Buffering muds with bivalve shell significantly increases the settlement, growth, survival, and burrowing of the early life stages of the Northern quahog, Mercenaria mercenaria, and other calcifying invertebrates. (5th January 2022)

• Record Type: Journal Article
• Authors: Curtin, Timothy P.; Volkenborn, Nils; Dwyer, Ian P.; Aller, Robert C.; Zhu, Qingzhi; Gobler, Christopher J.
• Is Part Of: Estuarine, coastal and shelf science. Volume 264(2022)
• Publication Date: 2022-01-05
• Subjects: Mercenaria mercenaria -- Ocean acidification -- Calcium carbonate -- Dissolution; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2021.107686
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: Acidic conditions in muddy sediments with high organic matter content can negatively impact the growth and survival of juvenile bivalves. Amending sediments with carbonate shell debris could be a strategy to buffer against low porewater pH and improve habitat suitability. To assess this approach, lab and field experiments were conducted to quantify the effects of shell amendments on sediment chemistry as well as growth, survival, recruitment, and burrowing behavior of larval and juvenile hard clams ( Mercenaria mercenaria ). Shell-amended treatments yielded statistically significant increases in porewater pH (+0.23–0.73) and aragonite saturation state, Ωar (+0.5–1.26). Clams transitioning from larval to juvenile stages showed significantly increased growth (4–5.7 μm day −1 ) and survival (33%) in buffered sediments, and settling larval clams benefited from sediment buffering more than recently settled juveniles. Juvenile hard clam (length 2–5 mm) burrowing was significantly increased (3–14%) in buffered sediments compared to unamended sediments. Consistent with laboratory findings, juvenile clams showed significantly increased growth rates (5.5–11.4 μm day −1 ) in carbonate-buffered sediment field experiments in Shinnecock Bay, NY, USA. In addition, native calcifying benthos ( Gemma gemma and foraminifera) preferentially settled in buffered sediments, with increased settlement of 150% and 80% for Gemma gemma and foraminifera, respectively. These results substantially extend and generalize previous indications that the addition of shell to muddy sediments can buffer porewater carbonate chemistry and make sediments more hospitable for young hard clams. Amending muddy sediments with shell is a simple, effective strategy to promote settlement, growth, and survival of hard clams and likely other calcifying benthos. Graphical abstract: Image 1 Highlights: Buffering of muddy sediments with aged shell hash significantly increased pH and Ωar . Buffered muds saw increased survival and growth for early life stage hard clams. Juvenile hard clams saw increased burrowing and growth rates in buffered sediments. Other benthos (foraminifera and Gemma gemma ) were also increased in buffered muds.