[BlueChip]

The Connecticut Blue Crab Population and Habitat Study 2010-2015
The Sound School – The ISSP and Capstone Project Proposal
Building a Network of Citizen Monitors
The Search for Megalops
Report 8 – August 16, 2012
You Do Not Need To Be A Scientist To Report!


• Megalops Hatch underway -females shed sponge eggs and head up estuaries to join males – “Time of the Doubles” soft shell catches increase.

• Connecticut’s First Crab Fisheries – Did Native Americans leave a history book for species and climate shifts? Developing a Connecticut habitat history may include The Blue Crab.

• Western areas must rebuild populations – Megalops set key to the Western CT 2013 Crab Year. 2012 Megalops set could be huge.

• Public asked to look for Chinese Mitten Crab – a potential invasive species for Connecticut. DEEP and Connecticut Sea Grant ask for your help.


Megalops Hatch Underway; Females Shed Sponges and Head Upriver – “Doubles” Appear in Central Connecticut

Crabbers were pleased to see very large jimmies with sooks or doublers after August 10th. Soft shell crab catches greatly increased in central Connecticut. One Old Saybrook crabber termed it “time of the doubles.” Female crabs are leaving the mouths of rivers and creeks and moving up to join with the males. Expect some of those 4.5 inches crabs now to shed into legal sizes. The changes in Central Connecticut were dramatic and widespread.

The number of “doubles” at Essex Town Dock jumped over the weekend with about half of the legal crabs now protecting a pre-shed female. Reports from Old Lyme, Clinton, Madison, and Guilford all mention the change. The lower estuaries are now filled with 2 inch and 4-inch crabs – making certain the fall fishery will be a good one. “It’s not like 2010, but better than 2011” commented a veteran crabber at Essex. In 2011, crabbers languished with catch rates fewer than 3 crabs per hour while 20 crabs per hour this year was not uncommon. After 5 hours of crabbing, he had 65 large blue crabs – a mixture of sevens, some eights; he felt he had broken the state record with a 9.25-inch crab (he had pictures) from a recent trip.

Hand liners except at the highest tides are catching mostly sublegal crabs, sometimes two or three at a time. Hookups occur often but in deeper holes or river bends on the outgoing tides. The line feels heavy and crabs frequently can be coached to the shore or dock floats but as soon as they are lifted off the bottom, they let go of the bait. This happened to me in the Indian River, Clinton and could be related to a water temperature difference. The hole at which I had the bait in was 71 degrees, a perfect temperature, but at the dock it was 76 degrees at the surface and brackish. After about a dozen hookups with serious resistance pulling them into shallow water and lifting only to have the crab let go was somewhat frustrating. One theory was as soon as they felt the warmer fresher water on top they let go. Another crabber said those are big males with a female and to protect the female, they won’t leave the bottom during the day. Not certain which one was correct, but it was frustrating none the less. After an hour of crabbing I left with 2 legal (barely) crabs and returned 22 shorts. The change in population composition the past week was quick and many conversations mention a tremendous change in smaller crabs at river mouths and an almost simultaneous increase in the doublers upstream.

Shoreline crabbers at high or moving tides have done well the past seven days with very large crabs but the still and low tides prove the most challenging. The best crabbing continues to be in Central Connecticut at high tides – of the 17 crabbers I spoke with during this period, all of them had caught crabs – (Central Connecticut Coast).

Western Areas Must Rebuild Populations – Megalops set key to 2013 Crab Year
2012 Megalops set could be huge

2012 Megalops set from female crabs here is now thought to be significant- perhaps with intensity not seen since 2009, Western Areas must rebuild populations that have been lost. People will remember the summer of 2009 as very hot, sometimes so hot to reflect upon water quality and habitat sustainability- (reference report #7 “Blue Crabs Pick Land over Niantic”). We had a hot summer (2009) algal blooms occurred and intense bunker (menhaden) fish kill happened from low oxygen in the Branford River, but the Megalops set must have been intense because the number of 2 inch crabs that next April was tremendous, something not seen here for nearly a century. This summer we may have another great Megalops set- we had a record number of sightings for female “sponge” egg carrying crabs in mid June, especially in Bridgeport/Fairfield and the Clinton Harbor areas. The prevailing winds have largely been from the southwest, perhaps adding to a potential Chesapeake Bay drift set, courtesy of the Gulf Stream.

With the warm temperatures the west sections may see a huge set of blue crabs- which should be about an inch across now- and could possibly reach the 3 to 4 inch size by October- setting up for another huge 2013 crab year. It would take a huge set for the west to replace all the year classes apparently missing- gone for some reason (see report #7). It seems, the west has to start all over again. It is still too early to say what happened, but some of the crabbers reported the signs of a major blue crab die-off last August and I minimized it, believing it to be just fresh water poisoning from thunderstorms. Now I believe I was wrong. I reviewed the reports from last year and the crabbers who were very concerned, and in several reports repeatedly said they saw huge numbers of dead crabs, might have been reporting on a much larger and serious event- a major blue crab die-off- several weeks before Irene.

From the Megalops report #12 of 2011 Western CT Blue Crab Observations from crabbers

July 27th- 15 keepers, 3 soft shells; observed about 75 crabs total, 80% 1.5 to 2.5 inches; 10% 3 inches and 10% legal size; The bottom dropped out of catches turning sharply negative then followed by reports of dead crabs on July 26, 27, and 28th. Even the run distribution changed after positive numbers: western 50/50 about half of the catch was now legal and even in central sections for the first time it had dropped to 75% legal and 25% sub legal, western and central reports count/keepers surpassed the teens, had climbed into the 20’s and some even higher. Eastern Reports are so few I can’t comment about catches in general, then the heat and heavy rains hit with one/two punch and catches/reports dropped and turned negative. If reports continue to mention dead crabs especially that 1.5 to 2 inch crab that could impact the remaining blue crab year, I’m not certain.

Some reports mentioned a 50% drop in catches compared to the last trip and some after catching a few crabs simply gave up. Just a few days before these areas were good to excellent. Several reports mentioned the dramatic difference in water temperatures and clarity. The water near shore felt “hot” or the area was full of brown water. Three veteran crabbers report of seeing whole dead crabs the following two days. After heavy rains two other in central areas expressed concern for what had been relatively quiet tidal areas, were now for a period a “rushing torrent of brown water- hot brown water no less.”

“Water was really warm for the first time in 10 years of crabbing here or better, I saw a good number of dead crabs.”


Something happened to these crabs and it is in the millions- what we catch with a string and chicken leg is just a small portion of the total population. I don’t think anyone would argue that the methods we use in CT can be termed as highly efficient, and in dense concentrations of crab it is effective, nevertheless. The population of Blue Crabs in western CT long Island Sound was significant in 2011 but now are gone- they have been lost. Why? I can’t guess but this only signifies how important user groups (crabbers) observations can be- and I missed it. About 10 reports mentioned dead crabs after rains, some crabbers, one in particular, said he had never seen such numbers of dead crabs in many years of crabbing in western CT and was very concerned about the fishing for next year- he was correct. It is a poor year to date in the west.

To the crabbers that were concerned about seeing so many dead crabs last July and August, your fears and concerns were apparently justified. It’s been a century since Blue Crabs were prevalent here and we are just beginning to learn what that means- habitat wise to have them. That is why I often mention that every observation, every catch report, every survey is important. The above observations illustrate the significance of these reports.

If the Megalops set survives in the west this summer that would be a great sign for western CT crabbers, perhaps not for this year, but for next.

Connecticut’s First Crab Fisheries – A History Record from Our First Fishers? Could blue crab be an indicator species for climate change. A Science, History, and Archeology – Research Project for High School Students.

One of the things I have experienced this vacation and dozens of conversations with blue crabbers is a large influx of new crabbers – some have lived in Connecticut for many years and this is their first summer crabbing.

A few conversations have pointed to Connecticut’s fishery history – and knowledge about blue crabs, including everything from “I didn’t know blue crabs lived in Connecticut” (a frequent statement) to a surprise of the extent of the current blue crab population (It is huge). Some were even shocked to see the numbers of blue crabs in a given area such as the Clinton, Madison, and Guilford shores.

The Clinton Harbor area within the Indian, Hammonasset and Hammock Rivers, the present blue crab population (all year classes) is estimated in the tens of thousands. The smallest crabs are rarely seen, so the true extent without shallow surveys is difficult to estimate, but a dense blue crab Megalops set can be millions.

Clinton has several productive crab fishing locations and its one of my frequent stops this vacation. Questions eventually include Long Island Sound, its relative health, and the many years of news reports about the lobster population declines which is currently at very low levels. How could blue crabs be so abundant and lobsters so scarce?

When you examine Connecticut’s fisheries history, you do see patterns of fisheries abundance related to climate, temperature, and energy. It is thought that for blue crabs and lobsters 1998 is a key transition year. (Fishery production statistics for climate change see paper “Blue Crab Great Years – and Then None?” September 8, 2010)..

Clinton Harbor is a good study area as it contains both a “core” history in its salt marshes and evidence of Connecticut’s first fishers – a local Native American people called the Hammonassets. Coastal Native Americans were very aware of New England’s coastal marine resources “seafood” and the first clam bakes are attributed to them. The shad bakes (roasts) still celebrated in the Essex/ Old Saybrook area is another direct descendant of earlier fishing practices. They appreciated nature’s bounty and we know that fish and shellfish were important food sources. Therefore, Native Americans may have left a historical record for us about long term climate, temperature, and energy system impacts to fish and shellfish populations. The resource use record therefore may mirror habitats, a “habitat history.” We call those records today shell middens - heaps of discarded shellfish shells, oyster, clams, and bay scallops, but also blue crab remnants, conch shells, and fish bones. Blue crabs might be a good indicator species of climate change or pronounced habitat shifts.

In times of great heat (which we are presently experiencing) shell heaps (middens) might contain greater numbers of blue crab claw tips, soft shell clams, and oysters – all do better in dry and high heat periods. Layers of lobster beaks, hard shell clams, and bay scallops could signal colder, more energy filled periods. These species do seem to change prevalence (positions) in more recent habitat histories. At the turn of the century midway into The Great Heat (1880 – 1920), the soft shell clams sets following the 1898 Portland Gale are legendary in Clinton Harbor. Bay scallops had long since disappeared from the much colder and stormier 1870s. It is hard to believe Greenwich, CT being a huge producer of bay scallops, but it was in 1872 – when it was brutally cold here. As the temperatures warmed after 1880, bay scallops and lobster populations retreated north and collapsed in the late 1890s. Blue crab, oysters, and soft shell clam abundance then soared.

Bay scallops would return to Connecticut and in record abundance during the New England Oscillation (also termed the North Atlantic Oscillation) when colder winters and powerful storms raked Connecticut’s coastline (1950 to 1965). The 1950s saw record cold, a huge increase in powerful storms but bay scallop production soared. Bay scallops like cold and energy – it helps maintain their habitats. If these climate and energy relationships have a habitat/ prevalence or connection they might be apparent in those shells heaps. When hot, blue crabs, soft shell clams, and oysters become abundant. In cold periods, lobster, hard clams and bay scallops reign. Coastal Native Americans so dependent upon seafood would observe changes and perhaps left us a history of their seafood use as long-term environmental fisheries history – hopefully the alkaline shells have buffered our acidic soils so that such a habitat history record still exists. Even the process of dipping (netting) blue crabs at night so productive here today appears to be an old one, and related to spear fishing.

In a 1958 National Geographic Story of Man Series – Indians of the Americas, Matthew W. Stirling refers to torchlight fishing on pg. 50 – mentioning the importance of seafood to the Algonquin culture.

“In summer, the usual spear fishing method was for two men to out in a canoe at night. The man in the stern paddled while the other speared fish attracted by the light of a bark torch in the bow.”

If this sounds familiar to the early turn of the century blue crab dipping, it should. Fishing by light at night is an old practice but an abundant supply made the practice worthwhile (it was productive). It is the change in abundance and assemblage relationships that midden remains may provide. The study of middens may answer some of our questions about climate change and habitat conditions for both cold and warm water species.

Taking this concept forward will involve high school students reviewing the available scientific records (fisheries) and archeological studies of the past century. This would include a full review of Colonial fishing records until present.

Most of our Connecticut fisheries history is currently stored at the DEEP Marine Fisheries loft in Old Lyme, CT. It represents the largest continuous fisheries records from the first legislative acts of the 1870s to the State of Connecticut Fish Commission to the formation of the State of Connecticut Department of Fisheries and Game to the present DEEP Marine Fisheries Division. In a recent meeting it was asked that this proposal be sent to other scientists, historians, and archaeological practitioners in Connecticut in support of perhaps a much larger environmental habitat history project for the state. That process is currently underway. One of the species proposed as a key habitat history indicator is blue crabs.

It is a multiyear project that has enormous environmental study benefits from monitoring climate habitat shifts, global sea rise, and contains fisheries management implications.

I would be pleased to respond to any questions at Tim.Visel@new-haven.k12.ct.us

Public asked to look for Chinese Mitten Crab – a potential invasive species for Connecticut. CT DEEP and Connecticut Sea Grant ask for your help.

Press Release: On August 3rd, the Connecticut Department of Energy and Environmental Protection and Connecticut Sea Grant issued a press release asking for the public’s help in identifying a potential invasive crab species. The Chinese Mitten Crab (Eriocheir sinensis) looks to be larger than the green crab (Carcinus maenas) also an invasive species and similar looking to the Purple Marsh crab (Sesarma reticulatum) found consuming salt marsh vegetation on New England marshes.

Distinctive in appearance are its claws (although I have never seen a live specimen) which have hairs on them that look like “mittens”. This is a species that grows to enormous densities and travel in “pods”. With the body carapace it can be 12 inches across including the legs.

The press release is reproduced here for any crabbers that have seen some of these crabs- please, a “do not release” request is in place. Directions for reporting if you catch one is included in the Press Release. Look to this website for detailed information including photographs: http://www.ct.gov/deep/cwp/view.asp?Q=509026&A=4174

A few key paragraphs are below:

The Department of Energy and Environmental Protection (CT DEEP) and Connecticut Sea Grant today confirmed that a juvenile Chinese mitten crab (Eriocheir sinensis) has been found in Connecticut waters. In late June, the crab was collected from the Mianus Pond fishway on the Mianus River (Greenwich) by Joe Cassone, Conservation Assistant for the Town of Greenwich Conservation Commission. The crab was first delivered to CT DEEP’s Marine Headquarters in Old Lyme, and following examination by CT DEEP and CT Sea Grant biologists, sent to the Marine Invasion Research Lab of the Smithsonian Environmental Research Center for a confirmation of the initial identification.

“This discovery is of some concern,” said CT DEEP Deputy Commissioner Susan Frechette. “In high densities, these crabs can damage fishing gear, clog pumps and intake pipes, cause riverbank erosion through their burrowing activities and out compete native species for food and habitat. However, these crabs are relatively new to the Atlantic coast, and at this time it is unclear as to what their effects will actually be.”

“It’s important that people keep an eye out for these crabs and report them,” says Nancy Balcom, Associate Director of Connecticut Sea Grant at the University of Connecticut. “Early detection of new species in our marine or fresh waters can help lead to more options for control and spread prevention. In 2010, there was a reported sighting of a crab in a pond near the Mill River in Fairfield that may have been a mitten crab. Unfortunately, we were unable to catch that crab to confirm its identification.”

Chinese mitten crabs’ claws are of equal size; all but the very smallest (<1 inch shell width) appear to have dark fuzzy growth on the claws with whitish tips (hence the name “mitten crab”). The smooth shell or carapace is brownish to greenish, up to approximately four inches across, with four spines on each side and a notch between the eyes. Total crab size, including legs, can be up to 12 inches. Individuals finding a crab that they suspect to be a Chinese mitten crab should keep the crab on ice or freeze it (please do not release the crab), note the exact location it was found, and contact CT DEEP Marine Fisheries (860-434-6043), CT DEEP Inland Fisheries (860-424-3474) or CT Sea Grant (Nancy Balcom, 860-407-9107). Any crab found in fresh water should be investigated, as there are no freshwater crabs in New England.


Thank you for all the reports – every observation is valuable as we learn more about our blue crab population. Email blue crab reports to tim.visel@new-haven.k12.ct.us

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.

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

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