Haemolymph condition of deep-water southern rock lobsters (Jasus edwardsii) translocated to inshore reefs

Abstract

Deep-water southern rock lobsters were translocated to inshore reefs harbouring high-market value southern rock lobsters as part of an experimental spatial management strategy to enhance their market traits, growth and post-harvest condition. We assessed the haemolymph condition of deep-water lobsters before and after (over a period of 14 months) translocation for comparison to resident lobsters at the release site using a range of moult and haemolymph indices. Moult indices indicated that deep-water lobsters were of a similar moult stage to resident lobsters before translocation, they moulted earlier than resident lobsters in their new habitat but were of a moult stage similar to resident lobsters when sampled 12 months after translocation. Comparisons of haemolymph parameters included the total haemocyte count, serum protein and electrotypes such as magnesium and potassium, which were all significantly different between deep-and shallow-water lobsters prior to translocation. These populations when sampled 12 months after translocation showed similar concentrations for all haemolymph parameters, suggesting an improved resilience to postharvest stress in translocated lobsters. Benefits of translocation to inshore areas on the post-harvest condition of deep-water lobsters could be due to improved body condition through the manipulation of habitat and diet but also from the reduced post-capture transport time and stress duration.

Spatial Variability in Condition of Southern Rock Lobsters (Jasus edwardsii) at the Start of the Tasmanian Fishing Season

“…Haemolymph protein concentration, and associated techniques to estimate it via refractometry, have been used as the main non-destructive index (e.g., Refractive index, Brix index) for measuring “nutritional condition” in lobsters [6–8]. Processors generally don’t assess nutritional condition but rather rely on observations of vitality (e.g.…”

“…It is therefore biased towards a measure of “physiological condition”, which can be readily reversible, if the physiological disturbance is within the homeostatic capability of the lobsters, or it can be non-reversible ultimately leading to mortality [9]. The study of crustacean haemolymph biochemistry, which includes a large range of organic and inorganic constituents, provides a measure of physiological condition and can provide useful information to the degree of stress in wild population, during live-holding and live transport [6, 10]. Haemocyanin is the oxygen-carrying protein in the haemolymph, and hypoxia or lack of oxygen can result in an increase in haemocyanin in crustaceans [11].…”

Bio-economics of commercial scale translocation of southern rock lobster

“…These differences are phenotypic rather than genetic (Morgan et al, 2013), with lobsters from deep-water regions in the south west of Tasmania tending to grow slowly in high density populations, while lobsters from shallow-water or northern areas grow far more rapidly (Gardner et al, 2006;Punt and Kennedy, 1997). Translocation involves capturing slow growing lobsters that are below the minimum legal size and moving these lobsters to regions where their growth improves and they develop more valuable market traits (Chandrapavan et al, 2010(Chandrapavan et al, , 2011a. The Government of Tasmania approved translocation trials in 2004 after assessing the risk of disease transfer and genetic effects to be negligible, because translocations are over much smaller distances than occurs with larval dispersal, and are comparable to distances over which adults occasionally move (Gardner et al, 2003;Morgan et al, 2013).…”

“…All lobsters were tagged, and the biological and ecological changes were monitored over the following 5 years. Key results from field trials were that slow-growing lobsters that were moved to inshore areas: (a) changed colour within a year (Chandrapavan et al, 2009a); (b) increased their growth rates to that of the new site (Chandrapavan et al, 2010); (c) survived in their new location ); (d) increased egg production ; (e) improved their condition and body chemistry (Chandrapavan et al, 2009b(Chandrapavan et al, , 2011a); (f) changed body morphology to a higher valued shape (Chandrapavan et al, 2011b); and (g) stayed at the release site (Green et al, 2013b). This research also demonstrated that these changes were phenotypic, not genetic (Morgan et al, 2013).…”

Overlap of Home Ranges of Resident and Introduced Southern Rock Lobster after Translocation

“…As red is inherently intimidating in freshwater fishes and terrestrial species (Barlow, 1983;Vercken and Clobert, 2008), and size differences can increase agonistic behavior in captive lobsters and catchability in wild J. edwardsii lobsters (Frusher et al, 2003;Thomas et al, 2003), there was concern that the SP lobsters might be at a disadvantage when introduced into the territory of LR lobsters due to color, size, and prior residence dominance and disorientation upon release. A larger translocation experiment using lobsters from the same source site but translocated to other sites on the Tasmanian coast was effective at changing the color, growth rate, body shape, and size, increasing the value and nutrition of the seafood product (Chandrapavan et al, 2009a(Chandrapavan et al, ,b, 2010(Chandrapavan et al, , 2011aGreen et al, 2010). For an assisted migration and restocking to be successful, transplants must survive and prosper in their new environment, establishing residences and home ranges (HRs), thereby increasing productivity (Hilborn, 1998;Bell et al, 2006Bell et al, , 2008.…”