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BlueChip



Joined: 29 Jun 2011
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Location: New Haven/Madison/Essex

PostPosted: Wed Jul 03, 2013 1:03 pm    Post subject: Blue Crab Study - The Sound School - Megalops Study - 7-3-13 Reply with quote

The Sound School – The ISSP and Capstone Project Proposal
Building a Network of Citizen Monitors
The Connecticut Blue Crab Population Habitat Study 2010-2015
You Do Not Need To Be A Scientist To Report!
The Search for Megalops
Megalops Report #4
July 3, 2013
The 2013 Blue Crab Year

•Large Crabs in Lower Central Connecticut Rivers
•Juvenile Crabs Surge in Central CT
•Large Crabs Abundant in Refugia Habitats
•Megalops Set Now Feared Lost; A 1960s Crab Season?
•Long Term Larval and Species Surveys Key to Understanding Habitat Quality.
Large Crabs are in Central CT Rivers


Crabbers are finding male crabs in lower rivers, large and hungry. Crabbing surged upward the last week of June, some of the best reports, Oyster River, Branford River and the lower reaches of the Connecticut River. Catches have definitely improved --the large clean blue shell males mostly and catch rates have inched up, 8 to 12 crabs/hour with some high catches reported in the Oyster River, Old Saybrook. But the crabbing conditions have been poor.
“Worst crabbing weather I have seen,” I quickly agreed a few days ago at Clinton Harbor. The constant rain by June 24-28 had turned the Connecticut River brown, thought to be the result of leaf breakdown, tannin. The amount of broken and dissolved leaf matter being washed into the Connecticut River must be enormous.

The conditions for spring crabbing in Connecticut have generally been poor; the only places that have crabs are the usual deep holes that get a good change of salt water. Some of the deeper areas close to salt water have been good, Old Lyme especially. The tidal wedge at the Essex Town Dock is building but weaker than usual; again the heavy rain can disrupt salt water flows. The NAO storm track (see report #1) continues to hold pouring tremendous moisture into New England.

On a discouraging note, the one and two inch crabs have yet to appear. These crabs are often in the upper reaches of salt marsh creeks and salt ponds, but the weather has even delayed a survey of Tom’s Creek in Madison; a good reference point as its marshes exist in an area that remains relatively free from huge runoff. Connecticut may have lost the spring and fall Megalops; they just are not showing up.

A seine survey of the Long Wharf- New Haven tidal flats recently yielded not one small blue crab.

A good news item is that enormous numbers of 3 to 4 inch crabs have made it.

See you at the docks. Tim

Crabbers Surprised by the Abundance of Sub Legal Crabs
As temperatures increased for the last two weeks of June and rains accelerated, crabbers found large male crabs very willing to take bait. Again the boaters who trapped the deeper saline holes and banks found the crabs first with some nice catches, but by July 1, crabs had spread out from these deep holes into the flats; crabs reached the Baldwin Bridge, Old Saybrook, June 27th and increased. What surprised even the most veteran crabbers was the increasing number of 3 to 4 inch sublegal crabs. From almost none caught before June 15 to a few the 20th, to 20 to 1 now and upward. One crabber “pulled out” because the small 4 inch crabs had consumed all the bait (Westbrook). The growing number of sublegal crabs points to a future upward catch level, but it’s still modest, six to 10 crabs/hour, some less and some more than that.

Still poor news from the western end of the state and regional crab reports no western activity. If the one and two inch crabs made it, we will know by July 15th.

Large Crabs abundant in refugia habitats

Pockets of habitat refugia have been known in New England for over a century. Periodic closures of salt ponds have been documented for hundreds of years. These coastal habitats are unique and being relatively shallow and therefore warmer and brackish they were the last places that blue crabs existed in the colder stormier 1960s. These salt ponds often had long narrow inlets to the sea that allowed tidal exchange but subject to storm openings and closures. They protected crabs from salt water predators and floods.
A typical salt pond habitat history is captured in the US Fish Commission section on New York Fisheries (1887), but could be considered typical for Southern New England Salts.

These semi enclosed ponds had soft bottoms with patches of eelgrass and provided seasonal small catches of blue crabs, most for home consumption. Reports from New York in the 1880s show the signs of these blue crab populations just before the beginning of The Great Heat in the 1890s. New England’s climate was moderating and was about to have the intense heat waves in the 1890s. Blue crabs soon became prevalent and spread out beyond salt ponds and moved in to rivers and coves after 1898. It was at this time that Southern New England fishers noticed the increase in blue crabs as lobster populations plummeted and then crashed shortly afterward 1898-1905.

Megalops Set Feared Lost -A 1960s season?

Is it any better crabbing now? The past 15 years as compared to the 1960s, I would have to say without a doubt it’s better now, much better.
The 1960s was a tough time for Connecticut’s coast and also the people who lived near it. The winter gales of the early 1960s were constant- some of the beaches in central CT weren’t really beaches anymore, the constant energy had stopped most of the sand from them exposing multitudes of cobblestones. A short step from a sea wall was now a life threatening fall to rocks below often amidst the remnants of seawalls from long ago.

In 1965, my father woke me in our Madison Webster Point home, “Come with me, you need to see this.” I’m certain the thrill of a sub zero walk in February to the opening of Tom’s Creek wasn’t exactly what I had in mind that morning, but I went and now am glad I did. When we got to the mouth of Tom’s Creek, it resembled an arctic rendering- frozen sand ice walls and snow. My father said something like, “Look out beyond, you need to remember this—I don’t think you will ever see this again.” He was correct. Icebergs were along Hammonasset Beach along with 10 foot high ice walls, the 1950s steel jetties put in under the 1950s flood and erosion were covered in sea ice like pictures of ships rigging where the thinnest line grew to the size of a telephone pole.

To the west towards Seaview Beach, ice walls several feet high were piled on one another looking more like the Arctic Circle than the summer community it was several month before. It was cold!

For the Connecticut shore, the constant gales were furious in the mid 1960s, 50 to 60 knot winds were common, mostly westerly’s after rain from a few Nor’easters a hundred miles away. Another person was watching that 1965 winter. John Hammond on Cape Cod was watching it also, an oyster grower who purchased Connecticut seed oysters and planted them on firm bottoms in Chatham Oyster Pond River, he had also noticed the severity and intensity of the 1960s, gales from Chatham, Massachusetts which protrudes sharply into the Atlantic Ocean. Soft shell clams which harbored blue crabs years ago had dwindled from 200,000 bushels in 1900 and was now down to only 540 bushes. In a 1968 Army Corps of Engineers study, the production of hard shell clams and bay scallops was each in access of 10,000 bushels. The colds and stormier weather had helped those fisheries he concluded, but natural oyster sets had always been limiting on the Cape, so for over a century Cape Cod oyster growers (planters as Mr. Hammond often referred) had purchased Connecticut seed oysters. Cold water slowed oyster growth and the numbers of bottom shifting storms had increased. (Pg C15) From 1870 to 1945 Nantucket the closest observation station recorded 160 gales around 116 had easterly wind components, the much feared “Nor’easters which had gale force winds that went on for hours.

Some of the early 1960s winters he described as punishing and blue crabs were then very scarce. In fact, the 1968 Army Corps of Engineers report and public hearings Mr. Hammond testified mentioning “concerns about cold temperatures and shellfish growth, during a public hearing Army Corps that talked about stabilizing the Chatham Inlet, which had narrowed and became dangerous shoals after storms. Although lobsters were covered at length in three different sections of the report, blue crabs were not mentioned at all, not once. What the report did mention was a surprising surge in bay scallop populations, in Pleasant Bay which had included some “border” disputes between Orleans and Chatham regarding bay scallop territory. Bay scallops were the crop that gathered the headlines, blue crabs were not included in the report, and Mr. Hammond subscribed to the larval drift theory believing that Cape Cod blue crabs were born hundreds of miles to the south and carried each year with tropical fish north by the Gulf Stream current. He had sometimes seen non native fish in the Oyster Pond River. He felt the winters were too long and cold for good blue crabs reproduction and it killed blue crabs. The cold which had so impacted bottom oyster growth was about to moderate. 1965 was the last year Long Island Sound froze over in that century.
The Megalops sets of last April and August are now feared lost from such a cold “1960s” winter. The larger crabs have done better, in the deeper saline pockets --habitat refugia from the cold and cold winter of 2012-2013.
What could that mean to our present blue crab population – everything -- if it continues to become colder and stormier?

Long Term Larval and Species Surveys – Key to Understanding the Habitat Changes for Blue Crab Populations

The Great Heat would bring many changes to New England’s fishing industry; the Atlantic Halibut trip reports show that by the time of the Gloucester fisher strike, it was already too late for the halibut. They had already sought more northern and colder waters. The last good halibut catches were made in progressively colder and deeper waters, very much different than the 1870s when halibut were caught practically on the beaches. Offshore fishers would often see new warm water species move north as valuable colder water species to their dismay could move as well. Fish were able to move (swim) when faced with changing habitat conditions.

As the climate moderated oysters which had been harvested to scarcity now set on any clean surface available. The period of warmth (and relatively few storms) would cause the greatest surge in oyster populations in centuries, helped now by aquaculture. This warmth and storm free period helped create the oyster industry but born in The Great Heat, it would soon perish under the North Atlantic Oscillation with colder temperatures and frequent hurricanes. Oyster sets now “failed” and offshore beds destroyed by the 1960s as oyster hatcheries were being built, much as the trout and lobster hatcheries before them. With habitat instability we often turn to life cycle modification. The Great Heat would make the greatest period of habitat instability for several species including the blue crabs.

Oyster growers a century ago had come to realize the importance of wind drive oyster larva. As George McNeil of City Point once described it as “the sound effect” connecting the prevailing July and August winds as from the southwest, driving oyster spawn back along Connecticut’s coast. The reason, he explained, while Long Island Sound was a relatively small body of water the southern side, New York’s north side of Long Island did not get a heavy shore oyster set like Connecticut. The oyster spawn Mr. McNeil felt, was blown towards the Connecticut side, not New York’s.

The oyster industry recorded its oyster sets, realizing the oyster set was the future of its industry. Much effort was expended at improving the habitat quality for oysters, preparing setting beds, hardening soft bottoms shelling and washing or stirring of shells to remove silt.

Unfortunately no one then 1900s was looking at the habitat quality for the blue crab Megalops sets; it wasn’t intentional, then in northern areas blue crabs were not considered a resource of value and when blue crabs increased after 1898 most fishery managers then were surprised rather than concerned. Attention then was upon the decline of lobster populations, a resource of value and of much concern.

For centuries fishery managers had focused upon valued species because that is what the public also viewed as important. That resource use bias is still with us today – as demonstrated by the repeat of the same reversal, lobsters for blue crabs. Many reports and grants have been issued for the decline of lobsters, but none it seems for the incredible resurgence of blue crabs in Connecticut.

Fishers often noticed the onset of habitat change, years before fisheries changed, and one of the most responsive species to habitat quality was the blue crab. One of the things that fishers noticed first was the dramatic changes here in habitat quality was from energy storms. The areas most impacted were bodies of water with inlets.

This is a New York Baymen testimony from an Army Corps of Engineers publication titled Storm Damage Reduction Reformulation Study

Bayman 5: Before the 1938 hurricane created Shinnecock Inlet, Shinnecock Bay’s only source of salt water was Moriches Bay. It was like Mecox Bay. There wasn’t much flush here. It used to stink from the lack of flushing. There were also crabs because of the brackish water before the 1938 Hurricane. The trouble is getting the crab spawn to survive. After the breach you could get 30-40 bushels of blue crab/day. Tiana Bay had a good set of blue claw crabs 3 years go. One bayman found 1 bushel of pregnant female blue claws. He left them in the bay so that the spawn would have a chance to survive, but the spawn died anyway. Yet the spider and sand crab spawn lived that same year. Before the 1938 hurricane, there were so many flounder that there was not enough food for them, and none of the flounders grew bigger than your hand. After the hurricane when the inlet was created, the flounders started to grow, but there were fewer of them. Now there are hardly any flounders.
Excerpted from: Atlantic Coast of Long Island, Fire Island Inlet to Montauk Point, New York- Baymen Interviews – April 2000 -Page 2-3

As energy flushing increased it helps provide food, greater water exchange (long a problem in the bay scallop fishery) and restore oxygen levels. The comments about blue crabs are especially valuable. Sorry no dates but I suspect it to be 1940s to 1950s. And it wasn’t just the New York or Niantic Bay scallopers who noticed this habitat change – it was the eastern Connecticut winter flounder recreational fishers who provide the most compelling testimony in the early 1980s. Fishers in eastern CT had long suspected restricting railroad causeways from reducing tidal flushing (energy pathways). Tests in some rivers bisected by railroad causeways found long ago buried oyster beds now covered by several feet of Sapropel. Those same habitats became productive blue crabbing areas three decades later. By that time the oyster shell flounders habitats were distant memories recorded in fishing journals kept by many sports fishers. With energy pathway open and cooler temperatures – those habitats could in fact reverse, again.
Those with natural energy pathways blocked will take much longer to reverse if they reverse at all- and the important ones historically to watch – salt ponds.
Some of the quickest habitat reversals are recorded in Southern New England Coastal salt pond habitat histories. Here if energy blocked tidal exchange coastal farmers and fishers would “help nature out,” taking the matter into their own hands literally. A blocked stream outlet would mean the ruin of a herring and alewife run, an available crop centuries ago to residents who did take a dim view of this habitat “reversal.” This is an excerpt of a letter provided me while working at the University of Connecticut Sea Grant regarding habitat changes in Quiambaug Cove, Stonington, Ct. It describes the practice that was common to my southern New England salt ponds. In times of heat and low energy, shallow and poorly connected inlets tend to “heal” or become blocked by sand. Landowners wishing to maintain the previous habitat value would reconnect passageways to permit tidal exchange. Horses and oxen teams were often utilized and it was termed breaching. This is a segment of a letter mailed to me in June 30, 1987 from Edgar P. Farnell, whose family had property at Stonington, Quiambaug:
“The buildup of muck and heavy vegetation is more of a concern. It certainly has had an effect on the cove as a whole including clams, oysters, crabs, fish and mussels. When the Filter Plant was built many years ago, the north end of the Cove increased the buildup of heavy mud that has continued for many years.

“When my father (deceased 1972) was young, he recalled that every spring landowners along the cove would use a team of oxen and plow to dredge the cove every year between the bridges at a perigee tide. This, no doubt, improved the tidal flow, because when I was a boy, the Cove had little of the muck which now prevails.

“I thought my Father’s recollection might be of help in validating your forecast that dredging the area between the bridges would have a dramatic effect on the quality of sea life within the Cove.”

Energy and Temperature have had and continue to have tremendous impacts to fisheries’ habitats in New England. That includes the blue crab.
Email blue crab reports to: tim.visel@new-haven.k12.ct.us
Every observation is valuable as we learn more about our blue crab population.

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