Regulatory Effects on Maryland Blue Crab Sustainability

By: Emma Cease ’22, an Environmental Science major.

The following work was created for FYS 101: Science of Reality TV.

Brief description: This is a thesis paper evaluating the successful measures taken by Maryland to revitalize the blue crab population. Reports from the late 1990s and early 2000s demonstrated extreme overexploitation of the species, but new program targets, updated regulations, and more accurate monitoring systems implemented by Maryland have turned blue crabs into a sustainable resource. Maryland’s actions serve as an excellent example of sustainable resource management.

In Maryland, the blue crab is much more than a regional cuisine, it is an integral natural resource that the state is economically dependent upon. In fact, the Chesapeake Bay is the source for half of the national blue crab harvest, and the seafood industry contributes almost $600 million to the Maryland economy (Maryland Government, 2019). The Chesapeake watermen who extract each year’s harvest rely on a successful catch for their livelihoods and have been doing so for many years. In terms of employment, there are an estimated 4,545 commercial watermen who harvest blue crabs as their primary occupation in Maryland (Maryland Government, 2019). So deeply ingrained into the state’s culture, the blue crab was even designated the state’s official crustacean in 1989, therefore major changes were required after past overharvesting threatened to bring an end to it (State Symbols USA, N.D.) Blue crabs in Maryland now serve as an example of a sustainable resource after their population drop and overharvesting was mitigated with new program targets, updated regulations, management, and the implementation of more accurate monitoring assessments.

In the late 1990s through the early 2000s, the vitality of crabs in the state caused immediate concern when stock assessments showed that crabs were being overharvested. In 1997, the initial evidence of blue crab overexploitation came from the first bay-wide blue crab stock assessment, which reported that the stock was “moderately to fully exploited and at average levels of abundance” (Maryland Department of Natural Resources, 2012). In other words, the crab population was being used for economic gain in an unsustainable way, and the levels of harvestable crabs were not showing signs of increasing. Accurate surveying had not been available previously, therefore crabs were being harvested based on thresholds that lacked accuracy. The shock of the diminished population on which so many were dependent set forth a focus of preserving the species in the following years.

To mitigate the current patterns of overharvesting, new program targets were created to refocus the crabbing industry and rebuild the blue crab population. The primary way of doing this was through amendments to the original 1997 Chesapeake Bay Blue Crab Fishery Management Plan. The first major amendment occurred after the 2003 stock assessment showed similar reports of overexploitation. The amendment set forth new targets for biomass exploitation, adopted fishery management thresholds, and created strategies to reduce fishing rates (Maryland Department of Natural Resources, 2012). More importantly, this first amendment formally recognized that monitoring the blue crab population and protecting habitat was important in the goal of sustainability. A second amendment was made to the plan after the 2011 stock assessment due to the stock increasing at too slow of rates to rebuild the population adequately. To alleviate this, a specific focus was taken on rebuilding the female portion of stock through new reference points based on maximum sustainable yield, reproduction rates, life-span, gender abundance, and distribution during assessments (Maryland Department of Natural Resources, 2012). More specifically, a “minimum safe level” of 70 million spawning-age females was assigned and a goal target of 215 million spawning-age females was made (Chesapeake Bay Program, 2015). By having established reference points and statistics to aim for through these amendments, the blue crab harvest moved in a more sustainable direction.

Updated regulations and management were another key revision that aided in the blue crab’s ability to achieve sustainability. After the initial assessments showed critically low levels of stock, Maryland created a temporary 2-year committee in 2001 to focus entirely on the reframing of management efforts. The Bi-State Blue Crab Advisory Committee received $150,000 by Maryland and Virginia and was instrumental in providing statements and recommendations on how to manage blue crabs (Chesapeake Bay Commission, 2001). The funding allowed the committee to focus on making evaluations that previously hadn’t been evaluated. Another key update came through the passage of House Bill 1253 in 2008 to change the boundaries of the Chesapeake Bay Critical Area zoning. Created in 1984, the Chesapeake Critical Bay Area Protection Program was “enacted as a far-reaching effort to control future land use development in the Chesapeake’s watershed” by preventing construction on land within 1000 feet of tidal areas of the Bay (Maryland Department of Natural Resources, 2019). The critical area zoning was a way to provide protection for the Bay and crab health, but it had become outdated over time. House Bill 1253 updated these boundaries using “the “stand-alone” sectional map amendment (SMA) process, where the SMA consists of only the map and not a master or sector plan,” thus increasing the size of critical areas (Maryland-National Capital Park and Planning Commission. N.D.). The updated regulations and management Maryland underwent was beneficial in increasing the amount of protection towards the Bay and crab stock, and it helped the preservation of the crab species as a whole.

The implementation of more accurate crab monitoring assessments also helped sustain the blue crab population. The data gathered by crab monitoring systems is crucial in establishing proper regulatory thresholds and having an accurate account of the current stock. Before 2006, there was no set crab monitoring system, therefore the data presented was not accurate compared to that of previous years. This changed in 2006 when the bay-wide winter dredge survey (WDS) was made the “primary fishery-independent survey for assessing blue crab stock…measuring sites (approximately 1,500) around the entire bay” (Maryland Department of Natural Resources, 2012). The WDS was much more comprehensive and accurate compared
to previous surveying systems, because it was “corrected in bias for gear selectivity, and extrapolated to estimate abundance” (Maryland Department of Natural Resources, 2012). Gear selectivity allows for fishermen to catch the intended sex and size of crab, as well as avoid catching other organisms, thus ending wasteful catches. Accuracy of crab monitoring was again improved in 2013 when self-reporting shifted from paper to digital. The older paper system was time-consuming and limited the ability for in-season harvest adjustments, therefore the Maryland Blue Crab Design Team “launched an electronic harvest monitoring system in which crabbers voluntarily report how many crabs they landed each day, updating their catch in real-time using onboard mobile devices” (The Baltimore Sun, 2013). This transition improved the overall accuracy of crab data, which in turn allowed better thresholds to be set to protect the crab population.

The many approaches taken to prevent the collapse of the blue crab population have created a much healthier current state of the blue crab population as compared to the early 2000s. According to the 2019 Chesapeake Blue Crab Advisory Report, the total crab abundance increased by roughly 60% from 372 million crabs in 2018 to 594 million crabs in 2019 (Chesapeake Bay Stock Assessment Committee, 2019). These plentiful numbers can be attributed to the combination of approaches the state took to stop further exploitation of the crab stock. Furthermore, the specific female target points have proven successful as “the percentage of female crabs removed by fishing in 2018 was approximately 23%. This exploitation fraction is below the target of 25.5% and the threshold of 34% for the 11th consecutive year since 2008” (Chesapeake Bay Stock Assessment Committee, 2019). Overall, the advisory report was able to conclude based on the recent statistics that the blue crab population has reached sustainable levels, because the “stock is not depleted and overfishing is not occurring” (Chesapeake Bay Stock Assessment Committee, 2019). The current sustainable status is one of great relief to the state, as compared to 2001 when the stock was at the lowest amount ever assessed.

The blue crab is a vital natural resource for Maryland’s economy. The decreasing population sparked an immediate response to preserve the state’s livelihood and culture. By recognizing that previous administrative techniques were not successful, Maryland created both new program targets and made amendments to former regulations. The overall reporting system for crab monitoring also transitioned from paper to digital, increasing reliability and convenience for watermen. Comparing the 2019 stock assessment to those of the early 2000s displays drastic differences. Instead of a threatened population, the blue crabs are an example of a well-sustained natural resource; one in which should serve as an example to other state’s management of important assets.


Chesapeake Bay Commission. 2001. Taking Action for the Blue Crab. Retrieved from​. Accessed September 22, 2019.

Chesapeake Bay Program. 2015. Blue Crab Abundance and Management Outcomes. Retrieved from ement_strategy.pdf​. Accessed September 29. 2019.

Chesapeake Bay Stock Assessment Committee. 2019. Chesapeake Blue Crab Advisory Report. Retrieved from _final.pdf​. Accessed September 29, 2019.

Maryland Department of Natural Resources. 2019. Critical Area Commission Background and History. Retrieved from​. Accessed September 28, 2019.

Maryland Department of Natural Resources. 2012. 1997 Chesapeake Bay Blue Crab Fishery Management Plan. Retrieved from 20121.pdf​. Accessed September 22, 2019.

Maryland Government. 2019. Maryland Economy. Retrived from Accessed September 29, 2019.

Maryland-National Capital Park and Planning Commission. N.D. Chesapeake Bay Critical Area Mapping Update. Retrieved from​. Accessed September 28, 2019.

State Symbols USA. N.D. Blue Crab. Retrieved from ue-crab​. Accessed September 29, 2019.

The Baltimore Sun. 2013. For watermen, better data means fewer restrictions. Retrieved from​. Accessed September 29,2019.

Emma Cease is an environmental science major who runs lots of miles for fun and spends any time she can outside. She is a Presidential Fellow, Environment and Society fellow, George’s General, Student Environmental Society member, and the vice president of the Running Club. Emma hopes to find a hands-on career in environmental science and help make a difference in the world. She is a fitness enthusiast and is called a “health junkie” by all her friends.

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