CTFishTalk.com: Blue Crab Report #14 - August 19, 2011 - Connecticut Saltwater Reports ( CT Saltwater Reports ) - A Community Built for Connecticut Fisherman.

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The Blue Crab Year -
The Search for Megalops – August 19, 2011- Report #14
You do not need to be a scientist to report!

Reports 1 to 13 are available – email Tim Visel at tim.visel@new-haven.k12.ct.us

• Three to 4 inch crabs reach legal size; run and catch transitions now evident;
• Heavy rains again cause concern for small crabs;
• What about the other crabs?
• Do all crab Megalops look alike?

The run has changed in all sections as these 3 inch to 4 inch crabs have shed into legal sizes. The western run is now 70% legal size, the central and eastern, about 50% legal size. It is thought that what happened last year cooler eastern temperatures slowed growth, so the western warmer areas would have a longer “growing season”. For example last summer the run at the Essex Town Dock August 30, 2010, was 95% legal while crabbers in the Pawcatuck River had a run of 20% legal. The eastern water temperature was several degrees cooler all summer long. The smaller spring 1.5 inch to 2 inch crab is now 3 to 4 inches while those June 4 inch crabs are now legal. As such catches generally have increased, we now have only 2 sizes, legal and up, and 3 to 4. What we need to see is those new 1 inch crabs, perhaps 1.5 inches by September 1st. Those small crabs should appear very shortly and in very large numbers (if the Megalops set was large).

At the same time Connecticut, especially the western sections have experienced another huge rainfall event, August 12th to 14th. Some sections received 6 inches or more of tropical like rainfall. Some central reports indicate large numbers of crabs leaving small areas at low tide by the hundreds. It could have been low oxygen or fresh water toxicity or a combination of both (see blue crab report #12, August 2). It’s too early to tell but such heavy rainfalls can kill small crabs or sweep them from estuaries, and unlike March/April, crab predators are numerous, especially large numbers of fluke. The worst case scenario is that we start to see dead small crabs on the shores of salt ponds and creeks. Those small crabs are very vulnerable to oxygen deficiencies, and heavy rainfalls. They might even be caught in those small mesh bait minnow seines in shallow areas.

I believe the very small crabs are in those shallow marsh ditches (many old ditches from previous mosquito/malaria control program of the last century) and the upper reaches of creeks. Kayakers might be the first to see these very small crabs and have obtained a few reports from kayak observations and they were very valuable, so you don’t need to be crabbing to report, any observations of small blue crabs would be a great help.

If any crabbers notice any dead or washed up small blue crabs (should be about an inch to 1.5 inch across) please send in a report- general location – shallow shore, marsh, creek central, east, west, etc would be appreciated; and of course no need to identify the exact location.

Any female crabs or especially female egg bearing sponge crabs, reports would be helpful. The past few days’ crabbers have been mentioning the absence of female crabs, everyone except for a couple of reports mention catches as nearly all male.

As I watched blue crabs and its population dynamics this summer, questions have been asked about species -- not that much is known about other crabs or populations other than the paper I referenced a few months ago: Spider Crab Podding Behavior and Mass Molting (DeGoursey and Stewart, 1981). This often brings up the question of other edible crab species here and one that has come up many times this summer. In several visits to Niantic Bay, for example, I have talked to and watched several families actively engaged in catching green crabs as food. Green crabs (Carcinus maenas) – green males and red/orange females. From time to time, I have heard this before, but my conversations this summer have been different; it is a fishery although small; it is a food catching activity.

In my visit to Niantic Bay (River) this summer I was amazed at the size of green crabs – they were huge. The green crab, a species native to northern Europe arrived about a century ago and devastated the soft clam fishery (steamer clams) in New England. It is still a serious predator of small clams and oysters and also predates upon bay scallops. It is a favorite bait (food) of black fish (tautog), and I’ve spent many hours harvesting them for local bait and tackle stores, and also for my fishing. So it was surprising to see such delight in landing a huge green crab (when I used to toss them back) and throwing away the size desired for blackfish bait; when I asked about it – the response was, “too small, let it get bigger”. The five gallon pail was half filled with gigantic green crabs. When I explained I was looking for blue crabs, I was told these (the green crabs) were better! I wasn’t that surprised, because I had seen similar crabbing off the Point Judith Pond Breakwaters in Rhode Island years ago.

In the Open Sea, by Sir Alistair Hardy (1959), he mentions this green crab fishery in England on page 144: (The green crab is invasive to our waters, an import from Europe a century ago) in the Channel Islands. The edible crab – the Rock and our Jonah crab is also described by Hardy (pg 145) as a fishery and we have two similar species (Atlantic Rock Crab – Cancer irroratus – reddish brown) and (Jonah Crab – Cancer borealis – red to purple top). In Maine it is a large fishery (picked crab meat) called Peekytoe. Rhode Island from time to time sells large rock crabs as an incidental catch to lobstering; also a deep water species called Red crab is a huge crab and very good eating (Chaceon quinquedens). These crabs however do not keep as well as lobsters and need very cold seawater systems. (See Sound School publication #21 on our website: http://www.soundschool.com/directory.html titled Gravity Fed Self Regulating Bio- Suspended Solids Pillow Filter for Crab and Lobster Tanks). Other native crabs are also edible, when working for the University of Massachusetts, a friend invited me to an evening meal in his home town of New Bedford. It was a wonderful Portuguese meal, a fisherman’s stew served with whole (but cleaned) lady crabs. Sometimes called the calico crab, they have spotted shells, smaller than blue crabs but with very sharp claws. These are the same bad attitude crabs that I ran into numerous times while swimming in Madison, so it was of interest to see them cooked and they were delicious. I found out that such whole crabs were considered a delicacy and some modern pasta sauce dishes include whole blue crabs.

But the lady crab (Ovalipes ocellatus) was especially delicious and tasted more like lobster than crab. I was very surprised having seen lady crabs along the sandy beaches so many times. I would suggest however extreme caution picking these crabs up, it’s like they are double jointed and can bite you quickly with very large claws. I feel they are faster than blue crabs and more dangerous.

Other crabs are also edible, the green crab: males green, females red/orange (Carcinus maenas), the Atlantic Rock crab, (Cancer irraratus) - reddish brown and the Jonah crab, Cancer Borrealis, red to purple top.

Of the two “ground crabs” Jonah and Rock crabs, it is the Jonah crab that is the larger of the two and is the one harvested in Maine, Rhode Island and Massachusetts. At this time the Maine crab fishery has grown in importance and now some 2.5 million pounds of crabs are harvested yielding several million dollars. I had a chance to visit Maine last week and had a Graffam Brothers Seafood, Rockport, Maine crab roll and it was excellent. Rhode Island lands Jonah crab and from time to time, a deepwater red crab. If you ever have a chance to taste red crab, do not turn it down; it is also delicious (Chaceon quinquedens). The landings of Rock and Jonah crab are thought to be small in Connecticut. Now for large spider crabs, (Libinia emarginata), yes, they are edible, in fact very good. After pulling thousands of them from our wooden lobster traps with my brother Raymond (1970s), we decided to try them. They are not the smaller crab found in the shallows close to shore; these 4 to 6 inch diameter crabs were in 50 to 70 feet of water. We picked out a dozen of the largest crabs; they look like a smaller king or snow crab. First, forget the legs/claws; the only portion that contains meat is the body section. Also, don’t think you can boil them like lobsters and blue crabs, their shells are not clean like blue crab or lobsters, but very muddy at times and covered with seaweed. We tried cleaning them (shells) but that didn’t work, well what did work was cleaning the crabs before cooking so you just boil the cleaned body sections. The picking was a challenge, the body sections are thick, but large hard shell crabs were packed with meat and when prepared in a crab salad, was very hard to distinguish from blue crabs, and in fact, it was very good. The marketing of these large “spider crabs” was a failure however, and this experiment was only practiced in years in which blue crabs were scarce and we wanted some fresh crab meat sandwiches.

Note, before crabbing in other states, always be sure to check fishing regulations. Most states have some regulations, size, season and permits. For example, it looks like from some of the Internet material the state of Maine issues both a recreational and commercial Jonah crab license -- best to check before crabbing. Connecticut, for example, does issue commercial blue crab licenses with the same gear provisions for a fee, while CT recreational crabbing remains no fee, free; same season, same sizes, etc.

One interesting section in Sir Hardy’s book, the Open Sea, Fish and Fisheries is a description of the Rock/Jonah crab fishery and one that sounds very similar to a blue crab, almost incredibly so, and one that doesn’t really fit Rock or Jonah crabs as swimming crabs, but he describes their behavior and habitats. (If you look at these crabs, they don’t look at all like the swimming crabs, and it’s hard to imagine them mass moving but they do).

“The crabs are actually more inshore animals in summer than in winter. In autumn, they migrate offshore into deeper water where the females extrude their eggs and attach them to their small abdominal appendages, in the spring they return to shallow water carrying their eggs which hatch in June and July into little Zoea larvae. In addition to this to and fro migration, some have been shown by tagging experiments to migrate considerable distances along the coast, journeys of 90 miles have been recorded.” (pg. 145)

It’s hard to imagine a Rock or Jonah crab as moving such distances, they look more like a tank than a race car, but they do. And if something that looks like a tank can travel such distances what about a crab that is nicknamed “beautiful swimmer” and blue crabs can really swim and fast. I can recall last summer crabbing at night and watching them swim by on the outgoing tide and they were moving! I hardly had time to pick up the crab net and they were gone.

At this time I’m getting more and more reports of large deepwater totally male blue crab populations – moving – in 15 to 25 feet deep water. The boaters with crab pots are doing quite well and good catches of large male blue crabs in many areas. Catches are being made in the 15 to 25 foot river channels, some dense concentrations in the west and occasional good catches in the Mystic River. The shore areas especially shallow water remain slow – it could be just too warm, not certain. What is interesting is the absence of female crabs; they are rare in recent catch reports.

Do all crab Megalops look alike?

I had a crabber ask that at the Sheffield Town Dock in Old Saybrook and it’s a great question (and I might add, one of a number of good questions this summer). I don’t know; I have seen many more green crabs with “sponges” so they must have a Megalops set, and lady crabs also; to be honest, I’m not certain. We might be seeing 3 or 4 different types of Megalops so we will really need that online video key. We might be able to short cut this effort by looking for habitats that blue crab Megalops prefer, shallow bands of sand that contain living immature soft shell clams, steamers. There is some evidence that the blue crab Megalops seeks out this habitat, the movement of the clams may leave chemical clues or waste products or siphon “noise” but numerous references mention Mya beds or estuarine shell as ideal habitats.

Most habitat references indicate it’s the shallow areas, the ones with cover, eelgrass perhaps other submerged vegetation that will allow the maturing crab to hide, or burrow. This zone is also frequented by two very aggressive predators, the Killifish fundulius species and sand shrimp, Crangon septemspinosa. It is thought that the blue crab Megalops seeks out or survives best in areas with estuarine shell, both clams and oysters to escape these predators.

One word of caution, it is expected that in searching shallow areas for crab Megalops, monitors will discover occasional sets of shellfish, oyster, soft shell clam (steamers) and perhaps quahogs (seed) as well. Although it is important to note the presence of such clam sets, shallow areas along the coast are usually closed to shell fishing and need a permit to harvest and retain them in the open or certified areas. Shallow areas even beaches can have high counts of bacteria after heavy rains and shellfish living in such waters do not meet state and federal harvest regulations. Many crabbing areas have signs notifying the public that shellfishing is not allowed. This concern has been the subject of some lengthy discussions at our Long Island Sound Habitat Restoration Committee, that the public is now largely unaware of a substantial Connecticut soft shell clam resource (the sets the past few years have been very strong). Recent visual surveys off the Town of Westbrook have shown clams in many areas.

But at the same time we have seen an increase in blue crabs; we have seen soft shell clams sets increase also, with the ever mentioned habitat association between the blue crab and Mya (steamer clams) and warmer Long Island Sound temperatures; it is a habitat association that is hard to ignore. A century ago here in CT between 1890 and 1920, summers were then particularly hot, blue crabs and steamers did quite well during this period. The soft shell clam sets in Clinton Harbor, lower Hammonasset River in 1900-1902 were some of the heaviest in our fishery history. The 1898 statewide oyster set was the set of the century and blue crabs became very prevalent along our shores. Rhode Island officials noted this also in Narragansett Bay a century ago and commissioned a special study to investigate the sudden increase in soft shells and blue crabs in 1905. The RI report printed in 1906 details the increase of soft shell clam sets, a surge in blue crabs but also dramatic drops in bay scallops and lobsters. The thirty-sixth annual report of the Rhode Island Commissioners of Inland Fisheries, January session, 1906 E L Freeman & Sons State Printers (336 pages) contains this section- The Continued Examination of the Physical and Biological Conditions of the Bay [Narragansett] begun in 1898, page 106-107.

“On Cornelius Island, in Wickford harbor, the (soft) clams set extremely thick in 1904. In the protected area, the clams were so thick at the time of setting, that there was not room for the growth of all of them, and so, as they increased in size, many were forced out upon the surface, so that in a short while, the ground was thick with (dead empty) shells --- Another case in point was observed at Greene’s’ Island on the east shore of this island is a long flat which in 1901 was set so thickly with clams that 7,910 were counted in a single shovelful.”

Clam / oysters (all shellfish) collected as part of the Blue Crab Study should be noted but not retained, and returned as soon as possible to the location sampled.

For now please continue to send in those observations and any locations of female sponge crabs and smaller crabs. Even if it’s just one sponge crab, every observation is important.

Observations this year will help guide the survey methods for next year.

Every observation is important you do not need to be a scientist to participate!

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.

All observations are valuable; please email them to me at tim.visel@new-haven.k12.ct.us.

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