic

The planting of degraded land with tree plantations may be effective at improving land use sustainability and profitability but it can also have significant effects on stream hydrology. In this paired catchment study, we report the stream hydrological response to partial (62%) afforestation of a steep pastoral catchment in the western Waikato Region, North Island, New Zealand. We comprehensively analyse

Echinoderms play important ecological roles in the benthic community, but the processes that regulate their distribution are still poorly understood. The aim of this study was to describe the community structure in the shallow rocky reefs of the Wellington region of central New Zealand. Five sites from a harbour and an open coast were surveyed for adult echinoderm density and habitat composition. Additionally

The genus Xenostrobus consists of small, marine and estuarine mussels that all appear similar externally. One of its estuarine species, Xenostrobus securis, with a native range in New Zealand and Australia, has become invasive in the Northern Hemisphere. No genetic data are available to determine if X. securis populations from the two countries are conspecific. Additionally, marine Xenostrobus from

Determining the genetic structure and population dynamics of harvested species are key aspects of effective fisheries management. New Zealand scampi (Metanephrops challengeri) is a species of nethropid lobster that supports a commercial fishery on the continental shelf and slope around New Zealand. To determine the genetic structure and historical population demography of New Zealand scampi, we sequenced

Microplastic pollution in aquatic systems has been reported globally at an alarming rate, with an increasing number of documented negative biological consequences. Research on microplastic pollution in freshwaters has barely begun in New Zealand, and few studies from smaller lotic systems such as streams exist globally. We investigated the extent of microplastic pollution within urban streams across

Genypterus blacodes, in terms of its fishing history and local economic importance, is an emblematic species harvested in Chilean Patagonia (41°00’–57°00’S). Most of the current fisheries and biological knowledge of this species come from the open ocean, whereas information about the species in fjords and inner channels is fragmentary. In 2018, two research surveys targeting G. blacodes were conducted

Water is an important component of many recreational opportunities and New Zealand invests significant resources in recreational water quality (RWQ) monitoring to assess risks to public health. However, monitoring primarily focuses on microbiological hazards and RWQ is considerably broader than this. The goal of this study was to take a comprehensive approach to evaluating RWQ while exploring the potential

Movement patterns of the Southern Rock Lobster Jasus edwardsii in Victoria, Australia were investigated from 8,533 tag-recapture events across a 20-year period (1992–2012). In total, 83% of lobsters were recaptured within 1 km of their tagging site and 93% within 5 km. While largely resident, elevated movements were observed within specific regions, with the overall direction of movement being from

ABSTRACT The length-frequency distribution of sperm whales (Physeter macrocephalus) was studied on the east coast of NZ using passive acoustic recorders moored offshore of Kaikoura, Cape Palliser and Castlepoint. Sperm whale’s echolocation signals are unique among odontocete species. Their clicks are composed by multiple pulses resulting from the sound transmission within the whale head. The total

The tetrasporophytic ‘Trailliella’ stage of the red algal genus Bonnemaisonia is reported for the first time from the Southern Hemisphere. Here we describe a bloom of the tetrasporophyte of B. hamifera from the mouth of the Waikouaiti River, Karitāne, South Island, where it occurred as thousands of free-floating tufts up to 1 cm wide in shallow water, accumulated in windrows on sand banks and beaches

Recruiting King George whiting Sillaginodes punctatus were studied to assess the potential for food competition with permanent resident fish species in a nursery habitat. Marine migrant post larval S. punctatus (<60 mm TL) consumed primarily harpacticoid copepods and had high (>0.6) diet overlap with permanent resident fish species Favonigobius leteralis and Stigmatopora nigra. Food electivity index

Phosphorus (P) stores in gravel-bed rivers are released for uptake by periphyton when pH levels exceed 8.5. The Tukituki River has low alkalinity water and frequently experiences periphyton blooms, and daytime pH > 9 during summer low-flows. We measured dissolved reactive P (DRP) and EPC0, the water concentration of DRP at which no net release or sorption from the river bed occurs, in sediment samples

Whitebait comprise a culturally, commercially and recreationally important fishery in New Zealand, where post-larvae are netted while returning from their marine phase. In this study, we expanded an historical (1964) sampling programme to gain a contemporary understanding of the species composition of the whitebait fishery; 87 rivers were sampled over six months in 2015. Over the entire country, >12

Dissolved nutrient uptake and metabolism by periphyton in a central North Island gravel-bed river were investigated using recirculating in-situ chambers. Dissolved inorganic nitrogen (DIN) uptake was correlated with photosynthesis and chlorophyll but N uptake and carbon fixation were partly de-coupled indicating storage. Dissolved reactive phosphorus (DRP) uptake was only weakly correlated with photosynthesis

Instream processes alter the concentration and bioavailability of nutrients as they are transported downstream. By relating primary production and periphyton composition to changes in nutrient concentration in a gravel-bed river this study made inferences about recycling and attenuation. Where dissolved inorganic nitrogen (DIN) was abundant, concentrations decreased linearly with distance but by less

Human settlement in Bay of Islands, New Zealand, beginning ∼1300 AD, wrought immense, conspicuous and enduring change to local shallow-water marine ecologies, this review addressing those transformations attributable to increased rates of anthropogenically induced, land-derived sedimentation. Elevated silt inflow, particularly after the late-1800s, in course led to ∼130% expansion in mangrove (Avicennia

National-scale analyses of land cover effects on water quality can aid in directing environmental policy. We compiled a coastal water quality database for New Zealand comprising 320 estuarine and coastal sites with records between 2013 and 2018. Previous literature had shown strong effects of agricultural and urban land cover on the quality of New Zealand’s rivers, so we examined their effects on estuaries

Knowledge of trophic status is fundamental to understanding the condition and function of lake ecosystems. We developed regression models to predict chlorophyll a concentrations (chl a) in New Zealand lakes for reference and current states, based on an existing dataset of total nitrogen (TN) and total phosphorus (TP) concentrations for 1031 lakes. Models were then developed to predict Secchi depth

SedNetNZ is used to model the effect of erosion control undertaken under the Sustainable Land Use Initiative (SLUI) and predict the effect of climate change on sediment load in the Manawatū–Whanganui region. Sediment load in 2004 is estimated at 13.4 Mt yr−1; by 2018, ≈5000 km2 of land had farm plans implemented and annual sediment load reduced by 6.2% of the 2004 load. If SLUI stops at the 2018 level

(2020). Microcoleus autumnalis and filamentous algae-dominated mats and chlorophyll-a increase with agricultural land use but respond differently to associated nutrient and sediment enrichment. New Zealand Journal of Marine and Freshwater Research: Vol. 54, Special issue: Land-use impacts on aquatic ecosystems: evidence and solutions —Tribute to John Quinn, pp. 449-466.

Introduced aquatic macrophytes can dominate small agricultural waterways in summer and autumn becoming a significant management problem. Excessive growth can clog waterways, causing drainage issues and reducing agricultural productivity while in-stream velocities are reduced and sedimentation increased. Consequently, water managers remove them by mechanical clearance, chemical spray and cutting which

We test the paradigm that in a future warmer ocean, shallower winter mixing will lead to less net primary production (NPP), by investigating whether warming between 2002 and 2018 led to changes in NPP in the Tasman Sea/New Zealand region. The 2002–18 trend in sea surface temperature (SST) was positive over most of the region, and was driven by increasingly warmer summers and marine heat waves (MHWs)

A comparison between 4 (near) global ocean reanalysis products is presented for the waters around New Zealand. The objective is to provide information for an educated choice of ocean estate estimate. The simulations are compared to satellite and in situ observations, and vertical sections are extracted to evaluate the representation of the main regional boundary currents and their transport. Overall

ABSTRACT Aotearoa New Zealand is a land and cultures surrounded by one of the planet’s larger marine exclusive economic zones per capita. Understanding, living within and utilising this domain requires a well-developed knowledge of the physical oceanography – fate, provenance and transfer of ocean-water, material and energy. In the Aotearoa New Zealand context, understanding and utilising the environment

ABSTRACT A 4-month time series of water column temperature structure on the shelf of North Island New Zealand is used to calculate the energy in the internal tide as stratification evolved between spring and summer. Average total energy in the internal tidal wave was 200 J m−2, with peaks reaching 600 J m−2. Wave energy was weakly correlated with stratification (r = 0.2) and with the spring-neap cycle

Analyses are presented of model simulations and Lagrangian drifter experiments designed to quantify circulation and dispersal in Tasman and Golden Bays, and their connection to Cook Strait, New Zealand. Observations made in autumn 2017 and summer 2018 are compared with numerical model results. The drifter experiments were focussed on three repeat experiments in each bay designed to measure the local

This study uses a combination of regional ocean modelling systems (ROMS), a sediment transport model (sedtrans05) and detailed grainsize data with the aim of determining the hydrodynamics and primary sediment transport pathways on the North Canterbury Shelf (NCS), South Island of New Zealand. Combining the results from the hydrodynamic model, sediment grainsize data and sediment transport model in

To meet the challenges of preventing and reversing adverse effects of land use on ecosystems, management actions need to be founded on strong evidence. We used the pressure-state-impact (PSI) framework to assess evidence of land-use effects on New Zealand freshwater ecosystems. The evidence consisted of published quantitative and categorical associations linking land-use pressures to state changes

(2019). Lake resilience: concept, observation and management. New Zealand Journal of Marine and Freshwater Research: Vol. 53, Special issue: Lake resilience: Concept, observation and management. Guest Editors: Deniz Özkundakci and Moritz K. Lehmann, pp. 481-488.

The mean, interannual variability, decadal variability, and longer-term trends in the across-track geostrophic velocity of the poleward-flowing boundary current along the Fiordland coast (the Fiordland Current, FC) are examined over the altimeter record (September 1992–May 2017). In the mean, the FC is southwestward, with stronger velocities in an inner current near the coast and weaker velocities

(2019). Plankton: A guide to their ecology and monitoring for water quality, 2nd edition. New Zealand Journal of Marine and Freshwater Research: Vol. 53, No. 3, pp. 480-480.

Critically endangered Māui dolphin (Cephalorhynchus hectori maui) are found exclusively off the west coast of New Zealand’s North Island. One important data gap troubling efforts to reduce the current unsustainable level of bycatch is the limited information on the offshore and alongshore limits of their range. Passive acoustic monitoring studies could address this data gap, but Māui dolphin habitat