Paul Bienfang

Ciguatera Fish Poisoning: Treatment, Prevention and Management

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world, and it causes substantial physical and functional impact. It produces a myriad of gastrointestinal, neurologic and/or cardiovascular symptoms which last days to weeks, or even months. Although there are reports of symptom amelioration with some interventions (e.g. IV mannitol), the appropriate treatment for CFP remains unclear to many physicians. We review the literature on the treatments for CFP, including randomized controlled studies and anecdotal reports. The article is intended to clarify treatment options, and provide information about management and prevention of CFP, for emergency room physicians, poison control information providers, other health care providers, and patients.

Progress in controlled breeding of Nassau grouper (Epinephelus striatus) broodstock by hormone induction

Abstract Human chorionic gonadotropin (HCG), luteinizing hormone-releasing hormone analogue (LHRH-a), and carp pituitary homogenate (CPH), used alone or in various combinations, were tested as spawning agents in captive E. striatus broodstock. Fifty hormone-induced strip-spawning trials were attempted using a two-injection sequence in which a priming dose (PD) was followed 24 h later by a resolving dose (RD). Hormone treatment strategies tested included, HCG alone (PD = 1000 IU kg −1 bw, RD = 500 IU kg −1 bw), LHRH-a alone (PD = 50–100 μg kg −1 bw, RD = 100–200 μg kg −1 bw), HCG (500 IU kg −1 bw) in combination with LHRH-a (50–100 μg kg −1 bw) as priming or resolving doses, and CPH (PD = 10 mg kg −1 bw) in combination with LHRH-a (RD = 50–100 μg kg −1 bw). As an alternative to hormone injection, intramuscular implantation of a cholesterol pellet containing LHRH-a (200–250 μg) was tested in two females. Females with mean oocyte diameters ranging from 482 to 561 μm were suitable for hormone-induced spawning. Oocyte diameter increased to 524–708 μm within 24 h of the priming dose and to 852–945 μm within 9–16.4 h following the resolving dose. Average diameter of spawned (water hardened) eggs ranged from 879–978 μm. Although fertilization rate (0–94.7%) varied widely among trials, successful spawnings (fertilization rate ≥ 50%) were obtained in all of the hormone strategies tested. Use of different hormones in combination showed no advantage over a single-hormone strategy. As HCG appeared to cause an immune response, LHRH-a is recommended for repeated application. Implantation of LHRH-a produced variable results, inducing ovulation in one female, but apparently inducing sex reversal in the other.

An Updated Review of Ciguatera Fish Poisoning: Clinical, Epidemiological, Environmental, and Public Health Management

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world. It causes substantial human health, social, and economic impacts. The illness produces a complex array of gastrointestinal, neurological and neuropsychological, and cardiovascular symptoms, which may last days, weeks, or months. This paper is a general review of CFP including the human health effects of exposure to ciguatoxins (CTXs), diagnosis, human pathophysiology of CFP, treatment, detection of CTXs in fish, epidemiology of the illness, global dimensions, prevention, future directions, and recommendations for clinicians and patients. It updates and expands upon the previous review of CFP published by Friedman et al. (2008) and addresses new insights and relevant emerging global themes such as climate and environmental change, international market issues, and socioeconomic impacts of CFP. It also provides a proposed universal case definition for CFP designed to account for the variability in symptom presentation across different geographic regions. Information that is important but unchanged since the previous review has been reiterated. This article is intended for a broad audience, including resource and fishery managers, commercial and recreational fishers, public health officials, medical professionals, and other interested parties.

The Role of Coastal High Latitude Ecosystems in Global Export Production

If one were to sit down and design a perfectly conservative pelagic ecosystem, it would likely have the following properties. First, it would be a steady-state system, in which the delivery of essential substrates would be constant over time to minimize transient oscillations of the food web to changing substrate supplies. Second, the biological components would be built upon small-sized primary producers (e.g., picoplankton), and consist of a complex network of numerous trophic levels of carefully balanced standing stocks, which are configured in a K-type strategy having numerous feedback loops for the regeneration of essential substrates. Third, the system would have negligible sinking rates to minimize vertical transport of material away from the photic influx at the surface. Fourth, the benthos would be located far away (i.e., in deep water) to maximize the time/opportunities for regeneration and, thus, minimize losses from the water column.

Pigment analysis of phytoplankton during a subarctic spring bloom: xanthophyll cycling

Abstract The objective in this study of the spring bloom in Auke Bay, Alaska, was to determine if light-dependent xanthophyll cycling can be used to estimate the rate of vertical mixing in a subarctic environment. This was done by measuring the concentration of the xanthophylls diadinoxanthin (DD) and diatoxanthin (DT) in phytoplankton samples collected from different depths and different times of the day and in samples incubated in situ. We sampled throughout the photic zone weekly from 16 March until 9 May 1989. Pigments typical diatom assemblages (e.g., Chl a and c , fucoxanthin, DT, DD, and s-carotene) were found throughout the sampling period. In situ incubations between dawn and early afternoon showed large differences in xanthophyll composition between incubated samples and those from the water column. Differences between samples collected in early morning and early afternoon were also found, as well as between samples collected at different depths. However, the technique was not found satisfactory to describe mixing events in this environment. Other factors besides light seemed to affect the concentrations of the xanthophyls, DT and DD. These findings cast doubt on the ability of DT: DD ratios to infer the vertical mixing history of field assemblages.

Modeling partial harvesting in intensive shrimp culture : A network-flow approach

Despite the promising laboratory results and theoretical arguments on the potential of partial harvesting in enhancing the productivity and profitability of intensive shrimp growout facilities, the implementation of partial harvesting in practical operation is rather difficult due to its complex nature. In this paper, we developed a practical model of partial harvesting using the network-flow approach so that it can be readily implemented and solved in MS EXCEL. We demonstrated the use of this spreadsheet model with data from a commercial shrimp farm in Hawaii. The results indicate that the model is capable of identifying the efficient harvest policy as well as assessing the viability of partial harvesting under a variety of managerial conditions and objectives.