bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage, or legumes. 5. Wheat yields, nitrogen benefits and water-use efficiency of chickpea-wheat rotation
Authors: Dalal R. C. , Strong W. M. , Weston E. J. , Cooper J. E. , Wildermuth G. B. , Lehane K. J. , King A. J. , Holmes C. J.
Published: August 2004

Summary. In this study, the benefits of
chickpea–wheat rotation compared with continuous wheat cropping
(wheat–wheat rotation) were evaluated for their effects on soil nitrate
nitrogen, wheat grain yields and grain protein concentrations, and water-use
efficiency at Warra, southern Queensland from 1988 to 1996.
Benefits in terms of wheat grain yields varied, from 17% in 1993 to
61% in 1990, with a mean increase in grain yield of 40% (825
kg/ha). Wheat grain protein concentration increased from 9.4% in a
wheat–wheat rotation to 10.7% in a chickpea–wheat rotation,
almost a 14% increase in grain protein. There was a mean increase in
soil nitrate nitrogen of 35 kg N/ha.1.2 m after 6 months of fallow
following chickpea (85 kg N/ha) compared with continuous wheat cropping
(50 kg N/ha). This was reflected in additional nitrogen in the wheat grain
(20 kg N/ha) and above-ground plant biomass (25 kg N/ha) following
chickpea.
Water-use efficiency by wheat increased from a mean value of 9.2 kg
grain/ha. mm in a wheat–wheat rotation to 11.7 kg grain/ha.mm in
a chickpea–wheat rotation. The water-use efficiency values were closely
correlated with presowing nitrate nitrogen, and showed no marked distinction
between the 2 cropping sequences. Although presowing available water in soil
in May was similar in both the chickpea–wheat rotation and the
wheat–wheat rotation in all years except 1996, wheat in the former used
about 20 mm additional water and enhanced water-use efficiency. Thus, by
improving soil fertility through restorative practices such as incorporating
chickpea in rotation, water-use efficiency can be enhanced and consequently
water runoff losses reduced.
Furthermore, beneficial effects of chickpea in rotation with cereals could be
enhanced by early to mid sowing (May–mid June) of chickpea, accompanied
by zero tillage practice. Wheat of ‘Prime Hard’ grade protein
(≥13%) could be obtained in chickpea–wheat rotation by
supplementary application of fertiliser N to wheat.
In this study, incidence of crown rot of wheat caused by
Fusarium graminearum was negligible, and incidence and
severity of common root rot of wheat caused by
Bipolaris sorokiniana were essentially similar in both
cropping sequences and inversely related to the available water in soil at
sowing. No other soil-borne disease was observed. Therefore, beneficial
effects of chickpea on wheat yields and grain protein were primarily due to
additional nitrate nitrogen following the legume crop and consequently better
water-use efficiency.
Bush-harvesting of the sedge Caustis blakei reduces vegetative growth and seed set
Authors: Johnston M. E. , Wearing A. H. , Webber J. H. , Swarbrick J. T.
Published: August 2004

Summary. Substantial quantities of the native sedge,
Caustis blakeiKukenthal (commonly called koala or
foxtail fern) are harvested from naturally occurring populations in south-east
Queensland as cut foliage and exported to Europe, USA and Japan. Light
harvesting (30%) of stems of C. blakei reduced
the number or size of marketable stems but did not alter the number and length
of new stems. Moreover, mean dry weight of harvested stems significantly
reduced over time, suggesting that even light harvesting was probably not
sustainable under the dry conditions experienced. Plants that were harvested 3
times per year had more marketable stems than plants that were harvested once
or twice per year at the same annual intensity.
Despite the infertility of the soil in the experimental site, the amount of
nutrients removed by harvesting stems was low and may not be the major factor
reducing growth. We suggest that limited carbohydrate supplies due to low
water supply and harvesting (particularly moderate and heavy harvesting) might
be the major causes of reduced growth. Regeneration of fire-sensitive species
such as C. blakei is likely to be prejudiced by
harvesting. Harvesting removed spikelets and reduced the number of spikelets
on new stems. Although only a small number of fruit were removed in this
experiment, the commercially harvested stems represent the current
season’s stems and are the most fecund. This loss could be significant
as C. blakei sets few fruit in any one year.
It is recommended that harvesting should be limited to only 30% of the
current season’s stems with a limit of 15% during dry seasons,
instead of the present harvesting limits of ‘30% of green
stems’ or ‘30% of the plant’. In the longer term,
propagation and commercial production will be necessary to supply the demand
for cut stems on both export and domestic markets.
Dry matter intake and nutrient selection by lactating cows grazing irrigated pastures at different pasture allowances in summer and autumn
Authors: Wales W. J. , Doyle P. T. , Dellow D. W.
Published: August 2004

Summary. Three experiments investigating the effects of
herbage allowance on the consumption of nutrients by lactating cows were
conducted on irrigated perennial pastures in northern Victoria during summer
and autumn. Experiment 1 was conducted in mid lactation (autumn–early
winter) with perennial ryegrass [54% of dry matter
(DM)]–white clover (22% of DM) pasture offered at allowances
of 15, 20, 30 and 40 kg DM/cow.day. Herbage intake increased
(P<0.001) from 8.0 to 14.6 kg DM/cow.day as
allowance increased and this was associated with a decrease
(P<0.001) in utilisation from 54 to 37%. The
cows consistently selected a diet 11% higher in
in vitro dry matter digestibility than that in the
pasture on offer, but selection for crude protein increased
(P<0.001) from 21 to 41% above that in herbage
on offer as herbage allowance increased. Neutral detergent fibre content of
the diet selected was lower (P<0.001) than that in
herbage on offer. Along with these changes, milk production increased
(P<0.001) from 9.0 to 15.5 kg/day as herbage
allowance increased at a marginal response of 0.99 kg milk/kg extra DM
consumed.
Experiments 2 and 3 were conducted in mid lactation (summer) on pasture
containing 28% paspalum, 26% weeds, 17% perennial
ryegrass or 36% paspalum, 19% weeds and 24% ryegrass
respectively. Pasture allowances were between 20 and 70 kg DM/cow.day.
Herbage intake increased (P<0.001) from about 8 to 17
kg DM/cow.day as allowance increased in both experiments and was
accompanied by a decrease (P<0.001) in utilisation
from about 40 to less than 25%. In experiment 2, the cows consistently
selected a diet with a similar in vitro dry matter
digestibility to that of the herbage pregrazing, regardless of allowance, but
selection for crude protein increased (P<0.05) from
25 to 45% above that in herbage on offer, as allowance increased. In
experiment 3, the diet selected was 13% greater
(P<0.001) in in vitro dry
matter digestibility and 42% greater (P<0.001)
in crude protein than the herbage on offer. Neutral detergent fibre content of
the diet selected was lower (P<0.001) than that in
herbage on offer in experiment 3, while the difference was small in experiment
2. Along with these changes, milk production increased
(P<0.001) (in experiment 2, 12.3–15.0
kg/cow.day; experiment 3, 10.0–15.8 kg/cow.day) as herbage
allowance increased, but the marginal responses were lower (0.28 kg
milk/kg extra DM consumed in experiment 2, 0.64 kg milk/kg extra DM
consumed in experiment 3) than observed in experiment 1 reflecting the
differences in pasture quality.
An evaluation of selective Helicoverpa armigera control options in sweet corn
Authors: Scholz B. C. G. , Monsour C. J. , Zalucki M. P.
Published: August 2004

Summary. Helicoverpa armigera is a
serious insect pest of sweet corn in Australia and is becoming increasingly
difficult to manage with conventional chemical insecticides due to resistance
problems. A number of alternative H. armigera control
options were evaluated in sweet corn and compared with deltamethrin and no
action (control). The alternative tactics evaluated were: heliothis nuclear
polyhedrosis virus plus Trichogramma nr.
brassicae releases;
Bacillus thuringiensis; and
Trichogramma alone. The H. zea
nuclear polyhedrosis virus + Trichogramma plots had the lowest cob damage
(6.0%), followed by the B. thuringiensis plots
(12.0%), Trichogramma alone plots (20.2%),
control plots (23.2%) and deltamethrin plots (53.5%). There was
no evidence to suggest that the Trichogramma nr.
brassicae releases had any impact on
H. armigera egg mortality. However, there was a large
natural population of Trichogramma pretiosum in all
plots. The application of deltamethrin reduced the action of these wasps and
predators, resulting in higher larval infestation and significantly more cob
damage. The findings indicate that the pathogens heliothis nuclear
polyhedrosis virus and B. thuringiensis can effectively
control H. armigera when their action complements high
natural levels of egg parasitism, and that they have potential for use in
integrated pest management programs in sweet corn.
Identification of a Brahman sire whose progeny have high marbling scores and high intramuscular fat content
Authors: Gazzola C. , O'Neill C. J. , Frisch J. E.
Published: August 2004

Summary. A Brahman sire (Select Brahman) whose steer
progeny had both high marbling scores and high intramuscular fat content has
been identified. The effect was independent of dam breed (5 different dam
breeds were analysed), was present in both grain-finished and pasture-finished
progeny, and was independent of hormone growth promotant treatment. From
pasture, over twice as many progeny from the Select sire (62.5%) had
high marbling scores as progeny from 10 other Brahman sires (25.9%).
The effect was not as marked in grain-finished steers but the Select sire
still produced one-third more high marbling progeny (84.6%) than the
other sires (63.6%). The Select sire’s progeny were equal to or
better than progeny from Tuli sires in producing high marbling scores. The
intramuscular fat content (3.5 ± 0.3 g/100 g) of the progeny from
the Select sire was greater than double that of progeny from other Brahman
sires (1.9 ± 0.2 g/100 g; P<0.0001) and
higher than progeny from Tuli sires (2.3 ± 0.1 g/100 g;
P<0.0001). The increased marbling and intramuscular
fat content were not associated with increased subcutaneous fat deposition,
decreased muscle deposition, lower growth rate or smaller mature size since
there were no differences in age, hot standard carcass weight, rump fat depth
and rib eye muscle area between the Select sire’s progeny and those of
other Brahman sires. The identification of a high marbling trait in a
Bos indicus sire is of considerable significance to the
northern Australian beef industry because it enables markets requiring marbled
carcasses to be targeted while maintaining the advantages of tropical
adaptation.
Changes in practices and decisions resulting from the paired-paddock model used in the Grassland’s Productivity Program
Authors: Trompf J. P. , Sale P. W. G. , Saul G. , Shovelton J. , Graetz B.
Published: August 2004

Summary. A detailed survey was undertaken in the spring
of 1995 with 20 wool producers in south-west Victoria and the south-east of
South Australia to determine the impact of their participation for 18 months
in a program called the Grassland’s Productivity Program. This program
involved groups of producers establishing paired-paddock comparisons on their
own farms with guidance from an experienced facilitator. Productive pasture
practices (increased fertiliser rates, responsive pasture species and high
stocking rates) were used in one paddock, while the remaining paddock was
managed with existing practices. A second group of 15 producers from the same
districts who did not participate in the Grassland’s Productivity
Program were selected at random and also surveyed.
Although the 2 groups of producers had similar pasture productivity parameters
(phosphorus fertiliser, stocking rates and pasture resowing rates) in the
autumn of 1993, the Grassland’s Productivity Program participants had
significantly (P<0.05) increased phosphorus
fertiliser rates on average from 5.7 to 10.5 kg P/ha, stocking rates from
9.4 to 10.7 dse/ha, and the area of the farm that was being resown to new
pasture from 2.9 to 4.0%, by the spring of 1995. There was no change in
the pasture practices of the non- Grassland’s Productivity Program
producers over this period. The Grassland’s Productivity Program
participants also increased their use of soil testing and plant tissue testing
and changed their rationale for making fertiliser and stocking decisions. The
decisions were now based on an assessment of soil fertility and animal
production target levels, together with accurate assessment of pasture
production and animal requirements, rather than on past experiences and normal
district practices.
The increased adoption of the productive pasture technology (practice change)
was directly related to a change in attitude to decision making. This change
in attitude or beliefs among Grassland’s Productivity Program
participants was a result of the action learning experiences that disposed or
modified existing beliefs, while integrating the productive pasture technology
in a contextualised manner. The paired-paddock approach to learning enabled
each participant to witness the productive pasture technology perform on their
own farm, in direct comparison with the existing management approach. The
participants developed increased confidence in their ability to manage this
technology from group-learning experiences, which occurred at regular group
meetings.
An efficient interspecific hybridisation protocol for Carica papaya L. × C. cauliflora Jacq.
Authors: Magdalita P. M. , Drew R. A. , Godwin I. D. , Adkins S. W.
Published: August 2004

Summary. A protocol for interspecific hybridisation
between Carica papaya and
C. cauliflora is necessary for gene introgression
between these 2 incompatible species. Carica papaya
× C. cauliflora hybrids were successfully created
using a new, efficient hybridisation protocol. This protocol includes the use
of highly viable pollen of C. cauliflora produced during
summer, autumn and/or spring, the use of an isolation time ranging from 90
to 120 days post-pollination of hybrid embryos, and the use of the most
compatible C. papaya cultivar 2001 for crossing with
C. cauliflora. Two types of interspecific hybrid
embryos, namely single and multiple, were isolated in all resulting fruit. The
application of gibberellic acid (0.6 or 0.8 mol/L) or 2,4-
dichlorophenoxyacetic acid (1.5 or 2.0 mol/L) to freshly cross-pollinated
flowers and pollination by mentor pollen did not promote either the rate of
successful crosses or the production of hybrid embryos. Using this efficient
protocol, hybridisation between C. papaya and
C. cauliflora conducted in 3 locations in south-east
Queensland produced 338 crosses which generated 43 736 seed. From these seed,
2100 hybrid embryos were recovered resulting in the production of 485
morphologically normal interspecific hybrid plants. Studies reported elsewhere
show that these hybrids are resistant to papaya ringspot virus type P.
Seasonal variations in foraging by ants (Hymenoptera : Formicidae) in two New South Wales citrus orchards
Authors: Stevens M. M. , James D. G. , O'Malley K. J. , Coombes N. E.
Published: August 2004

Summary. Pitfall traps were used to monitor the seasonal
activity of ants in 2 citrus orchards in the Murrumbidgee Irrigation Area of
south-western New South Wales for 22–24 months (November
1992–August/October 1994). Twenty-four species were recorded (22
species at Yanco and 18 species at Cudgel), with
Iridomyrmex rufoniger group species being numerically
dominant at both sites (63 and 59% of total captures at Yanco and
Cudgel respectively). Meat ants, Iridomyrmex purpureus
(F.Smith), were a significant (9%) component of trap captures at Yanco
where regular soil cultivation was practised, but were less common
(<1% of captures) at Cudgel. Sample species richness was generally
greater at the Yanco site (mean 9.3 species per trapping interval compared
with 6.6 at Cudgel). Total ant captures and sample species richness showed a
positive correlation with mean daily temperatures over trapping intervals.
Variations in seasonal activity were shown by the numerically dominant
species, with 2 distinct patterns being evident. Whilst all taxa were less
active during winter, some species [I. rufoniger
group sp. 2, Pheidole sp.,
Rhytidoponera metallica (F.Smith)] continued to
forage, albeit at reduced levels. Other species of
Iridomyrmex including I. rufoniger
group sp. 1 and I. purpureus ceased foraging almost
entirely during June–September. Iridomyrmex
species are known to interfere with the biological control of
honeydew-producing insects in citrus orchards, and our results indicate that
ant control programs in southern New South Wales should be initiated in late
August–early September to achieve optimal results.
Phosphate applied to soil increases the effectiveness of subsequent applications of phosphate for growing wheat shoots
Authors: Bolland M. D. A. , Baker M. J.
Published: August 2004

Summary. Amounts of phosphorus ranging from 0 to 599 kg
P/ha were applied as single (ordinary) superphosphate once only in 1976 to
plots of a field experiment on a lateritic ironstone gravel sand. Subterranean
clover (Trifolium subterraneum) and cereals (wheat,
Triticum aestivum, and barley,
Hordeum vulgare) were grown in rotation on the plots for
20 years after phosphorus application. In 1996, samples of the <2 mm
fraction of the top 10 cm of soil were collected from the field plots to
measure phosphorus retention by soil and for a glasshouse experiment. The
phosphorus retention index, a measure of the capacity of the soil to sorb
phosphorus, decreased from 35 to 2 mL/g as the amount of phosphorus
applied 20 years previously increased from 0 to 599 kg/ha.
In the glasshouse experiment, wheat was grown for 35 days in soil to which 9
amounts of freshly-applied powdered single superphosphate (0, 0.0125, 0.025,
0.05, 0.1, 0.2, 0.4, 0.8 and 1.6 g P/pot, for 1.8 kg soil/pot) were
applied to the original phosphorus treatments. The value of the curvature
coefficient of the Mitscherlich equation fitted to the relationship between
yield of dried shoots and the amount of fresh-phosphorus applied increased
with increasing amount of phosphorus applied 20 years previously. That is, the
fresh-phosphorus treatments became more effective for producing dried wheat
shoots as the amount of previously applied phosphorus increased.
Factors affecting preweaning lamb survival in continuously housed sheep
Authors: Malik R. C. , Razzaque M. A. , Aali M. A. T. , Al-Khozam N. M. , Al-Mutawa T. A. , Abbas S.
Published: August 2004

Summary. Preweaning lamb survival for intervals of up to
8 weeks was studied in the progeny of the local fat-tailed Naeemi and imported
Border Leicester × Merino ewes mated to Naeemi rams. An intensive system
of management with zero grazing was used to conform to the most probable type
of production system to be used in Kuwait. The effects of year and season of
lambing, litter size, sex, genetic group and birth weight were determined.
Lamb survival rates from birth to 1 week, from 1 to 4 weeks and from 4 to 8
weeks were 96, 99 and 97% respectively. Overall survival from birth to
weaning at 8 weeks was 91%. Genetic group, litter size, sex of lamb and
year of lambing had no significant effects on survival. Season was significant
from birth to 1 week, from 4 to 8 weeks and from birth to 8 weeks. Lamb birth
weight was the most important factor affecting lamb survival, through a
quadratic relationship between weight and survival.
Preface to 'Role of Reactive Phosphate Rock Fertilisers for Pastures in Australia'
Authors: Sale Peter W. G.
Published: August 2004

Summary. The dissolution of North Carolina phosphate
rock (NCPR) in soil was investigated in a laboratory study using surface soils
sampled from 28 permanent pasture sites. The relationships between phosphorus
(P) dissolved, P availability and various soil properties were investigated
using simple and multiple linear regression and the findings related to the
relative effectiveness of NCPR for pasture production at the sites. The extent
of dissolution of NCPR was positively correlated to P buffering capacity
(r2 = 0.42). Phosphorus
buffering capacity and titratable acidity together accounted for 72% of
the variance in dissolution. Bicarbonate-extractable P
(‘available’ P) generally increased as dissolution increased.
However, the increase in available P was consistently lower for soils with
higher P buffering capacity. The proportion of dissolved P that was available
also decreased with increasing P buffering capacity
(r2 = 0.63). Consequently,
the increase in available P was highest for soils with very low to low P
buffering capacity. This suggests that the effectiveness of NCPR as a
fertiliser may be more closely related to the availability of dissolved P,
than to the amount of NCPR dissolved in a soil. Consistent with this
laboratory finding, the agronomic effectiveness of NCPR relative to
superphosphate measured in the field tended to decrease with increasing P
buffering capacity. The agronomic effectiveness of NCPR was comparable with
superphosphate only at certain sites, and with some noted exceptions, most of
these had surface soils with very low to low P buffering capacity. The high
relative effectiveness of NCPR at these sites was mostly attributed to the
loss of superphosphate by leaching. Since NCPR dissolves much more slowly than
superphosphate, only a small amount of the P applied as NCPR would be lost
during leaching events. Slow dissolution of the remaining NCPR probably
supplied a small amount of dissolved P over an extended period of time, and
due to the low P buffering capacity, much of this was available to plants.
Review of the Australian stilt flies (Diptera : Micropezidae) with a phylogenetic analysis of the family
Authors: McAlpine David K.
Published: August 2004

The Australian taxa of Micropezidae (listed at end of paper) are keyed and
described. Crus, Scela,
Veru and Seva are new subgenera of
Metopochetus Enderlein. In all, 21 new species are
described in the genera Metopochetus,
CothornobataCzerny,
CrepidochetusEnderlein and
Mimegralla Rondani.
Cothornobata inermis (Malloch) is a new combination
(from Grammicomyia). Lectotypes are designated for
Calobata compressa Walker (now in
Metopochetus), Calobata bivittata
Macquart (now in
Metopochetus),Mimegralla contingens australicaHennig
(now M. australica),
Calobata contraria Walker [synonym
ofMimegralla sepsoides (Walker)]. Records of the
following from Australia are found to be erroneous:
Calobata albimana Macquart [synonym
ofTaeniaptera trivittata
(Macquart)],Mimegralla abana (Walker),
Calobata brevicellulata Macquart (now in
Mimegralla),
Calobata coeruleifrons Macquart (now in
Mimegralla) and
Metopochetus tipuloides (Walker). The erroneous record
of Cothornobata viriata (Enderlein) from Papua New
Guinea is corrected. Distributions of species are recorded by means of grid
references to a key map. Information on ecology and habits of Australian
micropezids is summarised. The populations of two flightless species are
vulnerable, because each is apparently dependent on an ecologically vulnerable
host-plant species (families Brassicaceae and Cephalotaceae). A phylogeny of
the recognised subfamilies and tribes of Micropezidae is given. Literature on
fossil micropezids is reviewed.
Reappraisal of Australian freshwater bryozoans with two new species of Plumatella (Ectoprocta : Phylactolaemata)
Authors: Wood Timothy S.
Published: August 2004

Of the 10 species of freshwater bryozoans previously reported from Australia,
only Fredericella australiensis,
Hyalinella lendenfeldi and
Lophopodella carteri can be positively confirmed from
existing preserved material. From a survey of all known museum collections of
freshwater bryozoans comes compelling evidence that a specimen labelled
‘Plumatella toanensis’ is actually
Hyalinella lendenfeldi, including the only known
statoblasts of this species. Plumatella agilis is
recognised tentatively pending new material.
Fredericella sultana,
Plumatella emarginata and
P. repens are not represented by any known specimens,
although they are likely to occur in Australia.
Hyalinella punctata and
Gelatinella toanensis have been previously reported in
error. Two other previously misidentified specimens, including
Hyalinella vaihiriae, are now reported as new species:
Plumatella velata and P. rieki. A
taxonomic key is given for Australian freshwater bryozoan species, including
species both verified from Australia and others only presumed to occur there.
Revision of the recent Indo - West Pacific comatulid genus Comaster Agassiz. Part 1. The type species of Comaster and Phanogenia Lovén (Echinodermata : Crinoidea : Comasteridae)
Authors: Messing Charles G.
Published: August 2004

The Indo–Pacific reef-dwelling comatulid crinoid
Comaster multifidus (MÜller, 1841) is the type
species of the genus Comaster Agassiz, 1836.
Re-examination of the type specimen of C. multifidus
shows that it does not conform to the concept of the species as currently
applied and does not belong in the genus as currently diagnosed. Instead, it
falls within ComanthinaA. H. Clark, 1909, and is
identical toComanthina variabilis Bell,
1882.Comanthina thus becomes a junior synonym of
Comaster because
Actinometra nobilis Carpenter, 1884, the type species of
Comanthina, is clearly congeneric with
A. variabilis. Species currently assigned to Comanthina
are herein transferred to Comaster. The other species
currently included in Comaster represent a distinct
taxonomic group and are herein transferred to the next most senior available
genus, Phanogenia Lovén, 1866. The holotypes of
the type species of Comaster and
Phanogenia are redescribed in detail.
Bathymetric and seasonal changes in photosynthesis and respiration of the phototrophic sponge Phyllospongia lamellosa in comparison with respiration by the heterotrophic sponge Ianthella basta on Davies Reef, Great Barrier Reef
Authors: Cheshire Anthony C. , Wilkinson Clive R. , Seddon Stephanie , Westphalen Grant
Published: August 2004

The phototrophic sponge Phyllospongia lamellosa is found
to depths of 30 m on Davies Reef. Studies of the photophysiology show that
this corresponds to the depth at which the sponge–symbiont system can
meet 80% of its daily respiratory carbon needs photosynthetically. Net
24-h production was constant to a depth of 20 m (20 µmol
O2 g-1 fresh weight day
-1 ) and then decreased to compensatory levels at 25 m.
The maintenance of net 24-h production to a depth of 20 m was characterized by
reductions in the sub-saturating light intensity
(Ik ), indicating increased
efficiency of light usage at depth. At depths greater than 20 m the changes in
Ik could not compensate for the
reduced light intensity.
The respiration rate of Phyllospongia (3–5
µmol O2 g-1 fresh weight
h-1 ) was significantly greater than that of the
heterotrophic sponge Ianthella (2.0–3.6 µmol
O2 g-1 fresh weight
h-1 ) to an extent that depended on season and location.
Respiration rates for both species changed similarly between seasons, being
higher in summer. There was no evidence for increased respiration rates in
shallower water (<10 m), suggesting that this is not a cause for the
reduced occurrence of Phyllospongia in shallow waters.
Hooking mortality of two species of shallow-water reef fish caught by recreational angling methods
Authors: Diggles B. K. , Ernst I.
Published: August 2004

The hooking mortality of two teleosts, the yellow stripey
Lutjanus carponotatus (Lutjanidae), and the wire netting
cod Epinephelus quoyanus (Serranidae), was examined for
fish captured with lures and bait from shallow waters (<2 m) on the Great
Barrier Reef. Total mortality for both species (n = 340 fish) over the
48-h observation period was low (1.76%). Baitfishing with single hooks
caused a significantly higher post-release mortality rate (5.1%) than
did lure fishing with treble or single hooks (0.4%), and was the
hooking method most likely to cause bleeding and damage to vital organs. Death
of fish was observed only in instances where hooks penetrated the pericardium
or body cavity. Handling time was significantly affected by fish size and
hooking location, did not vary significantly between fish species, and was
significantly reduced when barbless hooks were used in both lure and
baitfishing. One specimen of each species, deeply hooked in the gut or
oesophagus while baitfishing, was allowed to retain the hook; both fish
survived and subsequently regurgitated the hook during the observation period.
The relevance of these data to management of line fisheries on the Great
Barrier Reef is discussed.
Impact of the introduced poeciliid Gambusia holbrooki (Girard, 1859) on the growth and reproduction of Pseudomugil signifer (Kner, 1865) in Australia
Authors: Howe Effie , Howe Christopher , Lim Richard , Burchett Margaret
Published: August 2004

The impact of the presence of the introduced poeciliid
Gambusia holbrooki on the Australian pseudomugilid
Pseudomugil signifer was examined in open-air tank
experiments. G. holbrooki profoundly affected the
breeding of P. signifer. In the presence of
G. holbrooki, P. signifer did not
gain weight or grow in total length, ovarian weight and fecundity were greatly
reduced, and the ovaries were morphologically undeveloped. No eggs of
P. signifer were observed in tanks that also housed
G. holbrooki. The results indicate that, at least in a
captive situation, the presence of the exotic species had a very deleterious
effect on the breeding and hence possible survival of the native species.
These results are discussed with reference to the conservation of Australian
pseudomugilid species, especially those inhabiting confined habitats.
Macrofaunal community structure of beaches in northern New South Wales, Australia
Authors: Hacking Nicole
Published: August 2004

Macrofaunal community composition of ten exposed sandy beaches in northern New
South Wales, Australia, appeared to correlate with beach morphodynamic state
even though the data represented sampling at only a single time. Better
results were obtained by using the Beach State Index (BSI) rather than the
dimensionless fall velocity (?). Species number and abundance
significantly increased as the BSI value increased, whereas biomass was not
correlated with BSI. The New South Wales beaches had a higher species number
and abundance relative to BSI than did beaches in a published review of
beaches around the world.
Farm ponds in New South Wales, Australia: relationship between macrophyte and phytoplankton abundances
Authors: Casanova Michelle T. , Douglas-Hill Annabel , Brock Margaret A. , Muschal Monika , Bales Michael
Published: August 2004

The physical, chemical and biological characteristics of 65 farm ponds in the
Northern Tablelands and Central Western Slopes regions of New South Wales,
Australia, were similar to those recorded for Australian ponds in other
studies. The strongest single relationship between physico-chemical
characteristics and biological characteristics was for high abundance of
phytoplankton, low abundance of macrophytes, high turbidity, and high nutrient
concentrations in ponds on granitic soil. Variation among the ponds was such
that no other relationship was significant. Five groups of ponds were
discerned on the basis of their biological and physico-chemical
characteristics. One group could be classed as reasonably
‘pristine’, with high water clarity and high abundance of
macrophytes; another group presented highly eutrophic, phytoplankton-dominated
conditions. Ponds in these two groups can be described as being in
‘alternative stable states’. A third group had been modified with
the intention of improving the appearance or utility of the ponds. The last
two groups identified in this analysis had no specific parallels in the
literature. Abundance of macrophytes was related to good water quality, and
encouragement of increased abundance of submerged plants in farm ponds could
result in improved water quality.
Movements and stock structure of school mackerel (Scomberomorus queenslandicus) and spotted mackerel (S. munroi) in Australian east-coast waters
Authors: Begg Gavin A. , Cameron Darren S. , Sawynok William
Published: August 2004

Movements of school mackerel
(Scomberomorus queenslandicus) and spotted mackerel
(S. munroi) in Australian east-coast waters were
determined by tag and recapture methods and were used to investigate the stock
structure of each species. In all, 4427 school mackerel and 2106 spotted
mackerel were tagged and released between 1985 and 1995 in a collaborative
tagging exercise with the Australian National Sportfishing Association. School
and spotted mackerel were recaptured at rates of 2.1% and 1.8%
respectively. School mackerel moved small distances from their release sites
(26 ± 55 km, mean ± s.d.; maximum distance, 270 km), with these
restricted movements indicating the possible existence of a number of stocks.
In contrast, spotted mackerel moved large distances from their release sites
(202 ± 290 km; maximum distance, 1100 km). Temporal and spatial
movement patterns of spotted mackerel were characteristic of fish from a
single stock undertaking a seasonal migration. Commercial harvest information
in combination with tagging effort reflected the different movements of school
and spotted mackerel and strengthened the suggested stock structure of each
species.
Relationships amongst length, weight and growth of north-eastern New Zealand reef fishes
Authors: Taylor Richard B. , Willis Trevor J.
Published: August 2004

This paper examines relationships amongst length, weight and growth parameters
of teleost fishes found in shallow north-eastern New Zealand waters.
Length–weight equations are presented for 51 species. Fish growth was
described using the von Bertalanffy growth parameters
L∞ (asymptotic length) and
K (growth constant), which were available for 19
species. Literature-derived values for adult body length showed a strong
positive correlation with L∞
(r2 = 0.89), which, after
conversion to weight, was strongly negatively correlated with
K (r 2
= 0.80). Regression equations describing these relationships can be
used to predict L∞ and
K for fish species lacking such growth data.
Low concentrations of methaemoglobin in marine fishes of the Great Barrier Reef, Australia
Authors: Wells Rufus M. G. , Baldwin John , Seymour Roger S.
Published: August 2004

Concentrations of methaemoglobin (the oxidized non-functional ferric form of
haemoglobin) in the blood of marine fish are poorly documented. Although high
concentrations have been reported for fish maintained in captivity, baseline
values for wild populations are unknown. Two techniques, the cyanide
derivative method and the multiple wavelength method, were used to determine
methaemoglobin concentrations in blood samples from 25 species of marine
teleosts and elasmobranchs captured on the Australian Great Barrier Reef.
Although methaemoglobin generally accounted for less than 2% of total
haemoglobin, systematic errors occurred when these two standard methods,
developed for mammalian blood, were applied to the blood of some fish species.
Most problems arose from reactions of various blood components with the
reagents used in the cyanide derivative method. Consequently, the multiple
wavelength method generally was more reliable for estimating methaemoglobin in
the blood of marine fish. The low methaemoglobin concentrations in fish
studied on the Great Barrier Reef indicate high water quality and healthy
physiological condition.
Transformation of free tetrachloroguaiacol to bound compounds by fungi isolated from Lake Bonney, south-eastern South Australia
Authors: Leeuwen J. A. van , Nicholson B. C. , Levay G. , Hayes K.P. , Mulcahy D. E.
Published: August 2004

Chlorophenolic compounds have persisted in water and sediments of Lake Bonney,
south- eastern South Australia, following discontinuation of chlorine
bleaching at a sulfite-based pulp mill that discharges effluent into the lake.
During assessment of the persistence of chlorophenolics, several species of
fungi isolated from lake water and from a drain that discharges mill effluent
into the lake were studied for their capacities to degrade these compounds.
Epicoccum sp.,
Mucor circinelloides and
Penicillium expansum decreased concentrations of the
free form of tetrachloroguaiacol in a mineral-salts medium. This was due not
to degradation of the compound but to conversion to bound forms. These bound
forms of tetrachloroguaiacol were resistant to degradation by a
T. harzianum isolate that had previously been found
capable of degrading free tetrachloroguaiacol.
Effect of the Queensland Shark Control Program on non-target species: whale, dugong, turtle and dolphin: a review
Authors: Gribble N. A. , McPherson G. , Lane B.
Published: August 2004

The Queensland Shark Control Program (QSCP) has recorded a long-term annual
mortality of 0.1 humpback whale, 2 ‘small whales’ (species
uncertain), 20 dugong, <78 turtles (species and number released uncertain),
and <19 dolphin (species and number released uncertain). Available
population estimates suggest that the historic impact of the QSCP would have
been negligible on whales, 0.5% per year of the dugong population in
the southern Great Barrier Reef, minor on green and loggerhead turtle
populations, and unknown but probably minor on leatherback turtles and dolphin
populations. In response to improved methods between 1992 and 1995 the average
yearly mortality fell to 0 humpback whales, 4 dugong, 3 loggerhead turtles (11
turtles in total), and 10 dolphin (species uncertain); this suggests no impact
on whales, 0.1% per year of the dugong population of the southern Great
Barrier Reef, 1.6% of the yearly indigenous harvest of green turtles in
eastern Australia, and 0.2% per year of the loggerhead turtle
population in Queensland. Lack of population estimates and species
identification precluded impact calculations for dolphin. The number of rare,
vulnerable and endangered marine animals killed in the QSCP gear each year is
in tens rather than thousands and the effect of this incidental mortality on
their populations is probably minor.
A basis for mapping the erodibility of tidal flats by optical remote sensing
Authors: Hakvoort J. H. M. , Heineke M. , Heymann K. , Kühl H. , Riethmüller R. , Witte G.
Published: August 2004

A means of monitoring surface sediment stability of tidal flats with optical
remote sensing has been developed. Erosion shear stress and corresponding
bio-geo-chemical parameters of tidal flats were measured over five years in
the Sylt/Rømø Bight, Germany. Ground-based optical
reflectance spectra were measured during one year. A significant dependence of
erosion shear stress on the benthic diatom chlorophyll a concentration in the
uppermost 1-mm layer was found for muddy areas but decreased with decreasing
proportion of fine particles (< 63 µm). With a low phytobenthic
coverage there was a weak dependence of erosion shear stress on the proportion
of fine particles. There were two main classes of the reflectance spectra:
containing information on sediment type i.e. proportion of fine particles, and
containing information on benthic diatoms and other phytobenthic species.
There was a significant correlation between the reflectance spectra and
proportion of fine particles and also between reflectance spectra and benthic
diatom chlorophyll α concentration. Hence, the erodibility of tidal
flats can be mapped by optical remote sensing when benthic chlorophyll a
concentration and proportion of fine particles are used for estimation of the
erosion shear stress.
The habitat-survival function for Caribbean spiny lobster: an inverted size effect and non-linearity in mixed algal and seagrass habitats
Authors: Lipcius R. N. , Eggleston D. B. , Miller D. L. , Luhrs T. C.
Published: August 2004

The habitat-survival function (HSF) defines changes in survival relative to
habitat structure; forms include linear, hyperbolic and sigmoid (threshold)
curves, whose consequences on predator–prey dynamics are illustrated by
their first derivatives. Survival of two juvenile size classes of Caribbean
spiny lobster was evaluated as a function of plant biomass in tethering
experiments in mixed algal and seagrass patches adjacent to Bahía de la
Ascensión, Mexico, which serves as nursery habitat. The HSF was
hyperbolic for algal biomass; even modest increases of algal biomass
significantly enhanced lobster survival. The rate of change in survival as a
function of algal biomass (i.e. an approximation of the first derivative) was
greatest at low-to-moderate levels of habitat structure. Hence, survival in
these microhabitats is either low or rapidly changing with alterations in
habitat structure, and they should be avoided by juveniles. Seagrass biomass
did not significantly influence survival, although its levels were relatively
low. Smaller juveniles had significantly higher survival rates than larger
juveniles, probably because of the limited availability of appropriately
scaled refugia for larger juveniles; large juveniles may display an
ontogenetic shift from these habitats to coral reefs because of elevated
predation risk as they grow.
The Mexican artisanal shark fishery in the Gulf of Mexico: towards a regulated fishery
Authors: Castillo-Géniz J. L. , Márquez-Farias J. F. , Cruz M. C. Rodriguez de la , Cortés E. , Prado A. Cid del
Published: August 2004

Artisanal shark fisheries have been an important source of food and employment
in Mexico for many years. In the Gulf of Mexico, this multispecific fishery is
based on the seasonal abundance of several shark and teleost species. To
obtain fishery and biological information needed to manage the fishery and
conserve shark stocks, intensive monitoring of artisanal shark landings was
undertaken from November 1993 to December 1994. The State of Campeche had the
highest landings and effort. October 1994 had the highest monthly catch per
unit effort for all species and areas combined (27.2 sharks per trip).
Rhizoprionodon terraenovae (46%),
Sphyrna tiburo (15%), and
Carcharhinus limbatus (11%) accounted for most of
the landings numerically, and the highest catch per unit effort for
C. limbatus occurred late in the year as a result of
increased landings attributable to an annual southward migration from USA to
Mexican waters. The high proportion of neonate and juvenile sharks in gill-net
catches from shallow coastal waters suggests that the main shark nursery areas
are under heavy fishing pressure. In light of the heavy exploitation of shark
resources, the Mexican National Fisheries Institute recommends a number of
precautionary actions to avoid the collapse of this fishery.
Resumen. Las pesquerías artesanales de tiburones
han sido una importante fuente de alimento y empleo en México durante
muchos años. En el Golfo de México, esta pesquería
multiespecífica está basada en la abundancia estacional de
diversas especies de tiburones y peces. Para obtener la información
biológico-pesquera necesaria para manejar la pesquería y
conservar los stocks de tiburones, se realizó un monitoreo de las
capturas artesanales de tiburón entre noviembre de 1993 y diciembre de
1994. Campeche presentó las mayores capturas y esfuerzo. En octubre de
1994 se registraron las mayores CPUE para todas las especies y áreas
combinadas (27.2 tiburones por viaje).
Rhizoprionodon terraenovae (46%),
Sphyrna tiburo (15%) y
Carcharhinus limbatus (11%) constituyeron la
mayoría de las capturas numéricamente y las mayores CPUE para C.
limbatus se produjeron hacia finales de año a consecuencia del aumento
de las capturas atribuible a una migración anual norte-sur desde los
E.U. hacia aguas mexicanas. La alta proporción de neonatos y juveniles
capturados en redes agalleras en aguas costeras someras sugiere que las
principales áreas de crianza están sometidas a una alta
presión de pesca. En vista de los niveles de explotación el INP
recomienda diversas medidas precautorias para evitar el colapso de la
pesquería.
Intrinsic rebound potentials of 26 species of Pacific sharks
Authors: Smith Susan E. , Au David W. , Show Christina
Published: August 2004

A demographic technique is used to compare the intrinsic rates of population
increase of 26 shark species hypothetically exposed to fishing mortality.
These rates (r2M) are used as a
measure of the relative ability of different sharks to recover from fishing
pressure. The method incorporates concepts of density dependence from standard
population modelling and uses female age at maturity, maximum reproductive
age, and average fecundity. A compensatory response to population reduction is
assumed in pre-adult survival to the extent possible given the constraints of
the life-history parameters. ‘Rebound’ productivity was strongly
affected by age at maturity and little affected by maximum age. Species with
lowest values (r2M < 0.04)
tended to be late-maturing medium- to large-sized coastal sharks, whereas
those with the highest (> 0.08) were small coastal, early-maturing species.
Sharks with mid-range values (r2M
= 0.04–0.07) were mostly large (> 250 cm maximum size) pelagic
species, relatively fast growing and early maturing. Possible selection
pressures for these three shark groups, management implications, practical
applications for the derived parameter
r2M, and recommended areas of
research are discussed.
Haemocyanin function in the New Zealand abalones Haliotis iris and H. australis: relationships between oxygen-binding properties, muscle metabolism and habitat
Authors: Wells Rufus M. G. , Baldwin John , Speed Scott R. , Weber Roy E.
Published: August 2004

Abalone have a well developed capacity for anaerobic metabolism in the pedal
musculature, and during exercise the haemolymph oxygen stores may be reserved
for more oxygen-dependent tissues. This implies that the haemocyanin-based
oxygen transport system is poised towards oxygen storage rather than high
rates of oxygen delivery. This proposition was examined by determining
O2 -binding properties of haemocyanin from two species
of abalone that differ in behaviour and environmental oxygen requirements.
Both species showed reversed Bohr and Root effects leading to very high oxygen
affinity and reduced cooperativity at low pH. A marked temperature sensitivity
of haemocyanin–O2 binding in
H. iris (with heat of oxygenation at –55.7 kJ
mol-1) impairs oxygen loading above 20˚C and may
explain the reduced size and density of populations in warmer northern waters.
Muscle enzyme activities indicate low maximum rates of ATP production, with
arginine phosphate hydrolysis as the primary source of ATP for elevated levels
of muscle work. These data support the hypothesis that oxygen stores support
high levels of aerobic muscle work. However, the similarities in enzyme
profiles and haemocyanin properties could not be related to behavioural and
habitat differences.
Variation in algal assemblages on wave-exposed rocky shores in New South Wales
Authors: Underwood A. J. , Chapman M. G.
Published: August 2004

Data were collected in New South Wales from replicate sites on five
wave-exposed shores separated by hundreds of kilometres at three-monthly
intervals for four years, to examine large and small spatial and temporal
patterns in low-shore algal assemblages. These data were used to test
hypotheses from the models that algal assemblages show large-scale,
predictable changes in structure or, alternatively, that variation from time
to time is small-scale and differs from shore to shore or site to site on a
shore. There was considerable variation at all scales examined — among
replicate quadrats within sites, between sites on a shore and among shores.
Similarly, assemblages differed from one sampling period to the next and
changes in the assemblages over time periods of three months were as great as
from year to year. These changes were interactive, with no two sites or shores
showing similar temporal patterns. Thus, understanding diversity along a
coast-line requires detailed understanding of local processes. Without
adequate spatial and temporal replication in sampling designs and without
explanatory models, the large and complex variability in intertidal
assemblages at different scales cannot be documented and understood.