Friday, July 27, 2012

2012 Connecticut blue crab report #6

Here's Blue Crab Report #6 for The Search for Megalops:

The Connecticut Blue Crab Populations 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 #6 – July 19th, 2012
You Do Not Need To Be A Scientist To Report!

·         Connecticut DEEP confirms pesticide residues found in lobster tissue (organs) – blue crab concerns – my view;
·         Megalops set survival confirmed by many reports –small crabs abound in central Connecticut – Connecticut River crabbers doing well;
·         What’s happening to Connecticut’s blue crab populations?
·         Catches increase for central shore hand liners and trappers; where to crab;
·         Western CT, still has few crab reports; discouraging news from the Norwalk River;
·         Thanks for your reports!


This report was delayed for several days after the Connecticut Department of Energy and Environmental Protection (DEEP) announced the results of September 2011 testing that found residues (trace amounts) of Methoprene and Resmethrin in lobster organs.  Questions and dock discussions immediately turned to blue crabs health and potential impacts (if any) to Connecticut blue crab populations, especially the Megalops life cycle for blue crabs.

Blue crabs by their very biology and life cycle habitat requirements live next to and in salt marshes, the same areas that were reported to be treated with pesticides to reduce the West Nile virus threat (mosquito vector control).  At this time it appears that Connecticut switched treatment procedures in 2011, but additional testing is reportedly underway for lobsters.  No direct concern about blue crabs has been made in media articles.

The impact of insecticides upon lobster populations as claimed by lobster fishers for decades here needs a review, especially in high temperature, low salinity, low pH areas.  In 2010, I reported two instances of pesticide suspected impacts to blue crab populations- one in 1971 and one in 1982.  The report titled “Where Do All The Blue Crabs Come From?” dated December 2010 was made available in January 2011 and it is program report #2 for the Search for Megalops.

Without extending this discussion and delaying the report further, we’ve posted Report #2  for any blue crabbers interested in this topic on the web sites CT Fish Talk, The Blue Crab Forum and the Blue Crab blog run by Dr. Matthew Ogburn. 

Dr. Eric Schott of the University of Maryland Center for Environmental Science who also reached out to crabbers here on blue crab health issues before has also obtained this information.  (See reports #3 and#5 this year).

As a member of two Long Island Sound Study committees, to the CT lobster fishers who continue to report their concerns, my appreciation, confirming “You don’t need to be a scientist to report.”  We do need to know much about our shallow water habitats for many species.
Tim Visel

Small Crabs in Central Connecticut – Waves of small crabs reported.

After July 8, I obtained several reports of the first ¾ inch to 1 inch size blue crabs and its large numbers – perhaps in the millions.  On July 11th, what could be described as waves of small crabs were observed along the central coast.  Starting in Milford/West Haven on July 8th ending with small crabs in Guilford on the 10th and further reports from Milford and West Haven reporting huge numbers of small crabs on the 11th and 12th.  This is the first news about the Megalops over wintering set; it did survive both the stormy summer and October blizzard and should be the 3 to 4 inch crabs by September (next years legal crabs). 

The two inch and 3 to 4 inch size crabs also inched up along with the legal catches.  Look for crabbing to increase for central Connecticut it’s looking like a better crab season than 2011, still too early to tell about the east but historically the past few years crabs mature later about a month after, from cooler water, so what has been good crabbing in Clinton on July 15 has been August 15 for the eastern state – Pawcatuck River fishery.  The western areas continue to have few reports of legal size crabs, but one observer made an excellent comment:  the inch to ¾ inch crabs might still be present; they just don’t show up in the crab nets, the mesh size is too big and the small crabs just fall out.  That comment was followed by another:  that seine net surveys might be a better way to determine Megalops and small crab survival at least the first few weeks of the summer and I agree.  Use of a seine net is a better way and one used in the southern crab producing areas, good suggestions!

While catches continue to increase for hand liners and pots (traps) the central sections show improved numbers of small crabs running 2 to 1 to 3 to 1.  Crabbing in these areas will improve.

The great news is that the ¾ to 1 inch size is starting to show up and in large numbers!  Still waiting for any news about crabs in the west, particularly between the Housatonic and Norwalk Rivers, excellent blue crab areas in 2010 and 2011.  Two recent reports from the Norwalk area report few or no blue crabs as yet.

What’s happening to Connecticut’s blue crab populations – more about lobster and blue crab habitats

While watching quite an active Baldwin Bridge DEEP fishing pier (Old Saybrook side) over the weekend, and discussing recent catches one crabber came over and asked me, “What’s going on with Long Island Sound?”  He had caught 17 large blue crabs in an hour (not a complaint) while years ago that was a day’s catch.  I agreed and the recent newspaper accounts of declining lobster populations were a concern.  How could the crabbing be so good and the lobster populations be in such tough shape?

Several crabbers have asked about the abundance of blue crabs and lobster declines recently.  Part of the explanation of why crabbing in CT has been good for the last two decades and lobstering has not, is habitat quality.  I think it is important to include two key factors which are frequently overlooked in terms of historical habitat patterns, and fisheries abundance combining energy levels and temperature.

At the turn of the century it became very hot in New England (The Great Heat 1880-1920) and at this time blue crab abundance soared while Connecticut’s lobster population crashed.  We have good historical resources from the Biennial Reports of the CT State Board of Fisheries and Game that describe regional efforts to build lobster hatcheries at the turn of the century to replace post “Megalops” stage 4 lobsters.  All the New England states built lobster hatcheries between 1899 to 1910; all of them even Maine (New York also later).  In fact, the Maine facility in Boothbay Harbor Maine was the largest ever constructed in the US releasing hundreds of millions of stage 4 lobsters and “fry” into the environment and coastal waters.  Connecticut fishermen felt the lobster hatchery effort had helped and testimony from individual fishers and fishing families has survived in the historical literature, abstracted from the 1911-1912 ninth biennial report.  Since the lobster population crash, (1898 to 1905), by 1910 fishermen noticed increases in small lobsters and made comments about the increase of small lobsters in 1912. 

Report of the CT Lobster Hatchery (Started in 1905) for the Period of 1911-1912 – comments from fishermen (Guilford) pg 14, see footnote.
* Guilford – “As my figures show I have caught very few large lobsters and very few egg lobsters this year, but there is no question in my mind as to the increase of small lobsters, and that is due to the hatchery work.  Whether these will be permitted to remain in the water long enough to grow to legal size, is another question which I cannot answer, but I fear not all of them will.” (1912 comment)

* Guilford – “The marked increase of small lobsters is very gratifying, and is sufficient proof that the hatchery is one of the greatest institutions in the state, and I shall do all I can to help the Commissioners of Fisheries and Game in the protection and propagation.” (1912 comment)

* Guilford – “I never saw so many small lobsters in my life as there is this season.  Why don’t you try to pass a law so lobstermen have to space the slats further apart?” (1912 comment)

And page 16 is the following report (1912- lobster hatchery)

Noank Station in procuring the eggs for the operation of this station the same general policy has been pursued as heretofore, by purchasing the adult lobster with the egg attached.  These were collected from the fishermen the entire length of the coast, who are paid the full market price.  After the eggs have been removed and placed in the hatching section from which they originally were taken.  The fry hatched from the eggs are plated in the waters of Long island Sound, as near the same locality as possible from which they were taken.

During the biennial period 1,474 ripe egg lobsters have been collected, from which 25,585,990 eggs were obtained, resulting in the hatching of 22,750,000 fry which were planted in the coast waters.

During this same period there were also collected 1,586 green egg lobsters, making a total of 3,060 egg bearing lobsters collected, of which number 1,586 were held in cars during the winters, and the balance, 536, were returned to the water.

In the seven years of the operation of this hatchery, 208,761,870 fry have been hatched and liberated.”

Although Connecticut’s lobster hatchery effort was commendable it paled in comparison to the Maine Lobster Hatchery at Boothbay Harbor, in seven years 1905 to 1912, Connecticut procured and spawned out 4,500 eggers for about 209 million lobster (fry).  The Maine facility was spawning out almost 3 times as many eggers (14,000 each year) for hundreds of millions of Stage 4 lobster and fry each year.  Eventually most of the hatcheries released Stage 4 to help increase survival.

[State of CT Public Document No 19- Ninth Biennial Report of the State Commissioners of Fisheries and Game for the years 1911-1912 to His Excellency the Governor and the General Assembly, Hartford, published by the State 1912].

I think what we are experiencing today is a massive heat/energy habitat reversal.  As temperatures warmed, the habitat quality improved for blue crabs (I estimated that in 2010 Connecticut contained between 80 to 120 million blue crabs) and declined for lobsters.  This habitat reversal (failure) resembles the period between 1898-1905 – lobsters crashed and blue crab populations increased.  Key to this is the blue crab Megalops if it also finds Connecticut’s habitats more favorable and the reports this June and July of huge numbers of female sponge crabs also needs to be taken into consideration.  Is this new habitat/fishery territory- no not from examining the historical fisheries / literature, we have experienced this before.  When it got colder in the 1950s and 1960s, lobsters increased and blue crabs declined.

Catches Increase for Central Connecticut shore hand liners and trappers

What started off as a regular reporting period grew more complicated after July 10th.   Crabbing was generally good, shoreline potters and hand liners were observed with catches between 20 to 30 adults.  A Clinton Harbor catch (July 12) saw over 40 adults between 6 and 7.5 inches (I measured some with permission).  Catches at the DEEP Bridge also was good; this is the DEEP Old Saybrook Boat Launch facility.  This includes a large public pier which is excellent for families wanting to crab, but on weekends (July 14-15); I found the pier packed – a count of 42 crab traps alone.  Early mornings were the best; some crabbers were leaving around 7 a.m. reporting the best catches between 1 to 4 a.m. in the morning.

All the reports indicated the incoming tides are the best – slack tides “awful” and keeping baited traps on the bottom less problematic.  It’s about this temperature last year-- the deeper area channels and river bottoms became better for crabbers.  It was felt the warmer temperatures were not the best for crabbing on the shallows and after July 30 last year shore crabbers did better at night than those during the day.

Look for deeper water for the best catches in a few days; crabs move if it becomes too hot.  For example, the Lieutenant and Black Hall River crabbing occurs mostly from boat fishing just north or south of the bends. A local river trapper would set crab pots on the edges at the depth he would “strike (find) them” and at the bends tidal action tended to create these “holes”; (he declined to provide the location of his favorite deep sets).  Some of the best crabbing areas recently have been in dredge cuts made in tidal rivers, the one just north of Route 1 Bridge, Clinton side, on the Hammonasset River and just north of Route 1 Bridge Old Saybrook, Route 1 Bridge Oyster River.  The tidal dredge cut at Westbrook north of Route 1 has legally been posted, no crabbing.  This occurred during the 2010 crab season which saw crabbers seeking out “pole crabs” – those who were found clinging to pilings and dock floats and the increased use resulted in the postings (closures). Access to the water and crabbing spots has been the subject of many questions:  I would like to go crabbing where should I go?  One of the things that I have learned is that crabbing is hard to predict, it may be good one day and dismal the next.  The other question is access and CT DEEP has funded and built some excellent crab and fishing docks, an overall state shore guide is found at: http://www.lisrc.uconn.edu/coastalaccess/ 

Certainly a good family starting blue crabbing place could be the DEEP Marine Fisheries Dock/Pier Old Lyme, adjacent to the DEEP Marine Fisheries facility and the DEEP fishing pier at the Baldwin Bridge boat launch – Old Saybrook side slightly upriver.  Both sites are excellent for beginning crabbers and critical to providing public access to Long Island Sound.

As catches increase in Central Connecticut look for deeper access for best catches.

Western Connecticut Discouraging News – Almost no adult blue crabs!

Western CT crab reports are few and limited to sightings not catches in Western CT. Observers continue to report few if any crabs.  Aside from a few sightings in the Norwalk River the west has few blue crabs.  One observer who has been checking the Norwalk River (thank you again for all the reports) weekly has seen no crabs and no crabbers.  This is in stark contrast to the 2010-2011 seasons.   But as the summer progresses crabbing yet may improve, but it is discouraging to some crabbers nevertheless.  Key to the west aside from some salt ponds is the Housatonic River which had large sublegal populations in the salt marshes last year.  The first reports of large numbers of small crabs came this year from the east not the west which is also in opposition to the 2010-2011 seasons.  In 2011 the Housatonic River mouth was suspected in providing millions of small blue crabs that moved east and west with the tides and Bridgeport was one of the first early report locations last year, this year no adult crab catcher observation reports.  Female sponge crabs were reported earlier but soon left, perhaps for deeper water?

Any western crab reports would be greatly appreciated even if you went out and did not catch anything.  Just reporting the crabbing effort is a help.  News/observations of small blue crabs in the west, especially west of the Housatonic River would be especially important.


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

Program reports are available upon request, 1-4 catch/observation reports 1-15 are also available from last year.
For more information about New Haven Environmental Monitoring Initiative or for past reports please contact Susan Weber, Sound School Adult Education and Outreach Program Coordinator – email to: susan.weber@new-haven.k12.ct.us
If you would like to receive these Blue Crab reports, ask to be placed on the email directory.

If you do not wish to receive these reports, please let us know.
Looking forward to hearing about any Blue crab research.

Tim Visel

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.
Watch for the Megalops Portal on The Sound School website http://www.soundschool.com/
The Sound School is a Regional Agriculture Science and Technology Center that enrolls high school students from 23 cooperating towns.

Thursday, July 26, 2012

Do crabs in Long Island Sound contain pesticides? A historical perspective.

The following is from Tim Visel, contributor to the CT blue crab reports you'll find posted here.

Subject: Habitat Information for Blue Crab Fishermen- Pesticides and Blue Crabs – Megalops Program History Report #2, December 2010

The first part of July 2012 had regional news and media sources revealing that residues of two pesticides (trace amounts) had been found in sick/dying Long Island Sound Lobsters.  Connecticut lobster fishers had for decades expressed concern over mosquito control programs and the chemicals included in them.  The point of record being lobsters (and blue crabs) belong to the same insect family as mosquitoes- thus what could be damaging to them could also potentially impact both food producers and the health of lobster in Long Island. Many crabbers have asked about potential blue crab impacts, not confirmed at present.

One of the questions raised in Program Report #2- The Search for Megalops December 2010 was two personal accounts of suspected pesticide impacts to blue crab populations’ decades ago.  This report is being made available to crabbers/others who wish to learn more about blue crab habitats and possible chemical impacts to blue crab populations – especially after the Long Island Sound lobster media reports.

There is no information available currently regarding CT blue crab health on this issue.

There is no fee to obtain any of the program reports, 1 to 4.
For more information about the Search for Megalops, contact susan.weber@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 – email: susan.weber@new-haven.k12.ct.us


Where Do All The Blue Crabs Come From?
The Search for Megalops
Tidal Creek Clam Beds and Blue Crab Monitoring
Student Research Projects

Tim Visel, the Sound School – December 2010
The Need of an Environmental Fisheries History for
the Blue Crab Program Report #2
Blue Crabbing in the 1960s Central Connecticut

Growing up in Madison, Connecticut blue crabbing was always a high point of my summer vacation.  In our house soft shell crab was a special meal, but hard shell crabs made a great salad for sandwiches.  We used what everyone else used to catch blue crabs, a piece of fish, a section of twine and crab net-- a modest low tech gear to say the least.

The big unknown was would there be any blue crabs in the creek by the cottage we rented.  Some years were great and then some years none.  We never knew until we arrived, the question was where there any blue crabs?  Tom’s Creek in Madison was a typical saltwater creek – nothing really special except it was located at Webster Point in Madison next to the Marsh summer cottages.  Mr. Marsh the original developer of the cottages built a series of modest summer rentals (no heat but a fireplace) on the east side of Pent Road at Webster Point in Madison.  Originally a salt water farm owned by the Webster family, the parking lot for the cottages was adjacent to a salt marsh and in the middle of that marsh was Tom’s Creek at the west end edge of the Hammonasset State Park.  The creek was the key factor to our blue crabbing efforts, we rarely saw them along the shore but in the creek was a completely different matter.  Tom’s creek was a supermarket of seafood species, at high tide eels, snappers, flounder, at low tide clams, oysters and of course crabs.  At high tide we would cast fish heads on twine from the banks and at low tide seek the soft shells hiding beneath blades of sea lettuce.  Some years were great crabbing drawing dozens of Hammonasset State Park visitors to crab along the banks of Tom’s Creek.  We didn’t visit Madison in the spring but mostly July/August and by that time most of the crabs were five inches point to point.  It was with great anticipation that crab nets were loaded at Hamden for the trip to Madison.  Upon arriving the question was always the same did the blue crabs also arrive?

It was a good question because despite a previous good crabbing season the next year it could be few or none. For decades now, I always wondered why?  It would be two decades later that I would begin to put the pieces of the puzzle together which I might add is still very incomplete, but the better question is when does the blue crab larva arrive and better yet from what egg supply from which the larval stages are hatched? 

It was always a hit or miss with blue crabs in the 1960s but if the blue crabs weren’t in the snapper blues were in, so we always had something to catch and moved on.  But in wasn’t that easy with dad, he loved to crab and soft shells was a favorite.  So the absence of crabs in later years was more a problem with him than with my brother Ray or me.

Mosquito Spraying and Blue Crabs

It was 1971 or 72 that the first serious questions in my mind were raised about blue crab production.  We were commercial lobstermen at the time and my father announced that there were no blue crabs in Tom’s Creek.  We weren’t really surprised because of years past but this year was different.  He had seen people crabbing in Fence Creek, a smaller but similar creek to the west very close to East Wharf, Madison, where we had lobster pots.  He asked if the next time we went by to pull in Fence Creek and check it out.  We did several days later.  The usual treatment of a blue fish head and twine anchoring above the first bed over the oyster beds; we let two heads in – almost immediately they were covered with 2 to 3 inch (point to point) small blue crabs.  We had never seen so many small crabs.  Ray and I just looked at each other.  After just a few minutes we confirmed what our father had reported: over the oyster beds were tens of thousands of little blue crabs, some just an inch across.  We left the creek and returned the next day.  Next week Tom’s Creek became an active Blue Crab population.  It would be years later that I would put some of the habitat pieces together.            

First, the presence of small blue crabs over the oyster and clam beds of tidal creeks and the absence of small blue crabs along the open beach front.  In all the seines (minnow seines) we did along the Webster Point beaches for decades mostly failed to produce one immature blue crab.  While similar seines in the creek produced quite a few small blue crabs, I came to realize that ecological differences and habitat conditions of the shellfish beds provided perhaps more suitable habitat.  While the open areas of the beach did not (we would have picked them up in seines we frequently caught a smaller crab – with a calico shell we called lady crabs (Ovallipes ocellatus).  Secondarily, that something had happened to Tom’s Creek that had turned that environment at least temporarily against them (blue crabs).  Tom’s Creek had soft shell clams, hard shell clams and oysters such as Fence Creek, the tidal range was identical, no observed difference in salinity or temperatures.  Nothing I could think of could explain why Fence Creek, 1.25 miles away could have tens of thousands of blue crabs while Tom’s Creek had none – not one it seemed.  We tried to catch one but couldn’t on at least two attempts- not one crab.   

The difference in blue crab abundance between the two creeks was hard to explain.  We thought about it and it was my father who offered up an explanation.  Earlier in the spring the mosquito hatch had been quite severe along Hammonasset meadows and into the park camp grounds.  It was the practice back then that such heavy mosquito outbreaks were followed by spraying insecticide.  He concluded that some of it got into the creek and killed the small blue crabs (“Silent Spring” was one of his favorite books).  It was hard to ignore his theory but I doubted that this was the cause of the absence of blue crabs.  However our transplanted Fence Creek blue crabs did very well and were of source of large blue crab adults for us and numerous others from the Hammonasset State Park.  We would watch blue crabbers come and go and think of our blue crab transplant, why? 

In 1982 I would change my feelings about the blue crab and insecticide link.  On Cape Cod more than once I was called into investigate sudden die offs of crabs – green, fiddler and blue crabs.  In the two cases in Falmouth each was connected to watersheds containing cranberry culture/bogs.  On one occasion at Green Pond I noticed a cranberry grower applying chemicals to a nearby field – it was an insecticide.  The heavy blue crab mortality had occurred just after a heavy rain.  As soon at I noticed the cranberry bogs I thought of Tom’s Creek (after Ella Grasso’s administration the spraying for mosquito control was sharply curtailed) and the possibility of insecticide application could harm crabs, which in the Green Pond case had apparently also killed green crabs and fiddlers in large numbers. Since my employment at the University of Massachusetts, Cape Cod Extension Service, the cranberry industry has embraced IPM, Integrated Pest Management. Later that summer (1982)Green Pond would go anoxic and killed many small juvenile flounder that lived on or near clam beds – shell cover - something that has been found also in Connecticut habitat studies with bivalve shell litter a decade later.  Small flounder prefer shelly bottoms so did it seemed blue crabs on Cape Cod did also.

If Fence Creek had blue crabs and Tom’s Creek did not, this explanation insecticide seems plausible, but the next question was where did the blue crabs in Fence Creek come from and if they arrived into the creek in which form, we have never seen such large numbers of juveniles moving along the shore, perhaps they are easy prey for many species.  Instead we became suspicious that blue crabs arrived in our creeks as a very small microscopic stage and settled into habitats similar but not identical to the Chesapeake Bay setting among shellfish and clam populations in the creeks.  That would explain the sudden appearance of small blue crabs in April/May but that would need a female blue crab spawning population (tremendous) from the previous year.  We began to ask, where do all the blue crab eggs come from?

Standing Stock Populations – Annual Megalops Production Outside of Connecticut

Carrying Capacity for Blue Crab Habitats in Connecticut

The blue crab is amazingly fecund organism for its relatively short life span; a female crab is capable of producing up to 2,000,000 eggs in an abdomen egg sack called a sponge.  Similar to our lobsters here, this protruded egg mass is carried by the female until the eggs ripen and hatch.  They then are at the mercy of tides wind and currents as a planktonic crab larvae drifting or wandering.  The carrying capacity is limited by the size of the female spawning population and sufficient habitat after zoeal (microscopic) and Megalops stages six to 20 days later.

At the end of Megalops, blue crabs settle to the bottom and take on both pelagic and benthic characteristics they walk and swim seeking out lower salinity areas and shelter from numerous full salinity predators with plentiful food.  They need shallow somewhat protected areas often found in creeks. It is thought that tides and waves would kill Megalops set along the beachfront. It is at this time that blue crab in response to rapid growth begins now a lifelong shedding process, casting away exoskeleton (its shell) as a new soft shell is created.  Female soft shell crabs are especially vulnerable to predation so instinctively hide until the shell is hard in 5 to 10 hours.  They can be captured often protected by a clinging hard shell male.  It is at that point that fertilization often occurs.

Egg hatches vary as to temperature, in the Chesapeake region an early June hatch can produce visible blue crabs by August and three months later, November crabs can be 1 to 2 inches across.  In Connecticut, our populations reflect a much different story, we do not see millions of 1 inch crabs in November and December, and we now often see them in March or April, why?

In the 1980’s, and while working with Project Oceanology, a nationally recognized marine environmental educational program based in Groton, CT, we sought out the location of female crabs that had egged out or had developed a sponge.  We trawled the mouths of the Thames River and Poquonnock estuary, Pawcatuck, Hammonasset and East River systems in search of them.  We found a few but not the tens of thousands or millions that it would take to provide the survival necessary for the crabs now observed in CT.  That has matched observations from the recreational fishery itself; female sponge crabs in the 1960s were a rarity in Connecticut.  In decades of consistent shore crabbing I have only seen a few sponge crabs here in Connecticut, Rhode Island and Cape Cod.  Many crabbers mistakenly think that a darkened (apron) abdomen is an egg bearing female.  It is only considered egg bearing when the sponge egg sack is truly extruded.  Since high school, I have wondered why there are great population changes in blue crabs, some great years and then none.   They live to be 5 to 8 years; a good year should be followed by another?   In 1974, I asked the State for an experimental license to trap blue crabs for commercial purposes, noticing a pronounced fall migration out to deep water.  During this time my brother Raymond and I fished about 120 lobster traps between Clinton Harbor and the East River extending out to Faulkner’s Island. In the fall, we would catch large blue crabs; I began to believe that they don’t make it. So to me, in the 1970s it was resource going to waste.

Every year it seemed, in late November and early December we started trapping adult blue crabs in our lobster pots, first along the shore and finally in deeper water.  A local fisherman, John Walston, operated an eastern rig trawler out of Guilford Harbor confirmed this migration.  Mr. Walston, a commercial fisherman utilized a Wilcox flat net otter trawl primarily for catching winter flounder.  His towed area was between Kimberly and Faulkner’s Island and produced fresh winter flounder for local fish markets (1960s).  He also sold lobster bait and my interest was in that area.  While still in high school, I asked him about the blue crabs on deck and although he considered them a nuisance to his flounder business, he saved them for people he knew.  The area that he fished was the spot that female “blue crabs go to die”.  His words were to the effect that none make it out alive.  Asked when that happened, he responded February/March, “the starfish get them.”  That was the Kimberly reef area. My suspicions were apparently confirmed our blue crab year was a year-to-year event.

If none returned, then how was the reproductive cycle continued and if we have a great blue crab year, such as this one (2010) that must have needed a substantial female “sponge” population in 2009.  By 1988, after the Project Oceanology cruises, I was convinced that our population was perhaps not really “ours” but from somewhere else.  Perhaps connected to a transport system, we call the Gulf Stream.  My 1974 efforts were based primarily on resource waste and a new commercial fishing opportunity.  If large numbers of blue crabs were going to be eaten by starfish as claimed by Mr. Walston and other commercial fishermen, then returned females could not egg out, they didn’t have a chance.  Large numbers of “sooks” with eggs just didn’t happen in our waters (1970s).  In other words, the blue crabs not caught in the recreational fishery using primitive gears never returned and they ended up as a meal for hungry starfish instead. In 1978 I resubmitted a second proposal for a boat only Chesapeake style trap fishery October 1 to December 1, which was declined.  (It was thought that uncaught crabs returned to the same location following year.)

In the 1980s Gef Flemlin of the New Jersey Sea Grant Program then began working with Gulf Stream currents.  He documented those large rings of cyclonic rotations of warm water that on occasion would break away and sweep warm waters northward hitting the area between Long Island and the Cape.  It immediately hit me- that is where the eggs are coming from – down south from the Chesapeake Bay.

Bill Wilcox working for the University of Massachusetts Cooperative Extension Service and later the Martha’s Vineyard Commission has offered the same conclusion as a possible Megalops source (2005); his report is on the Internet.

“In the Chesapeake, the larvae (called zoeae) exit with the ebb tide and spend 30 to 45 days on the inner continental shelf passing through a number of life stages in the planktonic community. The final stage is only 1 millimeter wide.  They then metamorphose into the Megalops stage.  This stage is capable of swimming to the surface at night and downward during the day. At the right time it migrates vertically in the water column to ride wind driven currents as well as flood tide water’s back into the Bay.  There they look for an opportunity to settle into aquatic vegetation.  The Megalops stage lasts 6 to 20 days.  At the end of this stage, the Megalops molts into a juvenile crab (J1 stage) that is about 2.5 millimeters across.  It is likely that the crabs we recruit while a summer inlet is open originated from other ponds possibly quite remote from the Vineyard.  The combination of prevailing southwest winds, northward flowing Gulf of Stream as well as eddies and gyres that break loose from the Stream could transport them from several hundred miles away during the 50 day plus or minus planktonic stage.”[1]

The question remains if we do obtain Megalops from the Chesapeake region when do they arrive and where or what habitats do they prefer.  That is where high school marine science classes can help, they may be able to find them.  A logical place would be tidal creeks with living clam and oyster populations.  Samples of the bottom (not shellfish) could contain very small Megalops stage blue crabs.  That would necessitate a soft bottom community assessments and the use of a key to identify species.

Some of the assessment methods used with a very successful DEP program – Project Search might be suitable here.  Project Search has developed fresh water sampling techniques for use by volunteers and schools.

That program perhaps can be modified for an estuarine study – The Search for Megalops.

A second component would allow a seasonal boat only Connecticut River experimental trap fishery (not the hand operated pots) but the chimney style Chesapeake Bay “chicken wire trap”.  If large numbers of crabs did not return and are consumed by predators or killed by storms, it is a source of fresh Connecticut seafood going to waste?  Local CT River fishermen have often reported that the crabs never return in early spring- too much fresh water but did mention the local assemblages (mostly female) over wintering location off the Stonington Harbor Pawcatuck River (1960s). The third and more likely more controversial explanation is the link between insecticide use and blue crab mortality especially in the smallest sizes.  A final part of the puzzle might be determined by a DEP bottom trawl study of the area of Kimberly Reef and Faulkner’s Island focusing upon what Mr. Walston called the flounder bottom, east and north of Faulkner’s Island.  If large numbers of crabs go out to deep water (they need to go somewhere, we had millions of crabs in eastern CT last year); this area might provide some clues- he once termed it Connecticut’s blue crab graveyard.

Summary – It is clear that within the last decade, the population of blue crabs has soared; one would need to go back to the turn of the century to see such abundance.  It was a warmer than average period 1890-1920 and very hot in New England.  That is when so many shore communities started as a summer relief from the extreme heat in the cities.  That is also when numerous “salt water farms” such as the Webster Farm in Madison (Webster Point) were subdivided into lots for shore cottages along Connecticut’s coast. Blue crabbing became a popular shore activity at that time.

It is also true that a clear environmental history is needed for the blue crab and blue crab habitat.

If the summers continue to warm and winters become milder, the blue crab could indicate the first habitat shift of global warming here in Connecticut.

The increase, a welcome addition to crabbers and blue crab consumers alike, it comes as cold water species such as winter flounder and lobsters continue to fall.


Appendix I – Blue Crab Life Cycle Questions
Insecticides in Coastal Waters

I’m aware that blue crabs can survive several years as adults but even that is open to question – some say 3 to 5 years while other estimates go up to 8 years.

What was puzzling between the Tom’s Creek and Fence Creek event 1970-71 was the Blue Crabs were present in the creek bottoms in early spring – early enough to be influenced by mosquito spraying in May – June or the previous fall.  One explanation was the Megalops stage had arrived in the fall in large numbers in both creeks.  The suitable habitat appears to be shallow clam and oyster populations (even this needs to be confirmed) and over wintered in sandy shelly bottoms.  The explanation was that active insecticide fogging in the Dowd’s Campground had drifted into the Tom’s Creek Watershed.  (Spraying was common and I witnessed several spraying operations, the state mosquito control office, called the Vector Division, and was 1/2 mile north of Hammonasset State Park, where it continues today under a different name and mission).  One explanation was the insecticide had effectively killed the Megalops stage in Tom’s Creek while Fence Creek had no similar spraying.  As the Megalops started to grow in Fence Creek, the population difference became noticeable between the two systems. Local currents and tides made it impossible that only Megalops would be transported into Fence Creek and not Tom’s Creek.

What we didn’t notice and was quite apparent by absence, was adult blue crabs.  We usually didn’t start crabbing until late June or July.  Several earlier attempts did often yield blue crabs but they were rarely legal size 5 inches point to point.  It seemed to us at the time blue crabs grew to be legal size by mid to late summer.   Whatever had happened to Tom’s Creek had happened between late fall and early spring, the only difference was the mosquito control spraying.  Tom’s Creek had always been good – as areas that were adjacent, were also good for crabbing.

The stage that interested me the most was the Megalops stage but even that has its own questions.  Several papers on blue crab life history refer to the unique ability of blue crab larval stages when faced with cooler water temperature can in fact hibernate or suspend further development.  That would help explain the growth/survival differences between our waters and those of Chesapeake Bay.  In southern waters Megalops can grow longer and hibernate as juveniles in our waters Megalops hibernate over the winter and perhaps begin to grow when the waters warm in the early spring.  The blue crabs may be close to one year by date but only grew for more than 6 months.  That would explain slower growth in cooler waters – In late June in the Essex area only one in five crabs were legal by August only 1 in 25 crabs were “short” or sub legal (2010).  Catches in the Stonington area even in August showed larger numbers of crabs had yet to reach legal size.  (John Roy, senior aquaculture teacher, personal communication) – We really don’t know that much about blue crabs in our waters; additional studies therefore are warranted.  

Student research projects over the summer must be accomplished with field notes/observations, methods.       





[1] Blue Crab (Callinectes sapidus) ecology; review and discussion regarding Tisbury Great Pond, March 2004-modified May 3, 2004- Report by William M. Wilcox Water Resources Planner, Martha’s Vineyard Commission, Funding provided by the Riparian Owners of Tisbury Great Pond.

Monday, July 16, 2012

Connecticut blue crab report #5 - Small crabs and sponge crabs appear

The Connecticut Blue Crab Populations 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 #5 – July 9th, 2012
You Do Not Need To Be A Scientist To Report!

·         Small crabs reported in several areas – Bridgeport/Fairfield areas report heavy concentration of sponge crabs;
·         Hand liners frustrated by strong tides; nighttime netters do well;
·         Small crabs entering the Connecticut River at night using the strong flood tides;
·         Temperatures show slight increase as reports from USGS shows Connecticut River tidal wedge forming;
·         Conch populations now reported off Guilford, several small 2 inch crab sightings. 

In one of the best signs that large numbers of 3 to 4 inch and some 2 inch crabs survived Irene came from several recent observations about them; thank you for these reports! They are very helpful. 
Small 2 inch crabs have been reported in Wequetequock Cove, Stonington, north of Masons Island in the Mystic River, South Cove, Old Saybrook, Guilford/Madison shore; West Haven shore; the westerly side of the Housatonic River and in the Darien River.  Small 2 inch crabs were seen in the Oyster River, Hammonasset River and Branford River many observed with the incoming tides.  Dense concentrations of female ova carrying sponge crabs have now been reported for the east and west- the mouth of Pawcatuck River; Little Narragansett Bay; Mystic River below the Seaport; West Haven shore; the Bridgeport/Fairfield area (also the hot spot from last year).  All reports mention increases in the 3 to 4 inch size in crabs.  This predicts a good season. 

What has been “quiet” is information about Housatonic River.  Last year it had masses of 3 to 4 inch crabs at the southern marshes (mouth) and western side, but no reports of similar masses or adult crab movement?  One explanation could include that Irene delivered an immense amount of silt (and nitrogen also) from our long tidal rivers, the pictures of the silt entering the sound at the mouth of the Connecticut River is dramatic.  (See UCONN Sea Grant’s Wrack Lines issue Vol. II #2, Fall/Winter, 2011-2012 an incredible article. The article is titled: Tropical Storm Irene Delivered a Sunday Punch to Connecticut” by Marybeth Hart.  The article is outstanding and describes the tremendous storm changes/damage along Connecticut’s coast, (pg 3 to 6.)

Strong fresh water flows pushed the salinity very low in many rivers.  A similar occurrence may have occurred in the Housatonic River.  However despite the large Connecticut River fresh water runoff crabs survived in North Cove, Old Saybrook, the site of a dredged harbor of refuge (a refuge also, it seems for blue crabs) and the first reports of Connecticut River blue crabs can be seen here the past three years.

It is the frequent reports of large numbers of sponge crabs that may lead to a good “native” Connecticut Megalops set later this summer.  The amount of female ova carrying crabs is unprecedented according to some crabbers.  The numbers are certainly higher that than the 2010 and 2011 years sponge crab and small crab reports are very helpful and I thank those crabbers that sent in reports after report #4.

·         Up until the strong moon tides shore hand liners were doing good, but night time netters have pulled way ahead, with large catches.  Most of the hand liners have had difficulty with the recent strong moon tides, either keeping the bait on the bottom or after hookups having the crab ripped off the bait.  One clever blue crabber in Clinton used the strong tides to advantage casting a chicken leg up current with a small sinker and reeling the crab on the surface past a friend who then netted them (no second chance) with four fishing poles rigged this way a dozen large crabs came quickly as hand lines and potters caught little.
Look to see catches from shore improve as currents lessen.  Nighttime netters report good to excellent catches, but as yet very few soft shells.

·         Small crabs entering the Connecticut River at night.
July 6th had thousands of 2 inch crabs hitching a ride upstream on the moon tides past Essex Town Dock.  I observed hundreds of small crabs on the surface swimming past the dock.  In a flashlight beam they were hard to miss- the striped bass had noticed them also as frequent splashes signaled an evening feeding opportunity.  The tides have been very strong but the amount of small 2 inch crabs on the surface now was a surprise.  This size had been scarce until the Fourth of July but now seem to be present in many areas along the coast.  This is the late 2011 Megalops set (not the overwinter Megalops set) that grew before winter.  The 3 to 4 inch crabs are 30 days from legal size, weather depending and should be 5 inches by August 1st.
Will the adult population hold out until then, that’s not certain yet, although that did occur in 2010; we had the 2 inch and 4 inch crabs both mature into legal sizes during the summer with the large population of legal size adults the equivalent of 3 sets reaching legal sized all at once—and it was an incredible blue crab year (2010).

The reports of central Connecticut although positive, the western sections remain (except for a few isolated reports) quiet, just the opposite in 2011.  Perhaps the next few days will have some crab reports in the west.
Sometimes, according to some crabbers fishing drops because of shedding and then suddenly takes off again. 


Weather temperatures show slight increases-
Connecticut River wedge strengthens
Sea water surface temperatures continued to inch up and July 6th reports as follows from Long Island Sound current sea water temperatures from the NOAA National Data Buoy Center (Http://www.ndbc.noaa.gov/).
New Haven Harbor 71.4°F
Black Rock Harbor 69.3°F
Execution Rocks – (New York) 73.9°F
And areas south at Sandy Hook, New Jersey 81.9°F
And Montauk to the north a cooler 70.9°F

The salt water wedge strengthened considerably from July 2nd (thanks to a helpful United States Geological Service (website http://waterdata.usgs.gov/ct/nwis/40 Report #8) - that maintains a tidal sensor on the Connecticut River in Essex.  Here the site displays several functions but you can graphically watch the salt wedge strengthen in the Connecticut River; US Dept of Interior US Geological Survey titled USGS current conditions URL http://waterdata.usgs.gov/ct/nwis/current  
(If you have a chance check out this site it is very interesting.)  A nighttime Essex observation found hundreds of small crabs using the strong moon tides to move up river.
·         Small crabs a good sign/conch reported off Guilford, West Haven and New Haven.  The reports of 2 inch crabs earlier this spring in the east and now a few shore reports from Guilford to Fairfield are good signs.  These crabs depending upon the summer’s growth season with reach legal size before fall.  The smaller size less than an inch has yet to appear.

But add to that observations of small conch reported in Clinton Harbor, Guilford shore, Branford shore and Milford – some in areas and quantities seen never before only speaks to species changes/shifts in Long Island Sound.  Years ago, conch harvests in Connecticut were relatively small and generally not in commercial quantities.  That started to change in the 1960s.  As Long Island Sound warmed conch populations increase again subject to storm filled cold winters.  By the late 1970s conch became prevalent (channel whelk) especially in central Connecticut from Old Lyme to Milford.  They seem to populate the sand bars shoals along the 10 to 30 feet contours-smooth bottoms seem to be the best habitats.  But dense populations were reported last year in the Bridgeport area and this year between Branford and Clinton. 

The popularity of conch seafood dishes recipes has also increased once termed the forgotten shellfish and a coastal Native American favorite its popularity has jumped region wide in the last five years.  To learn more about conch, see the
 The History of Madison’s Finfish and Shellfish Industries.  It is report number
#47 on the Sound School directory http://www.soundschool.com/directory.html  The paper includes a description of Native American fisheries and some conch recipes.  For a more recent report on the Conch Fisheries of Connecticut contact Susan Weber at susan.weber@new-haven.k12.ct.us and ask for report titled, The Rise of the Abundance of Conch in Long Island Sound with Warmer Temperatures, December 2011.

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

Program reports are available upon request, 1-4 catch/observation reports 1-15 are also available from last year.

For more information about New Haven Environmental Monitoring Initiative or for past reports please contact Susan Weber, Sound School Adult Education and Outreach Program Coordinator – email to: susan.weber@new-haven.k12.ct.us
If you would like to receive these Blue Crab reports ask to be placed on the email directory.

If you do not wish to receive these reports, please let us know.

Looking forward to hearing about any Blue crab research.

Tim Visel

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.
Watch for the Megalops Portal on The Sound School website http://www.soundschool.com/
The Sound School is a Regional Agriculture Science and Technology Center that enrolls high school students from 23 cooperating towns.