[BlueChip]

Habitat Information for Fishermen CT Blue Crab Migrations
Adult Blue Crabs Enter CT River in Huge Numbers

Addendum: August 2012 Older Blue Crabs Enter the Connecticut River in Large Waves

The EPA/DEP Long Island Sound Study Proposal for a Connecticut Blue Crab Habitat History – March 2011

Tim Visel, The Sound School

During the past week several waves of adult blue crabs have now entered the CT River. These crabs show signs of many years surviving in the Long Island Sound.
With evidence of a second significant migration (2012) of large older Blue Crabs from river mouths (we think) to other areas has raised the questions again of over wintering locations in this extended period of heat. It appears that the dredged channel areas in some harbors are providing increased habitat services to over wintering blue crabs. Predation in offshore areas is thought to be extreme but we just don’t know. Fresh water spring runoff is thought to eliminate the Connecticut River blue crab population except perhaps for the North Cove dredged area. But here again we just don’t know that for certain. The population of Connecticut River Blue Crabs is now several hundred thousand perhaps millions as of August 2012. They cannot all fit into North Cove Old Saybrook, etc. We do know that hard shell crabs are often found in habitats that also contain oysters and soft shell clams. New Haven Harbor and adjacent areas have these shellfish populations and New Haven has had the densest blue crab population this season. We just don’t know what habitat is important to what stage of the blue crab life cycle here.

This report was written in March 2011 after the colder snow filled winter. CT River crabbing in 2011 did not even approach the 2010 season. The heavy spring rains are thought to eliminate much of the CT River Blue Crab population – this recent blue crab migration into the CT River had to come from somewhere else? The movement of masses of blue crabs into the CT River now (they first arrived on or about August 21st) in such large numbers raises three immediate questions.

1) Where did they come from – was this a natural or forced migration?
2) It is obvious that they over wintered not once but several times – and made it – even past the colder winter of 2011, how is that possible?
3) The Connecticut River Blue Crab fishery was very poor in 2011. Why did these crabs not join with the few survivors in 2011 – they are several years old?

All good questions that could be answered with some tagging programs and a good habitat history for Blue Crabs in Connecticut.

This is the EPA/DEP Long Island Sound Study habitat history proposal from March 2011 before the summer 2011 blue crab season. Nearly all of the questions are still valid today I welcome comments/suggestions. Please email me at tim.visel@new-haven.k12.ct.us

Tim Visel, The Sound School


EPA/DEP Long Island Sound Study HRI Committee
The Connecticut 2010 Blue Crab Season
The Search for Megalops – Aquaculture Science Projects for ISSP
The Oyster Shell / Clam Bed Habitats
May be Critical to Blue Crab Populations

Potential Agenda Item March 2011 Meeting
The Connecticut River Blue Crab Fishery Questions

Tim Visel
The Sound School
New Haven CT 06519

Email Tim Visel at tim.visel@new-haven.k12.ct.us


Abstract-
Most Connecticut blue crab fishermen would agree last summer’s blue crab season was one of the best in recent memory, several decades at least. Some even refer to it as the best season in a century – overall Connecticut witnessed wide-spread blue crab abundance. For many young people, it was their first experience crabbing, what a first year!
Based upon the number of fishermen in the lower Connecticut River (Old Lyme, Old Saybrook and Essex), several dozen families daily and easily caught a dozen crabs in a few minutes. Fishing methods ranged from the simplest of gears, a section of twine, a piece of chicken and a pole net, to the personally attended collapsible folding metal traps to the centuries old baited hoop net. All three methods were employed and were successful.
Questions were raised regarding the health of Long Island Sound and its ability to sustain such a large population of blue crabs while its offshore relative, the northern lobster is at such low levels. Later questions were asked about the appearance of such large numbers of blue crabs, when last year’s season was rated poor to fair at best. Connecticut lacks detailed information life history regarding carrying capacity and habitat conditions for its blue crab fishery.
Key Words – blue crab habitat history, larval and Megalops stages, larval surveys, populations size and catch statistics.
Introduction
The lower Connecticut River during the summer of 2010 would experience a tremendous blue crab season. It’s referred to as a season because legal-size blue crabs mature in late June to reach the 5 inch legal size tip to tip limit measured across its shell. Crabs with hard-shells smaller than 5 inches are returned as undersized while soft shell crabs, those with new soft exoskeletons can be kept at 3.5 inches. The blue crab season ends December 1st and any egg bearing females (sponge crabs) must be immediately returned unharmed to the water.
Observations of the lower CT River provided a limited view of the extensive recreational fishery. Although most crabs are caught from shore, a modest small boat/row boat crab fishery was observed. They would anchor in the shallows in the Essex Nott Island area and on a given tide (1.5 hours before high tide to 1.5 hours after high tide) catch 20 crabs per hour on good days. Catches were limited somewhat by currents too rapid and the bait lines rolled, too slack and crabs could not follow the biochemical traces of bait. Several night time crabbing trips were observed and catches ranged between 100 to 200 crabs. An evening trap fishery set from docks was also most productive, but in the Essex area, that success would depend upon the presence of eels. After dusk, eels would appear in large numbers attracted no doubt, by the chicken and baited fish lines. When that happened, crabbing success declined to a point it was discontinued. An eel pot for example set off the Essex town dock yielded a dozen eels in just an hour’s time after dusk.
A significant fishery existed by “pole fishing” – looking for resting blue crabs clinging to pilings and bulkheads. In the Essex area, 50% of the pilings had crabs on them. With thousands of driven pilings and docks on any given tide, thousands of crabs were on these manmade habitat structures. Crabbers used no bait, but would walk along docks and piers looking for “pole crabs”. This method was also effective in the lower CT River. One crabber caught a dozen crabs off pilings in just a few minutes returning to see new crabs clinging to the same poles! The final method involved baited traps and crab lines from shore, largely piers, docks and floats. This involved a crab net in which baited lines draw crabs close to the crabber for netting. The set traps (personally attended) metal crab tops were also used with success. Even the century’s old baited hoop net, a circular ring device with a baited center was effective. This gear, which dates back to Egyptian times, is only effective with extremely dense populations. It was used last summer in Essex and caught many crabs.
The extent of the CT recreational blue crab fishery was huge last year. The use of gear that is some of the simplest yet least effective and catches only a small percentage of available crabs was used. Few people would argue that a piece of twine with a chicken leg is an expensive or sophisticated fishing gear. It only can catch a very small fraction of crabs present, less than one percent. While the best collapsible traps have the highest capture rate, perhaps 5 percent of a given area at one trap in each 15 foot capture circle, with baited methods. Many crabs bypass the bait, swimming and crawling and once a crab enters a trap or attaches to a baited line, they tend to defend it from other crabs; that behavior in itself is self-regulating the overall gear effectiveness. The good thing about the recreational fishery in Connecticut is it a low entry cost, no license for recreational use, a crab net, a strong twine and a piece of chicken. A good crab net can last many years; many of the people I spoke with last summer spent less than 4 dollars for bait and twine each trip. About half of the people I spoke with at the Essex town dock were first time crabbers and they had a great time. It was hard not to catch crabs, there were so many of them.
It was logical that questions were asked about the blue crab resource: its size, reproductive characteristics and what crabbing will be like next year. Answers to these questions were difficult to provide. We lack a good environmental fisheries history for blue crabs. We have no habitat histories except accounts from the fishermen themselves. It is puzzling that we had such a large blue crab fishery absent the presence of a large fishery last year. Last year crabbers rated it as poor or bad, many went once and that was it. All agreed it was nothing like this year!
Description of the Fishery
The blue crab fishery is nearly all recreational – and primarily family use. For some serious crabbers and those that came numerous times, family events, picnics and social gathering’s were the destination of large catches. Others mentioned picked crabmeat or use in ethnic pasta sauces. Several filled coolers were observed (about 75 crabs) although one family after several hours had filled a blue laundry plastic tub of about 300 crabs. In one day I observed over 1,000 crabs caught from or landed on (from small boats) the Essex Town Dock. Jonathan Morrison of the US Department of the Interior, US Geological Survey, watched the activity at the Essex Dock for half hour during a lunch break as my son Willard brought me a blue crab to band every 30 seconds. You just had to be part of this to believe it!
Based upon the number of blue crabs fishers in the Old Lyme/Old Saybrook and Essex areas and on a pleasant weekend day were in excess of 100 and the average catch was 20 crabs/line/tide. I estimate that between 1 and 4 thousand crabs were taken each day. Family catches in excess of 50 crabs and that was not unusual. From July 1st to October 1st, perhaps another 500 to 1000 crabs were taken each night. If half the total fishery days were suitable 45 days yielded an estimated 100,000 caught blue crabs from the lower CT River last year.
Habitat Conditions
A combination of habitat and environmental factors combined to produce an outstanding blue crab season. First of all, blue crabs do better in warmer temperatures especially during the winter. It is known that we are in a period of exceptional warmth, perhaps unprecedented in recent fisheries history. Blue crab larva like to metamorphous in shallow clam and oyster beds and the winter proceeding was not that severe. After the usual spring rains, rainfall declined and salinities rose in tidal creek s and rivers, ideal habitats for crabs. Strong summer storms were few.
One of the largest habitat conditions or questions raised by crabbers last summer was the huge population surge from last year. The 2009 season last year was a lackluster one, a catch of 5 to 10 crabs for a three hour tide was good, and many just didn’t try. In the same areas, ten times that much was caught last year. In one three hour tide in late August 25 set crab lines off the Essex Town Dock caught one crab every minute for over one hour just before high tide (personal observation).
An obvious question was how did such a population increase happen and whether these crabs were last year’s uncaught crabs or new crabs that appeared from local waters. It’s a great question that’s connected to environmental, biology and habitat influences.
The Resource
One of the most often asked question and the subject of some serious questions was the size of the female blue crab spawning population. Female blue crabs sponge out or carry an orange color mass of eggs on their abdomen. It’s very noticeable and easily identified. Each mature female crab is capable of carrying up to 2,000,000 eggs but very few survive or are able to reproduce- about 3% do, or up to 6 crabs per female under ideal conditions. Working back from catches of last summer several million crabs were in our waters last year considering the suitable habitat in tidal creeks, coves and river mouths. Heavy catches of blue crabs were reported statewide, these reports included the Groton, Stonington area, the Oyster River to Hammonasset River. The Branford and Farm Rivers and to the west, Norwalk harbor was especially thick with blue crabs from local media and press reports. Good to excellent blue crab reports were common. To produce such a large population would require a sizeable population of egg bearing females. The problem was the 2009 fishery was so small and if the 2010 catch was in the hundreds of thousands of crabs the population for Megalops larval production should have been sizeable. We just don’t’ see large egg bearing female blue crab populations. If the crab catch was in excess of 200,000 blue crabs last year, with low efficiency fishing gear, the standing crop or adult blue crab populations most likely numbered several million. The hope is that the larger percentage of crabs that escaped our modest fishing methods last summer next year’s catch will be just as large. Blue crabs can live 5 to 8 years and leave our estuaries in October as sunlight angle decreases and waters cool. It is hoped that a large population will be detected next spring in DEP off shore trawl net surveys.
Spring Surveys for Megalops
The identification of preferred habitat and locations of dense blue crab larva (Megalops) has not yet been determined in CT. That will require a monitoring or survey program to locate them. A program similar to the very successful DEP Project Search for fresh water riffle dwelling organisms would be required. An opportunity exists for high school programs and students to look for Megalops in local waters. It also might be possible for several high schools to post result information on the Internet. Many coastal high schools probably have local crabbers already asking the same questions – Where did all the blue crabs come from?
Looking ahead to 2011
It’s apparent that large numbers of blue crabs escaped the traps and nets and left coastal areas in search of deeper more saline areas of Long Island Sound. Blue crabs stop eating in colder temperatures burrowing into soft sediments and hibernate for about 2 months existing off stored food reserves. They should emerge in late March as adults and begin feeding. A huge uncaught population should reappear then, they need to begin eating in March/April. Large numbers of adult crabs early this spring would be a welcome sign for another great blue crab year.
Remaining Questions
Blue crabs do face uncertain winter carrying over, storms and predation by fish, especially starfish and could be significant. Spring floods and heavy rains could cause fresh water poisoning – toxicity. Willard and I saw huge numbers of juvenile blue crabs killed three years ago in 2008 by a sudden freshset in the Connecticut River, by the Baldwin Bridge, DEP launch ramp. We saw thousands of two to 3 inch crabs washed up and along the banks; it was after a tremendous rainfall and the river was a brown color. We suspected fresh water poisoning. Serious questions remain if escaping adults make it past the winters here at all, and combine again in the summer fishery. We really don’t know what our winter carrying capacity is or what habitat conditions favor the blue crab. It has been suggested that smaller stages prefer tidal creeks especially clam and oyster habitats.
High school students, if they can survey small sections of shore bottoms (creeks) this spring and examine it under a microscope, may help answer some of these resource questions. A review of the existing literature indicates that the critical Megalops stage is able to slow or even stop its development in the face of cooling temperatures. In March or April, blue crab larval stages should become active and begin to feed. Sampling under shells or soft shell clam beds should yield Megalops during this period from a settlement in September/October.
A second explanation is that our crabs are Megalops that drifted out of the Chesapeake Bay got caught in the Gulf Stream and summer prevailing winds blew surface Megalops into Long Island Sound. Under this theory next year’s crabs are already here waiting to emerge this spring and start growing.
The severity of the winter, spring rains and storms all should be considered but at some point Blue crab larval forms need to exist. Where and at what densities remain large questions in seeking answers as to where our blue crabs come from.
Perhaps some high school science classes can help answer these questions as they have with the very successful DEP Program Project Search.
We look to the possibility of some for credit ISSP proposals from any interested Sound School students.

[cmorenito1]

im from danbury where can i go crap fishing