{"id":683917,"date":"2026-06-04T13:02:12","date_gmt":"2026-06-04T13:02:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/683917\/"},"modified":"2026-06-04T13:02:12","modified_gmt":"2026-06-04T13:02:12","slug":"rampant-spawning-then-a-heat-wave-leads-to-lots-of-dead-fish-in-the-charles","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/683917\/","title":{"rendered":"Rampant spawning, then a heat wave, leads to lots of dead fish in the Charles"},"content":{"rendered":"

If you\u2019ve walked or rowed along the Charles River the last few weeks, you may have been subjected to a grotesque scene: Several dead fish floating in the water. <\/p>\n

But Jason Stolarski, an aquatic biologist and the \u201cfish kill coordinator\u201d for MassWildlife, says he\u2019s not concerned about the number of dead carp reported in recent weeks. <\/p>\n

\u201cThey\u2019re very active when they spawn, so they expend a lot of energy. They\u2019re also releasing eggs and sperm into the water, and it costs energy to create those reproductive products,\u201d Stolarski said. \u201cBy the end of this activity, when they\u2019ve all spawned, they\u2019re just gassed, right?\u201d<\/p>\n

Essentially, he said that the carps\u2019 defenses were down after the seasonal breeding activity. So when the record-breaking heat wave tore through the Boston area last month, they were vulnerable to the high temperatures, or low oxygen in the water, or disease. <\/p>\n

\u201cThese fish died probably a few weeks ago, but they\u2019re still kind of just kind of floating around and being consumed by secondary predators and turtles and things like that.\u201d <\/p>\n

For passersby who see \u2014 or smell \u2014 the carp, there\u2019s really nothing to do. Still, Stolarski acknowledges it\u2019s upsetting. <\/p>\n

\u201cObviously when you see dead fish, particularly when you see aggregations of dead fish, your mind immediately goes to kind of the worst-case scenario \u2014 the river turned to poison, … there\u2019s some sort of agent that\u2019s killing things at will. And that\u2019s often not the case,\u201d he said. \u201cIt\u2019s not the end of the world, and the carp will be just fine.\u201d <\/p>\n

Marielena Lima with the Charles River Watershed Association says it\u2019s been a \u201cnoticeable\u201d amount of fish \u2014 and she wants to make sure people don\u2019t get up close and personal with bacteria-laden decomposing organisms. <\/p>\n

\u201cDefinitely don\u2019t touch it,\u201d she said. <\/p>\n

\u201cIt\u2019s such an early fish kill. Usually it happens later down in the summer when it\u2019s really hot,\u201d she added. \u201cBut we\u2019ve been in a drought for months now, so I think it\u2019s just kind of all these compounding effects on fish in our watershed.\u201d <\/p>\n

\"A<\/p>\n

A dead fish floats along the Esplanade between Harvard Bridge and Longfellow Bridge in this recent photo. <\/p>\n

\n Courtesy of the Charles River Watershed Association\n <\/p>\n

Stolarski said it\u2019s been a rough season, and offered another cause for the many dead fish on the river. The unusually cold winter led to way more fish than usual dying under thick layers of ice and snow in ponds across the state. So when the ice started melting a few months ago, those dead fish all rose to the surface, she said. <\/p>\n

\u201cUsually it\u2019s a pretty quiet job … but this year it\u2019s been quite busy,\u201d Stolarski said. \u201cThey\u2019re all natural, and it\u2019s all a function of how we treat how we treat the watershed that we live in.\u201d<\/p>\n

On the Charles, the fish being impacted appear limited to one species and aren\u2019t native to the area, so Lima isn\u2019t worried about environmental consequences. <\/p>\n

\u201cThankfully, it\u2019s only been invasive carp,\u201d Lima said. <\/p>\n","protected":false},"excerpt":{"rendered":"If you\u2019ve walked or rowed along the Charles River the last few weeks, you may have been subjected…\n","protected":false},"author":2,"featured_media":683918,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51],"tags":[79,201],"class_list":["post-683917","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/683917","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=683917"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/683917\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/683918"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=683917"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=683917"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=683917"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}