Price interactions between salmon and wild caught fish species on the Spanish market

Abstract

The introduction and rapid expansion of farmed salmon production in the mid 1980s has transformed the international market for salmon. Spain is one of the most important markets for fish within Europe and the world, and has seen a substantial increase in its demand for salmon. As in other European countries, this has raised concerns that the increased supply of salmon to Spain may have detrimental effects on the market prices of traditional (wild‐caught) species.

In this paper, the extent to which salmon competes with the main traditional fish species in the Spanish market is examined using market delineation methodologies. In particular, the potential interactions between species is examined in a multivariate cointegration framework. The results suggest that salmon is at best only a weak substitute for tuna, hake and whiting, but no significant interaction could be found.     

The quandary of quota management in the Torres Strait rock lobster fishery

Islanders, commercial non‐indigenous fishers and Papua New Guinea fishers share the tropical rock lobster fishery, Panulirus ornatus (Fabricius) in Torres Strait. As the fishery is in the process of moving from input to output controls, a pre‐implementation understanding of indigenous fishers' perceptions of the potential impact of different quota management systems is gained. This study, based on workshops and interviews, considers the impact of competitive quota, community quota and a hybrid system with individually tradeable quota (ITQ), and broadens the current biological focus of fisheries management through consideration of economic, social and cultural aspects. The perceived quota system impact on indigenous lobster fishers largely mirrors the experience internationally, with unlimited access and self‐determination considered most important. The heterogeneity of the indigenous sector increases the management complexity for this fishery, but needs to be taken into consideration if unexpected consequences of the chosen quota management system are to be avoided.     

Haemodynamic effects of ATP in dogs during hypoxia-induced pulmonary hypertension

Pulmonary hypertension may result from an increase in vascular resistance caused by persistent hypoxia. We have investigated the effects of adenosine triphosphate (ATP), administered into the pulmonary artery, on haemodynamic changes occurring in anaesthetized adult dogs subjected to acute hypoxic pulmonary vasoconstriction. Hypoxia alone (ventilation with 10% O2/90% N2) caused significant increases in mean pulmonary arterial blood pressure (PAP), central venous pressure (CVP), and cardiac index (CI) by 71, 102 and 38%, respectively. ATP (0.03-3.0 micromol/kg/min approximately 0.02-1.65 mg/kg/min), when infused under hypoxic conditions, significantly reduced both mean PAP and systemic arterial blood pressure (ABP) in a dose-dependent manner. The maximum decrease in mean PAP amounted to 20%; mean ABP, on the other hand, was decreased by up to 52% (P<0.01). Heart rate, CI, CVP and pulmonary occlusion pressure were not dose-dependently affected by ATP. Our data indicate that while pulmonary arterial administration of ATP in mature dogs during hypoxic pulmonary hypertension causes dilation in the pulmonary vascular bed, it is even more effective in dilating the systemic vasculature. This result suggests a need for further evaluation and warrants cautious use of ATP in the treatment of hypoxic pulmonary hypertension in adult dogs.     

Disc extrusion in a Rottweiler dog with caudal cervical spondylomyelopathy after failure of intervertebral distraction/stabilisation

A Rottweiler dog was presented with an 8 week history of hindlimb ataxia. Neurological examination localised the lesion to the cervical spinal cord. Myelography demonstrated dynamic compressive lesions at C5-6 and C6-7 consistent with a diagnosis of caudal cervical spondylomyelopathy. Distraction/stabilisation of both discs was performed using interbody polymethyl methacrylate. Both implants subsequently failed leading to extrusion of the remaining dorsal annulus fibrosus of the C5-6 intervertebral disc and nonambulatory tetraparesis. A ventral slot combined with distraction/stabilisation using screws and polymethyl methacrylate was performed and resulted in nearly full neurological recovery.     

Ustilospores of Tilletia ehrhartae, a smut of Ehrharta calycina, are common contaminants of Australian wheat grain, and a potential source of confusion with Tilletia indica, the cause of Karnal bunt of wheat

Australian wheat consigned for export from Australian ports was surveyed in March 2004 using a national diagnostic protocol for detection and identification of Tilletia indica . No ustilospores of T. indica were detected, confirming previous surveys which have failed to detect T. indica in Australia. However, the survey detected moderate levels of the common smuts Tilletia caries (syn. Tilletia tritici ), Tilletia laevis and Urocystis agropyri , and very low levels (average fewer than six ustilospores per 150 g sample) of an unidentified dark, tuberculate-spored Tilletia in ≈ 60% of samples tested. Comparison with herbarium specimens enabled identification of the majority of the tuberculate ustilospores as Tilletia ehrhartae , a smut fungus known to infect only Ehrharta calycina (perennial veldt grass) and which is common in southern Australia. A smaller number of tuberculate smut ustilospores were identified as Tilletia walkeri , a smut of Lolium spp. recorded in Australia but apparently uncommon. Both T. ehrhartae and T. walkeri bear sufficient resemblance to T. indica for misidentifications to be possible where only a very few ustilospores are seen, although T. ehrhartae ustilospores are always <25  µ m in diameter. The frequent presence of ustilospores of both T. ehrhartae and T. walkeri as contaminants of Australian wheat grain exports has significance for diagnosticians testing Australian export wheat, as it demonstrates the potential for tuberculate ustilospores of species other than those covered in existing diagnostic protocols to be misidentified as T. indica . This paper describes T. ehrhartae in detail, and provides criteria for its differentiation from T. indica , T. walkeri and some other species.     

Cardiovascular effects of propofol alone and in combination with ketamine for total intravenous anesthesia in healthy cats

This study was designed to compare the cardiovascular effects of equipotent maintenance of anesthetic doses (determined in a previous study) of propofol and propofol/ketamine, administered with and without noxious stimulation. Six healthy adult cats were anesthetized with propofol (loading dose 6.6 mg kg^?1, infusion 0.22 mg kg^?1 minute^?1), and instrumented to allow determination of blood gas and acid–base balance and measurement of blood pressures and cardiac output. The propofol infusion was continued for a further 60 minutes after which measurements were taken prior to and during application of a noxious stimulus. The propofol infusion was decreased to 0.14 mg kg^?1 minute^?1, and ketamine (loading dose 2 mg kg^?1, infusion 23 µg kg minute^?1) was administered. After a further 60 minutes, measurements were again taken prior to and during application of a noxious stimulus. The data were analyzed, using several Repeated Measures anova (first, ketamine/propofol and noxious stimulation were each treated as within‐subject factors; secondly, the levels of these two factors were combined into a single within‐subject factor). Mean arterial pressure, CVP, PAOP, SI, CI, SVRI, PVRI, oxygen delivery index, oxygen consumption index, oxygen utilization ratio, PvO₂, pHa, PaCO₂, bicarbonate concentration, and BD values collected during propofol administration were not changed by addition of ketamine and reduction of propofol concentration or by application of a noxious stimulus under propofol alone. Application of a noxious stimulus under propofol alone did, however, significantly increase HR and PaO₂, and these responses were not blunted by the addition of ketamine. Compared with propofol, administration of ketamine and reduction of propofol concentration significantly increased PAP and venous admixture, and significantly decreased PaO₂. Although application of a noxious stimulus to cats under propofol alone did not significantly change CVP, SI, CI, PVRI, oxygen delivery index, and oxygen consumption index, significant differences were found in these variables between propofol and propofol/ketamine. In conclusion, propofol alone provided cardiopulmonary stability; addition of ketamine did not improve hemodynamics but did decrease oxygenation.     

Cumulus–Oocyte Communications in the Horse: Role of the Breeding Season and of the Maturation Medium

Horse is a seasonal breeder and information on oocyte quality outside the breeding season is very limited. Ovaries obtained at the slaughterhouse are a convenient but often limited source of oocytes in this species. As the low quantity of ovaries leads to an intensive use of all available material, it would be useful to know whether ovaries collected during the non‐breeding season are suitable for in vitro maturation (IVM). In an attempt to characterize the effect of season on oocyte quality, we investigated the permeability of the gap junctions (GJ) present between cumulus cells and oocytes because of their important role in oocyte growth and maturation. We also compared the effect of supplementing the maturation medium with bovine serum albumin (BSA) or oestrus mare serum (EMS). A total of 645 oocytes isolated from 158 and 154 ovaries collected during the breeding and the non‐breeding season, respectively, were used in this study. Oocytes were matured for 30 h in TCM 199 supplemented either with 10% EMS or with 4 mg/ml BSA. The presence of permeable GJs between cumulus cells and oocytes was investigated with the injection of a 3% solution of the fluorescent dye Lucifer yellow into the ooplasm. No differences in efficiency of oocyte retrieval or oocyte meiotic competence were detected between oocytes collected during the breeding and non‐breeding season. The vast majority (90%) of the oocytes collected during the breeding season had fully functional communications with their surrounding cumulus cells but such communications were completely interrupted in 55.3% of the oocytes collected during the non‐breeding season. During the non‐breeding season, the proportion of oocytes whose communications with cumulus cells were classified as closed or intermediate at the end of maturation was lower in the group matured with BSA than with EMS (71.4 vs 97.7, p < 0.05). The same trend, although not statistically significant, was observed during the breeding season also. The presence of BSA caused an incomplete cumulus expansion during both seasons. Our data indicate that oocytes collected during the non‐breeding season do not show any meiotic deficiency but lack active communication with the surrounding cumulus cells at the time of their isolation from the ovary. No data are available at present for determining the consequences on the developmental competence even if data from other species suggest that this is likely.     

Prospective evaluation of pancarpal arthrodesis for carpal injuries in working dogs in New Zealand,using dorsal hybrid plating

Abstract

AIM: To determine whether working dogs in New Zealand with carpal injuries and treated with unilateral pancarpal arthrodesis (PCA), using a dorsal hybrid-plating method, are able to return to satisfactory working ability.

METHODS: Fourteen working dogs presented to the Veterinary Specialist Group (VSG) and the Massey University Veterinary Teaching Hospital (MUVTH) with carpal injuries were prospectively treated using dorsal hybrid plating. Dogs were eligible if actively involved in farm, hunting or police work. Dogs had a standardised PCA surgical procedure performed, and similar instructions for post-operative care were provided. Dogs were re-evaluated clinically and radiographically at 6 weeks, 6 months, and 12 months after surgery. A questionnaire was completed by 12 owners, to assess each dog's working ability.

RESULTS: Twelve months following arthrodesis, 10/12 (83%) dogs could perform most or all duties normally. Eleven owners (92%) reported that the result of the surgery met their expectations, and nine owners (75%) were very satisfied with the outcome of the surgery. No owners were disappointed or very disappointed with the surgical outcome. Post-operative complications requiring surgical removal of the implant occurred in three (25%) dogs.

CONCLUSIONS: Unilateral PCA using a standardised surgical procedure and dorsal hybrid plating of carpal injuries has a good prognosis for working dogs in New Zealand to return to work.

CLINICAL RELEVANCE: These results may allow veterinarians to provide a more accurate prognosis to owners of working dogs that have debilitating carpal injury     

Alkaline and Acid Phosphatase, β‐Glucuronidase and Electrolyte Levels in Fractionated Stallion Ejaculates

Seminal plasma (SP) is a mixture of contents from the testes, epididymides and accessory sex glands. The sperm concentration is highest in the first few jets, or fractions, of the ejaculate, and the composition of SP varies between these fractions because accessory gland secretions are released in a specific order. The aim of this study was to compare the levels of Na, Cl, K, Mg, Ca, inorganic phosphate (Pi) and the enzymes alkaline phosphatase (AP), acid phosphatase (ACP) and β‐glucuronidase (BG) in the different fractions of the ejaculate and in different stallions. All semen collections were done using a computer‐controlled phantom that collects the ejaculatory jets separately in five cups. The cups with the highest (HIGH) and the lowest (LOW) sperm concentration were analysed. In Trial I, semen was collected from three reproductively normal stallions. In Trial II, ejaculates of two reproductively normal stallions were compared to those of two subfertile stallions. In Trial III, semen was collected from seven stallions with varying reproductive history. The sperm‐rich fractions contained the highest levels of AP, ACP, BG and inorganic phosphate, and the values were positively correlated to the sperm concentration. Significant differences between the subfertile and the fertile stallions pairs in HIGH : LOW ratios were found in Pi and Cl concentrations. The highest concentrations of Ca and Mg were found in the last fractions with low sperm concentrations, with no significant differences between the fertile and the subfertile stallion pairs. The concentrations of K, Na and Cl were similar in HIGH and LOW fractions and in whole ejaculate samples. Pre‐sperm fluid contained the highest concentrations of Na and Cl. Some of the possible variation in storage tolerance between ejaculates and ejaculatory fractions could perhaps be explained by differences in the composition of SP.     

Doppler and Contrast‐Enhanced Ultrasonography of Testicles in Adult Domestic Felines

The objective was to characterize the vascular patterns of testicular blood flow of adult cats, measuring the systolic velocity (SV), diastolic velocity (DV), resistance index (RI), gate time (wash‐in) peak enhancement and output time (wash‐out) of the contrast and addition of tissue fill characteristics. Forty‐five adult cats were selected, and the echotexture, echogenicity, size, contours and margins of testicles were assessed via ultrasound. By Doppler were evaluated the blood flow and determined of vascular index in testicular artery (SV, DV and RI) and via contrast‐enhanced ultrasonography determine the time for phases: wash‐in, wash‐out and peak enhancement. Sonographic findings presented normal. Testicular artery was observed in the spermatic cord with tortuous patter and showed monophasic‐patterned waves and low vascular resistance and with systolic peak evident. Values of indices vascular were as follows: SV = 6.73 cm/s, DV = 2.8 cm/s and RI = 0.54 for left testicles; and SV = 6.23 cm/s, DV = 2.77 cm/s and RI = 0.53 for right testicles. Contrast filled the subcapsular vascular structures and after a few seconds, a homogeneous moderate enhancement of the parenchyma, with parenchymal vessels still distinguishable and after the peak phase, a rapid homogeneous decrease in echogenicity. Values of time for contrast‐enhanced ultrasonography were as follows: wash‐in = 8.78 s, peak enhancement = 21.62 s and wash‐out = 75.36 for left testicles; and wash‐in = 10.76 s, peak enhancement = 21.50 s and wash‐out = 81.81 for right testicles. Doppler and contrast‐enhanced ultrasonography of the testicles in healthy adult cats was easily implemented and may provide baseline data for this organ to allow the use of these techniques as a diagnostic tool for evaluating testicular abnormalities in sick cats.