Thursday, August 16, 2012

CT 2012 Blue crab report #7

From Tim Visel with The Search for Megalops:

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 7 – August 9, 2012
You Do Not Need To Be A Scientist To Report!


·         Crabbers move to deeper cooler waters – boaters seem to do better – Central CT crabbing shifts as summer temperatures rise.
·         Dipping for crabs by torchlight, Noank, CT at the turn of the century; Blue Crab Skiff Plans available soon.
·         Keep those crabs alive! The knuckle bander process. Crabbing surges in central Connecticut.
·         Regional differences become apparent – concerns for Megalops set in Western, CT.


Crabbers move to deeper, cooler waters

Most of the crab catches from shore now occur at high tides: two crabbers commented, “It’s getting too warm- water temperature.”  A couple of crabbers last year reported a change over from place to deeper areas when water temperatures hit 72⁰F; after that they used a small skiff with crab pots.

Central CT catches at low tide decreased measurably and many small crabs are caught then.  This was especially the case in the Clinton/Madison area which saw the numbers of just 5 inch crabs suddenly increase; many were still too “short”.  A Clinton Harbor crabber retained 23 crabs, but estimated he had returned over 50 small crabs.  Dozens of small 3 inch crabs were observed at both the Oyster and Indian Rivers; crabbers at the pier next to the Baldwin Bridge DEEP boat launch also commented about the dramatic increase in small crabs.  Obtaining the “bottom” temperatures seemed like a good idea, especially if the 72⁰F temperature is a border line perhaps for larger crabs.  A slight modification to an inexpensive thermometer and a crab line with a 2 ounce sinker gave me a quick way to check some temperatures at some popular blue crab locations over the weekend.

Saturday, July 28 – Temperature readings.

Essex Town Dock Deep end – 6 feet, low tide 79⁰F: 11:40 a.m.
Essex Town Dock Shallow – 1 foot, low tide 79⁰F: 11:50 a.m.
Rt. 95, Baldwin Bridge, Old Saybrook; DEEP Fishing Pier, shallow end 78⁰F: 12:01 p.m.
Old Saybrook, Sheffield St. Town Dock (North Cove) 75⁰F 1:02 p.m. (DLW)
Old Saybrook Route 1, Oyster River Dredge Cut 74⁰F 3:24 p.m. DLW+ 2hours
Westbrook Town Dock, Hammock Rd 72⁰F 3:38 p.m. mid tide
Clinton Public Crab Dock, Indian River 74⁰F 4:28 p.m. high tide
Clinton Town Dock Riverside Ave. (Hammonasset River) 72⁰F high tide

Catches in the 72⁰ to 74⁰ range were better than higher; Essex crabbers left with no crabs at low tide; I was surprised to see how warm it was.  However, high tide was a completely different matter with 7 and 8 inch crabs at high tide.

About the middle of August last year, crabbers moved to deeper cooler waters, but with this year’s heat, we may be seeing that shift earlier.  The warmer temperatures did not seem to bother the two inch crabs which surrounded shallow water baits.  Crabbers that had baits into deeper areas commented that it was better at high tides.  It’s thought that cooler waters come in with the tide, and cooler temps, higher salinities, and perhaps increased oxygen levels help adult crabs’ more than the smaller ones.  Crab respiration increases with temperature, a rise of 10⁰ C, the respiration roughly doubles; in other words, a respiration rate of 68⁰ F is twice that at 50⁰ F.  Warm water contains less oxygen so the perception (observation) that larger crabs move to deeper cooler waters has a basis in biological fact.  Seawater at near freezing can contain 12 mg of oxygen per liter of water, but at 86⁰ F can drop below 5 mg/liter.  Extremely high temperatures can kill marine organisms by suffocating them.  I see some first time crabbers trying to keep large 7 and 8 inch crabs alive in a small pail of warm water.  Occasionally many of the crabs perish in such small amounts of hot seawater, and frequently suggest a cooler with an ice pack keeping crabs cool and moist rather than in small water pails.  It’s a frequent mistake but directly related to warm water suffocation on a much wider scale; we usually call such widespread events as die offs and frequently they occur during the hottest period of summer water temperatures.  Crabs (and lobsters) have the ability to alter metabolic processes out of water if kept cool and moist can survive for many hours and if given the choice will avoid such oxygen containing water.  These warm water die offs are frequently found in the blue crab historical fisheries literature.

In Alabama and even in Chesapeake Bay, extremely low oxygen in coastal waters often records blue crabs walking out of them, sometimes by the hundreds of thousands.  In southern areas this event is known as “Jubilees,” thought to reflect the ease in capturing a potential dinner.  In the Chesapeake they are known as crab wars.  When faced with extremely low dissolved oxygen, blue crabs emerge and can crawl out of the water (Blue Crab- Callinectes sapidus by William F. Van Heukelem, University of Maryland).
A mini “Jubilee” occurred in Connecticut a few years ago noticed by residents of Niantic Bay during very hot period in August.  Stagnant hot algae filled water became oxygen depleted.  Blue crabs headed for land in apparent effort to escape the low oxygen waters and died in the process.  The account is in the WTNH (Channel 18(archives with the title: “Crabs Picking Land Over Niantic Bay”.  On August 7, 2009 this was reported by Jamie Muro from the description of Niantic River algae blooms and reported air temperatures; it’s a safe bet that hypoxia killed blue crabs in shallow water.
Connecticut River crabbers (pots) now report very good catches and crab floats – pier areas have been good also.  The shore hand liners, catches at low tide here have been much lower than at high waters – Central CT crabbing has been generally good, better than last year. The large increase in small 3 to 4 inch crabs is a positive sign for even a better fall fishery.

Dipping Crabs in Noank at the turn of the century – Nighttime netters from small skiffs count crabs by the bushel.

12 ft Blue Crab Skiff Plans available soon from The Sound School

Numerous accounts from the turn of the century (pg 645, The Crab Fisheries US Fish Commission Bulletin, 1887) talk about dipping crabs by torch light in a two person row boat.  A small skiff with a forward torch and dipper with a rear sculler, a single oar mounted to a pin or leather strap.  This allowed the boat to be propelled quietly from the stern (sculling) while allowing the person forward to have a clear view to net crabs (the water must have been a little clearer back then).  The coves and shores of Noank 1920s are frequently mentioned for catching blue crabs from flat bottomed skiffs.  These skiffs were often low profile craft that could be both rowed- two oars or skulled with one rear oar.  Sculling itself was quite an art but having watched a couple of fishermen do it, it was quite effective, especially in shallow water.  You could push and direct the skiff quickly from the transom, often standing, to see what was ahead and receive signals from the “dipper” in the bow.  Several late summer dock conversations the past two years had crabbers wishing to reach the deeper and cooler waters of late summer to catch crabs, but unable to do so, for lack of a small flat bottom shallow water skiff.  When asked about it, I’m partial to the Brockway design, a flat bottom plywood skiff once produced in Old Saybrook, CT.  The Brockway skiffs originally were built to the design of the Connecticut River Duck and Turtle boats of the last century.  They were low profile skiffs, excellent for duck hunting and setting and hauling turtle traps then.[1]

But today the design survives for many fisheries, and sports fishing is one of them. Originally built as an oak frame planked skiff, at Brockway Boat Works of Old Saybrook, it was later changed the planked vessels and gave way to the plywood skiffs wide and narrow versions of various lengths.  In the middle 1950s higher sides added to make them suitable for use in the open Long Island Sound.  I used an old low profile (1959) Brockway in high school, a 12 foot skiff built in the tradition of the successful Connecticut River Duck and Turtle Boats (also called CT River Guide Boats as for use by hunting camps in the 1920s). 

This skiff belonged to Charles Beebe, late of Madison, who continued to use it for river fishing until the 1970s.  I have it now thanks to Bruce Beebe, and should have the design plans shortly.  It is a transition skiff built in the old thwart and riser style but out of high grade marine plywood.  As it is a low profile version it makes an excellent blue crabbing bay and cove skiff- sculled or rowed.  Cost of a vessel has been a concern, especially in today’s times but this skiff can be built by a handy person requiring just a few power tools.  It can be built from higher grade exterior A C plywood and standard pine stock from a lumber yard or home improvement store.  Two larger high sided versions a 14 foot skiff and 16 foot skiff plans are already available on our website.  Plans and directions, “How to Build a Brockway Style Skiff” were first published in 1982 and reprinted and can now be found on our school website: for the 14’ Brockway, #35 and corrections #36; the 16’ skiff at #40 and corrections #41. These skiffs are the higher sided version, not the low sided skiffs for the rivers and coves a century ago.

Many people have built Brockway style skiffs from these plans and pictures /plans are available at no fee.  If you are interested in seeing what this vessel is like, one of the few surviving Connecticut River duck and turtle skiffs can be found at Essex, CT.  During the Great Heat 1880-1920 warmer winters and unusually warm springs caused a surge in game bird populations – geese, rail and brant duck (bird) hunting became big business as out of state hunters turned to local fishermen to guide them into the Connecticut River marshes.

For those interested in this unique CT River skiff design only a few survive to modern times.  The best example of this skiff I have found can be seen at the Connecticut River Museum Steamboat Dock, 67 Main Street Essex, CT. (http://ctrivermuseum.org).  It is in the small house boat exhibit room and dates from the 1920s.  This 16 foot skiff was used for bird hunting (rail and brant) in the Connecticut River marshlands was sculled allowing access to the bird hunters at the bow seats.  The skiff is on display at the Connecticut River Museum and is in outstanding condition and belonged to Captain Suter a local CT River guide (rail boat circa 1920s).

Unfortunately Brockway Boat Works closed in 1997 with the passing of Earle Brockway and the availability of these hard chine flat bottom plywood skiffs has lessened.  They did not draw much water, allowing them into the shallows, and could be beached with ease (non-extensive keel structure); rolled on planks, rowed well (coves, creeks and bays).  Having spent many hours in Mr. Beebe’s 12 footer blue crabbing, the low profile version allowed easy netting.

Years ago some crabbers will recall several Connecticut marinas had fleets of plywood Brockway’s for rent to crabbers and snapper blue fishermen.  Clinton Harbor’s Holiday Dock for instance once had a collection of Brockway’s, but no longer.  However many Brockway’s have been built from the 1982 University of Rhode Island/United State Agency for International Development (USAID) that Mr. Brockway approved for Peace Corps efforts).  Several Brockway style skiff builders have shared their experiences (and learning curves) on the Internet.  Some even built them for resale.  In 2010, United States Agency for International Development reissued the 1982 Brockway skiff construction manual and is available at: http://pdf.usaid.gov/pdf_docs/PNAAN485.pdf

So, if you have modest power tools and are handy at woodworking, you will find that a Brockway style skiff for crabbing is rarely surpassed.

If you would like to obtain a set of plans, let us know. We have put the 12 foot skiff plans (FFA Entrepreneurship Boat Building Kit) in high gear and they should be ready shortly.

If you would like a set of plans mailed to you for the cost of postage, or emailed to you free, please clearly print your email address and they will be sent when the plans are ready.
If you send us your home address we will send a hard copy to you when they are ready, and we request postage if mailed to you.

The 14 and 16 foot skiff Brockway plans are free on our website.  For those interested in learning more about the Peace Corps Brockway effort, please visit our publications directory at www.soundschool.com/directory.html  For the 14’ Brockway, see #35 and corrections #36; for the 16’ Brockway, see #40 and corrections #41.

For fishermen wanting to learn more about the Brockway boat yard, Brockway Boat Works or the Brockway style of construction, the Branford Adult Education Program will hold an evening workshop on Building a Brockway Style Skiff on Thursday, November 15th at Branford High School.  Please enroll at www.erace-adulted.org or call 203 488 5693 for more information.  There is a fee of $39 for the presentation and includes a discussion of the Brockway boat with PowerPoint slides of the Brockway, (the boat yard no longer standing); additionally copies of the 14’ and 16’ Brockway plans are included with the registration and will be given out during the class.  The last presentation had former and present Brockway owners exchanging accounts of both Mr. Brockway and the Brockway skiff uses.

As August temperature approaches, look for the deeper cooler areas for the best crabbing. Shoreline hand liners should look for higher tides.

Keep those crabs alive! Crabs are valuable as seafood. Catches surge in central CT.

I have seen several pails of blue crabs likely wasted this summer in the high heat.  Blue crabs will attack each other in a bucket and in the water for that matter and if crushed or cut can quickly bleed to death in high heat and absent water (which helps clot the blood).  It is easy to miss because it is not red blood and had therefore hard to see but claw loss is visible and a sign of injury. This has occurred when very large 7 and 8 inch crabs mixed with smaller sizes.

Dead blue crabs and lobsters spoil quickly in high heat and out of oxygen containing water (thus the extensive live lobster retail trade today and dropped claws and separated abdomen will “fan out” exposing the once covered thorax exoskeleton.  If the crab is limp and appendages dangle, it is most likely spoiled.

What works is a cooler with some of those pre-frozen ice packs and a series of wet cloth towels – one ply so that the cloth can “breath” – cloth dish towels work great.

Crabs covered in moist cool cloth will be relatively motionless (if not disturbed) and can be kept alive for many hours.  Sometimes I see crabs buried with bags of ice, but the fresh water (if not drained) can kill crabs, and super chilling does bring the crabs’ metabolic rate to very low levels.  Such cooled crabs may appear dead, but given some time to warm up, (not hot) will become active again.

One of the ways to reduce post capture mortalities is to reduce the fighting and killing capacity of the crabs themselves; similar to the lobster industry, by banding them.  My son Willard and his friend Dave Krug in 2010 came up with a system that worked for them.  Willard took his old lobster banding tool and those small lobster rubber bands and after a few trial and error attempts, banded the knuckles (elbow) joint, but not the claw, which is very different from the lobster banding/industry.  With the knuckle banded (using the scissors like lobster bander) which still required rubber gloves the crushing and tearing capacity was greatly reduced if not eliminated.  No longer could the crabs reach out on foot and leap to attack other crabs in a pail/bucket or crabbers for that matter.  After banding a few crabs, it’s a relatively quick process but it immediately cut down on crab waste.

At Clinton Harbor, I watched a bucket transfer which consisted of one mass of tangled and biting crabs clinging in dead grips.  Because the shells were so hard, the shells were not mangled but claws were sliced and crushed in the process only attending to the blue crabs “bad temperament.”   It’s a little more effort to band and requires a banding box, (six to eight inch high plastic tub) a lobster industry bander (we discovered that a wider tap helped spread the band a little better.  (Some of the jumbo crabs in 2010 were so big it was an effort with the standard size lobster band) Blue crabs are placed in this large shallow plastic tub banded and then cool stored.  One word of caution, several crabbers have given excess catches to unsuspecting observers, perhaps not knowing crabs can bite, but in my mind (and 15 years of inshore commercial lobstering experience) lobsters are much safer to handle then blue crabs.  The public expects lobsters to be banded at commercial fish markets etc, and they are much slower than blue crabs.  This probably is the reason the live lobster market has accepted (banding) and live blue crab market never established banding (to my knowledge).  I have heard too many horror stories of people sticking their hand into a “gift” of blue crabs only to emerge into 2 or 3 clinging to hand/fingers.  This will most likely leave the gift recipient with a lifelong memory and a not to pleasant one at that.  Although few crabbers use them I always used rubber gloves when banding; once banded they are quite easily grabbed from the rear.  They can still pinch but cannot fight.  In summation, blue crabs are hard to handle and the larger the crab the worse it gets.  The very hot weather here has led to some significant loss of crabs and there just too delicious to waste.  I have sent a description of the blue crab knuckle band process to Blue Crab Info at http://www.bluecrab.info/forum/index.php and CT Fish Talk at http://www.ctfishtalk.com/ and the blog Blue Crab Forum run by Dr. Matt Ogburn at http://bluecrabblog.blogspot.com/2012/07/2012-connecticut-blue-crab-report-6.html
If you are interested in this process please look at the sites.  They also have crab reports, crab industry discussions and crab research information.

The central Connecticut crab fishery has surged with large crabs.
Late reports mention only a few crabs in western Long Island Sound but Niantic Bay and Thames River, Mystic River have isolated reports of blue crabs. Some Mystic River catches reported from other sources have been “good.”

Regional Differences in late July become apparent – concerns for the survival of the western Connecticut Megalops set.

Regional differences became apparent – central sections now see many small crabs, western areas report few to none; and concerns for Megalops set in western Long Island Sound has been the mention of many crabbers.

The continued absence of post Megalops blue crabs in western areas is becoming more than a question – is now a concern with extremely warm April and May temperatures, small post Megalops crabs (those inch crabs) should have been noticeable by July 1 – July 15, at the latest.  Instead it has been very quiet as per crab catches/observations.  This is at the same time the central sections finds a good supply of overwintered adults (mostly males) in late April and numerous smaller females – June to July.  Reports of western CT blue crabs have been very few so far this year.

The west is apparently missing in the adults’ overwintering size – 5 inches and up, the 3 to 4 inch year class (overwintering 2011 Megalops); the 2 inch size (spring/summer 2011, Megalops sets – and most likely an early Chesapeake drift set and a possible later fall native Connecticut set).  And now a possible Chesapeake Bay early Megalops that set this spring and now is about a 1 inch across (suggested post Megalops growth starting May 15).  We should see another surge of 1 inch crabs this fall from a “native” sponge crab hatch in August-September.  These could make 2 inches by December while the inch size crabs at present (in central sections) could grow to 3 to 4 inches before colder temperatures set in.  All of these growth patterns are dependent as reported by numerous blue crab researchers upon water temperature water quality and food availability.

Why the disappearance of western CT crabs?  That remains an open question; certainly the 2011 crab year was greatly reduced in the central and eastern sections after the somewhat harsh cooler 2010-2011 winter.  However, 2011 saw the west with dense blue crab populations early in the season that appeared to move east as the summer progressed.  This was especially the case in the Norwalk and lower Housatonic Rivers.

With the recent information, barring only sudden changes most of the western crabs did not make it for a number of possible reasons- making observations of this area very important.

If you go crabbing west of the Housatonic River and don’t catch anything, the observation is important.  The appearance of small blue crabs post Megalops set, would be a great sign for next year.  In general best blue crabbing by far appears to be between West Haven and East Lyme at the present.

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


[1] The nighttime torch dip net fisheries were well established in southern states after the Civil War, but as the blue crab became prevalent in Southern New England, the practice spread north (1900s).  In oral history the bays and coves are frequently mentioned in the Noank area (See the US Fish Commission Report, The Crab Fisheries pg.645, 1887 by Richard Rathbun).

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