Monday, September 23, 2013

2013 Connecticut Blue Crab Report #9 - First Young of the Year Arrive and other news

From Tim Visel at The Search for Megalops:

The Sound School – the ISSP and Capstone Project Proposal
Building a Network of Citizen Monitors
 
The Search for Megalops
The Connecticut Blue Crab Population Habitat Study 2010-2015
You Do Not Need To Be A Scientist To Report!
The Search for Megalops –Report #9 -2013 – Blue Crab Year
September 18, 2013 

  • Blue Crabbing Improves in Central Connecticut
  • Essex, Connecticut Blue Crab Capital?
  • Boats and Shore Crabbing
  • Crabs Detected Moving West
  • “Rusty Crabs” Now Dominate Many Areas
Blue Crabbing Improves in Central Connecticut

The first 10 days of September saw crab catches inch up in central and eastern CT with the highest reports now coming from the Mystic and Connecticut Rivers. All the coves, creeks and bays from New Haven east have crabs, a few yellow face but mostly hard shells; the small 3 to 4 inch size seem to be increasing between Branford River and Clinton, while new western Connecticut reports mention large numbers of 1 to 2 inch size, a good sign not so much for this year but an excellent one for next year; still no report of widespread Megalops sets. In 2010 and early 2011, the towns that reported the densest Megalops sets were Darien, Westport, Fairfield and Bridgeport.

We would need to see that Megalops set around now, if it were to have enough time to reach an inch point to point before hibernation.

The fall crab fishery looks to be excellent in the Connecticut River. And I need now to apologize to these crabbers in Essex who first told me about overwintering crabs in the marina basins there in 2008. I now believe those overwintering locations to be important to the Connecticut River crab fishery especially for North Cove, Old Saybrook.  North Cove has been dredged since 1954 and has constantly shown early multiple year classes even spring, for 5 years. South Cove to the immediate south has a large causeway and is relatively shallow, and it does not seem to have any crabs early spring. The same situation has been reported in many lower rivers: East in Guilford, Hammonasset in Madison, Branford, West in Guilford and Westbrook’s Patchogue and Menunketesuck Rivers. The fall fishery barring any weather events should be outstanding

Tim Visel

p.s. Late note: Large Megalops crab hatch reported off Westbrook to Guilford, September 12-16, more in next report. 

Essex, CT Blue Crab Capital? 

A film crew for New England Boating that has been filming special interest segments featuring several New England’s harbor destinations and had heard that Essex not only had some of the largest marine businesses and historic maritime settings to visit but had become a popular destination for a burgeoning blue crab population. The Connecticut River blue crab fishery has in the past few years become almost as recognized as the lower river striped bass fishery each spring. The location has not been lost on regional boating community especially those from New York who anchor in the lower river and catch, cook and consume fresh blue crabs from the boat. The film crew was in Essex (hosted by Essex Island Marina) to visit several popular Essex destinations but wanted to experience blue crabs also.  Two local crabbers William Doane and Dylan Defrino of Essex helped out.  After a slow attempt to find the crabs north of Nott Island, William and Dylan returned to channel edges by the marinas and found many hungry crabs waiting for food. Essex has dredged channels freeing the bottom of vast collections of leaves and mud and in the process creating it seems excellent habitat for blue crabs. These channel areas are thick with crabs and this is where small boats provide a key advantage for crabbers and the 12 foot Brockway style or similar blue crab skiff is a must late summer (my opinion). (See Special Report #5, 2013) for information about Blue Crab Skiff boats and shore crabbing).  Look for the Essex New England Boating special in late September on NESN.Com

Boat and Shore Crabbing

Although many Megalops reporters crab from canoes and kayaks, I am old school and prefer a flat bottomed skiff. The densest population crabs in the Connecticut River are now in Essex Cove channels, and a flat bottomed crab skiff (Brockway style) would be my boat of choice now; these were low profile skiffs designed for blue crabbing and snapper blue fishing (see report August 1, 2012 Blue Crabbing Skiff for Fishers, Clinton Harbor). They have a two position rowing setup that also can be rowed from the rear seat, while the bow seat becomes a “dipper” position looking for soft shells at low tide, while at high tide, the skiff is an effective hand-lining platform, two adults 2 and 3 children. At night the design draws only a few inches and can be sculled form the rear (seat (early version was just a notch out in the transom with a leather strap nailed across it) while “flash lighting” crabs from the bow along marsh edges. Many crabbers expressed interest in the design last year (report August, 2012) but the storms last year made finishing the 12 foot skiff construction bulletin impossible. It is now being completed and plans should be available soon. The Brockway style skiffs are constructed from high grade exterior plywood and modest power tools, and with painting and reusable care will last for decades. The 1958 skiff I used with Mr. Charles Beebe [1] in the East River, Guilford in the early 1970s is the one in my back yard and still holds its shape although no longer seaworthy. Having used the blue crab skiff many times I can attest to the versatility from blue crabbing, gill netting menhaden and to the snapper turtle trapping; it was dependable and seaworthy when carrying weight. I should be finished in a few weeks with the plans, and perhaps a winter project to be ready for next crab season? For more information about design plans, contact Susan Weber, Adult Education at susan.weber@new-haven.k12.ct.us

Crabs Detected Moving West

I almost sent out a mid-August report about this and I thank those western crabbers who sent in reports about 1 to 2 inch crabs. They showed up in large numbers in Milford around August 20th and a series of reports indicated westward movement again with strong tides (see Report 8, August 23, 2013), but there just wasn’t enough of them to identify it as organized movement. The good news for western crabbers is that mixed in with the 1 and 2 and 3 inch crabs are a few legal sized crabs 5” and up. Some crabs are now being caught in Milford, Westport, Stratford, Fairfield and Norwalk. It’s very slow crabbing 3 to 5 crabs per hour – far different to the 10 to 30 crabs/hour in central and eastern sections. It is however, a good sign but the Saugatuck is still quiet. It is thought that in the warm weather sulfides might still be present there from the tremendous amount of leaf litter it has received after Irene and Sandy. We have seen blue crab populations sharply decline in Connecticut before.

After some large catches in the 1920s, Connecticut blue crab commercial catch in 1930 topped 200,000 lbs or about 500,000 crabs[2] (pg 147), New England Historical Catch Statistics, US Fish & Wildlife Service Statistic Digest #59, Charles H. Lyles, GPO Washington 1967.  In 1931, crab production fell sharply in New England.  This decline was most remarkable in Massachusetts which saw production tumble from 4.3 million lbs (10 million crabs) in 1929 to only 200,000 lbs in 1931. New York’s blue crab catch dropped from 1.2 million lbs (1888) to only 105,000 lbs in 1931. (Middle Atlantic Fisheries Historical Catch Statistics, US Dept. of Fish & Wildlife, 1967 pg 215). Although the US Fish & Wildlife collected commercial fishery statistics people in Connecticut were recreationally blue crabbing as blue crabs was a popular seafood at New York’s Fulton Fish Market. On average 120 day season Connecticut’s 1930 catch would be about 4,000 crabs/day. These statistics did not include the recreational catch then, but as previously described was substantial.

Water Temperatures Maxed Out – Habitat Compression is Evident

Everything is late this year commented an Essex Town dock crabber on August 30th. I would agree about 30 to 40 days late thought to be the remnant of a very cold spring; we entered this crab season with water temperatures 3 to 4 degrees below average and lateness continued the entire summer, and still waiting for the Megalops. In July of 2010 (Report 13, August 15, 2011) crabs hit Essex town dock around 4, 5, 6 of July, this year it was a month later around August 10th. The “doubles” showed up late also and now increasingly present in every center and eastern location. On August 30th, the water temperature was 78 degrees at the Essex Town Dock.  One of the most noticeable events this summer has been large concentration of crabs however, in deeper saline pockets in marinas. This has been noticeable in the dredged channels of Middle and North Coves, Essex. Crabs appear to be compressed at low tides in these areas (makes concentration of crabs easier to catch) and at higher tides move into the shallows. As cool nights begin, look for crabs to be less “compressed”. This warm water at low slack tide has produced some of the poorest crabbing results. At the Baldwin Bridge on September 1, 2013 crabs were noticeable in the shallows but not moving; snapper blues were also present but to the frustration of several anglers, kept ignoring bait but nosed the surface looking for that 1 inch deep layer of slightly higher oxygen and it was hot, nothing was moving. I suspected low oxygen conditions.

Look for these conditions to improve slightly and new reports of a large number of 3 to 4 inch crabs now in Clinton could even improve crabbing this fall. If water temperatures remain warm, it may signal another molt – shedding before winter sets in.

“Rusty Crabs” Now Dominate in Many Areas

One of the changes this season has been the dramatic declines in yellow face crabs, about 1 out of 10 crabs I have observed being caught are yellow face (see Report 3, June 19, 2012) but now many crabs appear rusty with rock hard shells. These have appeared in greater numbers (even some 4 inch crabs are rusty) and do not have the bright blue clean shells of early spring.  These crabs have very hard shells, are packed with meat but have not shed, and some crabbers report that they haven’t for two to three years (see special report 5, September 16, 2013) making them perhaps the 2010 Megalops set, which was tremendous.

In 2009-1010 heavy Megalops and “star” crabs were recorded in the Bridgeport/Fairfield area, but this year the number of sponge crabs reports dropped off considerably.  It may be that heavy Megalops sets are not yearly but periodic, and that one huge set could sustain a fishery for several years.

With about a month before water temperatures begin to shock Megalops into hibernation it would be a good sign to see sponge crabs and a Megalops set. Look to minnow seines for evidence of the first small crabs (Report #9 August 30, 2012) along the beach front in or near tidal creeks.

Email blue crab reports to: tim.visel@new-haven.k12.ct.us  

All blue crab observations are valuable as we learn more about our blue crab population.   

The Search for Megalops is part of a Project Shellfish/Finfish Student/Citizen Monitoring Effort Supported by a 2005 grant to The Sound School from the National Fish and Wildlife Foundation grant #2005-0191-001. 

Program reports are available upon request. 

For more information about New Haven Environmental Monitoring Initiative or for reports please contact Susan Weber, Sound School Adult Education and Outreach Program Coordinator at susan.weber@new-haven.k12.ct.us 

The Sound School is a Regional High School Agriculture Science and Technology Center enrolling students from 23 participating Connecticut communities.


[1] The low profile makes it ideal for netting crabs and setting small trot lines. It is not a vessel for the open Sound (low sides) and is a pond, bay and river boat.
 
[2] The US Fish & Wildlife Service statistical conversion for Connecticut blue crabs is 2.4 crabs to the pound. See Statistical Survey Productive Section 14, page 402 statistical Digest #44, 1957, US Dept of the Interior
 

Tuesday, September 17, 2013

2013 Connecticut Blue Crab Special Report #5 - Crabbing improves and plans for crabs skiffs available

From Tim Visel at The Search for Megalops:
The Sound School – The ISSP and Capstone Project Proposal
     Building a Network of Citizen Monitors
The Connecticut Blue Crab Population
Habitat Study 2010-2015
  You Do Not Need To Be A Scientist To Report!
The Search for Megalops
The Search for Megalops Special Program Report #5

September 16, 2013

The Sound School
Items of Interest to Blue Crabbers 
  • Connecticut River has Second Wave of Crabs – Crabbing Improves
  • Brockway Style Construction Plans Available for 12, 14, 16 Foot Skiffs – Press Release  

Connecticut River Experiences Second Wave of Crabs – Over 1,000 crabs/day now harvested from Connecticut River and adjacent areas  

Catches have improved in the Connecticut River as catches likely total more than 1,000 crabs/per day (although many crabbers feel it is much more than that).  The last two weeks a new wave of rusty – super hard shells has moved up the Connecticut River into Deep River.  Crabs have also been sighted in Hamburg Cove but no direct catch reports as yet.  The further up river seem to be the largest crabs and Essex area crab catches are now predominately “rusty.”  These crabs are super hard shells that seem to be very happy in their tight living quarters and this late in the season I am surprised they did not shed?  Only a few yellow face crabs have been observed this year.  Some conversations from crabbers have mentioned to me that a yellow face crab is two years, no shed, but rusty crabs may be more than that.  In fact yellow face crabs may turn “rusty.”  I am not certain that this is true but was mentioned to me many times this summer, but I did see that in lobsters when I commercially lobstered off Madison with my brother between 1967-1981.  In late winter, we would catch a “grounds keeper” a lobster 2 to 3 lbs in size with a dark red shell, barnacles, even small mussels.  They were hard as a rock then and shells hard scrapes, missing chunks, they looked like wrecks.  The amount of meat that came out of these lobsters however was huge, and they seemed okay also in these very tight rock hard shells.
Crabbing at higher tides has definitely been better from shore in central Connecticut, lower tides in the dredged marina channels. 
The male crabs caught in Essex on September 9th and September 11th were mostly rusty and packed.  If the waters remain warm perhaps there is enough time for a shed, and if so watch for a pulse of crabbing in early November as newly shed crabs feed heavy storing food for over the winter/hibernation.  I have had to adjust that hibernation period and now believe blue crabs now feed into December – January. 
Great news from the west!  The last two weeks have seen now good reports from Darien, Fairfield and especially Milford.  In Milford the crabbing is now good and several reports from Milford mention a good mixture of year classes, 1 to 2 – 3 to 4, and 5 inches and up.  No reports yet from the Housatonic or Saugatuck Rivers – Norwalk River has yielded just a few crabs but reports of crabs now mixed in around oyster beds among the Norwalk Islands is a good sign.
No signs of a Megalops set, still waiting for some inshore beach seine reports. 
During the warm spells this fall look for the densest concentrations of crabs in deeper areas especially dredged marina channels.  Reports vary according to the tide, temperature, and current flows.  Observations of Connecticut River crabbers indicate for shore hand liners moving tides at high tide have been yielding the best catches. 
At night at low tides seek out channels as a habitat “compression” occurs as crabs seek out slightly cooler waters that contain higher oxygen levels. 
* Workshop to Review Sound School Construction Method for a Brockway Style Blue Crab Skiff
Many crabbers the past few years have mentioned the need of a small flat bottom skiff recalling the ones formerly made at Brockway Boat Works in Old Saybrook.  Although Brockway Boat Works closed in 1997 fishers can still have a Brockway style skiff by building their own.  Although Brockway Boat Works has closed the design features that made them famous has remained.  Thanks to Mr. Earle Brockway.
In 1982, Earle Brockway assisted an international effort to replace thousands of small craft lost in typhoons by approving the distribution of his skiff construction plans.  In 1983 a 16 foot plywood skiff construction guide was made available to Peace Corps Volunteers by the ICMRD Dept of the University of Rhode Island.  In January 2010, the United States Agency for International (USAID) Development reissued the 1982 construction guide and is available for a small reprint fee.  Since that time interest in flat bottom fuel efficient skiffs has tremendously increased as they can be built at home with modest tooling.
The 14’ and 16’ guides with corrections/suggestions are available from The Sound School Adult Education and Outreach Program.  For information please contact Susan Weber, Outreach Coordinator at susan.weber@new-haven.k12.ct.us.

Since 1998 overall interest in the Brockway Style of skiff construction has grown steadily.  The design has widespread international representation and over the decades plans have been sent to every continent.  Several commercial firms offer similar designs today and acknowledged them to be based upon the Connecticut Brockway’s.  The Brockway style skiff is becoming one of the most recognized vessel types in the last century and flat bottom skiffs are renown for their fuel efficiency.  That feature alone has caused a renewed interest in them especially the Brockway skiff series.
So many crabbers during the summers of 2009 and 2010 mentioned a need for a small family style row boat for crabbing I decided to put this design to paper.  We have a CNC router at Sound School and a workshop this winter could be held if sufficient requests come in.  A workshop could include participants leaving with all the plywood pieces cut out ready to assembly on your own.  That was presented in a proposal developed as part of a NFTE class project by Sound School student, Zachary Gough also in 2010.  By 2011 the need existed for a small skiff to go blue crabbing in late summer and the Brockway old low profile crab skiff would be perfect. 
One thing that has changed since the 1970s was a huge State DEEP commitment to increase boating and fishing access.  The coastline is now dotted with DEEP boat ramps and fishing piers. Launching a flat bottom skiff near blue crabbing locations are made easy by such infrastructure that DEEP created to support fishers in our state.
Crabbing from a flat bottom skiff has been in existence here for a century.  In a middle 1970s in a book titled successful crabbing (Ernest and J. Cottrell et al IMP-Camden, Maine 1976) describes this practice on page 39.
“The rowboat is traditional for crabbing, but use any boat that allows you to stand well up in the bow and see the area in front of the boat while poling or padding along.  Generally, a small so that you can maneuver it easily and low so that you can avoid being affected too much if it happens to be windy.
It is best to go against the tide, because any muddy water that might be stirred up will go to the rear of the boat, and the crabbing area will stay clear.  Also, if a crab is spotted, it is easier to stop the boat without alarming it.  Avoid letting your shadow fall on the crab. 
With the net ready at hand, paddle or pole along slowly.  Look carefully at any little depressions on the bottom and around any obstacles.”
This is a press release being sent out in central Connecticut but some blue crabbers might want to get a first look at the 12 foot skiff plans (presently being compiled by Edward Flanagan, Senior Aquaculture Technology teacher) at an October 3rd workshop in Branford.
Brockway Style Construction Plans Available for 12, 14, 16 Foot Skiffs  

Press Release – The Sound School

The Return of the Blue Crab Skiff
Workshop to Provide Plans for Century Old Skiff Design
New Haven, Connecticut – September 10, 2013
Connecticut has recently experienced a tremendous surge in blue crab reproductive capacity in local waters. A large increase in blue crabs has created much interest in fishing for these tasty crustaceans. Decades ago Connecticut marinas had plywood skiffs that could be rented on a daily basis to go blue crabbing. They had low profiles to allow for easy dipping and hand-lining for blue crabs; low sides, flat bottoms and easy to row features made for a great day of blue crabbing in coves and bays.
Sound School Senior Technology teacher, Edward Flanagan will start a construction project that will focus upon the 12 foot low profile blue crab skiff. Sound School students will be working on two 12 foot plywood skiffs this fall.  So many crabbers contacted The Sound School last year after information was posted concerning plans for the Blue Crab Skiff (Blue Crab – Info – Forum™ posting (August 1, 2012) and other websites Connecticut Fish Talk™ and the International Blue Crab blog that we soon will have these construction diagrams available.
The last Connecticut builder of these plywood work skiffs, Brockway Boat Works in Old Saybrook closed many years ago; however the increase in blue crabs has created renewed interest in this traditional blue crab skiff.  On October 3rd, 2013 at the adult education program of ERACE held at the Branford High School, plans and design information for the 12 foot Brockway skiff will be made available. There is a fee to attend the workshop and all workshop participants will obtain construction plans/technical bulletins for the Brockway 12 foot blue crab skiff and 14 and 16 foot Brockway fishing skiffs. For more information please call 203 488.5693 or register online at: www.erace-adulted.org

Blue Crabbing was popular a century ago -

At the turn of the century it was very warm in Connecticut, and during summers it was hot.  Shoreline towns grew quickly in these summer “heats” as those that could leave the cities heat waves to spend a few weeks at the Connecticut shore did so next to cool waters and shore breezes.  During the day inland temperatures rose quickly and the rising air masses quickly caused those cooling southwest breezes.  What was at times unbearable heat waves in cities during 1880 to 1920 the so called Great Heat seemed to help the blue crab.  As summers became increasingly hot in the 1890s so did the blue crabbing increase.  The blue crabbing seemed to yearly improve from some of the 1900s shore reports (see Groton Long Point Land Company history) with each summer.  Noank, Connecticut was the place to go blue crabbing with low sided wood skiffs, flat bottom sculling (transom oar) allowed “dippers” to sneak up resting crabs at night (torch light dipping) or to the under running of trotlines with a bow netter during the day or just handling single baits often from a wood rectangular spool frame – still called “crablines.”  As the heat grew more intense blue crabs (like people) sought out slightly deeper cooler waters away from the beach fronts which at times water temperatures could be in the 80s*.  Then a low profile wood float bottom “blue crabbing” skiff became the boat of choice.
Skiffs were used at high tide in channels or at low tide looking for soft shells blue crabs long considered a delicacy.  Although Noank was once famous for its prospering lobstering center (1880s), by 1898 the lobster fishery there had largely “failed” lobstering was terrible then, the prolonged heat had killed the smallest stage four lobsters.  As the lobster sets decreased, the Blue Crabs Megalops larval stage survived by the millions.  Blue crabbing surged into the 1900s.  During this time Connecticut’s bays, coves, and river mouths contained numerous flat bottom skiffs.  These rowboats were put to use in harvesting blue crabs and poling (sculling) for crabs especially soft shell crabs mixed in eelgrass meadows became a popular activity for summer visitors.
Rowboats had become a feature of summer shore life and Groton Long Point Shore community contained in its areas a salt pond called the lagoon.  George Peck recounts blue crabbing around 1910 from a skiff in the 1970s (Groton Long Point).  “When I was a little fellow, dad took me crabbing in the upper lagoon, then a saw grass marsh.  For safety, he tied me to the stern seat.  Some how I managed to fall overboard Dad reached in, pulled me out by the hair, and went on crabbing.  He made so little of it that I didn’t know I should have been scared (Groton Long Point Fifty Years And Then Some 1971).  These flat bottom skiff were ideal for the shallow areas that then held blue crabs.
And every Connecticut shore community had a local builder of skiffs.  Some with particular styles in the Guilford area a famous builder of skiffs was Louis Jacobs of Guilford (1910) (Guilford Keeping Society 1976).  But every fishing community had its own local builder of skiffs for clamming, oystering, shad fishing or as tenders to fish traps and fish pounds.  Skiffs were a part of every fishing community.  In Men, Fish And Boats (Alfred Stanford 1934) describes New England skiffs as be constant feature for inshore fishing villages as Menemsha, Cutty Hunk the inlet to Judith Pond, Block Island among others.  The advantages of the low profile skiff would be reinforced by its selection for the cover of Popular Netcraft catalog.  In 1946 here a low profile skiff is highlighted for its ease in netting a fly cast fishing rod catch in fresh water.  Low sides and greater stability made these skiffs very serviceable for blue crabs in the 1920s.  In later years lobsters returned with cooler ocean temperatures but blue crabs yet fewer than before remained a favorite yet unpredictable summer “visitors.”
In later years in Old Saybrook, Connecticut boat builder Brockway Boat Works became a regional supplier of flat bottom skiffs and were quickly put to use blue crabbing.  The flat bottom skiffs were well known for drawing little water, easy to row and provided a stable platform from which to blue crab.
The increase in the blue crabbing has seen an increase an interest in these blue crab skiffs however Brockway Boat Works closed in 1997 with the passing of Earle Brockway.  Since that time interest in the Brockway skiff has increased and much of the earlier features, a strong durable fishing and shore work boat but in addition its low operating coast.  The hull shape flat bottomed makes it one of the most efficient fuel conscious designs today and this aspect alone has reinvigorated interest in the Brockway design in New England.
Several boat building firms now offer a Brockway style skiff.
On October 3rd The ERACE Adult Education program at Branford High School will review Sound School construction plans for this 12 foot Blue Crab Skiff.  Many crabbers expressed interest in building a skiff and the workshop will review the 14 and 16 foot skiff designs as well.
For more information please call 203-488-5693 or register online at
Email your blue crab reports to: tim.visel@new-haven.k12.ct.us
Every observation is valuable as we learn more about our blue crab population. 
The Search for Megalops is part of a Project Shellfish/Finfish Student/Citizen Monitoring Effort Supported by a 2005 grant to The Sound School from the National Fish and Wildlife Foundation grant #2005-0191-001.
Program reports are available upon request.
For more information about New Haven Environmental Monitoring Initiative or for reports please contact Susan Weber, Sound School Adult Education and Outreach Program Coordinator at susan.weber@new-haven.k12.ct.us
The Sound School is a Regional High School Agriculture Science and Technology Center enrolling students from 23 participating Connecticut communities.

* In 1901 to 1905 Tarpon were frequently caught in Narragansett Bay.

Wednesday, September 4, 2013

Juvenile Blue Crabs Numbers are Low in Maryland this Summer

From Smithsonian Environmental Research Center summer intern Katie Sinclair:

Since 2007, the Fish and Invertebrate Ecology Lab at SERC has been collecting data on the abundance of blue crabs in Maryland tributaries of Chesapeake Bay. Every summer, the lab uses crab tows—a meter-wide net on skids that glides along the bottom--to collect crabs and fish. The blue crabs are counted and measured, and the presence of fish species is noted. As part of my summer internship with the Smithsonian Environmental Research Center, I helped with the blue crab project. This year, we sampled 2 sites in each of 7 areas across the bay, doing 12 crab tows per site. Sampling took place from late June to early August. We also sampled at a new site in Herring Bay.
 
 
The average number of crabs per site was much lower than during the period from 2010-2012. For example, there were six times as many crabs in the Rhode River in summer 2012 compared to this summer (see Figure 1). This finding was consistent with the very low number of juvenile crabs reported earlier this year in the 2013 Chesapeake Bay Winter Dredge Survey, which is conducted throughout the bay by Maryland Department of Natural Resources and the Virginia Institute of Marine Sciences. The lowest number of crabs was found in Middle River, which was the northernmost site (see figure below). Because young crabs migrate into the bay from the open ocean, sites like upper Tangier Sound that are closer to the mouth of the bay and have extensive marsh and seagrass habitats often have higher numbers of crabs.

Although we do not yet know for certain why the abundance of crabs is so low this summer, evidence suggests it is due to low numbers of reproductive females during the summer 2012 spawning season.  In 2008, new protections on harvesting adult female blue crabs were enacted, which has led to higher numbers of female blue crabs in four of the five years since (according the Winter Dredge Survey). However, the winter of 2012 was the one year in which the number of spawning-age females was very low. With few females in winter 2012, it is likely that reproduction was also very low in the summer of 2012. Our survey is designed to target crabs that are roughly one year old. Because of this, it appears likely that the low number of crabs caught in our survey (and in the 2013 Winter Dredge Survey) was the result of low reproduction in summer 2012. Other factors such as weather, harvest, predation, habitat loss or water quality could also have played a role.

While it is yet unknown exactly why there was a low number of female blue crabs found in the 2012 Winter Dredge Survey,  the relatively high number of females in four of five years since 2008 suggests that the protections placed on female blue crabs are working. Long-term monitoring data from SERC’s summer crab survey, the Winter Dredge Survey and other sampling programs show that protecting the population of adult females is one way to ensure that the blue crab, an important ecological and commercial species, remains abundant throughout the Chesapeake Bay.