Dissolution mortality of juvenile bivalves in coastal marine deposits

Abstract

We evaluate experimentally the effect of carbonate saturation state at the sediment-water interface (SWI) on survivorship of various size classes of the juvenile bivalve Mercenaria mercenaria. Populations of 0.2-mm, 0.3-mm, 1-mm, and 2-mm M. mercenaria were introduced to sediments realistically undersaturated (experimental, saturation state with respect to aragonite ϭ ⍀ aragonite ϭ IMP/K ϭ ϳ0.3) and saturated (control, ⍀ aragonite ϭ ϳ1.5) Ј sp with respect to aragonite in order to evaluate the impact of saturation state and dissolution on survivorship. Linear regression analysis was used to examine mortality within each treatment over time and show significant mortality for each size class in experimental-undersaturated treatments only (P Ͻ 0.05). Mortality rates in experimentalundersaturated sediments were Ϫ11.8, Ϫ4.8, Ϫ1.9, and Ϫ1.1% d Ϫ1 for the 0.2-, 0.3-, 1.0-, and 2.0-mm bivalves, respectively. Analysis of covariance (ANCOVA) was used to examine differences in mortality between treatments over time and show significantly different mortality rates for the 0.2-, 0.3-, and 1-mm individuals (P Ͻ 0.05).

Effects of past, present, and future ocean carbon dioxide concentrations on the growth and survival of larval shellfish

“…Hence, within an ecosystem setting, mortality rates of early life history bivalves that develop under modern day and higher CO 2 levels would be expected to be even greater than the rates observed during our experiments. Given that bivalves in coastal areas naturally experience extremely high mortality rates in the transition from larvae to benthic juveniles (9), increases in mortality due to elevated CO 2 could have profound effects on estuarine bivalve populations (5).…”

“…The experimental enrichment of CO 2 to levels expected in the coming century has been shown to dramatically alter the growth, survival, and morphology of numerous calcifying organisms including coccolithophores, coral reefs, crustose coralline algae, echinoderms, foraminifera, and pteropods (5-7). Many shellfish also produce calcareous shells, and juvenile and adult clams, mussels, and oysters have been shown to be adversely affected by elevated CO 2 (8)(9)(10)(11)(12). The earliest life history stages of shellfish, larvae, have been shown to be especially vulnerable to high CO 2 , displaying large declines in survival and delays in metamorphosis at levels predicted to occur later this century, suggesting recruitment of these populations may be adversely impacted by ocean acidification (12)(13)(14).…”

Effects of Coverage by Benthic Seaweed Mats on (Northern Quahog = Hard Clam) Mercenaria Mercenaria in a Eutrophic Estuary

“…This is because heterogeneous sediment with mixtures of coarse particles has been shown to reduce the effects of crustacean predators The length of the boxes represents 1.5 3 interquartile range (IQR) above the third quartile and 1.5 3 IQR below the first quartile, and the red crosses represent the minimum and maximum outliers. Latitude and longitude coordinates of(reviewed by Kraeuter, 2001) and act as a buffer to low pH in fine-grained sediments (Green et al, 2004(Green et al, , 2009.…”

Long-term exposure to elevated pCO2 more than warming modifies early-life shell growth in a temperate gastropod

“…Differences in mineralisation over the individual life cycle can therefore lead to higher mortality in juveniles due to predation or parasitism, because shells are not yet as stable nor as thick as in adults. These shells are also thought to dissolve more easily in conditions of lowered pH, especially in or just after the settling process (Green et al, 2004). Such conditions have been found increasingly often in marine environments around the world as a consequence of global climate change.…”