Macruronus Novaezelandiae Research Articles

Biocompatible supercapacitor engineered from marine collagen impregnated with polypyrrole and tungsten disulfide

There is an urgent demand for highly stable energy storage systems that are biocompatible, environmentally friendly, and made from affordable, sustainable materials. Research on biologically sourced materials as green energy storage devices such as supercapacitor (SC) technologies are emerging, but they are often expensive, complicated to manufacture, and fail to meet the required performance levels. This article presents a simple and innovative method to fabricate a human skin comfortable SC electrode using collagen extracted from hoki (Macruronus novaezelandiae) fish skin. Polypyrrole and tungsten disulfide nanoparticles were incorporated into the collagen matrix via early wetness impregnation to provide the required electrical properties. Electrochemical investigations revealed that the areal capacitance of the composite material was 348 mF cm−2 and cyclic testing showed that the capacitance retention is 98 % after 50,000 cycles. The collagen-based composite demonstrated excellent biocompatibility to HEK293 cells grown over a 1-week period. This novel technique for producing biodegradable and biocompatible SC electrodes from renewable source paves opportunities to utilize other sources of biomaterials for smart electronic applications.

Hybrid experimental designs for joint estimation of absolute and relative retention curves for trawl gears

Abstract Methods for jointly estimating both the size-specific relative retention and absolute retention (retention probability) of two experimental trawl gears are considered. One approach would be to undertake comparative fishing of both gears, from which their comparative catchability can be estimated directly. If comparative catchability can be corrected for differing sampling effort and fishing efficiency of the two gears, then relative retention can be estimated. Furthermore, if a suitable functional form of the absolute retention curve is assumed, then estimates of absolute retention can potentially be obtained. However, these estimated retention curves are seen to have extremely large statistical variability and will not be useful in practice. On the other hand, if the gears are each fished with a non-selective control, then absolute retention can be directly estimated, from which estimates of relative retention can immediately be obtained. However, these estimates of relative retention have greater variability than would be obtained by comparative fishing with the same level of sampling effort. It is shown that a hybrid selectivity design that includes both comparative fishing of the experimental trawls and fishing with a non-selective control provides a more balanced approach. An extensive simulation study is conducted using scenarios based on recently published work on selectivity experiments targeting cod (Gadus Morhua) and hoki/blue grenadier (Macruronus novaezelandiae).

Size selectivity of a novel non-mesh codend (the Modular Harvesting System) in a New Zealand deepwater fishery

The Modular Harvesting System (MHS) is an inflatable membrane-like fabric tube with escapement holes that replaces the mesh codend of a trawl, and is designed to reduce damage to catch by providing fish a low-flow, low-turbulence environment that allows them to maintain swimming control and avoid compaction during trawling and haulback. The MHS gear is now used within New Zealand’s most valuable finfish fishery, deepwater hoki/blue grenadier (Merlucciidae, Macruronus novaezelandiae). This work presents the novel research used to estimate the size selectivity of the MHS gear, and to compare this to the selectivity of the conventional mesh trawl. Management objectives required estimates of the absolute size-selectivity of both the MHS and conventional gears, and also an estimate of their relative selectivity. An innovative statistical power analysis was developed to specify the required number of twin-trawl tows and number of fish to measure to ensure the desired statistical power to detect a meaningful difference between conventional and MHS gears. A novel twin-trawl experiment was employed whereby the conventional and MHS gears were each paired with a nonselective control, and then the conventional and MHS trawls were paired. All catch data were simultaneously analyzed in a hybrid selectivity model. The MHS and conventional gears had similar estimated size-selectivity curves, and they were not significantly different.

Industry remotely operated vehicle imagery for assessing marine communities associated with subsea oil and gas infrastructure on the continental shelf of South-East Australia

Introduction Offshore oil and gas (O & G) infrastructure provides hard substrata of structural complexity in marine environments and has been shown to have ecological value, particularly in oligotrophic environments. As infrastructure approaches end of life, understanding such values is critical to inform decommissioning decisions. MethodsThis study uses a decade of industry remotely operated vehicle (ROV) imagery to describe fish, invertebrate, and benthic communities on gas field infrastructure. Sampling was conducted over 22 km of flowline, three wells and one manifold in the temperate waters of Bass Strait, south east Australia in depths of 155 to 263 m.ResultsA total of 10,343 mobile animals from 69 taxa were observed. A higher diversity of fishes were observed on flowlines (28 taxa) compared to wells (19 taxa). Fish and invertebrate communities observed along flowlines were distinct from those observed on wells/manifold, however, there was also high spatial variability among the different flowlines surveyed and between the three wells and manifold. These differences appear to be driven by habitat and depth preferences of the species observed. Many sand-affiliated species were associated with buried sections of flowlines (Tasmanian giant crab Pseudocarcinus gigas, Balmain bug Ibacus peronii, slender sand burrower Creedia haswelli, red cod Pseudophycis spp., blue grenadier Macruronus novaezelandiae) whilst reef-associated and schooling species were observed on the wells/manifold (jackass morwong Nemadactylus macropterus, redbait Emmelichthys nitidus, splendid perch Callanthias australis). Species of ecological importance were also noted including the Australian fur seal (Arctocephalus pusillus doriferus), long-lived foxfish (Bodianus frenchii), and handfish (Brachionichthyidae spp).DiscussionThis study describes the habitat value of oil and gas infrastructure in a data poor temperate region that is important for understanding how the decommissioning of these structures may affect local marine ecosystems and fisheries. Therefore, it is critical to understand the habitat value of O&G infrastructure to marine life in the Bass Strait and whether decommissioning of these structures affect local marine ecosystems and fisheries. This study shows the complexity of determining temporal change in biodiversity values associated with these O & G structures from historical industry datasets that will be key for informing future decommissioning options. We also provide some guidance on how future quantitative data can be obtained in a systematic way using industry ROV data to better inform ecological investigations and decommissioning options.

Suitability of Marine- and Porcine-Derived Collagen Type I Hydrogels for Bioprinting and Tissue Engineering Scaffolds.

Collagens from a wide array of animals have been explored for use in tissue engineering in an effort to replicate the native extracellular environment of the body. Marine-derived biomaterials offer promise over their conventional mammalian counterparts due to lower risk of disease transfer as well as being compatible with more religious and ethical groups within society. Here, collagen type I derived from a marine source (Macruronus novaezelandiae, Blue Grenadier) is compared with the more established porcine collagen type I and its potential in tissue engineering examined. Both collagens were methacrylated, to allow for UV crosslinking during extrusion 3D printing. The materials were shown to be highly cytocompatible with L929 fibroblasts. The mechanical properties of the marine-derived collagen were generally lower than those of the porcine-derived collagen; however, the Young’s modulus for both collagens was shown to be tunable over a wide range. The marine-derived collagen was seen to be a potential biomaterial in tissue engineering; however, this may be limited due to its lower thermal stability at which point it degrades to gelatin.

Warmer temperature decreases the maximum length of six species of marine fishes, crustacean, and squid in New Zealand

As global oceans continue to warm and deoxygenate, it is expected that marine ectotherms will reduce in body size resulting from the interactive effects of temperature and dissolved oxygen availability. A temperature-size response describes how wild populations of ectothermic species grow faster and reach a smaller size within warmer temperatures. While temperature-size responses are well observed in marine ectotherms, the mechanisms underpinning such a reduction in body size remain debated. Here, we analyse the relative influence of temperature, dissolved oxygen concentration, and geographic location (which encompasses multiple latent variables), on the maximum body length of four fish, one crustacean, and one squid species, which inhabit shallow to deep sea (1000 m) New Zealand waters across a temperature gradient of 1.5 to 18 °C. We found that all study species displayed a temperature-size response, with the strongest response exhibited by the largest species, hoki (Macruronus novaezelandiae). We also found that temperature was more important than dissolved oxygen concentration in determining maximum body length, as dissolved oxygen levels were at or near saturation in the study area. Our results suggest that larger-bodied species may experience the strongest temperature-size responses, and support expectations from the gill-oxygen limitation theory (GOLT) and the oxygen and capacity limited thermal tolerance (OCLTT) concept that increases in oxygen demand may be size- and temperature-dependent, thus driving a reduction in maximum body length of marine ectotherms with warming.

Assessment of Fish Quality Based on the Content of Heavy Metals.

The aim of this study was to estimate the fish quality in terms of the Cu, Fe, Mn and Zn contents. The research material was the muscle tissue of the fish crucian carp (Carassius carassius Linnaeus, 1758), flounder (Platichthys flesus Linnaeus, 1758), Gilthead seabream (Sparus aurata Linnaeus, 1758), mackerel (Scomber scombrus Linnaeus, 1758), Blue grenadier (Macruronus novaezelandiae Hector, 1871), rainbow trout (Oncorhynchus mykiss Walbaum, 1792), tench (Tinca tinca Linnaeus, 1758), tilapia (Oreochromis niloticus Linnaeus, 1758), Walleye pollock (Gadus chalcogrammus Pallas, 1814) and perch (Perca fluviatilis Linnaeus, 1758.). Heavy metals were determined with the atomic absorption spectrometry method (AAS). Significantly high concentrations of zinc (19.52 mg/kg wet weight), copper (0.77 mg/kg) and iron (6.95 mg/kg) were found in the muscles of crucian carp (p < 0.05) compared to the other fish studied, whereas Walleye pollock had a higher content of manganese (0.266 mg/kg) (p < 0.05). All studied fish species do not pose a threat to humans from these four metals. This was indicated by quality indexes (THQ and HI) whose values were below one. The values of these metals also did not exceed the maximum allowable concentrations established by the FAO (1983), but monitoring both the aquatic environment and the fish living there is necessary, for example, for the time-changing abiotic and biotic factors that can cause an increase in metals in the organs of fish.

Pivotal discrepancy measures for Bayesian modelling of spatio-temporal data

Within the field of geostatistics, Gaussian processes are a staple for modelling spatial and spatio-temporal data. Statistical literature is rich with estimation methods for the mean and covariance of such processes (in both frequentist and Bayesian contexts). Considerably less attention has been paid to developing goodness-of-fit tests for assessment of model adequacy. Jun et al. (Environmetrics 25(8):584–595, 2014) introduced a statistical test that uses pivotal discrepancy measures to assess goodness-of-fit in the Bayesian context. We present a modification and generalization of their statistical test. The initial method involves spatial partitioning of the data, followed by evaluation of a pivotal discrepancy measure at each posterior draw to obtain a posterior distribution of pivotal statistics. Order statistics from this distribution are used to obtain approximate p-values. Jun et al. (Environmetrics 25(8):584–595, 2014) use arbitrary partitions based on pre-existing spatial boundaries. The partitions are made to be of equal size. Our contribution is two-fold. We use K-means clustering to create the spatial partitions and we generalise Jun et al.’s approach to incorporate unequal partition sizes. Observations from a spatial or spatio-temporal process are partitioned using an appropriate feature vector that incorporates the geographic location of the observations into subsets (not necessarily of the same size). The method’s viability is illustrated in a simulation study, and in an application to hoki (Macruronus novaezelandiae) catch data from a survey of the sub-Antarctic region.

Genome-wide analysis reveals the genetic stock structure of hoki (Macruronus novaezelandiae).

The assessment of the genetic structuring of biodiversity is crucial for management and conservation. This is particularly critical for widely distributed and highly mobile deep‐water teleosts, such as hoki (Macruronus novaezelandiae). This species is significant to Māori people and supports the largest commercial fishery in New Zealand, but uncertainty about its stock structure presents a challenge for management. Here, we apply a comprehensive genomic analysis to shed light on the demographic structure of this species by (1) assembling the genome, (2) generating a catalogue of genome‐wide SNPs to infer the stock structure and (3) identifying regions of the genome under selection. The final genome assembly used short and long reads and is near complete, representing 93.8% of BUSCO genes, and consisting of 566 contigs totalling 501 Mb. Whole‐genome re‐sequencing of 510 hoki sampled from 14 locations around New Zealand and Australia, at a read depth greater than 10×, produced 227,490 filtered SNPs. Analyses of these SNPs were able to resolve the stock structure of hoki into two genetically and geographically distinct clusters, one including the Australian and the other one all New Zealand locations, indicating genetic exchange between these regions is limited. Location differences within New Zealand samples were much more subtle (global F ST = 0.0006), and while small and significant differences could be detected, they did not conclusively identify additional substructures. Ten putative adaptive SNPs were detected within the New Zealand samples, but these also did not geographically partition the dataset further. Contemporary and historical N e estimation suggest the current New Zealand population of hoki is large yet declining. Overall, our study provides the first genomic resources for hoki and provides detailed insights into the fine‐scale population genetic structure to inform the management of this species.

Determination of rate constant, order reaction model and shelf life of crude hoki (Macruronus novaezelandiae) oil

This study was aimed to determine the rate constant, order reaction model and shelf life of crude hoki oil. Fish oil was kept in dark rooms at 2, 20, 30 and 40oC respectively. After 0, 2, 5, 10, 15 and 20 weeks of storage, samples were taken out. The samples were analysed for chemical parameters (peroxide value), physical parameters (refractive index, and colour absorbance) and sensory parameters (odour and taste). Order reaction model was determined by revealing the mode of deterioration involved and employing order reaction equations, i.e. C = C0 ± k0t and In C = In C0 ± k1t for a zero order reaction and a first order reaction respectively. The results showed that the rate of peroxide value changes as well as odour and taste scores changes tended to follow zero order reaction. Meanwhile, the colour loss in crude hoki oil followed both zero- and first order reaction. It was suggested that odour from cold samples was to be employed in generating a shelf life prediction equation. The linear equations ln k = 5.15 – 2077 1/T (r2 = 95.61%) and ln = 3.93 + + 2102 1/T (r2 = 99.98%) were used to estimate the rate constant and predict the shelf life of crude hoki oil, respectively. The estimated shelf life of crude hoki oil stored at 2°C was up to 41 weeks.

A New Zealand green-lipped mussel oil-enriched high-fat diet exhibits beneficial effects on body weight and metabolism in mice.

To induce diet-induced obesity (DIO) in rodents, diets high in saturated fat and/or carbohydrates are commonly used. In the laboratory, standardised diets evolved over time without paying particular attention to the effect of fat composition on metabolic alterations. In the present study, customised high-fat diets (HFD) enriched with a combination of lard and different concentrations of New Zealand green-lipped mussel (Perna canaliculus) oil or MSC Hoki (Macruronus novaezelandiae, blue grenadier) liver oil, important sources of n-3 PUFA, in comparison with a solely lard-based diet, were fed to lean and DIO male C57BL/6 mice and their effects on metabolic parameters were monitored. Intriguingly, an isoenergetic HFD containing 63 % of total fat in the form of mussel oil and only 28 % in the form of lard attenuated HFD-induced body weight gain after 1 and 4 weeks, respectively. Consistently, changing a lard-enriched HFD to the mussel oil diet reduced body weight markedly even after mice had been exposed to the former diet for 10 months. The weight-reducing effect of the diet was not caused by altered energy intake or expenditure, but was associated with reduced visceral fat mass. Collectively, these data suggest a novel weight-reducing potential of green-lipped mussel oil.

Hypothesis of Antimora spp. (Moridae) Dispersion in the World Oceans Based on Data on Modern Distribution, Genetic Analysis, and Ancient Records

Based on the analysis of the current distribution, the results of the molecular genetic study into the diversity of the mtDNA region (the first subunit of the cytochrome c oxidase I gene (COI)) in the samples of the blue hake Antimora rostrata and the Pacific flatnose A. microlepis, and the generalization of literature data on fossil records of morids (Moridae), a scheme for hypothetical spreading of these species in the oceans is presented.

Responding to Climate Change: Participatory Evaluation of Adaptation Options for Key Marine Fisheries in Australia’s South East

Planned adaptation to climate impacts and subsequent vulnerabilities will necessarily interact with autonomous responses enabled within existing fisheries management processes and initiated by the harvest and post-harvest components of fishing industries. Optimal adaptation options are those which enable negative effects to be mitigated and opportunities that arise to be maximised, both in relation to specific climate-driven changes and the broader fisheries system. We developed a two-step participatory approach to evaluating adaption options for key fisheries in the fast-warming hotspot of south-eastern Australia. Four fisheries (southern rock lobster, abalone, snapper and blue grenadier) were selected as case studies on the basis of their high to moderate vulnerability to climatic effects on species distribution and abundance. Involved stakeholders undertook a “first pass” screening assessment of options, by characterising and then evaluating options. In the characterisation step potential adaptation options for each fishery, contextualised by prior knowledge of each species’ climate change exposure and sensitivity, were described using a characterisation matrix. This matrix included: the specific climate vulnerability/challenges, the implications of each option on the fishery system as a whole, the temporal and spatial scales of implementation processes, and realised benefits and costs. In the evaluation step, semi-quantitative evaluation of options was undertaken by stakeholders scoring the anticipated performance of an option against a pre-determined set of criteria relating to perceived feasibility, risk (inclusive of potential costs) and benefit. Our screening assessment represents a pragmatic approach to evaluate and compare support for and the effects of alternative adaptation options prior to committing to more detailed formal and resource intensive evaluation or implementation.

Modori reaction in blue grenadier and Alaska pollock frozen surimi and myosin degradation behavior upon addition of protease inhibitors

ABSTRACT The changes in protein degradation behavior in fish surimi upon addition of different protease inhibitors were examined, with the aim of identifying the proteases involved in the modori reaction in different species and grades of fish and at different temperatures. The modori reactions at 40, 50, and 60°C in four frozen surimi samples: grades FA and KA blue grenadier and grades SA and RA Alaska pollock were investigated. In the grade FA blue grenadier surimi, the modori reaction primarily involved metalloproteases at 40°C, serine proteases and cysteine proteases at 50°C, and cysteine proteases at 60°C. The reaction in the grade KA blue grenadier surimi involved multiple proteases at 40°C, and metalloproteases and cysteine proteases at 50 and 60°C. In the Alaska pollock surimi, multiple proteases were suggested to be equally involved in the modori reaction at 40, 50, and 60°C in both grades SA and RA samples.

Acoustic Assessment of the Micronekton Community on the Chatham Rise, New Zealand, Using a Semi-Automated Approach

Micronekton are a key component of the pelagic food web of the Chatham Rise east of New Zealand. The Chatham Rise is an important fishing area for hoki (Macruronus novaezelandiae), New Zealand’s largest finfish fishery, and a predator on mesopelagic fish. Four fisheries oceanographic voyages provided multi-frequency acoustic data (18, 38, 70 120 and 200 kHz) and midwater trawls, which were used to define a classification tree to separate micronektonic organisms. We carried out validation and sensitivity analyses that showed that we were able to classify pearlside (Maurolicus australis) and euphausiids. Other mesopelagic targets (mainly myctophids) were classified together based on their acoustic frequency response. Using scripting in the open-source software ESP3, we applied our classification tree to an independent time series of acoustic data from trawl surveys on the Chatham Rise between 2009 and 2018, that was not used for model development or validation. Our methodology allowed us to study temporal and spatial patterns of M. australis, euphausiids, and total backscatter in the water column. Total backscatter associated with micronekton has varied over the last ten years, with no clear trend. The abundance of euphausiids showed a significant decreasing trend over the last ten years. Abundance of M. australis also decreased since 2012, though this was not significant. This work contributes to on-going efforts to monitor and detect changes in the pelagic ecosystems.

Isolation and Characterisation of Major and Minor Collagens from Hyaline Cartilage of Hoki (Macruronus novaezelandiae).

The composition and properties of collagen in teleost (bony fish) cartilage have never been studied. In this study, we aimed to identify and characterise all collagen species in the nasal cartilage of hoki (Macruronus novaezelandiae). Four native collagen species were extracted using two techniques, and isolated with differential salt precipitation. We were able to assign the identity of three of these collagen species on the basis of solubility, SDS-PAGE and amino acid analyses. We found that hoki cartilage contains the major collagen, type II, and the minor collagens, type IX and type XI, which are homologous to those found in mammal and chicken cartilage. Using these extraction protocols, we also isolated a full-length type IX collagen from cartilage for the first time. In addition, we detected a 90 kDa, highly glycosylated collagen that has not been identified in any other species. For each isolate, structural and biochemical characterisations were performed using circular dichroism and Fourier transform infrared spectroscopy analyses, and the thermal denaturation properties were determined. Our results showed that the properties of hoki cartilage-derived collagens are similar to those of collagens in mammalian cartilage, indicating that teleost cartilage could provide biological ingredients for the development of biomaterials to treat cartilage-related illnesses.

Blue Hake Antimora rostrata (Gadiformes: Moridae) off the Atlantic Coast of South America: an Overview on Its Distribution and Biology

Long-term data on spatial and bathymetric distributions, preferred bottom temperatures, length and weight of blue hake Antimora rostrata caught off the Atlantic coast of South America are presented based on published and unpublished materials. The species frequently occurred in waters of southern Argentina where catches were considerably higher as compared with Brazilian waters. The blue hake were captured at depths from 97 to 2162 m (average depth 1279 m). Most of the specimens (65.1%) were collected at depths from 700 to 1300 m, similar to depths in other parts of the species’ range. Bottom temperatures at sites of blue hake captures in Brazilian waters were 2.18–4.20°C (average 2.93°C). Specimens in bottom trawl catches were 9–61 cm in total length, averaging 34.84 cm. The bulk of the catches (85.5% of individuals) were fish of 25–45 cm. Body weight ranged from 70 to 1380 g (average 437.5 g). Frequency of occurrence decreased from southern Argentina to northern Brazil; complete absence of records in the Central Western Atlantic might relate to different means by which the blue hake colonized the Pacific and Atlantic coasts of South America.

A first attempt to evaluate the age and growth of blue hake Antimora rostrata (Moridae, Gadiformes, Teleostei) from the Lazarev and Weddell seas (Antarctic)

AbstractFor the first time, the results of the study of the age and growth of blue hake Antimora rostrata in the waters of the Lazarev and Weddell seas (Antarctic) are presented. The longline catches were represented by fish from 42 to 69 cm in total length with weights between 420 and 2,900 g, and most individuals aged 25 to 27 years. A minimum age of 16 years was observed in a fish 47 cm long and weighing 450 g, while a maximum age of 35 years was recorded for an individual of 69 cm in length and 1,640 g in weight. The blue hake in the Lazarev and Weddell seas shows similar growth patterns to the fish from the Ross Sea and waters off Greenland.

Nanostructure of electrospun collagen: Do electrospun collagen fibers form native structures?

Collagen extracts can be electrospun to form fibers. The nanoscale structure of these fibers is not known but is expected to affect the biocompatibility of the spun materials. Collagen extracts from Macruronus novaezelandiae (hoki) skin were electrospun to form a fibrous material. The structure of the electrospun collagen fibers was analyzed and compared with the structure of native collagen, gelatin, and electrospun gelatin. Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and SDS-PAGE were used to characterize the basic molecular structure of the biomaterials and synchrotron-based small-angle X-ray scattering (SAXS) and Transmission electron microscope (TEM) were used to investigate the fibril nanoscale structure (molecular arrangement). ATR-FTIR and SDS-PAGE revealed characteristic patterns of intact alpha chains in the electrospun collagen and hydrolyzed fragments in electrospun gelatin, as expected. TEM revealed fibers in both the native collagen material and the electrospun samples. However, SAXS patterns showed axial periodicity was not present in the electrospun fibers. This is indicative of the spinning process forming fibers that lack internal fibril structure, in contrast to the hierarchical structure of native collagen. The architecture of collagen affects its function. By characterizing the molecular and fibril structure of electrospun collagen and comparing it with native collagen fibrils, we may inform functional studies of collagen, including its configuration for cell attachment and recognition.

Seafood Phospholipids: Extraction Efficiency and Phosphorous Nuclear Magnetic Resonance Spectroscopy (31P NMR) Profiles

AbstractThe absolute concentration of phospholipids (PL) (μmol g−1, wet tissue) in five marine tissues was determined using quantitative phosphorous nuclear magnetic resonance spectroscopy (31P NMR). Hoki (Macruronus novaezelandiae) roe was identified as a “high‐PL” seafood, containing 15.97 ± 4.72 μmol g−1 (wet tissue) of these compounds. This was 2–4× higher than the concentration of PL in monkfish (Lophius spp.) fillets (4.26 ± 1.52), arrow squid (Nototodarus sloanii) mantle (8.95 ± 0.89), Greenshell™ mussel (Perna canaliculus) (7.04 ± 0.87), or hoki liver (6.03 ± 0.76). The amount of PL extracted from these tissues was dependent on the extraction method used, with the Folch (1957) method consistently extracting more oil (and more PL) from all five tissues than the Bligh and Dyer (1959) and Jensen (2003) methods. The individual PL profiles of each tissue are also reported.