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1.
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 on estuaries, while controlling for marine dilution and freshwater flushing. Sites with greater freshwater influence had higher nutrient and faecal indicator bacteria concentrations, and turbidity, indicating that open coast and estuarine water quality is reduced predominantly via flows from the land. Nitrate, ammonium, total and dissolved reactive phosphorus, and water column chlorophyll-a concentrations were greater in estuaries with higher urban land cover and total phosphorus concentrations were greater with higher agricultural land cover. There was a marginally significant increase in turbidity as agricultural land cover increased. This is the first national-scale compilation and analysis of New Zealand coastal water quality data, and the first national analysis of land cover effects on water quality in New Zealand estuaries. 相似文献
2.
Kevin J. Collier 《新西兰海洋与淡水研究杂志》2013,47(2):349-351
Absorbance at 360 nm and dissolved organic carbon (DOC) concentration were measured on 47 filtered water samples collected from streams and rivers of the west coast of South Island, New Zealand. The regression equation (DOC (g m‐3) = 59.6 Abs1 cm + 1.9) calculated from the data, reliably predicted DOC concentration within the range 1.6–43.2 gm‐3. This relationship is similar to that found fsr some Venezuelan and south‐eastern United Stales waters indicating that it may have widespread utility for estimating DOC concentrations in soft waters where DOC is dominated by humic substances 相似文献
3.
J. L. McKoy 《新西兰海洋与淡水研究杂志》2013,47(3):263-275
Bankia neztalia was found in temperate waters around New Zealand, mainly south of New Plymouth and Tauranga. Bankia australis was found in warm‐temperate waters north of Nelson; it requires water temperatures above 19–20°c for successful breeding and is euryhaline. Lyrodus pedicellatus also occurred in warm‐temperate waters north of Nelson and had a lower water temperature limit for survival of about 10 °c. Lyrodus medilobatus occurred in warm‐temperate waters on the north‐east coast of the North Island north of Tauranga. Nototeredo edax is uncommon and occurred over the same range as B. australis. The presence of shipworms in wood collected from depths of greater than 50 m around New Zealand is reported. Teredora princesae is recorded from driftwood around New Zealand. 相似文献
4.
Nitrogen and phosphorus in New Zealand streams and rivers: Control and impact of eutrophication and the influence of land management 总被引：2，自引：0，他引：2
Abstract Given sufficient light and heat, the growth of aquatic macrophytes and algae associated with eutrophication is generally controlled by the concentration, form and ratio between nitrogen (N) and phosphorus (P). Data from 1100 freshwater sites monitored for the last 10 years by New Zealand's regional councils and unitary authorities were assessed for streams and rivers with mean nitrate/ nitrite‐N (NNN), dissolved reactive P (DRP), total N (TN) and total P (TP) concentrations in excess of New Zealand guidelines, and to generate a data set of N:P ratios to predict potential periphyton response according to the concentration of the limiting nutrient. The frequency of sites exceeding the guidelines varied from 0 to 100% depending on the parameter and region, but South Island regions were generally more compliant. The dissolved inorganic N (DIN) to dissolved reactive P (DRP) ratio was used to group data into three nutrient limitation classes: <7:1 (N‐limited), between 7:1 and 15:1 (co‐limited), and>15:l (P‐limited), by mass. P‐limitation was the most frequent scenario in New Zealand streams (overall, 76% of sites were P‐limited, 12% N‐limited, and 12% co‐limited). The mean concentration of the limiting nutrient for each site was combined with empirical relationships to predict periphyton densities (the average of N‐and P‐limited growth was used for sites with co‐limitation). This assessment predicted that 22 sites were likely to exceed the periphyton guideline for protecting benthic biodiversity (50 mg chlorophyll a m?2), but this assessment is likely to be highly changeable in response to climatic conditions and present and future land use. As an example, we modelled N and P losses from an average sheep and a dairy farm in Southland (South Island, New Zealand) in 1958, 1988, 2008 and 2028. We predicted that with time, as farm systems have and continue to intensify, N losses increase at a greater rate than P losses. Since the pathway for N to reach fresh waters may be more tortuous and take longer than P to reach a stream or river, focusing mitigation on P losses may have a quicker effect on potential algal growth. In addition, with time, it is expected that P‐limitation in New Zealand's rivers and streams will be more widespread as N‐losses are unabated. Hence, although strategies to decrease N losses should be practised, mitigating P losses is also central to preventing eutrophication. 相似文献
5.
PA Franklin 《新西兰海洋与淡水研究杂志》2013,47(1):112-126
Maintenance of suitable conditions in lowland rivers for both fish passage and resident species is crucial to ensuring the long-term sustainability of fish populations. The dissolved oxygen concentration of water is a key factor controlling habitat quality for fish and a critical measure of stream health. Continued land use intensification and greater exploitation of water resources has contributed towards increasing the frequency and duration of low dissolved oxygen events in lowland rivers and the associated risk of adverse effects on fish communities. Revised guidelines are therefore proposed to support setting of biologically relevant dissolved oxygen limits for the protection of New Zealand freshwater fish communities. These guidelines account for both event magnitude and duration, identify different protection levels based on the risk of negative impacts and are based on current scientific knowledge on the tolerances of New Zealand fish species. 相似文献
6.
Cylindrospermopsis raciborskii is a planktonic freshwater cyanobacterium that is becoming increasingly prevalent in water bodies worldwide. During a survey of toxic cyanobacteria in New Zealand, C. raciborskii was identified in a sample collected from Lake Waahi (Waikato). This is the first identification of this species in New Zealand. Liquid chromatography‐mass spectrometry and liquid chromatography‐tandem mass spectrometry were used to confirm the presence of the cyanotoxins cylindrospermopsin (CYN) and deoxy‐cylindrospermopsin (do‐CYN). Detection of CYN and do‐CYN demonstrates that C. raciborskii is a now a species of concern in recreational, stock drinking, and potable water supplies in New Zealand. 相似文献
7.
Lepidocybium flavobrunneum (Smith, 1849) is widespread in warmer oceanic waters and has recently been recorded in the catches of tuna longline vessels in the New Zealand region. Twenty‐five specimens were caught at 31°46′‐32°03′S, 170°49′‐171°11′ E on 23–27 June 1979, thus extending the known range of the species to northern New Zealand. 相似文献
8.
Laboratory experiments demonstrated that migrant juvenile banded kokopu (Galaxias fasciatus Gray) were more sensitive to suspended sediment (SS) than other native fish species. If juvenile migrants avoid waters made turbid by SS and their recruitment to adult habitats up stream is reduced, then adult abundance may decline in turbid rivers. To test this, we compared the abundance of diadromous native fish between turbid and clear rivers. The duration (% time) for which SS concentrations exceeded 120 mg litre‐1 (a critical level from laboratory experiments) during the migration season (August‐December) was estimated for over 150 New Zealand river sites. Turbid rivers were defined as those where SS concentrations exceeded 120 mg litre‐1 for over 20% of the time and clear rivers as those where SS concentrations exceeded 120 mg litre‐1 for less than 10% of the time. Eight turbid rivers and seven clear ones were identified where sufficient data on SS and native fish populations existed to permit a comparison. The mean occurrence of banded kokopu was reduced by 89.5% in turbid rivers and, although other diadromous fish species were also less common, banded kokopu was most affected. Densities of adult banded kokopu were also significantly lower in optimal stream habitats in three turbid compared with three matched clear rivers. We therefore concluded that the abundance of adult banded kokopu was reduced in turbid rivers and propose that this is because of reduced recruitment of juveniles in turbid rivers. 相似文献
9.
J. S. Burgess 《新西兰海洋与淡水研究杂志》2013,47(3):551-553
Examination of bacteriological, water pollution in river and nearshore ocean waters of southern Hawke Bay suggests that presentation and analysis of data expressed in terms of the median, as stipulated by New Zealand water pollution legislation, is often unsatisfactory. Data distributions are non‐normal and statistical comparisons over time and area difficult. These difficulties can be largely overcome by a simple log transformation of data. 相似文献
10.
11.
Concentrations of microbial ATP in 15 New Zealand lakes were determined using 2 extraction techniques. ATP was found in both the paniculate (>0.45 μm) and dissolved (<0.45 μm) fractions of the water samples. Higher concentrations of paniculate ATP were obtained when ATP was extracted directly from freshwater samples rather than following pre‐concentration on to membrane filters. Recovery of particulate ATP declined with increasing volumes of sample filtered. The magnitude of the filtration effect varied unpredictably between lakes and within lakes with time. Corrections for the presence of dissolved ATP were necessary before estimates of particulate ATP could be made by the direct extraction technique. Concentrations of dissolved ATP up to 1.2 μg L‐1 were observed. The direct extraction technique is recommended for more accurate determination of particulate ATP in New Zealand freshwaters. 相似文献
12.
Hans W. Paerl 《新西兰海洋与淡水研究杂志》2013,47(2):297-305
Size‐fractionation by Nuclepore filters shows that about one‐third of the biomass of freshwater phytoplankton is 0.2–3 μm in size. Autoradiographs of natural water from North and South Island lakes of various trophic states, incubated with ‘'C‐bicarbonate, reveal the contribution of this ‘ultraplankton’ to primary production. The lakes sampled in 1975–76 were Rotongaio, Rotorua, Tarawera, and Taupo (North Island); Brunner, Johnson, Kangaroo, Ohau, Pukaki, Rotoiti, and Wakatipu (South Island). In general, oligotrophic and mesotrophic lakes contain most ultraplankton, forming 11–35% of the biomass and 33–76% of the primary productivity. In both New Zealand and North America the importance of ultraplankton seems grossly underestimated, probably because it normally escapes detection in standard Utermohl and direct nitration examinations. 相似文献
13.
R. M. McDowall 《新西兰海洋与淡水研究杂志》2013,47(4):673-682
The poeciliid fish, Phalloceros caudimaculatus (commonly referred to as the “caudo"), is recorded from the wild for the first time, occurring in stock‐water troughs on a farm near Kamo in Northland, New Zealand. The populations in the stock troughs reputedly came from a nearby stream c. 10 years ago, although a preliminary search has failed to reveal them to be there now. Presence of an additional exotic fish in New Zealand fresh waters is a matter for concern, and requires management. To facilitate recognition off. caudimaculatus, and its distinction from other poeciliids present here, a diagnosis is provided to enable identification, together with notes on natural history, and a key for the identification of the five species of Poeciliidae now known from natural waters in New Zealand. 相似文献
14.
I report on a group of orca (Orcinus orca (Linnaeus, 1758)) near the Bay of Islands, New Zealand, which were a lighter coloration than orca usually seen in these waters. Differences in pigmentation included a light grey caudal peduncle area and a dorsal cape, which has previously only been described for Antarctic orca. The size and shape of the eye patches were not consistent with orca photo‐identified in New Zealand. I suggest that this group of orca, although observed in New Zealand waters, were of Antarctic origin. 相似文献
15.
This study presents a review of extensive literature and reports new findings extracted from previously collected cores. Globally lowered sea level during the last glacial maximum (LGM) reduced the cross-sectional area in the Korea Strait, minimizing volume transport of the paleo-Tsushima Current and increasing freshwater input to the East Sea. The higher supply of freshwater played an important role in compositional changes of surface water in the sea, indicated by low sea surface salinity (down to about 20‰) and light d 18O of planktonic Foraminifera (lighter than 1‰) recorded in core sediments. The Korean fluvial systems (Nakdong and Seomjin rivers) emptying into the southeastern sea of Korea may have contributed substantially to freshwater supply to the surface layer of the LGM East Sea, although Chinese paleo-river (Huanghe and Yangtze rivers) waters, together with the paleo-Tsushima Current, also seem to have supplied some freshwater to the sea. The higher supply of river waters to the East Sea is strongly evidenced by the high amount of terrigenous material (quartz, feldspar and rock fragments) in core sediments. In addition, high magnetic susceptibility, high grain density, and high C/N ratios were documented in cores MB98PC-11 and 95PC-1. In contrast with earlier studies, we propose that Korean rivers played a more substantial role in supplying freshwater to the East Sea during the LGM than previously thought. 相似文献
16.
Eight marine species of the Dinoflagel‐late genus Dinophysis are recorded from New Zealand coastal waters. Some notes are given on the morphology and range of variation in the New Zealand specimens as seen in the scanning electron microscope. 相似文献
17.
A metre‐long transparent tube for measuring visual water clarity was developed as part of the New Zealand Stream Health Monitoring and Assessment Kit (SHMAK) for use by non‐scientists. Water clarity measured using the tube (the horizontal sighting range of a black target) was compared with that measured using the standard “black disk” method (in which a black target is viewed horizontally underwater) to determine the feasibility of estimating black disk clarities from clarity tube readings. Readings using the two methods showed good agreement for waters with clarity <c. 50 cm. In clearer waters the slope of the relationship depends on the reflectivity of the background material used in the clarity tube. With a reflective background (white, reflectance c. 75%; or grey, reflectance c. 55%), the clarity tube readings are directly proportional and approximately equal to the black disk readings. With a black background (reflectance c. 5.5%), clarity tube readings >c. 50 cm are lower than the black disk visibility and follow a logarithmic relationship with visibility, which enables useful readings to be made in clearer water. Independent testing of the relationship showed that black disk visibilities may be predicted with reasonable confidence in waters that contain very low concentrations of dissolved humic materials (yellow substance). In waters that are noticeably brown‐coloured, the relationship is less consistent especially at black disk visibilities of more than 1.5 m. Recommendations are given for the use of the clarity tube. 相似文献
18.
Three manta rays were seen and photographed in the western Bay of Plenty, New Zealand, in March 1968. Although the species or genus could not be identified, this sighting represents the first substantiated record of the manta ray family (Mobulidae) in New Zealand and confirms the statements of fishermen that, in summer, mantas occasionally appear in offshore game‐fish waters in north‐eastern New Zealand. 相似文献
19.
Drift was collected over 24‐h periods in five rivers in South Island, New Zealand, to determine whether diel periodicity was consistent across a range of river types, and whether the pattern was similar for different life stages/sizes of selected taxa. Total drift density (numbers per 100 m3 ) of aquatic invertebrates was greater at night than during the day in all rivers; peak abundance occurred shortly after sunset in clear water rivers and shortly before sunrise in a turbid, glacier‐fed river. Densities of drifting Deleatidium spp., Nesameletus spp. (both Ephemeroptera), Aoteapsyche spp., and Hydrobiosidae (both Trichoptera), were generally greater at night than during the day. However, the timing of peak abundance in the drift for other common taxa varied between rivers. Larger Deleatidium spp. larvae (> 1.00 mm head width) were more common in the drift at night than during the day in all rivers. However, this was not apparent for Aoteapsyche spp. and Hydrobiosidae, for which diel differences in the size of drifting animals were not consistent even within the same river. The propensity for some aquatic invertebrates to drift at night may influence fish feeding behaviour, particularly with respect to the timing of feeding and the species or life history stages of their prey. 相似文献
20.
Migrating eels in a Canterbury river,New Zealand 总被引：1，自引：1，他引：0
A. M. R. Burnet 《新西兰海洋与淡水研究杂志》2013,47(2):230-244
A fish trap in the upper reaches of the South Branch stream, Canterbury, New Zealand, caught eels from December 1957 to October 1964. The downstream migrations of immature and adult eels of both New Zealand freshwater species (short‐finned Anguilla australis and long‐finned A. dieffenbachii) were recorded. These migrations showed a seasonal and a lunar periodicity, and the larger runs were also influenced by rainfall, water volume, or the passage of a depression. Seasonal peaks were marked for mature eels of both species, and for immature A. australis, but not for immature A. dieffenbachii. 相似文献