California Red Abalone Research Articles

Use of management strategy evaluation to understand the value of citizen science in managing an iconic California recreational fishery

Data-limited fisheries present significant challenges to fisheries management around the world. Landings data represent the simplest and most common source of fishery information, but length data of harvested species can offer particularly useful insight into the strength of fishing pressure and the status of stocks. However, unbiased length data can be difficult and costly to collect, which highlights a need for understanding the utility of non-conventional data collection programs, such as those generated by community members and citizen science programs to improve management decision-making. In this study, our objective was to understand the value of citizen science for management using the iconic California recreational red abalone (Haliotis rufescens) dive fishery. To accomplish this, we employed management strategy evaluation (MSE) to simulate this benthic invertebrate fishery that was sampled by two different fishery independent survey protocols: a community science survey program led by trained volunteers and a professional science survey program led by a state agency. We subjected the data to a range of uncertainties, by including time-varying life history parameters, environmental variability, and effective sample size scenarios, to understand the management level consequences of each survey methodology. Our results show that community science program data collection can serve as a high-quality data source, can be linked directly to fisheries management decisions via a Harvest Control Rule (HCR), and can be a useful information source even in the absence of conventional data sources. Our results are specific to the California red abalone fishery, but they also highlight the potential broader value of community science data collection programs for improving information content of small-scale and recreational fisheries.

An indicator‐based decision framework for the northern California red abalone fishery

AbstractAmong abalone species that were once harvested along the California coastline, red abalone (Haliotis rufescens) supports the remaining recreational fishery. To support development of a red abalone fishery management plan, non‐governmental organizations have initiated expanded data collection and developed fishery management strategies. The latter is the subject of this study, as we present a management strategy evaluation (MSE) of a multi‐indicator decision tree. The decision tree relies on landings from each of 56 fishing sites and length frequency information collected during fishery‐independent diver surveys at a subset of sites. The decision tree was designed to cope with existing data limitations and to ensure that localized meta‐population dynamics were adequately considered in decision‐making. It was also necessary to balance the potential for localized abundance changes with the practical issue of implementing fishery regulations at larger spatial scales. The MSE demonstrated that undesirably low stock sizes could be avoided while also continuing to maintain a viable fishery, even under environmental conditions that are detrimental to abalone populations. Under less‐severe environmental conditions, stock size was maintained, on average, above the biomass associated with production of maximum sustainable yield. Our discussion centers on steps that were taken to refine the decision tree and to incorporate feedback from scientists and stakeholders and to facilitate transparent evaluation of management options.

Characterization of the growth-related transcriptome in California red abalone (Haliotis rufescens) through RNA-Seq analysis

One of the largest detriments in the abalone aquaculture industry is the inherently low growth rate of this marine gastropod. In order to confront this issue, greater molecular knowledge is needed on growth traits. Therefore, transcriptome analyses were performed using RNA-Seq for groups of California red abalones (Haliotis rufescens) cultured under the same conditions, but with high growth rates (HGR) or low growth rates (LGR). De novo assembly generated 44312 contigs used as references for RNA-Seq analysis. Results showed a total of 1437 differentially expressed contigs, among which, 435 were up-regulated in the HGR group and 1002 in LGR individuals. Overall, LGR abalones evidenced a greater number of exclusive transcripts and differentially transcribed genes. These results provide a valuable resource of novel transcripts in this species and further understandings of the molecular bases regulating growth traits in H. rufescens.

Molecular characterization of IRAK-4 and Interleukin-17 genes in the California red abalone (Haliotis rufescens) exposed to Vibrio anguillarum

Molecular characterization of IRAK-4 and Interleukin-17 genes in the California red abalone (Haliotis rufescens) exposed to Vibrio anguillarum

SNP discovery and High Resolution Melting Analysis from massive transcriptome sequencing in the California red abalone Haliotis rufescens

The California red abalone, Haliotis rufescens that belongs to the Haliotidae family, is the largest species of abalone in the world that has sustained the major fishery and aquaculture production in the USA and Mexico. This native mollusk has not been evaluated or assigned a conservation category even though in the last few decades it was heavily exploited until it disappeared in some areas along the California coast. In Chile, the red abalone was introduced in the 1970s from California wild abalone stocks for the purposes of aquaculture. Considering the number of years that the red abalone has been cultivated in Chile crucial genetic information is scarce and critical issues remain unresolved. This study reports and validates novel single nucleotide polymorphisms (SNP) markers for the red abalone H. rufescens using cDNA pyrosequencing. A total of 622 high quality SNPs were identified in 146 sequences with an estimated frequency of 1 SNP each 1000bp. Forty-five SNPs markers with functional information for gene ontology were selected. Of these, 8 were polymorphic among the individuals screened: Heat shock protein 70 (HSP70), vitellogenin (VTG), lysin, alginate lyase enzyme (AL), Glucose-regulated protein 94 (GRP94), fructose-bisphosphate aldolase (FBA), sulfatase 1A precursor (S1AP) and ornithine decarboxylase antizyme (ODC). Two additional sequences were also identified with polymorphisms but no similarities with known proteins were achieved. To validate the putative SNP markers, High Resolution Melting Analysis (HRMA) was conducted in a wild and hatchery-bred population. Additionally, SNP cross-amplifications were tested in two further native abalone species, Haliotis fulgens and Haliotis corrugata. This study provides novel candidate genes that could be used to evaluate loss of genetic diversity due to hatchery selection or inbreeding effects.

Efficacy, tissue distribution, and residue depletion of oxytetracycline in WS-RLP infected California red abalone Haliotis rufescens

Oxytetracycline (OTC) was recently demonstrated to be an effective therapeutant for California red abalone ( Haliotis rufescens) infected with the agent of withering syndrome (WS), a Rickettsia-like prokaryote (WS-RLP). This study examined the influence of temperature on the efficacy and pharmacokinetics of oral OTC treatments on WS-RLP infected red abalone, H. rufescens. Medication was administered in an artificial diet containing 1.85% active OTC at a rate of 103.4 mg/kg abalone for 10, 20 and 30 days at both 13.4 °C and 17.3 °C. Drug residue concentrations, WS-RLP burden and WS-associated pathological changes within foot muscle and digestive gland were measured 3, 17, 23, 42, 63, 81, 102, 122, and 160 days after OTC treatment. In all samples the highest concentrations of OTC were detected on the first sample day. Furthermore, all sampling periods showed significantly less OTC in foot muscle samples relative to corresponding digestive gland samples ( p < 0.001). While drug depuration occurred rapidly from foot muscle, unusually high concentrations and long depuration times were measured within the digestive gland. The pharmacokinetic trends in both the foot muscle and digestive gland at 13.4 °C were adequately described by a one-compartment model, while the digestive gland depuration models within the 17.3 °C treatments conformed to a two-compartment model. At both temperatures treatment duration gave rise to significant differences in OTC accumulation and depletion ( p < 0.001). Despite this, terminal elimination rate constants were similar. Estimated half-lives were similar among all treatments for digestive gland (23.8–27.5 d) and all treatments for the foot muscle at 13.4 °C (10.7–13.4 d; calculated only for the 13.4 °C treatments). At both temperatures all three durations of drug treatment led to significant reductions in WS-RLP prevalence, foot muscle atrophy, and mortality. WS-RLP re-challenge trials initiated 44, 88, and 122 days following the 10-day treatment at 17.3 °C showed reduced susceptibility to re-infection for up to 88 days after treatment, suggesting that digestive gland OTC residues confer long-term resistance to pathogen. Atomic absorption spectroscopy conducted on both foot muscle and digestive gland found significantly higher concentrations of iron, zinc, and manganese in the digestive gland, offering an explanation behind the underlying mechanism of OTC retention for extended periods within this tissue.

Genetic structure of natural populations of California red abalone (Haliotis rufescens) using multiple genetic markers

Mitochondrial cytochrome oxidase subunit one (COI) sequence, nuclear microsatellites, and amplified fragment length polymorphisms (AFLPs) were used to evaluate connectivity among nine red abalone (Haliotis rufescens) populations sampled between August 1998 and November 2003 along approximately 1,300 km of California coastline from Crescent City (41°46′N, 124°12′W) to San Miguel Island (34°02′N, 120°22′W). COI sequences and microsatellite genotypes did not show significant genetic divergence among nine sampled populations. A subset of five populations spanning the geographic range of the study was scored for 163 polymorphic AFLP markers. Of these, 41 loci showed significant divergence (P < 0.001) among populations. Still, no AFLP markers were diagnostic for any of the study populations, and assignment tests did not consistently assign individuals to the correct population. Although the AFLP data are the first to suggest there is significant genetic differentiation among California red abalone populations, the discordance between the different genetic markers needs further study before unambiguous conclusions can be drawn with respect to connectivity among the populations.

Characterizing the metabolic actions of natural stresses in the California red abalone, Haliotis rufescens using 1H NMR metabolomics

Withering syndrome in California red abalone (Haliotis rufescens) is caused by the Rickettsiales-like prokaryote (WS-RLP) Candidatus Xenohaliotis californiensis. WS-RLP infection is not sufficient to cause withering syndrome, and for reasons not yet well understood additional stressors such as elevated water temperature appear to influence disease development. Using nuclear magnetic resonance (NMR) based metabolomics, we have investigated the influence of food availability, temperature, and bacterial infection, both individually and in combination, on the metabolic status of the red abalone. Food limitation caused dramatic reductions in all observed classes of foot muscle metabolites, while at the same time metabolite levels within the digestive gland were preserved or increased. We also found that food limitation in combination with elevated temperature led to greater metabolic perturbations in both tissue types than those observed under food limitation alone. WS-RLP infection and food-limitation resulted in many of the same metabolic changes within the tissues studied, although the effects of infection were less severe. We observed increased levels of homarine in the digestive gland of both food-limited and WS-RLP-infected animals, yet only observed increased homarine levels in the foot muscle of infected abalone. These results further support the recently established glucose-to-homarine ratio in foot muscle as a potential marker for differentiating WS-RLP-infected animals from those of both healthy and food limited abalone. Furthermore, we found that the NMR metabolic data correlates well with histological measurements supporting the use of the metabolomics approach for characterizing both normal and pathological events in marine species, particularly during periods of environmentally relevant stress.

Population genetics of black abalone, Haliotis cracherodii, along the central California coast.

Over the past three decades, the black abalone, Haliotis cracherodii, has experienced precipitous declines in abundance over portions of its range in southern and central California. The potential for recovery of these populations is dependent in part on dispersal processes; that is, can distant populations serve as sources of recruits to locales that no longer harbor H. cracherodii? Here we use population genetic analysis to assess levels of population subdivision and infer recruitment processes. Epipodial tissue samples were obtained from over 400 black abalone from seven geographic sites between Santa Cruz and Santa Barbara counties in central California. Allelic frequencies were determined for each population at three polymorphic enzyme-encoding loci (GPI, AAT-1 and PGM). Significant allelic frequency differentiation among sites was observed at all three loci. Genetic distance was found to be independent of geographic distance over the approximately 300-km sampling range. In addition, a limited number of DNA sequences (total N=51) were obtained for the mitochondrial cytochrome oxidase subunit I gene (COI) from five of the populations. Since the same common COI haplotype dominated each population, this analysis had little statistical power and failed to detect population structure. The observed level of population differentiation at allozyme loci was three-fold higher than that observed in California red abalone, H. rufescens. The species differ in their breeding period and it is suggested that the relatively short, summer breeding season of black abalone limits dispersal because larvae experience reduced variance in oceanographic conditions relative to red abalone that spawn year-round. Based on these results, rates of recolonization and recovery of locally depressed or extirpated black abalone populations are likely to be slow despite harvest restrictions.

Infestation of Haliotis rufescens shells by a sabellid polychaete

The shell of the California red abalone ( Haliotis rufescens) can be host to a variety of organisms, including boring sponges, clams and polychaetes. These boring organisms usually do not seriously affect the growth of the abalone because they normally inhabit the outer portions of mature abalone shells. Abalone cultured in an aquaculture facility are marketed at a young age and seldom host many of these shell-dwelling organisms. Recently, however, some red abalone raised in aquaculture facilities in California have been found to be hosts to a sabellid polychaete. This polychaete infests the leading edge of the shell and can significantly interfere with the normal growth of the abalone. A cursory review of the literature does not reveal any previous cases of sabellids inhabiting the shells of abalone. This paper presents some of our observations and assumptions about this unique discovery.

Experimental evidence for the effects of polyphenolic compounds from Dictyoneurum californicum Ruprecht (Phaeophyta: Laminariales) on feeding rate and growth in the red abalone Haliotus rufescens Swainson

The effects of polyphenolic compounds from brown algae on grazing and growth rate of the California red abalone Haliotis rufescens Swainson were examined. Abalone consumed three phenolic-poor algal species, Laminaria sinclarii (Harvey) Farlow, Macrocystis pyrifera Agardh, and Nereocystis luetkeana Postels et Ruprecht (mean phenolic content = 0.52% dry mass), at a greater rate than two phenolic-rich species, Dictyoneurum californicum Ruprecht and Cystoseira osmundacea Agardh (mean phenolic content = 4.60% dry mass). This inverse relationship between phenolic content and consumption rate also existed after the algae were macerated and the liquid portion of the blended slurry incorporated in agar discs. However, the correlation between grazing rate and phenolic content imprpve d in this latter experiment, thus suggesting that abalone grazing was deterred significantly by the morphology of L. sinclarii and, to a lesser extent, of M. pyrifera. Polyphenolics extracted from D. californicum reduced abalone grazing rates by 90% when incorporated into agar discs at a concentration of 6 mg·ml −1. Although abalone were unable to maintain body mass when fed ad libitum on macerated M. pyrifera incorporated into agar discs, polyphenolics from D. californicum further inhibited shell growth when added to the discs at 5 mg·ml −1. The abalone ate less of the phenol-containing discs than of the discs lacking phenolics. Our results support findings of several prior studies that polyphenolic compounds from brown algae deter grazing by coastal zone herbivores in the northeast Pacific Ocean.

Amino acid sequence of an egg-lysin protein from abalone spermatozoa that solubilizes the vitelline layer.

Spermatozoa of the California red abalone (Haliotis rufescens; Phylum Mollusca, order Archeogastropoda) possess an acrosomal protein that dissolves the egg vitelline layer during fertilization. Evidence strongly suggests that the dissolution mechanism is a stoichiometric, nonenzymatic process that depends on the hydrophobic nature of the sperm protein which should therefore be termed an egg-lysin. Here we report the complete amino acid sequence of this unique protein. Peptides obtained by cyanogen bromide cleavage and trypsin and V8 protease digestions were isolated and subjected to automated Edman degradation. Seven unique CNBr fragments accounted for the intact lysin and the proteolytically derived peptides were used to establish the order of these fragments. The protein is composed of 134 amino acids and contains 36 charged amino acids. The majority of these occur at distances of 2 or 3 residues from each other. A stretch of 41 amino acids contains 10 positively charged amino acids and no negatively charged residue. Model building experiments demonstrated that the charged residues that may occur in alpha-helical regions of the protein would occupy one-half of the circumference of such helices. The other half would display predominantly hydrophobic residues. This arrangement of the charged and hydrophobic residues may account for the biological properties of the lysin.

The Growth and Survival of the California Red Abalone in Japan

The Growth and Survival of the California Red Abalone in Japan