scholarly journals Adaption potential of Crassostrea gigas to ocean acidification and disease caused by Vibrio harveyi

Author(s):  
Davide Nordio ◽  
Natalie Khtikian ◽  
Sean Andrews ◽  
Daniela Bertotto ◽  
Karen Leask ◽  
...  

Abstract The survival and development of bivalve larvae is adversely impacted by ocean acidification and Vibrio infection, indicating that bivalves need to simultaneously adapt to both stressors associated with anthropogenic climate change. In this study, we use a half-dial breeding design to estimate heritability (h2) for survival to Vibrio harveyi infection and larval shell length to aragonite undersaturated and normal conditions in laboratory-reared Crassostrea gigas. Phenotypic differences were observed between families for these traits with heritability estimated to be moderate for survival to V. harveyi challenge (h2 = 0.25) and low for shell length in corrosive (Ωaragonite = 0.9, h2 = 0.15) and normal conditions (Ωaragonite = 1.6, h2 = 0.15). Predicted breeding values for larval shell length are correlated between aragonite-undersaturated and normal conditions (Spearman r = 0.63, p < 0.05), indicating that larger larvae tend to do better in corrosive seawater. Aquaculture hatcheries routinely cull slow-growing larvae to reduce and synchronize time taken for larvae to metamorphose to spat, thus inadvertently applying size-related selection for larger larvae. This indirect selection in the hatchery populations provides a plausible explanation why domesticated oyster populations are less sensitive to ocean acidification.

2015 ◽  
Vol 11 (2) ◽  
pp. 140-147
Author(s):  
M Okpeku ◽  
MB Nodu ◽  
A Essien ◽  
CT Fekorigha

Periwinkles are invertebrates rich in protein and omega-3 fatty acids. These make them relished delicacies. Three hundred and fifteen (315) individual periwinkles were hand-picked from mangrove swamp river banks and intertidal zones of Twon-Brass in Bayelsa State and Abonnema town of Rivers State. Shell length and the weight of both the meat and shell were taken with Veneer caliper and a sensitive electronic scale balance respectively. Information on the economics of production was gathered from market women and harvesters through the use of structured questionnaires. The present study indentified possible phenotypic differences among periwinkle harvested in Bayelsa and Rivers States base on shell length and meat weight differences. Periwinkle harvested in Rivers is bigger and heavier than those harvested in Bayelsa State. Prediction of meat and total weight of from shell length was done using regression analysis. The study also identified the involvement of the different age groups that form the work-force in the States; showing that there are more young adults and teenagers in the business of harvesting and sales than aged people. There are more men involved in the business than women. There is a decline in size, quantity and availability of periwinkle presently than in the past, a factor that could be attributed to over-harvesting.Key Words: Bayelsa, Morphology, Niger Delta, Periwinkle, Rivers.


2019 ◽  
Author(s):  
Emma Timmins-Schiffman ◽  
José M. Guzmán ◽  
Rhonda Elliott ◽  
Brent Vadopalas ◽  
Steven B. Roberts

AbstractPacific geoduck clams (Panopea generosa) are found along the Northeast Pacific coast where they are significant components of coastal and estuarine ecosystems and the basis of a growing and highly profitable aquaculture industry. The Pacific coastline, however, is also the sight of rapidly changing ocean habitat, including significant reductions in pH. The impacts of ocean acidification on invertebrate bivalve larvae have been widely documented and it is well established that many species experience growth and developmental deficiencies when exposed to low pH. As a native of environments that have historically lower pH than the open ocean, it is possible that geoduck larvae are less impacted by these effects than other species. Over two weeks in larval development (days 6-19 post-fertilization) geoduck larvae were reared at pH 7.5 or 7.1 in a commercial shellfish hatchery. Larvae were sampled at six time points throughout the period for a in-depth proteomics analysis of developmental molecular physiology. Larvae reared at low pH were smaller than those reared at ambient pH, especially in the prodissoconch II phase of development. Competency for settlement was also delayed in larvae from the low pH conditions. A comparison of proteomic profiles over the course of development reveal that these differing phenotypic outcomes are likely due to environmental disruptions to the timing of molecular physiological events as suites of proteins showed differing profiles of abundance between the two pH environments. Ocean acidification likely caused an energetic stress on the larvae at pH 7.1, causing a shift in physiological prioritization with resulting loss of fitness.


2009 ◽  
Vol 6 (12) ◽  
pp. 3009-3015 ◽  
Author(s):  
J. N. Havenhand ◽  
P. Schlegel

Abstract. An increasing number of studies are now reporting the effects of ocean acidification on a broad range of marine species, processes and systems. Many of these are investigating the sensitive early life-history stages that several major reviews have highlighted as being potentially most susceptible to ocean acidification. Nonetheless there remain few investigations of the effects of ocean acidification on the very earliest, and critical, process of fertilization, and still fewer that have investigated levels of ocean acidification relevant for the coming century. Here we report the effects of near-future levels of ocean acidification (≈−0.35 pH unit change) on sperm swimming speed, sperm motility, and fertilization kinetics in a population of the Pacific oyster Crassostrea gigas from western Sweden. We found no significant effect of ocean acidification – a result that was well-supported by power analysis. Similar findings from Japan suggest that this may be a globally robust result, and we emphasise the need for experiments on multiple populations from throughout a species' range. We also discuss the importance of sound experimental design and power analysis in meaningful interpretation of non-significant results.


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