Academic literature on the topic 'Abalone fisheries'

Tujuan penelitian adalah menguji efisiensi pembesaran juvenil teripang pasir, Holothuria scabra dan benih abalon, Haliotis squamata pada sistem polikultur. Penelitian dilakukan di Balai Besar Riset Budidaya Laut dan Penyuluhan Perikanan Gondol. Wadah percobaan berupa bak fiber volume 1 m3, abalone dipelihara dalam keranjang plastik ukuran 45 cm x 45 cm x 25 cm sebanyak dua buah/bak, sedangkan teripang dipelihara di dasar bak dengan sistem air mengalir. Kepadatan abalon 50 ind./keranjang dan teripang 100 ind./bak. Ukuran panjang dan bobot juvenil teripang yang digunakan adalah 3,17 ± 0,77 cm; 1,74 ± 0,64 g; dan benih abalone 3,16 ± 0,48 cm dan 4,82 ± 0,87 g. Jenis pakan abalon berupa rumput laut Gracilaria sp. dan Ulva sp. sedangkan teripang diberi pakan berupa bentos selama enam bulan pemeliharaan. Sebagai perlakuan adalah pemeliharaan teripang dan abalon: A (tanpa pemberian bentos), B (ditambah bentos), dan C (ditambah bentos dan tanpa abalon), masing-masing perlakuan diulang tiga kali. Parameter yang diamati meliputi pertumbuhan, sintasan, kualitas air, dan kandungan proksimat feses abalon. Hasil menunjukkan bahwa pertumbuhan juvenil teripang pasir berbeda nyata (P<0,05); rata-rata panjang total dan bobot badan pada perlakuan B lebih tinggi (4,45 ± 1,06 cm; 8,06 ± 1,19 g) dibandingkan dengan perlakuan lainnya. Sebaliknya sintasan juvenil teripang pasir tidak berbeda nyata antar perlakuan (P>0,05). Pertumbuhan bobot benih abalon berbeda nyata antar perlakuan (P<0,05) dengan nilai rata-rata pada perlakuan A (16,75 ± 2,96 g) dan B (12,77 ± 2,69 g). Sedangkan pertumbuhan panjang cangkang dan sintasan tidak berbeda nyata (P>0,05). Produktivitas polikutur pada perlakuan A mencapai 208,54 g untuk teripang dan 4.656 g untuk abalon; diikuti perlakuan B mencapai 118,55 g untuk teripang dan 3.493 g untuk abalon dan perlakuan C sebesar 34,50 g.The aim of the research was to examine the grow-out efficiency of sea cucumber, Holothuria scabra, and abalone, Haliotis squamata fry in a polyculture system. The research was conducted in the Institute for Mariculture Research and Fisheries Extension, Gondol. Containers used in this research were nine fiberglass tanks each with a volume of 1 m3. The abalone fry were reared in two baskets sized 45 cm x 45 cm x 25 cm while sea cucumber fry were reared on the bottom of the tank and. Water exchange used a flow-through system. The density of abalone was 50 fry/basket and sea cucumber was 100 fries/tank. The averages of length and body weight of sea cucumber were 3.17 ± 0.77 cm and 1.74 ± 0.64 g, respectively. The abalone fry had the averages of length and body weight of 3.16 ± 0.48 cm and 4.82 ± 0.87 g, respectively. Feeds used for the abalone fry were Gracilaria sp. and Ulva sp. while for sea cucumber was benthos. These feeds were used during the six months of the research. Treatments were grow-out of sea cucumber and abalone: A (without benthos), B (with benthos), and C (with benthos but without abalone), each treatment had three replicates. Parameters measured were growth and survival rate, water quality, and proximate analysis of abalone feces. The results showed that the growth of sea cucumber was significantly different (P<0.05), mean of total length and body weight of treatment B was higher (4.45 ± 1.06 cm; 8.06 ± 1.19 g) compared to the two other treatments. On the other hand, the survival rate of sea cucumber fry was not significantly different among treatments (P>0.05). The growth of body weight of abalone was significantly different (P<0.05) among the treatments in which the average for treatment A was 16.75 ± 2.96 g and treatment B was 12.77 ± 2.69 g. The growth of carapace length and survival rate were not significantly different (P>0.05). The productivity of polyculture in treatment A reached 208.54 g for sea cucumber and 4,656 g for abalone; followed by treatment B of 118.55 g for sea cucumber and 3,493 g for abalone and treatment of C 34.50 g.

Recruitment failure has been implicated in the decline of several abalone fisheries. Traditionally, fisheries scientists invoke theoretical stock-recruitment relationships to predict trends in abundance of an exploited stock under various harvest regimes. The empirical evidence in support of a positive relationship between spawning stock and recruits is not strong. A further problem in interpretation of such relationships is that both 'stock' and 'recruitment' have various definitions in fisheries and ecological literature. The definition of a stock for abalone is not clear. As emphasized in this review, which considers each stage in the life history of abalone, the abundance of spawners is one of many sources of variation in recruitment. The evidence for invertebrates, particularly those with high fecundity, is that recruitment varies independently of the abundance of spawners. This is also the case for abalone, where recruits have been measured as the density of immediate post-settlement individuals, juveniles, or as adults entering the exploitable stock. A problem with stock-recruitment hypotheses is that they have intuitive appeal. It is considered 'dangerous' to manage fisheries under the assumption that a reduction in the number of spawners by fishing will not affect recruitment. Such danger to abalone stocks has been more recently assessed by egg-per-recruit analyses, whereby various harvest strategies are examined relative to reference points for egg production. These studies are reviewed and assessed relative to the often conflicting aims of managers and scientists. This review of studies of recruitment variation in abalone emphasizes the need for a more rigorous, autecological approach to stock assessment in which field experiments are conducted over realistic spatial and temporal scales, permitting robust testing of hypotheses.

This paper concerns the conservation of abalone stocks in a genetic and fisheries sense. We review genetic and ecological information relating to the differentiation of abalone stocks in South Australia and propose that metapopulation theory provides an apt framework in which to develop the concept of an abalone stock. We consider what is a minimum viable population for abalone and illustrate our discussion with a case study of an abalone population that declined through a combination of fishing, recruitment failure, and inadequate protection by a refugium. Refugia can play an important role in abalone conservation by maintaining egg production and genetic diversity and by preserving populations for scientific study.

Abalone species are important for recreational and commercial fisheries and aquaculture in many jurisdictions in Australia. Clinical infections with viral, bacterial and parasitic pathogens can cause significant losses of wild and cultured stock, and subclinical infections may result in decreased productivity and growth. Infections with abalone herpesviruses (AbHV), Vibrio spp. and parasites of the genus Perkinsus are of particular concern to Australian fisheries. Here we provide a brief overview of these three major pathogen groups and their diagnoses from an Australian perspective.

The Arabian abalone occur in the Arabian Sea’s rocky coastal zone in association with conspicuous macrolgal communities in which it represents the dominant herbivorous component. Despite such ecological importance and although the commercial exploitation of abalone presents a considerable contribution to Omani fisheries, almost nothing is known about the biology of this species. This report presents results of research carried out in the field and with laboratory cultures, and draws general conclusions related also to the fisheries management of these possibly overexploited abalone populations, Cobort observations in the field and measured increments of cultured specimens showed a growth rate significantly higher than in other abalone species, i.e. greater than 3 mm shell-increment per month. The very early sexual maturity demonstrated by captivity spawnings of approximately one year old animals is also quite unusual. The ejected eggs formed mucous mono layers attached to the substratum whereas other abalone species produce pelagic eggs. Jvenile coborts in nature and the periodic spawning of cultured animals indicate the major spawning in spring and postmonsoon one in autumn. The models previously applied in fisheries management of abalone in Oman assumed only one spawning per year, the first being at age 2+, and a slower growth-rate. These models should be reconsidered using the new data, which may partially explain why abalone are less overexploited than one would expect looking at heavy harvesting. In view of a projected commercial abalone cultivation our laboratory rearing experiments showed that both natural and/or artificial food may be used, provided this contains-apart from standard ingredients, the seaweed-borne components (probably phycobillins) required for a normal parasite , resistant shell formation. With regard to artificial reproduction, our preliminary trials showed that spawning , fertilization ,and initial larval rearing present no problems. The steps from the pediveliger to larval settlement, however ,seem to be fatally exposed to eilitate attacks. Further research is needed in order to eliminate this critical problem.

Pinto abalone (Haliotis kamtschatkana kamtschatkana) populations in Washington State (USA) and British Columbia (Canada) continue to decline despite fisheries closures. For successful recovery, supplementation may be necessary. To determine appropriate culture methods, juveniles were reared in habitat-enriched tanks (supplemented with rocks, macroalgae and sea urchins) or conventional aquaculture tanks and assessed for growth and survivorship in the laboratory over 15 months. No differences in survivorship or growth were observed. Subsequent experiments examined whether abalone behaviour (habitat selection and movement patterns) differed between rearing treatments. Abalone were exposed to one of three predator treatments (sea star arm, small crab, or no predator (control)) and filmed for 8 h. Abalone from habitat-enriched tanks changed habitats significantly more often than abalone from conventional tanks regardless of predator treatment. Significant differences in the percentage of time that abalone occupied the various habitats were also observed. Abalone in the sea star and control treatments primarily occupied the rocks, whereas abalone in the crab treatment behaved differently depending on the rearing method; conventionally reared abalone spent more time in corners, whereas abalone from habitat-enriched tanks spent more time exposed. These results demonstrate that rearing conditions can affect abalone behaviour and should be considered for abalone restoration efforts worldwide.

Many Koreans regard abalone (Haliotus discus hannai) as a desirable luxury food because of its limited availability and high price. Abalone aquaculture was developed during the late 2000s, and production has greatly increased in Korea, reaching 9,147 tons in 2014. Policy experts said this trend means many fishers who cultivate abalone could increase their income. However, their incomes had not increased since fishers started cultivating abalone, because a conventional “addition” was applied to abalone transactions. The distribution structure for abalone products relies almost entirely on wholesalers instead of fisheries cooperatives, which are commonly used for other types of seafood products. Therefore, a new distribution structure was required in the Korean abalone industry. The objective of this study was to document how the establishment of an abalone cooperative by the local government has affected fishers’ income and production since 2009. This research was conducted in Wando District in South Jeolla Province, which accounts for over 90% of the domestic abalone production. Wholesalers, fishers, and a public officer were interviewed. A shift from a wholesalercontrolled distribution structure to a cooperative run by the local government helped to reduce the “addition” and increase fishers’ incomes overall.Res. Agric., Livest. Fish.3(2): 345-353, August 2016

[abstFig src='/00280003/16.jpg' width=""155"" text='Overview of a small size underwater robot' ] In abalone fishing with spearing, size of abalone which was allowed to catch is strictly controlled in Japanese law. Therefore, fisherman usually judge size by observing from a boat. However, this is difficult, due to aging. Therefore, we have been developing an underwater robot to assist fisherman in determining abalone size by using a stereo camera. The robot is small size and uses 6 thrusters to achieve 5 DOF motion in an underwater environment.

Past theoretical models suggest fishing disease-impacted stocks can reduce parasite transmission, but this is a good management strategy only when the exploitation required to reduce transmission does not overfish the stock. We applied this concept to a red abalone fishery so impacted by an infectious disease (withering syndrome) that stock densities plummeted and managers closed the fishery. In addition to the non-selective fishing strategy considered by past disease-fishing models, we modelled targeting (culling) infected individuals, which is plausible in red abalone because modern diagnostic tools can determine infection without harming landed abalone and the diagnostic cost is minor relative to the catch value. The non-selective abalone fishing required to eradicate parasites exceeded thresholds for abalone sustainability, but targeting infected abalone allowed the fishery to generate yield and reduce parasite prevalence while maintaining stock densities at or above the densities attainable if the population was closed to fishing. The effect was strong enough that stock and yield increased even when the catch was one-third uninfected abalone. These results could apply to other fisheries as the diagnostic costs decline relative to catch value.

Penelitian ini bertujuan untuk menganalisis efektivitas ekstrak visceral abalon tropis haliotis asinine dalam percepatan regenerasi luka sirip kaudal ikan nila (Oreochromis) dan menganalisis efektivitas simplisia mucus abalon tropis haliotis asinine dalam percepatan regenerasi luka sirip kaudal ikan nila (Oreochromis). Penelitian ini dilaksananakan di bulan Juli tahun 2023 bertempat di bertempat di Lembaga Pengkajian dan Penerapan Teknologi Sumberdaya Perikanan dan Kelautan (LP2T-SPK) Konawe Sulawesi Tenggara. Rancangan penelitian ini adalah eksperimen pre post test only control group design dengan uji analisis data menggunakan uji nonparametrik yaitu Uji Kruskal Wallis. Hasil analisis penelitian menunjukan bahwa ekstrak visceral abalon tropis Haliotis asinina terbukti paling efektif dalam mempercepat regenerasi histologi luka sirip kaudal pada ikan nila (Nila oreochromis) dibandingkan dengan kelompok perlakuan mucus dan kelompok kontrol dengan tingkat kemaknaan (U = 0,000 p = 0,000). This study aimed to analyze the effectiveness of the visceral extract of tropical abalone Haliotis asinina in accelerating the regeneration of caudal fin wound of tilapia (Oreochromis). This research was carried out in July 2023 at the Institute for the Assessment and Application of Fisheries and Marine Resources Technology (LP2T-SPK) Konawe, Southeast Sulawesi. The design of this study was an experimental pre post test only control group design with data analysis using a nonparametric test, namely the Kruskal Wallis Test. The resulth of the study showed that the visceral extract of tropical abalone Haliotis asinina proved to be the most effective in accelerating the histological regeneration of caudal fin wounds of tilapia (Nila oreochromis) compared to the mucus treatment group and the control group with a significance level (U = 0.000 p = 0.000).