Mardi Gras Oyster Science Roundup

It’s carnival time in New Orleans. Who want to catch up on the latest oyster related papers?

Researchers in Australia, studying the impacts of environmental stressors on the Sydney rock oyster Saccostrea glomerata found that while larvae of adults conditioned to high CO2 concentrations fared better than the control group when exposed to high CO2 concentrations, those same conditioned larvae were more vulnerable to combinations of stressors. Stressors evaluated included elevated CO2, elevated temperature, reduced salinity and reduced food concentration. Larvae from the high CO2 exposed adults also had a higher metabolic rate.

  • Parker, Laura M., et al. “Adult exposure to ocean acidification is maladaptive for larvae of the Sydney rock oyster Saccostrea glomerata in the presence of multiple stressors.” Biology Letters 13.2 (2017): 20160798.

A group of researchers, including LSU’s Megan LaPeyre, developed a bioenergetics model to assess the impact of oyster restoration scenarios on associated transient fish species. Their model indicated that oyster reef restoration has a direct impact on transient fish biomass and that “favorable oyster population growth rate during early restoration years” is important for increased mean oyster biomass and that of transient fish species. The authors cautioned however that “The model also revealed that a transient fish’s diet solely dependent on oyster reef-derived prey could limit the biomass of transient fish species, emphasizing the importance of habitat connectivity in estuarine areas to enhance transient fish species biomass.”

  • McCoy, E., Borrett, S. R., LaPeyre, M. K. and Peterson, B. J. (2017), Estimating the impact of oyster restoration scenarios on transient fish production. Restor Ecol. doi:10.1111/rec.12498

A report prepared by Morgan State University for the VA Center for Transportation Innovation and Research evaluated the suitability of recycled concrete from roadways as a bottom conditioning material for oyster aquaculture. “Bottom conditioning” here means laying down a layer of hard substrate on which spat-on-shell can be laid. This specific report, which is part of a larger effort, looked for the presence of pollutants from recycled concrete aggregate samples. The authors found no hydrocarbons or water excractable SVOC. Concentrations of other regulated pollutants were orders of magnitude below environmental standards.


January 2017 Oyster Science Roundup

It’s the 2nd Day of 2017 and already there are some cool papers coming out.  Here are a few that caught my eye.
  • Researchers at TX A&M in Corpus Christi documented macrofauna abundance at intertidal oyster reefs and other estuarine habitats.  Oyster reefs tended to support higher density and species richness compared to seagrass and marsh edge, but that’s not the whole story.  The location of the reef relative to other features. ” These results indicate the importance of intertidal oyster reefs to macrofauna and that reef location within the estuarine mosaic influences density and community assemblages.”  
    • Gain, I.E., Brewton, R.A., Reese Robillard, M.M. et al., Macrofauna using intertidal oyster reef varies in relation to position within the estuarine habitat mosaic,  Mar Biol (2017) 164: 8. doi:10.1007/s00227-016-3033-5
  • Researchers in Brazil exposed C. gigas and C. brasiliana oysters to different thermal regimes for 28 days to gain insight into biochemical impacts of ocean temperature increase.  The authors found that life stage and species were important factors.  The introduced C. gigas  juveniles experienced significant mortality and other effects at higher temparature, while adults were less affected.  C. brasiliana oysters were less affected by increased temperatures at all life phases.
    • Anthony Moreira, Etelvina Figueira, Iracy L. Pecora, Amadeu M.V.M. Soares, Rosa Freitas, Biochemical alterations in native and exotic oyster species in Brazil in response to increasing temperature, Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, Volume 191, January 2017, Pages 183-193, ISSN 1532-0456,
  • A team out of the Gulf Coast Research Laboratory, University of Southern Mississippi developed a model for predicting the transmission of dermo in the Eastern Oyster.  The authors suggest that overfishing may increase the susceptibility of a population to dermo infection.  They also suggested that coupling the infection model with hydrodynamic models could create a useful management tool.
    • G. Bidegain, E.N. Powell, J.M. Klinck, E.E. Hofmann, T. Ben-Horin, D. Bushek, S.E. Ford, D.M. Munroe, X. Guo, Modeling the transmission of Perkinsus marinus in the Eastern oyster Crassostrea virginica, Fisheries Research, Volume 186, Part 1, February 2017, Pages 82-93, ISSN 0165-7836,
  • A group out of LSU (Geaux Tigers!) exposed progeny of oyster stocks from differing salinity regimes to a variety of conditions along a salinity gradient.  The authors found that the different stocks may be genetically differentiated.  For example, some were more resistant to low salinity conditions, while other stocks were more resistant to dermo infection.
    • Justin M. Leonhardt, Sandra Casas, John E. Supan, Jerome F. La Peyre, Stock assessment for eastern oyster seed production and field grow-out in Louisiana, Aquaculture, Volume 466, 1 January 2017, Pages 9-19, ISSN 0044-8486,
  • Our neighbors to the north found that the Easter oyster, in the northernmost part of its range could become quiescent for months during the winter, including periods where the oysters were buried.  Early burial, which extends the quiescent period, led to increased mortality.  Removing buried oysters during the quiescent period actually accelerated mortality because the oysters began depleted energy reserves.  The authors suggest that aquaculturists avoid soft estuarine sediment whenever possible.
    • Luc A. Comeau, André Mallet, Claire Carver, Jean-Bruno Nadalini, Réjean Tremblay, Behavioural and lethal effects of sediment burial on quiescent Eastern oysters Crassostrea virginica, Aquaculture, Volume 469, 20 February 2017, Pages 9-15, ISSN 0044-8486,

Mississippi residents call for oysters, oysters, oysters

File Mar 02, 3 47 17 PM

Actually “oysters & sea grass, oysters & sea grass, oysters & sea grass!”  Last week, I went to the Mississippi Marine Living Resources Summit.  Thinking it was just another networking opportunity, I was pleasantly surprised to find myself contributing to Mississippi’s coastal plan.  Even more pleasantly surprising was the cross section of coastal Mississippi who attended.  There were the usual scientists, engineers, university people, NGO folks and consultants.  But also homeowners, boat owners, beach combers, commercial fishermen & even a group of Vietnamese fishermen.  Everyone there was passionate about their coastal waters and natural resources.

So why the chorus calling for oysters and sea grass?  The consensus is that the natural resources are integral to the very identity of coastal Mississippi.  Oyster reefs & sea grass beds are the foundations of the whole coastal ecology as well as the “canaries in the coalmine” for estuarine health.  By rebuilding the reefs, and bringing back the sea grass beds,  all those other resources (shrimp, crabs, specs, reds etc…) have a chance to thrive.  At the same time, if the oyster reefs and sea grass beds are thriving, you know that you’ve got healthy water.

At ORA Estuaries, we grow oyster reefs into living coastal protection structures.  By combing restoration with engineered infrastructure, we stretch those hard-to-come-by dollars further.

If you like what we are doing, please lend us your support by voting for our company in the New Orleans Entrepreneur Week Big Idea.  Visit every day between now and March 23rd.

Thank you so much,

Tyler Ortego, Founder ORA Estuaries