Its triggers \u2014 dry weather and a sudden dip in temperature with the turn of the season \u2014 aren\u2019t mysterious, but other questions are harder to answer. Why did this pistachio tide last so much longer than any before it? And how did this happen amid so much positive momentum for a cleaner harbor? <\/p>\n
Even the harbor\u2019s leading scientists remain stumped. <\/p>\n
\u201cAs I\u2019ve learned more and more, I realize that I don\u2019t think we understand it well,\u201d said Eric Schott, an expert in urban waterways who\u2019s studied the harbor for close to 30 years. <\/p>\n
Schott, an associate professor in the University of Maryland\u2019s Institute of Marine and Environmental Technology, was speaking in a Fells Point conference room earlier this month. The annual Waterfront Partnership event meant to mark Baltimore\u2019s progress toward a swimmable harbor had just concluded, and, outside the window, the pistachio tide\u2019s drab waters lapped against a tall ship.<\/p>\n
\u201cI\u2019ve had my simple-minded thoughts about what to do,\u201d Schott said, \u201cand I sort of don\u2019t want to even suggest them.\u201d <\/p>\n
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Eric Schott is part of a group of scientists, developers and downtown boosters that are launching a yearlong study to find environmental engineering solutions to this season’s historic pistachio tide. (Jerry Jackson\/The Banner)<\/p>\n
In the wake of this historic tide, experts like Schott have eyed the nearly $1 billion redevelopment plan<\/a> for Harborplace as an opportunity to re-engineer the Inner Harbor against these environmental crises. Schott has applied for a $50,000 grant to bring together local scientists, advocates and developers to study the pistachio tide and possible solutions.<\/p>\n While thermal inversions like the one Baltimore\u2019s harbor just experienced happen naturally, humans have made the consequences worse. Decades of industrial pollution, sewage and urban runoff have depleted oxygen and fed sulfur bacteria in the harbor\u2019s depths, creating the conditions for ecological carnage when the water column turns over. <\/p>\n This particular pistachio tide lasted the better part of a month and drove a mass die-off of wildlife<\/a>. Between late August and late September, the Maryland Department of the Environment says, 206,000 Atlantic menhaden died across three separate fish kills.<\/p>\n In total, the MDE estimates that 216,000 fish and over 400 blue crabs died in the harbor this season \u2014 figures some observers consider an undercount. According to state records, the harbor hasn\u2019t experienced fish kills this deadly since the 1980s. A 1988 event left 100,000 fish dead and another in 1984 killed close to a million. <\/p>\n Thousands of dead menhaden float in Baltimore\u2019s Inner Harbor in September. (Ariel Zambelich\/The Banner)<\/p>\n In short, the harbor experienced the ecological equivalent of a \u201cheart attack,\u201d said Adam Lindquist, vice president of the Waterfront Partnership, at the release of the group\u2019s harbor health report card this month<\/a>. <\/p>\n And \u201cit\u2019s going to take a big solution,\u201d he said afterwards.<\/p>\n Lindquist is one of Baltimore\u2019s most vocal advocates for a swimmable harbor. He\u2019s keenly aware that, while pistachio tides aren\u2019t harmful to humans, dead fish and a stinking harbor do little favor for his movement. <\/p>\n Some measures for improving the harbor\u2019s ecosystem are already incorporated into the vision of MCB Real Estate, the local developer tasked with the expensive job of reimagining the downtown waterfront. The developer recently met with the Waterfront Partnership\u2019s leadership to discuss ideas for stemming the pistachio tide.<\/p>\n MCB\u2019s roughly $900 million vision, recently approved by a voter referendum<\/a>, would constitute the most consequential change for the downtown waterfront in half a century.<\/p>\n A still from a video rendering of MCB Real Estate’s vision for Harborplace. (MCB Real Estate)<\/p>\n The plan includes<\/a> raising the promenades to protect against sea level rise, expanding green space and planting 500 new trees around the harbor to provide cooling and absorb runoff. In the water, the developer wants to add roughly 36,000 square feet of wetlands, expanding on the micro-ecosystem outside the harbor\u2019s National Aquarium. <\/p>\n Renderings of MCB\u2019s plans feature people swimming. (These images have drawn criticism<\/a> for fantastical-seeming ideas; they also show cable cars<\/a> crossing above the harbor). <\/p>\n The Waterfront Partnership, meanwhile, is exploring the possibility for a permanent swimming area in the harbor. <\/p>\n Baltimore\u2019s most fervent water advocates acknowledge that the harbor will never resemble its form a few hundred years ago, before Europeans arrived, when the Patapsco River was lined with marshes and its shallow waters offered a vibrant home to crab, menhaden and oysters.<\/p>\n Over the centuries, Baltimore\u2019s harbor was industrialized, dredged and heavily polluted. Even its borders have changed: The harbor once extended north all the way to Water Street, an extra three city blocks, but the city filled in that area with rubble after the Great Fire of 1904. <\/p>\n The city removed the harbor\u2019s natural shorelines and \u201cput it in a vertical box,\u201d said Charmaine Dahlenburg, director of field conservation for the National Aquarium, which tracked the harbor\u2019s oxygen levels during the pistachio tide.<\/p>\n This particular pistachio tide lasted the better part of a month and drove a mass die-off of wildlife (Adam Willis\/The Banner)<\/p>\n \u201cThe harbor became the way it is over 200 years,\u201d she said, \u201cand we\u2019re not going to clean it up in two years.\u201d<\/p>\n Dahlenburg remembers a major pistachio tide in 2016 as the first time scientists measured the consequences for oxygen. It\u2019s not clear whether other cities suffer from the same problem, but she pointed to the aquarium\u2019s new floating wetland as a potential model for a more resilient harbor. When the pistachio tide tanked oxygen across the ecosystem, the wetland provided a safe area for fish. <\/p>\n Harbor advocates have mulled other creative fixes, too.<\/p>\n A pair of boats<\/a> tool around the Thames in London<\/a>, finding oxygen-starved areas to inject with oxygen, an intriguing option to Chris Streb, an environmental engineer in Baltimore with the firm BioHabitats. <\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/10\/4HSG3H3VXRGSFLSUHSIB3VWDF4.jpg\")
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