Capital-Gazette Newspaper – June 29, 2022 | Capital, Annapolis MD
Author/Byline: Scott Dance | Page: 1A | Section: Main
This summer Maryland will impose new restrictions on crabbing in the Chesapeake Bay – including the first-ever limits on how many bushels of male blue crabs watermen can haul each day – in response to a troubling decline in the population of the beloved crustaceans.
Regulations issued this week, to be in effect starting in July, will limit commercial watermen to at most 15 bushels a day of male crabs in August and September and will end their harvest two weeks earlier than normal on Nov. 30. And the new rules will tighten existing restrictions on the commercial harvest of female crabs and the recreational harvest, too.The changes come weeks after an annual survey of Chesapeake blue crabs found they number the fewest since scientists began tracking their population in the 1990s.
That state fishery managers moved to limit even the harvest of male crabs demonstrates the gravity of the situation. Limits are typically only imposed on female crabs as a means of ensuring enough of them survive to spawn, but with a more than 60% decline in the overall estimated blue crab population since 2019, scientists, environmentalists and representatives from the seafood industry are signaling that more protections are needed to help boost crab reproduction. “We’re trying to take an approach that ensures our abundance remains at a sustainable level,” said Genine McClair,director of the Maryland Department of Natural Resources’ blue crab fishery management program. Allison Colden, Maryland senior fisheries scientist for the Chesapeake Bay Foundation, called the new restrictions encouraging but said they should not be the only actions to protect the “iconic” species.
It is impossible to pinpoint what has caused such a steep decline in the crab population, but factors likely include water pollution and how it harms underwater grasses, which crabs use to hide from predators, Colden said. There is also growing concern that the rapid spread of invasive blue catfish, which eat crabs and practically anything else they can find, may be responsible for much of the crab population decline.
Scientists are scheduled to gather in the fall for a workshop organized by the federal Chesapeake Bay Program to discuss what environmental factors may be having the biggest impact on blue crab survival.
“Targeted research into these factors’ impact on the crab population is a critical next step to help protect communities that depend on blue crabs,” Colden said in a statement.
It does not appear overfishing on its own is contributing to the population decline, experts say. Population estimates are used to guide changes to the female crab limits every year, and the number of spawning-age females remains above what scientists consider to be a critical threshold to ensure population stability.
But harvest restrictions are the main tool the state natural resources agency can use to steward the blue crab population, because its health depends largely on fluctuations in nature. Favorable weather and winds are needed to ensure crabs can successfully spawn, typically once or twice in mid- and late summer, and that the newest generations survive. Spawning-age females have traditionally been the focus of those harvest restrictions. But there are guidelines for a sustainable number of male crabs, too – it’s just that in normal years, there are so many males that it’s much more difficult to harvest an excessive number. In any given year, to ensure a sustainable population and a proper balance of male and female crabs, the aim is to allow harvest of no more than 34% of the entire estimated population of male crabs, McClair said. As the number of male crabs has declined, reaching a record low this year, that threshold has been tested and, in at least one year, surpassed, she said. There is research to suggest that the elevated harvest pressure on male crabs could be limiting the overall population. A team of scientists at the Smithsonian Environmental Research Center in Anne Arundel County found in two studies that a smaller male crab population means each one mates more frequently, and often before he has regenerated stores of sperm. Because females mate only in the first few days after maturing and use those sperm to spawn the rest of their lives, some end up with a diminished capacity to reproduce.
“In places where there is a really intensive fishery for males, we see females that receive less sperm,” said Matt Ogburn, a senior scientist at the center. “Across the whole Chesapeake population, we estimate that limits the total number of fertilized eggs produced by the population by 5 or maybe as much as 10% compared to if no females were sperm limited at all.” The hope is that the new restrictions on male crab harvests will at least stop the downward trend in crab abundance, if not help the species rebound significantly.
“We want to see good above-average juvenile abundance next year,” McClair said. “The measures we’re taking are warranted for this year, and we’re going to evaluate again in 2023.”
Robert T. Brown, president of the Maryland Watermen’s Association, said he worries that limiting the male crab harvest for the first time may be “a little bit of a knee-jerk reaction” that could have a significant impact on the state’s seafood industry. Watermen are used to dealing with cuts to their harvest quotas, but have no insurance or government subsidies like farmers would during a bad season, he said. They enjoyed a busy oyster season this winter, at least. However, Brown was cautiously supportive of the new crab harvest measures. “We’ll see how it goes for the season,” he said. “We’ve got to protect our resource.” Commercial harvest of female crabs will be limited to between 9 and 17 bushels a day in July and August and 17 to 32 bushels in September and October, depending on the type of license a waterman holds. A bushel contains roughly five to seven dozen crabs, depending on their size.
That means cuts of 15% to 25% to daily commercial harvest limits compared to the 2021 crabbing season, depending on the license. It’s not clear whether that will translate to a correspondingly large hit to the state’s seafood industry, because watermen don’t hit their limits every day.
The new harvest guidelines also apply to recreational crabbers who are catching the crustaceans from a boat. A boat with two or more licensed recreational crabbers is limited to a bushel of male crabs a day, down from a previous limit of two bushels. The recreational harvest, which is limited to male crabs, is estimated to account for 8% of the annual crab harvest. Virginia has also proposed new crab harvest restrictions, including shortening the crabbing season and reducing daily catch limits. Chesapeake crabs spend parts of the year in both Maryland and Virginia waters, migrating up and down the bay. McClair said there is reason to hope for a rebound, because even a depleted crab population is capable of a healthy spawning year under the right conditions.
“The nice thing about blue crabs is that they can bounce back very quickly,” she said. The question is whether conditions will allow that to happen.