Estimation of terminal molting probability of snow crab Chionoecetes opilio using instar- and state-structured model in the waters off the Pacific coast of northern Japan

Structural and mechanical properties of the decapod exoskeleton affect foraging, defense, and locomotion, making the ability of decapods to maintain their calci ed exoskeleton a crucial physiological process. Ocean acidi cation (OA) poses a threat to marine biomes and their inhabitants, particularly calcifying organisms. Vulnerability of the snow crab, Chionecetes opilio, a commercially important, highlatitude species, to OA has not been explored. Although all oceans are experiencing acidi cation, abiotic factors in high-latitude areas increase the rate of acidi cation. We examined the effect of long-term (2year) exposure to decreased seawater pH (7.8 and 7.5) on exoskeletal properties in post-terminal-molt female C. opilio. Since the effects of OA vary among body regions in decapods, exoskeletal properties (microhardness, thickness, and elemental composition) were measured in ve body regions: the carapace, both claws, and both third-walking legs. Overall, the C. opilio exoskeleton was robust to OA in all body regions. Decreased pH had no effect on microhardness or thickness of the exoskeleton, despite a slight (~6%) reduction in calcium content in crabs held at pH 7.5. In contrast, exoskeletal properties varied dramatically among body regions regardless of pH. The exoskeleton of the claws was harder, thicker, and contained more calcium but less magnesium than that of other body regions. Exoskeleton of the legs was thinner than that of other body regions and contained signi cantly greater levels of magnesium (~2.5 times higher than the claws). Maintenance of exoskeletal properties after long-term OA exposure in C. opilio suggests that wild populations may tolerate future ocean pH conditions.

show abstract

Section: )mentioning

confidence: 99%

Adult snow crab, Chionoecetes opilio, display body-wide exoskeletal resistance to the effects of long-term ocean acidification

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The lifespan of snow crabs is estimated at 14-16 years for males, and 11-12 years for females, making them a relatively long-lived decapod species (Adams, 1979). Both male and female snow crabs can live 3-5 years after completing their terminal molt and reaching sexual maturity (Alunno-Bruscia & Sainte-Marie 1998; Ueda et al 2009). In Alaska, snow crabs have supported valuable sheries, bringing in an ex-vessel revenue of $101.7 million in 2020 (Garber-Yonts and Lee, 2020; NOAA Fisheries 2021).…”

Section: )mentioning

confidence: 99%

The snow crab, Chionoecetes opilio, displays body-wide exoskeletal resistance to the effects of long-term ocean acidification

Algayer

Mahmoud

Saksena

et al. 2022

Preprint

View full text Add to dashboard Cite

Structural and mechanical properties of the decapod exoskeleton affect foraging, defense, and locomotion, making the ability of decapods to maintain their calcified exoskeleton a crucial physiological process. Ocean acidification (OA) poses a threat to marine biomes and their inhabitants, particularly calcifying organisms. Vulnerability of the snow crab, Chionecetes opilio, a commercially important, high-latitude species, to OA has not been explored. Although all oceans are experiencing acidification, abiotic factors in high-latitude areas increase the rate of acidification. We examined the effect of long-term (2-year) exposure to decreased seawater pH (7.8 and 7.5) on exoskeletal properties in post-terminal-molt female C. opilio. Since the effects of OA vary among body regions in decapods, exoskeletal properties (microhardness, thickness, and elemental composition) were measured in five body regions: the carapace, both claws, and both third-walking legs. Overall, the C. opilio exoskeleton was robust to OA in all body regions. Decreased pH had no effect on microhardness or thickness of the exoskeleton, despite a slight (~6%) reduction in calcium content in crabs held at pH 7.5. In contrast, exoskeletal properties varied dramatically among body regions regardless of pH. The exoskeleton of the claws was harder, thicker, and contained more calcium but less magnesium than that of other body regions. Exoskeleton of the legs was thinner than that of other body regions and contained significantly greater levels of magnesium (~2.5 times higher than the claws). Maintenance of exoskeletal properties after long-term OA exposure in C. opilio suggests that wild populations may tolerate future ocean pH conditions.

show abstract

“…Because fishing pressures have been low since March 2011, other factors have caused this continued decrease. In fact, the 2‐year projected abundances that were needed to calculate the allowable biological catch (ABC) had probably been overestimated since 2012 by a previously developed model (Ueda, Ito, Hattori, Narimatsu, & Kitagawa, 2009), with the fishing mortality coefficient ( F ) set at almost zero (Shibata et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Estimating the maximum sustainable yield of snow crab (Chionoecetes opilio) off Tohoku, Japan via a state‐space stock assessment model with time‐varying natural mortality

et al. 2020

Self Cite

View full text Add to dashboard Cite

A maximum sustainable yield (MSY) obtained by maintaining or restoring fish stock levels is a tangible benefit of ecosystem services. Snow crab (Chionoecetes opilio) off Tohoku, Japan has been managed by a total allowable catch since 1996, although the abundance has not increased. Surprisingly, there was no increase after 2011, when fishing pressure was greatly reduced because of the Great East Japan earthquake. This implies that some of the crab's biological characteristics, such as recruits, natural mortality coefficient (M) and terminal molting probabilities (p), might have changed. We developed “just another state‐space stock assessment model” to estimate the MSY of the snow crab off Tohoku considering interannual variations in M and p. The multimodel inference revealed that M increased from 0.2 in 1997 to 0.59 in 2018, although it did not vary according to instars, sex or terminal molt. The parameter p also increased by 1.34–2.46 times depending on the instar growth stages from 1997 to 2018. We estimated the MSYs in three scenarios, which changed drastically if M and p were set as they were in the past or at the current values estimated from this study. This result indicated that the MSY of snow crab would also vary with time based on their time‐varying biological characteristics.

show abstract

Estimation of terminal molting probability of snow crab Chionoecetes opilio using instar- and state-structured model in the waters off the Pacific coast of northern Japan

Cited by 6 publications

References 15 publications

Adult snow crab, Chionoecetes opilio, display body-wide exoskeletal resistance to the effects of long-term ocean acidification

Adult snow crab, Chionoecetes opilio, display body-wide exoskeletal resistance to the effects of long-term ocean acidification

The snow crab, Chionoecetes opilio, displays body-wide exoskeletal resistance to the effects of long-term ocean acidification

Estimating the maximum sustainable yield of snow crab (Chionoecetes opilio) off Tohoku, Japan via a state‐space stock assessment model with time‐varying natural mortality

Contact Info

Product

Resources

About