{"id":952363,"date":"2026-10-30T21:42:09","date_gmt":"2026-10-30T21:42:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/952363\/"},"modified":"2026-10-30T21:42:09","modified_gmt":"2026-10-30T21:42:09","slug":"how-crushed-shells-protect-against-ocean-acidification","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/952363\/","title":{"rendered":"How crushed shells protect against ocean acidification"},"content":{"rendered":"

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\"Crushed<\/p>\n

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image:\u00a0<\/p>\n

In the study, UC Davis researchers added crushed shells, pictured here, to sand to better understand how the practice can protect shell-making animals from the negative effects of ocean acidification.<\/p>\n

view more\u00a0<\/a><\/p>\n

Credit: Hannah Kempf\/UC Davis<\/p>\n

New research from the University of California, Davis reveals why adding crushed shells to beach sand helps protect shell-making animals \u2014 such as clams, oysters and mussels \u2014 from the detrimental effects of ocean acidification.\u00a0<\/p>\n

In a study appearing in Biogeosciences<\/a>, the researchers designed an experiment at the UC Davis Bodega Marine Laboratory<\/a> in which they mixed crushed shells, or shell hash, into sand where baby Pacific littleneck clams burrowed and grew. They then monitored the clams\u2019 growth and the water\u2019s chemistry over a 90-day period.\u00a0<\/p>\n

Adding shell hash, the researchers found, altered the chemistry of the water that fills the tiny spaces between sand particles, decreasing its overall acidity and creating a better environment for shell growth.\u00a0<\/p>\n

\u201cWe found that, on average, clams grew larger shells when shell hash was present in their\u00a0treatment,\u201d said study first author\u00a0Hannah Kempf<\/a>, an environmental scientist at the California State Water Board who graduated from UC Davis with a Ph.D. in earth and planetary sciences in 2024. \u201cInterestingly, we also found that, on a genetic level, the \u2018acidification\u2019 signal was dramatically minimized when shell hash was present.\u201d\u00a0<\/p>\n

The findings suggest that shell hash can buffer, on a very local level, the impacts of acidification and promote clam growth.<\/p>\n

Indigenous communities have long added shell hash to sands to keep coastal ecosystems healthy. The research illuminates the biology underlying why this method is effective.\u00a0<\/p>\n

\u201cThis was the first time the question was studied from a genetic perspective,\u201d said study corresponding author\u00a0David Gold<\/a>, an associate professor of earth and planetary sciences at UC Davis.\u00a0<\/p>\n

Why does ocean acidification hurt shell-making organisms?\u00a0<\/p>\n

Ocean acidification occurs when seawater absorbs excess carbon dioxide from the atmosphere.<\/p>\n

As the water becomes more acidic, Kempf said, it becomes more energetically costly and difficult for shell-making animals to build their shells. Acidic seawater can even dissolve shells. Larvae and juveniles are thought to be especially vulnerable to its negative effects.\u00a0<\/p>\n

To understand why adding shell hash acts a buffer against ocean acidification, the researchers raised baby Pacific littleneck clams in four different conditions: seawater with sediment, acidified seawater with sediment, control seawater with sediment plus shell hash, and acidified seawater with sediment plus shell hash.\u00a0<\/p>\n

Over 90 days, the researchers sampled the seawaters three times a week, monitoring acidity, salinity, temperature and dissolved oxygen. They also tracked the clams\u2019 shell growth and after 90 days, they sampled the clams\u2019 mantle tissue for follow-up gene sequencing.\u00a0<\/p>\n

Not only were the clams raised in shell hash-rich sediments larger on average, but the gene expression profiles of those raised in acidified seawater with shell hash were largely indistinguishable from those raised in non-acidified waters.\u00a0<\/p>\n

\u201cAdding crushed shells removed the negative genetic changes that occur when young clams are raised in acidified water,\u201d said Gold.\u00a0\u00a0\u00a0<\/p>\n

Lessons from Indigenous science\u00a0\u00a0<\/p>\n

Study co-author\u00a0Tsim Schneider<\/a>, an associate professor of anthropology at\u00a0UC Santa Cruz<\/a>, said there is significant evidence from traditional ecological knowledge that shell hash is beneficial to the health of shell-making animals.\u00a0<\/p>\n

In the Pacific Northwest, he said, some Indigenous communities create large-scale structures that enlarge intertidal spaces, promoting habitats for invertebrates and other marine organisms.\u00a0<\/p>\n

\u201cFor me, one of the interesting aspects of this research is the potential to engage more fully with tribes on designing projects that promote their long-standing expertise and Indigenous science,\u201d said Schneider, who is also affiliated with the National Science Foundation\u2019s\u00a0Center for Braiding Indigenous Knowledges and Science<\/a>. \u201cIf there’s a history of adding shell hash to clam beds in California, for example, western science might be able to better support communities interested in reawakening dormant cultural knowledge and coastal stewardship practices.\u201d<\/p>\n

The research was supported by a\u00a0California Sea Grant<\/a> and the\u00a0Russell J. and Dorothy S. Bilinski Fellowship<\/a>.\u00a0<\/p>\n

Method of Research<\/p>\n

Experimental study<\/p>\n

Article Title<\/p>\n

Shell hash promotes growth in Pacific littleneck clams (Leukoma staminea) by altering pore water chemistry<\/p>\n

Article Publication Date<\/p>\n

29-Oct-2026<\/p>\n

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.<\/p>\n","protected":false},"excerpt":{"rendered":"image:\u00a0 In the study, UC Davis researchers added crushed shells, pictured here, to sand to better understand how…\n","protected":false},"author":2,"featured_media":952364,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[49,48,66],"class_list":["post-952363","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ca","tag-canada","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/952363","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=952363"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/952363\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/952364"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=952363"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=952363"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=952363"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}