Evaluation Of Cranial Facial Bone Formation And Tissue Histopathology Of Embryonic And Juvenile Commercially Important Finfish Species Exposed To Increasing Levels Of Co2 And Ph Due To Ocean Acidificationbstract: There is compelling evidence that the average atmospheric (current concentration ~
370 ppm) and oceanic CO2 has continued to increase over the past century and if it continues on
its current trajectory it could as high as 750 ppm by the year 2100 (IPCC 2007).. Our working
hypothesis is that embryonic and early life stages of fish will have deformed bone formation and
lesions in other tissues due to chronic elevated levels of CO2. The potential impact of a
concomitant increase in temperature will also be examined and may exacerbate the effect. Over
the next three years five different species will be subjected to dose response exposures varying
CO2 and temperature that are predicted over the next century. The rearing, spawning and
exposure studies will be carried out at the NOAA NEFSC Howard Laboratory, Sandy Hook, N.J.
and the specimens will be provided to us as fixed samples. The embryos and juvenile fish will be
processed for examining the cranial facial bone structure using Alcian Blue staining followed by
morphometrics. The lengths of the primary cranial facial bones will be measured and also
examined for bone density based on staining. The fish prepared for histolopathological
evaluation will be whole sectioned and stained with hematoxylin and eosin or special stains
when appropriate. The whole mounted sections will allow for examination of brain, gills, bone,
heart, kidney, liver, spleen, muscle, and gastrointestinal track, and all lesions will be recorded.
The information will be compared to the exposure regiments and determinations made as to if
there is a dose related effect from acidification and or temperature. Replicating the results in the
first year will continue in the latter years. In addition, the mechanisms by which these effects are
occurring will be further examined in the later years of the grant. The information obtained in
this grant will aid researchers, resource managers and policy decision makers in evaluating the
impacts of ocean acidification and temperature rise on early life stages from three commercially
important (summer flounder - P. dentatus, winter flounder - P. americanus, black sea bass – C.
striata) and 2 endangered (shortnose sturgeon – A. brevirostrum, Atlantic sturgeon – A.
oxyrinchus) finfish species.