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Wild populations of pinto abalone (Haliotis kamtschatkana) in Washington State have declined by 97% since 1992, despite a fishery closure since 1994. No recruitment has been detected recently, indicating probable reproductive failure due to low densities. A pilot programme placed a total of over 11,000 hatchery‐origin juveniles, age 18–22 months, at 10 sites in the San Juan Islands.Observed (naive) year 1 survival averaged 10.2% (0–23% range) and was most influenced by site compared with lineage or size‐at‐outplant. Families survived in the approximate proportions that they were outplanted, and there was little support for an effect of size‐at‐outplant on survival.Detection was low due to the small chance of sighting individuals on complex substrate. When derived from repeated sampling, an upper bound on naive detection rate averaged 0.38 and increased with size. When derived from a closed capture–recapture model, average detection was estimated at 0.19.Growth was highly variable and confounded with detection, but an average 3.4% of detected outplants across all sites (0–7.5% range) had reached reproductive size in 2017.A state‐space model of exponential population growth was modified to account for imperfect detection and yielded an estimated density of abalone for each survey. Seven out of eight sites included in the model remained above a target abalone density of 0.3 m−2 throughout the project.The majority of tagged abalone made little net movement over weekly and annual timescales, although some emigration likely reduced survival estimates.The restoration programme is transitioning from a pilot phase to a production phase, including optimization of hatchery and outplant processes. Existing well‐performing sites will receive additional cohorts every 4–5 years to maintain aggregation densities. New sites will replace poorly performing ones, although this is hampered by a poor understanding of the mechanisms behind site performance. [ABSTRACT FROM AUTHOR]

Managing for simultaneous recovery of interacting species, particularly top predators and their prey, is a longstanding challenge in applied ecology and conservation. The effects of sea otters ( Enhydra lutris kenyoni) on abalone ( Haliotis spp.) is a salient example along North America's west coast where sea otters are recovering from 18th- and 19th-century fur trade while efforts are being made to recover abalone from more recent overfishing. To understand the direct and indirect effects of sea otters on northern abalone ( H. kamtschatkana) and the relative influence of biotic and abiotic conditions, we surveyed subtidal rocky reef sites varying in otter occupation time in three regions of British Columbia, Canada. Sites occupied by sea otters for over 30 years had 16 times lower densities of exposed abalone than sites where otters have yet to recover (0.46 ± 0.08/20 m2 vs. 7.56 ± 0.98/20 m2), but they also had higher densities of cryptic abalone (2.17 ± 1.31/20 m2 vs. 1.31 ± 0.20/20 m2). Abalone densities were greater in deeper vs. shallower habitats at sites with sea otters compared to sites without otters. Sea otter effects on exposed abalone density were three times greater in magnitude than those of any other factor, whereas substrate and wave exposure effects on cryptic abalone were six times greater than those of sea otters. While higher substrate complexity may benefit abalone by providing refugia from sea otter predation, laboratory experiments revealed that it may also lead to higher capture efficiency by sunflower stars ( Pycnopodia helianthoides), a ubiquitous mesopredator, compared to habitat with lower complexity. Sea otter recovery indirectly benefitted abalone by decreasing biomass of predatory sunflower stars and competitive grazing sea urchins, while increasing stipe density and depth of kelp that provides food and protective habitat. Importantly, abalone persisted in the face of sea otter recovery, albeit at lower densities of smaller and more cryptic individuals. We provide empirical evidence of how complex ecological interactions influence the effects of recovering predators on their recovering prey. This ecosystem-based understanding can inform conservation trade-offs when balancing multifaceted ecological, cultural, and socio-economic objectives for species at risk. [ABSTRACT FROM AUTHOR]

Abalone populations have declined worldwide, generating interest in enhancement using hatchery-reared individuals. In many cases, such restoration efforts have met with limited success due to high predator-induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone ( Haliotis kamtschatkana) as a case study to determine whether hatchery-reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery-reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery-reared individuals remained subdued. Anti-predator behavioural deficits in hatchery-reared abalone were more pronounced in 4-year-old individuals than in 1-year-old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery-reared abalone to predators, and are likely a major cause of their elevated predator-induced mortality when outplanted. [ABSTRACT FROM AUTHOR]

We documented the diet of the Black Oystercatcher (Haematopus bachmani) on Haida Gwaii, British Columbia, Canada, (2004-2010) with prey remains from 99 territories in Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve and Haida Heritage Site. The ranking of its four main prey types did not vary annually. Numerically, the prey comprised 50-75% limpets, 14-34% mussels, 8-18% chitons, 1-2% Northern Abalone (Haliotis kamtschatkana), and <1% other species. In 2009, we estimated prey availability and prey preference by Ivlev's electivity index. Northern Abalone, limpets, and chitons were highly preferred; mussels, turban snails, and barnacles were taken in proportion to their occurrence or avoided. Black Oystercatchers preferred abalone of 50 mm, smaller than the mean size available, in contrast to the selection of larger-than-average prey, typical for other prey species. In 2010, 52% of nesting territories sampled contained remains of Northern Abalone, despite that species' small contribution to the diet. The Northern Abalone has never been reported as prey of the Black Oystercatcher despite its high vulnerability to predation at low tides. We speculate that the recent inclusion of the Northern Abalone in the Black Oystercatcher diet on Haida Gwaii may indicate a greater abundance of Northern Abalone than in other regions of its distribution. The frequency of the oystercatcher's feeding on abalone was unexpected because under Canada's Species at Risk Act, the Northern Abalone was listed as "endangered" in 2010, after the population continued to decline after legal protection from harvest in 1990. [ABSTRACT FROM AUTHOR]

ABSTRACT Northern abalone ( Haliotis kamtschatkana) in British Columbia, Canada, are listed as endangered and are protected from fishing, yet their populations continue to decline. It is suspected that supplementation of wild populations with hatchery-reared abalone will be necessary for the recovery of this species. This study examines the magnitude, timing, and causes of post-outplanting mortality of hatchery-reared late-juvenile northern abalone., Abalone survivorship declined precipitously following outplanting, with 83% of abalone surviving 24 h after release and only 34% surviving 2 weeks in the wild., Handling, tagging, and temperature variations experienced during the outplanting procedure did not cause mortality. The majority of the abalone mortality in this study was attributable to predators. Additional factors accounted for only 1-2% mortality over 7 d., A 1-week acclimatization period within predator exclosures did not improve subsequent survival of outplants., These results demonstrate that the ouplanting of hatchery-reared abalone as a method of restoring wild populations of this endangered species is primarily constrained by high mortality during the first few days after outplanting, and that almost all of this early mortality is caused by predation. Predation mortality will therefore have to be overcome if outplanting of hatchery-reared juvenile abalone is to be an effective restoration strategy., Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Effective conservation of threatened species depends on the ability to assess organism physiology and population demography. To develop genomic resources to better understand the dynamics of two ecologically vulnerable species in the Pacific Northwest of the United States, larval transcriptomes were sequenced for the pinto abalone, Haliotis kamtschatkana kamtschatkana, and the Olympia oyster, Ostrea lurida. Based on comparative species analysis the Ostrea lurida transcriptome (41 136 contigs) is relatively complete. These transcriptomes represent the first significant contribution to genomic resources for both species. Genes are described based on biological function with particular attention to those associated with temperature change, oxidative stress and immune function. In addition, transcriptome-derived genetic markers are provided. Together, these resources provide valuable tools for future studies aimed at conservation of Haliotis kamtschatkana kamtschatkana, Ostrea lurida and related species. [ABSTRACT FROM AUTHOR]

Failure to account for interactions between endangered species may lead to unexpected population dynamics, inefficient management strategies, waste of scarce resources, and, at worst, increased extinction risk. The importance of species interactions is undisputed, yet recovery targets generally do not account for such interactions. This shortcoming is a consequence of species-centered legislation, but also of uncertainty surrounding the dynamics of species interactions and the complexity of modeling such interactions. The northern sea otter (Enhydra lutris kenyoni) and one of its preferred prey, northern abalone (Haliotis kamtschatkana), are endangered species for which recovery strategies have been developed without consideration of their strong predator-prey interactions. Using simulation-based optimization procedures from artificial intelligence, namely reinforcement learning and stochastic dynamic programming, we combined sea otter and northern abalone population models with functional-response models and examined how different management actions affect population dynamics and the likelihood of achieving recovery targets for each species through time. Recovery targets for these interacting species were difficult to achieve simultaneously in the absence of management. Although sea otters were predicted to recover, achieving abalone recovery targets failed even when threats to abalone such as predation and poaching were reduced. A management strategy entailing a 50% reduction in the poaching of northern abalone was a minimum requirement to reach short-term recovery goals for northern abalone when sea otters were present. Removing sea otters had a marginally positive effect on the abalone population but only when we assumed a functional response with strong predation pressure. Our optimization method could be applied more generally to any interacting threatened or invasive species for which there are multiple conservation objectives. Definición de Metas de Recuperación Realistas para Dos Especies en Peligro Interactuantes, Enhydra lutris y Haliotis kamtschatkana [ABSTRACT FROM AUTHOR]

To investigate contemporary pinto abalone Haliotis kamtschatkana kamtschatkana recruitment events and juvenile abundance, 66 abalone recruitment modules (ARMs) were deployed at two depths and three sites in the San Juan Archipelago (Washington State) that were historically inhabited by substantial abalone populations. Based on published studies from California and British Columbia, ARMs are proven tools for surveying juvenile pinto abalone abundance. Abalone recruitment modules provide complex habitat and protection from predation. The ARMs were surveyed in situ for juvenile abalone abundance six times over the course of 26 months. Only eight abalones were observed, including three juveniles that were less than 50 mm (shell length). The mean density of juvenile abalones inhabiting the ARMs across all three sites during the 2006 surveys was 0.012/m2. The absence of juvenile abalones within the ARMs, combined with sharp regional declines in adult pinto abalone abundance, suggests limited local recruitment of this species, which is currently designated as threatened in Canada and as a species of concern in the USA. Received January 24, 2011; accepted May 25, 2011 [ABSTRACT FROM PUBLISHER]

Abstract: Increasing levels of anthropogenic carbon dioxide in the world''s oceans are resulting in a decrease in the availability of carbonate ions and a drop in seawater pH. This process, known as ocean acidification, is a potential threat to marine populations via alterations in survival and development. To date, however, little research has examined the effects of ocean acidification on rare or endangered species. To begin to assess the impacts of acidification on endangered northern abalone (Haliotis kamtschatkana) populations, we exposed H. kamtschatkana larvae to various levels of CO2 [400ppm (ambient), 800ppm, and 1800ppm CO2] and measured survival, settlement, shell size, and shell development. Larval survival decreased by ca. 40% in elevated CO2 treatments relative to the 400ppm control. However, CO2 had no effect on the proportion of surviving larvae that metamorphosed at the end of the experiment. Larval shell abnormalities became apparent in approximately 40% of larvae reared at 800ppm CO2, and almost all larvae reared at 1800ppm CO2 either developed an abnormal shell or lacked a shell completely. Of the larvae that did not show shell abnormalities, shell size was reduced by 5% at 800ppm compared to the control. Overall, larval development of H. kamtschatkana was found to be sensitive to ocean acidification. Near future levels of CO2 will likely pose a significant additional threat to this species, which is already endangered with extinction due in part to limited reproductive output and larval recruitment. [Copyright &y& Elsevier]

Abstract: The northern (or pinto) abalone, Haliotis kamtschatkana, is a broadcast-spawning marine gastropod that was recently listed as endangered in Canada. To aid in species recovery, a captive-breeding and supplementation program is underway in Barkley Sound, British Columbia. We genotyped first generation progeny for five microsatellite loci and used a pedigree reconstruction program (Pedigree 2.2) to identify their genealogical relationships in the absence of information on parental genotypes. We analyzed progeny from three separate group-spawning events and inferred considerable variation in the number of offspring produced by each parent; in the most severe case a single male sired all the progeny produced during one spawning event. After only one generation of captive-breeding we found a 55–60% reduction in allelic richness and a 17–18% reduction in heterozygosity relative to the diverse wild source population. This study illustrates the difficulty of managing genetic diversity in hatchery populations of a broadcast-spawning species, even when gametes are collected separately from each individual broodstock. [Copyright &y& Elsevier]

Abstract: Bayesian hierarchical models were developed to estimate the growth parameters of northern abalone, Haliotis kamtschatkana, using tag-recapture data with a mixture of single and multiple recaptures. Individual variability in the growth parameters L ∞ and k of the von Bertalanffy model was incorporated in the analyses. The models developed fit the data well based on the Bayesian p-values. Variability in L ∞ for individuals was high relative to the variability in L ∞ for the population, and variability in k for individuals was about the same as the variability in k for the population. Simulations showed that estimates of the growth parameters were accurate (relative biases <5%), when variability in both L ∞ and k or just in L ∞ was accounted for. The “true” values of the parameters, L ∞ and k, were contained in the estimated 95% credibility intervals in 90–94 out of 100 simulation runs on 100 simulated data sets. Overall, allowing for variability for both L ∞ and k resulted in moderately more accurate estimates than allowing for just L ∞. On the contrary, estimates were unreliable when variability in just k was considered. Using the WinBUGS software program, the calculation procedure was rather simple irrespective of which growth parameter was modeled with variability. [Copyright &y& Elsevier]

Pinto abalone (Haliotis kamtschatkana kamtschatkana) index stations in the San Juan Archipelago were systematically monitored by the Washington Department of Fish and Wildlife from 1992 through 2006. During this period, abalone abundance declined by 77% and the mean shell length (SL) increased 10.4 mm. Abalone densities at all index stations are currently well below the threshold of 0.15 abalone·m–2 required for successful fertilization. From 1992 to 1996, 16% of individuals encountered measured <90 mm SL, while only 6% of the individuals from 2003 to 2006 were in this small size class. Similarly, the number of those >114 mm SL was greater in the 2000s than in the 1990s. The mean SL of all live abalone observed in the 1990s (107.62 ±0.87 mm) was significantly different from the mean SL of empty shells (114.21 ±2.1 mm), but no difference was detected between the mean SLs of empty shells and live abalone in the 2000s (114.97 ±1.42 mm). Taken together, these data suggest recruitment failure from an Allee response to low population densities. [ABSTRACT FROM AUTHOR]

Abstract: Growth of abalone in the wild and hatchery is density-dependent in response to intraspecific competition for food and/or space. To determine if a candidate aquaculture species, Haliotis kamtschatkana, exhibits density-dependent growth we raised animals at three density levels and two food treatments: unlimited (ad libitum) and rationed (individual portions were the same among density treatments). We also tested for differences in food consumption, foraging patterns and stacking behaviour among the density levels. We observed density-dependent growth in the rationed treatments, indicating that relatively high growth rates at lower densities are driven, in part, by factors other than differences in food consumption. However, overall the quantity of food consumed related directly to growth; treatments fed ad libitum had higher growth rates. Furthermore, even when food was provided in excess, foraging was restricted to ~2 h after sunset in all treatments and the amount consumed per abalone was significantly lower at high densities. This is probably because high density animals could not access the food provided: fewer were observed foraging and they had to move from prominent stacks. Our results indicate that both temporal and spatial access to food are critical and that managers can observe foraging and stacking by abalone in tanks to determine if a specific design will limit food consumption, and ultimately growth. [Copyright &y& Elsevier]

The article examines climate change contributing to range reductions and localized extinctions in northern and flat abalones. The section analyzes northern and flat abalone along the Pacific coast of the United States, comparing data with historic records from 30 years ago to test whether there has been a shift in the southern range as would be predicted with ocean warming. It focuses on northern abalone which is a species of concern, has a broad geographic distribution, and was once the basis of important commercial and recreational fisheries.

Crossing of the pleurovisceral nerve cords in gastropods has supported the view that gastropods evolved by 180° rotation between the ventral and dorsal body regions. Indeed, a rotation of this type occurs as a dramatic morphogenetic movement (“ontogenetic torsion”) during the development of basal gastropods. According to a long-standing hypothesis, ontogenetic torsion in basal gastropods preserves an ancient developmental aberration that generated the contorted gastropod body plan. It follows from this reasoning that crossing of the pleurovisceral nerve cords during gastropod development should be mechanically coupled to ontogenetic torsion. The predicted mechanical coupling can now be examined because of the discovery of an early differentiating neuron in Haliotis kamtschatkana (Vetigastropoda) that expresses 5-hydroxytryptamine-like immunoreactivity. The neuron appeared to delineate the trajectory of the pleurovisceral nerve cords beginning before ontogenetic torsion. Before torsion, the neuronal soma is embedded in mantle epithelium at the ventral midline and two neurites extend anteriorly toward the apical sensory organ. Contrary to expectation, the two neurites of this cell did not cross-over during ontogenetic torsion because the soma of this mantle neuron shifted in the same direction as the rotating head and foot. Full crossing of the pleurovisceral nerve cords occurred gradually during later development as the mantle cavity deepened and expanded leftward. These results are consistent with a generalization emerging from comparative studies indicating a conserved developmental stage for gastropods in which the mantle cavity is localized to one side, despite a fully “post-torsional” orientation for other body components. Developmental morphology before this stage is much more variable among different gastropod clades. [ABSTRACT FROM AUTHOR]

Marine invertebrate species have usually been overlooked in favor of high-profile vertebrate species for facilitating dialogue towards area conservation. The northern abalone (Haliotis kamtschatkana) is proposed as a focal ("flagship") species whose protection and recovery could concentrate public concern for abalone and its associated kelp forest ecosystems in Haida Gwaii (Queen Charlotte Islands), British Columbia. I explain how issues of culture, commerce, and conservation unite to create a strong role for northern abalone in preparations for creating a large marine conservation area within Haida Gwaii. Culture is relevant, as local indigenous people (the Haida) are currently denied access to constitutionally established subsistence fishing rights for northern abalone. Commerce is involved as ongoing kelp forest-associated fisheries co-occur with northern abalone. Finally, this is a challenging precedent in Canadian marine conservation, as restoring two "listed" species­ at risk (northern abalone and their predator, the sea otter (Enhydra lutris)) is potentially mutually exclusive. As part of the forthcoming public consultations towards establishing a marine conservation area, the opportunity provided by northern abalone to focus ideas and values should be seized. [ABSTRACT FROM AUTHOR]

Presents information on a study which reviewed the status of the Haliotis kamtschatkana Northern Abalone species in Canada as of 2001. Distribution; Habitat; Population size and trends.

Ontogenetic torsion in archaeogastropods has strongly influenced theories about early gastropod evolution, but the seminal studies by Crofts (1937, 1955) remain the major source of information about tissue movements during this developmental process. Computer-generated reconstructions of histological sections indicate that the cephalopodium of Haliotis kamtschatkana Jonas, 1845 rotates by a full 180° relative to the shell and visceral lobe during the first quarter of pre-metamorphic development. However, a portion of pallial epithelium, including some of the shell field, accompanies the rotating cephalopodium; a process facilitated by detachment of the pallium from the apertural rim of the protoconch. Transmission electron microscopy indicates that a tract of the larval retractor muscle, which Crofts (1955) implicated in the mechanism of torsion, inserts on both pedal and pallial cells. A deep invagination of shell field epithelium is a major focus of rotational torque. As a result of pallial deformation during cephalopodial rotation, the anus and gill rudiment are restricted to the right half of the larval body for 2 days after cephalopodial rotation by 180° has been completed. Scanning and transmission electron microscopy indicate that grooves in the lateral flanks of the protoconch correspond to the deep invagination of shell field epithelium. The grooves are not created by a coiling type of accretionary shell growth or by flexion of the protoconch. A calcareous shelf is secondarily added to the periostracal template of the protoconch along its visceral apertural rim. Morphogenetic movements during ontogenetic torsion in this species are more complex than a simple rotation between cephalopodium and visceropallium and the protoconch shows no evidence of exogastric coiling. [ABSTRACT FROM AUTHOR]

Ten novel microsatellite loci were isolated in pink abalone, Haliotis corrugata, using (GT)15 and (CT)15 enriched genomic libraries. Two previously reported Haliotis kamtschatkana microsatellites cross-amplified in H. corrugata. A set of 12 polymorphic microsatellites were evaluated in a wild population sample ( N = 49). The number of alleles ranged from two to 55, and the observed and expected heterozygosities ranged from 0.104 to 0.939 and from 0.213 to 0.982, respectively. Significant deviations from Hardy–Weinberg equilibrium at three loci and no linkage disequilibrium were observed. Haliotis corrugata microsatellites cross-amplified in other abalone species, two in H. fulgens, and seven in H. rufescens. [ABSTRACT FROM AUTHOR]

Understanding changes over historical timescales is essential to gauge conservation status of a species. Modern ecological data typically neglect past magnitudes of change, which fortunately can be evaluated by bridging disparate knowledge sources. We synthesized zooarchaeological, historical, traditional, and western science knowledge to document changes in relative abundance of key species in Canada's northern abalone social–ecological system (SES) from the Holocene to present. Integrated models fit to traditional and western science data revealed 3.7% annual population decline from 1940s to 2010s for large abalone, although traditional knowledge density estimates were 9.5× higher than those derived from western science. Abalone are presently scarce compared to the mid‐1900s, but more abundant than before the early 1800s, calling their endangered status into question. Linking multiple knowledge sources can build SES understanding, facilitate power sharing, and support ecologically sustainable and socially just conservation outcomes. [ABSTRACT FROM AUTHOR]