Jasus Lalandii Research Articles

Sustainability and present-day approaches to fisheries management — are the two concepts irreconcilable?

Sustainability may be defined as the maintenance of the quality, diversity and availability of fishery resources in sufficient quantities for present and future generations. But how do modern management systems aim to achieve this in the face of natural fluctuations and human-induced pressures? Using four case study fisheries (northern Atlantic cod and North Sea cod [both Gadus morhua], Pacific sablefish Anoplopoma fimbria, and South African West Coast lobster Jasus lalandii), we examine the components and considerations used in the development of management systems. Historically, these considerations have been biology-based, incorporating reference points appropriate for management goals or targets. Following some quite spectacular failures, however, inputs from disciplines such as socio-economics and ecosystem science are increasingly important drivers behind management decisions, but have the potential to increase management complexity greatly. We identify three areas of particular importance. Precautionary, robust and responsive management is needed, with pre-agreed actions to be taken when particular conditions are experienced. Management decisions need to be based upon adequate scientific information, particularly given the increasing variety of drivers for management. Finally, fisheries management needs to be a collaborative process, involving all stakeholders, thereby raising the credibility of management for all participants. Integrating all these aspects within the fisheries management framework is complex, but when combined with the realisation that harvests are likely to be lower than historical levels, there appears to be a greater chance of successful sustainable exploitation.

Mitigation of incidental mortality of Australian sea lions in the west coast rock lobster fishery

The Australian sea lion is a listed threatened species under Australian Commonwealth legislation, based on limited population size and the likelihood of further declines in population abundance. Incidental mortality of this species in the west coast rock lobster fishery was identified as a key threat to the distinct sub-population of about 700 ind. on the west coast of Australia. Reports of incidental mortalities in this fishery from a variety of fishery-dependent sources suggested that a minimum of 4 to 5 mortalities occur every fishing season. All reported captures were in shallow waters (<20 m) and within 30 km of a breeding colony. Foraging ranges of vulnerable-sized animals were confirmed by use of satellite-linked transmitters and time-depth recorders. Mitigation of this incidental mortality was effected by means of modifying the lobster pots with a sea lion exclusion device within the area of known interaction. The mandatory implementation of this programme resulted in a very high compliance rate (95%) in the first season and was achieved through active consultation and involvement of the industry, and of fishery and wildlife managers.

Mitigation of incidental mortality of Australian sea lions in the west coast rock lobster fishery

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 5:335-344 (2008) - DOI: https://doi.org/10.3354/esr00140 Gear-selectivity-based regulation in a mixed fishery Raúl Prellezo1,*, M. C. Gallastegui2 1AZTI-Tecnalia, Marine Research Division, Txatxarramendi Ugartea z/g, 48395 Sukarrieta, Spain 2Dpto. de Fundamentos del Análisis Económico I, Universidad del País Vasco-EHU, Lehendakari Agirre 83, 48015 Bilbao, Spain *Email: rprellezo@suk.azti.es ABSTRACT: In this paper we analyze the optimal management of a mixed fishery where the harvest is composed of a target and a bycatch species. In contrast to other studies, we have included the selectivity of the fishing gear as a control variable. The fishery is regulated by means of total allowable effort and with 2 different systems of total allowable catch (TAC): an aggregated and a disaggregated TAC. The main result obtained is that in an aggregated TAC program, the selectivity level and the decision to discard depend only upon the marginal profits of both species, but that in the case of a disaggregated program, other factors such as gear selectivity have to be taken into account. KEY WORDS: Mixed fisheries · Fishing gear selectivity · Bycatch · Harvest quotas Full text in pdf format PreviousNextCite this article as: Prellezo R, Gallastegui MC (2008) Gear-selectivity-based regulation in a mixed fishery. Endang Species Res 5:335-344. https://doi.org/10.3354/esr00140 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 5, No. 2-3. Online publication date: December 23, 2008 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2008 Inter-Research.

Making management procedures operational—innovations implemented in South Africa

Abstract Plagányi, É. E., Rademeyer, R. A., Butterworth, D. S., Cunningham, C. L., and Johnston, S. J. 2007. Making management procedures operational — innovations implemented in South Africa. – ICES Journal of Marine Science, 64: 626–632. Operational management procedures (OMPs) have become an indispensable fisheries management tool in South Africa in light of their ability to consider the consequences of the main sources of assessment uncertainty. An overview is provided of the MP approaches applied to the major South African fisheries for hake, sardine and anchovy, and west coast rock lobster. As these are among the first OMPs to be implemented worldwide, some for periods longer than 10 y, they provide useful examples of some of the successes and problems encountered with the approach. Particular emphasis is given to some recent innovations and adaptations. These include moves to (i) joint two-species OMPs for the hake and sardine/anchovy resources; (ii) a reference set of weighted operating models for primary testing and tuning in preference to a single model; (iii) consideration of a “research-conditional” approach for hake to allow greater catches in the short term, conditional on research being implemented to resolve a key uncertainty; and (iv) incorporation of some ecosystem considerations by developing appropriate robustness tests (which link with moves towards an ecosystem approach to fisheries). Key lessons gained from experience over the past decade of OMP implementation in South Africa are summarized.

Behavioural response of invasive Mytilus galloprovincialis and indigenous Perna perna mussels exposed to risk of predation

We compared the behavioural responses of an indigenous South African mussel (Perna perna) and an invasive mussel (Mytilus galloprovincialis) to the risk of predation. Both species were subjected to the specific risk of predation by the native rock lobster Jasus lalandii and the general risk of predation simulated by the presence of damaged conspecifics. We hypothesised that, because M. galloprovincialis evolved in allopatry from the rock lobster, P. perna would respond more strongly to J. lalandii, but that there would be less difference between species in their response to damaged con- specifics. The results confirmed our initial hypotheses. M. galloprovincialis crawled farther under both predation treatments and generally aggregated more than P. perna. P. perna has a larger foot, and our results therefore do not reflect morphological differences between the species but imply greater sensitivity in M. galloprovincialis to chemical cues. Crawling distance was not enhanced under predation threat relative to the control; therefore, increased clumping due to more rapid ran- dom movement cannot explain our results, indicating that chemical attraction among individuals is important. P. perna clumping behaviour was significantly greater when exposed to local lobster efflu- ent or damaged conspecifics, whereas M. galloprovincialis clumped more when exposed to a general threat of predation but exhibited naive behaviour to local predator effluent. This lack of responsive- ness to a native predator could be due not only to the recent arrival of the European mussel, but also to the relatively low selective effects of predation in South Africa.

Mitochondrial DNA variation of the west-coast rock lobster, Jasus lalandii: marked genetic diversity differences among sampling sites

Jasus lalandii (Milne-Edwards 1837), the west-coast rock lobster, occurs in the shallow, cool–temperate waters along the south and west coasts of southern Africa. This species has a long history of intensive exploitation, which has had a significant impact on population numbers in the past. To enhance our current understanding of lobster population structuring, genetic data from the mitochondrial (mt) DNA 16S rRNA gene was generated for 235 adult individuals collected at eight sampling sites. Most individuals (59.6%) share a common haplotype and 35 unique haplotypes were dispersed throughout the range. In total, 97.2% of the variation was found among individuals within sampling sites and 2.8% was among sites. Pairwise ΦST analyses revealed shallow, yet significant structure between Hout Bay individuals and some other sampling sites. The J. lalandii haplotype network indicates a starlike structure with no geographic signal; however, genetic diversity sharply decreases towards the edges of the species distribution. The general lack of phylogeographic structure among J. lalandii populations probably results from the absence of strong barriers to larval dispersal. Based on our mtDNA data there is no justification for the recognition of separate fishing stocks, but the high genetic diversities of populations at Hout Bay and Cape Hangklip, the latter currently outside of marine protected areas, makes these populations critical to conservation efforts.

Effects of exposure to air on the escape behaviour and haemolymph chemistry of the South African Cape lobster, Jasus lalandii

The Cape lobster Jasus lalandii is fished commercially on the southwest coast of South Africa and undersized individuals are often left exposed to air during fishing operations before being returned to sea. In addition, mass strandings leave beached individuals exposed to air. The effects of exposure to air on undersized J. lalandii (carapace lengths 60–74 mm) were analysed for a range of exposure periods (0, 15, 30, 60, 120 and 300 min) that realistically spanned conditions experienced during fishing operations or following mass strandings. Four approaches were used to assess the effects: (1) changes in the speed and nature of escape responses; (2) frequencies of capture by a predator; (3) changes in haemolymph chemistry; (4) growth rates. The time-to-first-response of lobsters after being returned to water was correlated with duration of exposure to air, ranging from 0.2 s by unexposed (control) lobsters to 13 min by individuals exposed for 300 min. The number of tail flips, the distance swum after release and the efficacy of escape from an octopus also decreased significantly as exposure to air increased. A progressive decrease of haemolymph pH from 7.5 in control lobsters to 6.89 in those exposed for 300 min indicated increasing metabolic acidosis. Haemolymph l-lactate concentration increased linearly with emersion time from 1.07 μmol/ml in controls to 18.5 μmol/ml in lobsters exposed for 300 min, reflecting at least a partial switch to anaerobic metabolism. Overall, these physiological effects diminished the lobsters’ response time and ability to escape, leaving them vulnerable to predation. No effects of exposure to air on subsequent growth rate were detected. Due to the severity of the effects of prolonged air-exposure, existing contingency plans to rescue lobsters after mass strandings will be futile unless they can be returned to the sea rapidly.

The effects of appendage loss on growth of South African west coast rock lobster Jasus lalandii

Capture by traps, sorting by fishers and discard of lobsters smaller than a minimum legal size (MLS) may induce physical injuries, such as loss of appendages, which can reduce somatic growth rates and population productivity. Heavily fished populations of rock lobster Jasus lalandii off western South Africa are prone to physical injuries, we investigated the extent of and effects on growth of various degrees of appendage loss. Lobsters injured by removal of legs, feeding legs or antennae were kept in cages at sea until moulting, and their subsequent growth and recovery of appendages monitored. Incidence of injury in wild populations was recorded by observers on lobster fishing vessels at sea. Growth decreased significantly following the loss and re-growth of ≥3 appendages, mortality rate increased, and injured lobsters moulted earlier than uninjured individuals. Five to 9% of trap-caught lobsters had missing appendages, although most of these (80%) had only one or two missing appendages. Most multiple injuries were found in lobsters larger than the MLS. The proportions of injured male and female lobsters in commercial catches declined sharply during the moulting season, but increased gradually thereafter coincident with rising cumulative fishing effort. The low relative estimate of appendage loss suggests that regulations to reduce injuries are effective.

The potential for using acoustic tracking to monitor the movement of the West Coast rock lobster Jasus lalandii

Although acoustic tracking has been used to study the movement of several species of clawed and spiny lobsters, only recent technological advances have provided sufficiently small transmitters to examine the utility of using acoustic tracking as a means to analyse the movement of relatively small spiny lobsters, such as Jasus lalandii. The effect of the transmitter on the mobility of J. lalandii was tested in aquarium experiments and was shown to have no influence on movement in three separate experiments. Thereafter, adult male rock lobsters (86–98mm carapace length) were tracked in field trials for up to 32 days at Betty's Bay (n = 4) and Hermanus (n = 5) off the Western Cape, South Africa. Tracking J. lalandii in the field using acoustic tags was successful, even in areas with dense kelp beds and rocky outcrops. The signal from the transmitters was readily detectable from the surface and subsequent use of underwater tracking equipment enabled visual confirmation of the position of the rock lobsters. Lobsters moved significantly longer distances (>45m day−1) in the first two days following tagging than during any subsequent time period (<10m day−1). This suggests that transmitter attachment and/or handling altered the movement pattern for the first 72 hours after tagging. During the period of observation, J. lalandii displayed classical nomadic behaviour.

Effects of tag-related injuries and timing of tagging on growth of rock lobster, Jasus lalandii

The effects of capture, tagging and release on the growth of male Cape rock lobster Jasus lalandii collected at Olifantsbos (historically a slow-growth site) and Knol (fast-growth site) were studied under controlled conditions in aquaria, cages at sea, and in situ. Growth increments achieved after the first captive moult were related to year and area of capture, moult-condition (pre- or intermoult) at tagging with T-bar anchor tags, and treatment of lobsters (tagged, injured or starved, the latter a proxy for displacement from suitable habitats). Captive lobsters moulted between August and October, as in wild populations, and lobsters collected from Knol grew more than those from Olifantsbos. Premoult lobsters tagged during 2002 grew an average of 62% (Knol) and 67% (Olifantsbos) less than untagged control animals, and 24 and 32% less in 2003. Lobsters treated during intermoult generally grew significantly more than those treated during premoult. Loss of appendages and restricted feeding also reduced growth, although the extent varied between years and treatments. The most important result emanating from this study is that tagging during premoult negatively impacts on growth of J. lalandii , but this effect is absent when lobsters are tagged during intermoult.

Evolution of operational management procedures for the South African West Coast rock lobster (Jasus lalandii) fishery

The commercial fishery for Jasus lalandii, the South Africa West Coast rock lobster, began in the late 1800s and at its peak in the early 1950s yielded an annual catch of 18 000 t. Although this annual catch has dropped to only some 2000 t over recent years, the fishery remains South Africa's third most valuable for landed value. The primary reason for the low total allowable catch (TAC) over these recent years has been a marked drop in somatic growth rate that occurred at the end of the 1980s, for reasons that remain unexplained. A key problem in formulating TAC recommendations with longer‐term objectives in mind, has been uncertainties about likely future trends, particularly in somatic growth and recruitment. To address this problem, an “operational management procedure” (OMP) was adopted in 1997 and has twice been re‐evaluated and modified (in 2000 and 2003) in the light of further data and changing perceptions of resource dynamics. The history of this process is reviewed, concentrating on the most recent modification. In particular, a summary is given of the process by which the merits of alternative management procedures were evaluated over a range of important uncertainties about the dynamics of the resource. This summary includes a discussion of the key trade‐offs between resource rebuilding, future TAC trends and TAC variability, and the eventual choice that was made. The paper concludes by listing a number of lessons learnt concerning best practice for OMP development as this process evolved.

Role and efficacy of marine protected areas for the South African rock lobster, Jasus lalandii

Protected areas for the South African rock lobster, Jasus lalandii, were sampled by using divers, traps and ringnets at sites within and adjacent to four protected areas (St Helena Bay, Saldanha Bay and Table Bay rock lobster sanctuaries and the Betty’s Bay marine reserve), over two years. Virtually no rock lobsters were found in St Helena Bay sanctuary, probably because of periodic harmful algal blooms. Abundance was greater in Saldanha Bay sanctuary than in adjacent fished areas, but only once in two years. Sizes were, however, larger in this sanctuary than the fished areas. By an order of magnitude, fewer and smaller rock lobsters were caught within the Table Bay sanctuary than in adjacent areas. Only at Betty’s Bay were rock lobster sizes and abundance consistently greater inside than outside the reserve. Fecundity was similar among sites, with females in protected areas contributing no more to egg production than would be expected by the proportional area occupied by protected areas. Rock lobsters do benefit from protection in Betty’s Bay reserve, but the west coast sanctuaries appear poorly located and seemingly contain large areas of unsuitable substrate. They clearly need relocation to be effective.

Historical commercial West Coast rock lobster Jasus lalandii landings in South African waters

Historic data from 1891 to 2001 on the annual exports of rock lobster Jasus lalandii products (canned, frozen tails, raw whole frozen, cooked whole frozen and live) from the South African west coast are used to estimate the annual commercial landings by this fishery. Conversion factors were developed to convert canned, tailed and whole cooked product weight to whole weight. The fishery expanded rapidly from the early 1900s up to the Second World War. Production declined temporally during the war years before peaking in the early 1950s at just under 17 000 tons. Since then, commercial landings have declined to between 10% and 15% of what they were at the height of the commercial fishery. The possible causes for the decline in catch are discussed; overexploitation is undoubtedly one, but human-use patterns and coast-wide reductions in the growth rate of lobsters since the late 1980s are considered to have also contributed.

The West Coast rock lobster Jasus lalandii as a valuable source for chitin and astaxanthin

Estimates are made of the maximal amount of chitin and astaxanthin that can potentially be retrieved from material of the South African West Coast rock lobster Jasus lalandii. Three different sources were investigated: (a) industrial waste from lobster processing factories, i.e. the cephalothorax plus legs, (b) whole lobsters, to represent material available on the beaches after mass strandings caused by red/black tides, and (c) exuvia, i.e. the entire exoskeleton that is shed during moulting (exuvia will be available regularly once industrial mariculture of J. lalandii is established). Industrial lobster waste contains 36g chitin kg−1 wet weight and 18mg astaxanthin kg−1 wet weight; whole lobsters have 43g chitin kg−1 and 13mg astaxanthin kg−1; and exuvia yield 159g chitin kg−1 and 63mg astaxanthin kg−1. The total theoretical amounts available from source (a) is 3.6 tons chitin and 1.8kg astaxanthin, from (b) 86 tons chitin and 27kg astaxanthin, whereas the amount available from (c) depends, of course, on the exact extent of lobster in mariculture; once this industry is established, material from this source will form a substantial part of the available amount of chitin and astaxanthin. Each of these sources is too small to support a permanent industry but, if astaxanthin and chitin are extracted, and other crustacean sources (e.g. shrimp waste, South Coast rock lobster waste) are also utilised, temporary harvesting could increase profitability of existing lobster processing, alleviate the need for imports of these compounds and create much-needed jobs in remote areas. Currently, established chemical methods are used to extract chitin from the exoskeleton; astaxanthin is destroyed in this process. Therefore, to extract both chitin and astaxanthin from the same source, the established method must be replaced by biochemical methods that do not destroy astaxanthin. Preliminary data with the protease papain, show that treatment with this enzyme allows the extraction of intact astaxanthin at a 22% higher yield than untreated material. The stability of astaxanthin that was extracted in organic solvents can be increased by antioxidants, such as butylated hydroxyanisole and butylated hydroxytoluene; the loss of astaxanthin was reduced to 6–7% during 6 months of storage with the antioxidants.

Using a GLMM to estimate the somatic growth rate trend for male South African west coast rock lobster, Jasus lalandii

A decrease in somatic growth rate, and hence productivity, of the South African west coast rock lobster population which occurred in the late 1980s has had important ramifications for subsequent TACs set for this resource. These are critically dependent on monitoring growth rates and determining whether an increase back towards earlier higher levels is underway. The available data are not well balanced by season and location, and a GLMM approach is used to take account of season–location interactions by treating these as random effects. This results in much less precise estimates of annual somatic growth rate than had been suggested by an earlier fixed effects GLM approach, and has necessitated a change in the philosophy underlying management of the resource.

The effects of temperature and diet on the survival, growth and food uptake of aquarium-held postpueruli of the rock lobster Jasus lalandii

Aquaculture of the rock lobster Jasus lalandii has been considered, but is hindered by a paucity of knowledge about conditions that promote yields. This study investigated the influences of temperature and diet on the growth of aquarium-held postpueruli of J. lalandii. First, postpueruli (11.5±0.2 mm CL) were exposed to temperatures spanning 12–24 °C for a total time period of 77 days, while being given a constant diet of mussel flesh. Under these conditions, intermoult period (IMP) was longest at 12 °C (50.6±1.2 days) and at 24 °C (>57 days), and shortest at 18 °C (35.5±1.1 days). Growth increments (GI) were large at 12–18 °C, smaller at 21 °C and negative at 24 °C. Survival was 100% at 12–16 °C, above which mortalities rose to 70% at 24 °C. Food consumption, body mass and condition all peaked at 18 °C. Thus, growth was optimal at 18 °C, but survival greatest at 12–16 °C. Second, diet-controlled experiments examined the effects of three different diets (blue mussel, commercial shrimpfeed or an alternation of the two) on survival, growth (IMP and GI) and food uptake of postpueruli (11.0±0.3 mm CL) held at 18 °C for a total time period of 77 days. Feeding rate, average growth, body mass and condition were all highest on the mussel diet, and lowest on the shrimpfeed, and the postpueruli consumed more mussel flesh than shrimpfeed. There was little difference in survival of postpueruli subjected to the three diet treatments. A diet of exclusively blue mussel yielded higher growth, body mass, condition and food uptake than a diet of either shrimpfeed alone or an alternation of mussel and shrimpfeed. The postpueruli acclimated well to culture conditions and survived on a diet of artificial pellets, thus showing good potential for mariculture. On the present evidence, greatest returns are likely at 16–18 °C and with a diet of mussel flesh.

A bio-economic application to the Cape Rock Lobster resource using a delay difference modelling approach

In many species, like the Cape Rock Lobster (Jasus lalandii), the life cycles of males and females differ. This may motivate the use of two-sex models in a stock-assessment analysis. It is also true for this resource, that juveniles do not reach sexual maturity immediately. Therefore a delay-difference model is appropriate. In this study we follow a bio-economic approach and use a two-sex delay-difference model to determine a maximum economic yield strategy. Thus we determine an economic optimum steady state solution at which to harvest this resource subject to the biological constraints of the species.

Molecular cloning and localization of a cDNA encoding a crustacean hyperglycemic hormone from the South African spiny lobster, Jasus lalandii

A cDNA, encoding a crustacean hyperglycemic hormone (cHH) of the South African spiny lobster, Jasus lalandii has been cloned. The cDNA consists of 1773 bp with an open reading frame of 399 bp that encodes a preprohormone of 133 amino acid residues. The preprohormone consists of a 25 amino acid hydrophobic signal peptide, a 32 amino acid cHH precursor-related peptide (CPRP) and the cHH sequence of 72 amino acid residues. The cHH sequence is flanked N-terminally by a Lys-Arg cleavage site and C-terminally by Gly-Lys, where Gly serves as an amidation site. The deduced amino acid sequence of the CPRP is in complete agreement with a peptide previously elucidated from sinus glands of J. lalandii, code-named CPRP 2 and the sequence of the cHH peptide matches that of the minor cHH isoform of J. lalandii, i.e. crustacean hyperglycemic hormone-II (cHH-II), which was also previously obtained by peptide sequencing. In situ hybridization on eyestalks revealed strong cHH-II mRNA expression in a subset of neurosecretory cells of the X-organ.

Science and Fisheries Management in Southern Africa and Europe©

Case studies on southern African sardine and anchovy, Cape hake and West Coast rock lobster off southern Africa are described and compared with North Sea herring and cod, and Nephrops in European waters. The comparison shows that, in Europe, despite comprehensive institutional arrangements for fisheries management based on a long history of fisheries research, management of stocks has not been particularly successful, and this contrasts with the rather more successful regime in southern Africa. The failure in Europe reflects the difficulty of curtailing international fisheries that have expanded and developed over many years on a complex of shared stocks and mixed fisheries, despite major advances in scientific methodology and strong scientific advice. The European examples also show how scientific uncertainties, and deficiencies in compliance with the Total Allowable Catch system, have contributed to management failure.

Aquarium Experiments Comparing the Feeding Behaviour of Rock Lobster Jasus Lalandii on Abalone and Sea Urchins at Two Sites on the West Coast of South Africa

Predation by the rock lobster Jasus lalandii is influential in regulating the composition of shallow-reef communities on the west coast of South Africa. Two previous and independent studies addressing this topic, but conducted 600 km apart (one in Cape Town and the other in Port Nolloth on the west coast of South Africa) and using different experimental protocols, revealed contradictory results regarding the feeding behaviour of J. lalandii. The Port Nolloth study showed that juvenile abalone Haliotis midae hiding under sea urchins Parechinus angulosus were safe from predation by rock lobsters, which seemed to prefer the sea urchins as food. However, the Cape Town study showed that rock lobsters preferentially selected juvenile abalone over sea urchins. Because of the importance of these results to abalone ranching and the South African abalone fishery, the experiments were repeated at the two study sites, using a standardized experimental protocol. Rock lobsters from both sites showed a strong preference for juvenile abalone over sea urchins, even in the presence of kelp Ecklonia maxima. There was no significant difference (F 3.92 = 0.09, p > 0.1) in abalone consumption by rock lobsters between the two sites. Therefore, at least in the absence of preferred prey such as mussels, sea urchins appear to provide only limited protection to juvenile abalone from rock lobsters.