{"id":543916,"date":"2026-03-18T05:52:08","date_gmt":"2026-03-18T05:52:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/543916\/"},"modified":"2026-03-18T05:52:08","modified_gmt":"2026-03-18T05:52:08","slug":"in-chesapeake-bay-the-primary-cause-of-death-for-baby-blue-crabs-the-grown-ups","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/543916\/","title":{"rendered":"In Chesapeake Bay, the Primary Cause of Death for Baby Blue Crabs: The Grown-Ups"},"content":{"rendered":"

Here are two things you don\u2019t often hear about. First, the primary cause of death for a coveted marine animal isn\u2019t climate change. Second, scientists spent nearly four decades confirming the actual cause: cannibalism.<\/p>\n

According to new research, adult blue crabs were responsible for roughly 97% of injuries\u2014more than half being lethal\u2014sustained by younger blue crabs in Chesapeake Bay. So instead of protecting their young, adults of the species are doing quite the opposite\u2014they\u2019re eating them. The study, published yesterday in the Proceedings of the National Academy of Sciences<\/a>, tracked cannibalism in blue crabs for an impressive 37 years, confirming that this behavior was a pattern, not an anomaly.<\/p>\n

\u201cCannibalism is common but poorly quantified in marine populations, including fish, crustaceans, cephalopods, and sea urchins,\u201d Anson Hines<\/a>, the study\u2019s lead author and director emeritus at the Smithsonian Environmental Research Center, told Gizmodo in an email.<\/p>\n

Are the crabs okay? \"AA basket of blue crabs caught during a survey by the Smithsonian Environmental Research Center. Credit: Smithsonian Environmental Research Center <\/p>\n

As a species, blue crabs are valuable both for fisheries and the natural environment, according to the U.S. National Oceanic and Atmospheric Administration<\/a>. These crabs are both predator and prey in their geographic range, making them a central part of the local food web. This is especially true in Chesapeake Bay, the largest estuary in the United States.<\/p>\n

But blue crabs are also \u201cinfamously aggressive and cannibalistic,\u201d Hines added. For instance, Hines\u2019s own team and other researchers had identified blue crab remains inside the stomachs of blue crabs. Documenting this behavior was one thing\u2014understanding it was another. The goal of any species is to stay alive and propagate; cannibalism doesn\u2019t sound like the smartest choice.<\/p>\n

Tracking crab cannibalism <\/p>\n

And so, Hines and his team set out to systematically study this odd behavior and determine how much of a threat cannibalism posed to young blue crab populations. The project, which started in 1989, lasted for 37 years. The challenge lay in maintaining consistent schedules and methods, Hines recalled, but these efforts allowed the team to gather some high-quality data to explain high-level weirdness.<\/p>\n

For the study, the team tethered juvenile crabs to small metallic spikes in the water, which in fisheries actually help the younger crabs hang around and hide from predators inside the sediment, according to a Smithsonian statement<\/a>. That said, this trick doesn\u2019t work on larger crabs, who can reportedly use \u201cchemical and tactile cues\u201d to track prey.<\/p>\n

\"TetheredA group of tethered juvenile blue crabs with red floats, ready to deploy for the field experiment underwater. Credit: Smithsonian Environmental Research Center <\/p>\n

Repeated instances of this experiment revealed many fascinating insights into crab cannibalism. Overall, the intensity of cannibalistic behavior varied by the seasons, peaking in the warmest months when adult crabs were most active, the paper explained. Size also mattered, as smaller juvenile crabs were more likely to be eaten. On the other hand, crabs hiding in shallower waters (around half a foot) had better chances of survival.<\/p>\n

Most surprisingly, the team \u201cdid not find any predation by fish on juvenile blue crabs over the 37 years,\u201d Hines said. \u201cAll of the predation was attributed to cannibalistic attacks by blue crabs.\u201d<\/p>\n

Protecting the crabs <\/p>\n

The team still isn\u2019t fully sure what, if any, the evolutionary benefits are. However, the researchers note in the paper that cannibalism could be the crabs\u2019 way of controlling the population. Still, the findings offer some tips for creating shelters for juvenile crabs.<\/p>\n

This is especially important, as the shallow, mid-salinity zones where younger crabs were most likely to survive are the areas most affected by sea level rise, storm surges, and the introduction of invasive species, Hines explained. Based on the findings, the team is now at work developing a stock-assessment model for Chesapeake Bay\u2019s blue crabs, which should help \u201cimprove a sustainable management strategy,\u201d Hines said.<\/p>\n","protected":false},"excerpt":{"rendered":"Here are two things you don\u2019t often hear about. First, the primary cause of death for a coveted…\n","protected":false},"author":2,"featured_media":543917,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[49,48,145435,8943,66,323],"class_list":["post-543916","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-ca","tag-canada","tag-crabs","tag-marine-conservation","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/543916","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=543916"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/543916\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/543917"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=543916"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=543916"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=543916"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}