ABSTRACT This study describes some of the characteristics of the spawning runs of rainbow and brown trout from Lake Otamangakau, into Te Whaiau Stream. More than 55,000 fish undergoing spawning migrations were enumerated in a fish trap between 1994 and 2013. During that period, the spawning run size increased for both species, but particularly for rainbow trout, which exhibited a concurrent decline

ABSTRACT Galaxiid post-larvae constitute five of the six species in New Zealand’s iconic whitebait fishery. Distinguishing the five species needs to occur at a younger age than is convenient for easy identification. Traditional identification uses subjective characteristics such as colouration of fresh specimens and fin position, but supervised classification methods could be more accurate and less

ABSTRACT A summary is presented of the anthropogenic debris recorded up to 2020 in stomachs of marine fishes from New Zealand waters. This material (mainly plastics) was found in the stomachs of 28 species, with 24 of these species identified in two studies alone. Most of the New Zealand records were not identified in recently published global assessments of plastic ingestion by fish; the likely reasons

ABSTRACT Stream bank erosion has been anecdotally identified as an important source of sediment in New Zealand catchments, however, there have been few attempts to quantify its contribution. Here we use a radionuclide-based sediment tracing approach to determine the relative contribution of stream bank- and hillslope-derived sediment within three catchments in the upper North Island of New Zealand

ABSTRACT This study assessed the potential of the mud snail Amphibola crenata as a bioindicator of estuarine health. Multiple sites with varying contaminant inputs were identified within a small, shallow estuary (Avon-Heathcote/Ihutai in the South Island of New Zealand). Population structures of field-collected A. crenata were related to measurements of sediment trace metal profiles. Whole-body soft

ABSTRACT Coastal squeeze of saltmarshes (CSS) has substantially eliminated valuable intertidal habitats and worsened local tidal hydrological environment by disintegrating tidal creek networks and losing tidal connectivity (TC). In this study, we explored the process response of creek network structure and TC to CSS dynamics, taking the southern Bohai Bay of China as a case study area. With the Landsat

ABSTRACT A full account of the world’s species is important for understanding how natural systems are structured, how they function and how they will respond to natural and anthropogenic pressures in the future. Despite the well-known importance of parasites in natural systems, they are too often underrepresented from studies on biodiversity and ecological functioning. In this review, we provide a

ABSTRACT Tarakihi (Nemadactylus macropterus) is a demersal fish that supports valuable commercial, recreational, and customary fisheries in New Zealand. However, little is known about its stock structure. The population genetic structure, genetic diversity, and demographic history of N. macropterus were investigated using the hypervariable region one of the mitochondrial control region. 370 samples

ABSTRACT Isotope fractionation of fatty acids can reflect the metabolic pathway of fatty acids in organisms, but few studies have been conducted. In this study, stable carbon isotope fractionation of fatty acids in sea cucumber (Apostichopus japonicus) was conducted by feeding experiments of comparing the fatty acid profile and δ13C of fatty acids in body wall to diet. The results showed that the fractionation

ABSTRACT Lake sediments are the physical remnants of past allochthonous and autochthonous carbon and mineral inputs and therefore have the potential to illuminate both past terrestrial carbon cycling and within-lake biological productivity. However, there are currently no robust, rapid, and inexpensive methods to chemically characterise the organic matter (OM) components in lake sediments, which limits

(2021). The physics of New Zealand’s shelf seas: introduction to the special issue. New Zealand Journal of Marine and Freshwater Research: Vol. 55, Special issue: The physics of New Zealand’s shelf seas. Guest Editors: Craig Stevens, Joe O’Callaghan, Stephen Chiswell and Moninya Roughan, pp. 1-5.

ABSTRACT We assembled water-temperature data (1.0–15 m depth horizon) from several field studies (spanning 2003–2020) within Pelorus Sound to generate composite time-series of temperature at four locations. We also examined satellite-sensed sea-surface temperature records for the region (2002–2019). Time-series were deseasoned and Sen-slopes were calculated as measures of long-term trend. All of the

ABSTRACT Satellite-derived estimates of sea surface temperature (SST), chlorophyll (Chl), and fluorescence line height (FLH), from 22 sites ∼20 km offshore from the West Coast of the South Island, New Zealand (WCSI) are used to investigate long-term trends in SST, the frequency and magnitude of cool and warm events, and their impacts on SSC and FLH. WCSI trends have been towards higher temperature

ABSTRACT The Campbell Plateau is a dominating bathymetric feature of New Zealand’s subantarctic region, strongly influencing the dynamics of both the Subtropical Front (STF) to the north and the Subantarctic Front (SAF) to the south. We present a consistent survey across New Zealand’s subantarctic of the relationships between front positions, bathymetry and water masses. The northwest side of the Campbell

ABSTRACT Macroinvertebrate communities in running waters are commonly used as bioindicators of fine sediment pollution, but few studies evaluate impacts across multiple years. We used a 5-year dataset from 46 rivers in Southland, New Zealand to investigate the consistency of the relationship between deposited fine sediment and stream macroinvertebrates across three categories of agricultural land-use

ABSTRACT White sea catfish Genidens barbus is an endangered amphidromous species distributed between northeastern Brazil and northern Argentine Patagonia, whose migratory behaviour at the southern end of its range is unknown. Here, the migratory patterns of this species were studied including marine and freshwater (Patagonian stock) environments via otolith core-to-edge Sr/Ca and Ba/Ca profiles. Based

ABSTRACT The common bully (Gobiomorphus cotidianus) was used as a bioindicator to assess the impacts of geothermal, bleached kraft mill effluent (BKME), sewage, and thermal discharges in the Waikato River, Northern New Zealand. A range of morphological and physiological parameters were measured to assess fitness in fish sampled upstream and downstream from these point sources. Isotopic signatures gave

ABSTRACT Satellite-derived estimates of sea surface temperature (SST), chlorophyll (Chl), and fluorescence line height (FLH), from 22 sites ∼20 km offshore from the West Coast of the South Island, New Zealand (WCSI) are used to investigate long-term trends in SST, the frequency and magnitude of cool and warm events, and their impacts on SSC and FLH. WCSI trends have been towards higher temperature

ABSTRACT The distribution of marine mammal species in many areas remains poorly understood, especially as observations for some taxa are rare and large-scale surveys are time consuming and extremely costly. Here, we present 36 records of 7 cetacean species (Balaenoptera brydei, B. musculus subspp., Delphinus delphis, Globicephala sp., Grampus griseus, Physeter macrocephalus, Pseudorca crassidens) in

ABSTRACT Meiofaunal assemblages are often overlooked, yet they are important ecological components of estuarine ecosystems. To evaluate variations in meiofaunal communities in estuarine habitats, we conducted a comprehensive analysis of meiofaunal density, distribution and relationships with environmental parameters in a mangrove-dominated ecosystem at Mangawhai, Northern New Zealand, in summer (March)

Kākahi (Echyridella spp.) are freshwater cultural keystone species in New Zealand; they represent a valuable mahinga kai (species used as a food) resource and have high cultural significance to Māo...

Dedicated studies on aquatic disease in New Zealand began in 1974, inspired by a developing aquaculture industry. Since then, two main aquatic disease study areas have emerged: (1) aquatic disease ...

Fluvial dynamics are driven by multiple environmental factors and scales. Studies coupling hydrological and nutrient dynamics of mountain streams are almost non-existent in the Northern Patagonian ...

The eutrophication of lake ecosystems due to anthropogenic activities has impacted lakes worldwide and shallow lakes are particularly vulnerable. The retention of phosphorus (P) in lake sediments a...

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 ...

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 be...

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 ...

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 exa...

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 de...

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: Uni...

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 ...

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 indi...

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 interaction...

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

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, t...

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 o...

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 variab...

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. parahaemoly...

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 in...

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 Rea...

Stream-lake networks include multiple transition zones between lake-like and river-like conditions. This study analysed environmental features, macroinvertebrate assemblages (MIB) and functional fe...

This special issue of the New Zealand Journal of Marine and Freshwater Research is a tribute to one of New Zealand’s eminent freshwater scientists, Dr John Quinn, who sadly passed away in November ...

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 ...

ABSTRACT 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

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, ...

ABSTRACT 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

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 sto...

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 ...

ABSTRACT 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

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 generation...

ABSTRACT 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)

ABSTRACT 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

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 incr...

ABSTRACT 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

ABSTRACT 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

ABSTRACT 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

ABSTRACT 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

ABSTRACT 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

ABSTRACT 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

ABSTRACT 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