Thursday, August 27, 2015

$5 or $50 Reward for Tagged Crabs in Chesapeake Bay


If you crab in Chesapeake Bay this summer or fall you might run across a crab with a pink or white tag like the ones pictured here. Reporting them is worth $5 or $50 for each tag. My lab at the Smithsonian Environmental Research Center in Edgewater, MD has tagged nearly 15,000 crabs since June 2014 and 1 out of every 20 is worth $50. If you catch a tagged crab, please help our study by recording the information requested on the back of the tag and calling the number or visiting the website listed on the front the tag.

The tags are on both male and female crabs. Tagged crabs have been released at sites throughout Maryland and Virginia. We've had a lot reported already but we know there are quite a few more out there. We've even had a couple that were caught as far away as North Carolina.

If you've already reported but haven't heard back from us, please be patient. We're working as fast as we can but a hundred or more reports each week it's hard to keep up.

Tuesday, July 21, 2015

2015 Connecticut Blue Crab Report #4

From Tim Visel at The Search for Megalops:

The Search for Megalops – Report #4 – July 20, 2015
Small Blue Crabs Surge in Central CT
The Sound School Regional Vocational Aquaculture Center
Inter-District Marine Education Programs
Capstone Project ISSP Blue Crab Monitors
Blue Crab Research in Long Island Sound 2015
You Do Not Need to Be a Scientist to Report
July 20, 2015
Tim Visel

Follow Megalops reports on the Blue Crab Info™ Northeast Crabbing Resources. IMEP fish habitat reports can also be found on the Blue Crab Forum’s™ “fishing, eeling and oystering” thread. Thanks also to Connecticut Fish Talk ™ for including Megalops Reports under the Saltwater Reports thread and the Blue Crab Blogspot™, Dr. Matt Ogburn, for posting all Megalops Reports.

·         Small Crabs Surge in Central CT
·         Megalops set uncertain
·         Are high blue crab catches sustainable
·         Eelgrass and Sapropel cycles
Small Crabs Surge in Central CT
“Don’t put the crab nets away yet” was a response from a veteran Megalops reporter – just a few days after the June 15th report thousands of 3 inch crabs showed along central CT, the usual good spots – CT River to West Haven in general,  but very dense populations of 2 to 3 inch crabs were reported in the Clinton Harbor/Indian River area (multiple reports) Branford River and Gulf Pond in Milford.  Some eastern CT coves have reported some adult survivors – Alewife and Jordan coves.  Adult crabs however remain scarce; one crabbing family I spoke with who visits Connecticut from South Carolina to crab here reported 2 crabs from the Oyster River (Old Saybrook).  Last year same day on afternoon of June 27th 2014 crabbing yielded 26 crabs but they had a great day crabbing regardless.  He surmised the waters were still too cool and he felt the run was a month off, I agreed it was a cold winter and cool spring-- a month off was generous.  I feel for some species, it is 6 weeks. A cold summer is come to define the first few weeks, it seems as though spring continues.  A recent conversation with a Baldwin Bridge DEEP fishing pier blue crabber (Old Saybrook side) July 13 was trying it again the previous week: July 6th yielded not one crab. The pier had no crabbers at high tide, he was alone.
However some of the first run descriptions come from Clinton Harbor – 20 to 1 in other words twenty small crabs are observed or caught to one legal crab.  Branford River (by the high school) 10 to 1 and Oyster River Old Saybrook about the same (when rates for legal crabs are above 2-3 crabs an hour.)

Gulf Pond in Milford with North Cove, Old Saybrook—all report small crab sightings but no large catches as late.  The Western CT Rivers and Western CT areas remain in general very “quiet.”  The CT River Fishery is also slow – a good number of 3 inch crabs at the mouth indicates the fall 2014, Megalops set or some of the 2013 set at least in some areas made it over the winter in the marshes.  A second wave of crabs would be a good sign (see following section).  In 2011 three distinct waves of small crabs were identified (see Megalops Report July 11, 2011) and built into an amazing CT River fishery – 60 to 80 crabs/hour (four lines) which was interrupted by Hurricane Irene on August 27th to August 29th.

A second Megalops wave now would make it to legal size by September 15th in time for a fall fishing but what would be needed is warmth and little storm activity.  The good news is we have some crabs that will shed into legal size over the summer – many crabbers are hoping for a better fall fishery.  
See you at the docks.
Blue Chip
Megalops Set Uncertain

One of the ways that habitat transitions can be measured is the strength of reproductive success. That is usually described as a species range. The range varies of course to habitat parameters and the recent warm period most likely shifted the Blue Crab range far into northern waters.  It had been there before a century ago and the recent cool down and increase in storm intensity may destroy blue crab Megalops in a variety of ways but that needs observations over a long period of time to confirm any changes. We may have already seen that happen in the Hudson River blue crab populations. As our hot and relatively dry period extended into the 1990s, fresh water river flows declined; salt water tidal wedges even at times eliminated it; that also happened here during heat and dry summers, blue crabs were observed in Deep River, even Chester (Megalops Special Report, September 27, 2012); the salt wedge was strong. These hot days and springs seemed to favor our blue crabs while harming alewife returns in streams most impacted by warm storm water. When you look at anadromous fish returns in the 1950s and 1960s, they were good years. The American Shad peak year is 1958 and not so great for the blue crab. Changes in rainfall storm intensity even prevailing winds can alter a blue crab Megalops set, but increases here were gradual, all starting it seems in 1998.  It is not any given year, but a series of years which could be called a trend. Between 1998 and 2008, blue crab populations in Southern New England tended to increase and then explode in 2010 leveling to 2012 and now after its best year, apparently failing. Colder winter temperatures is the latest factor to be reviewed but I feel it is many factors - cooler temperature, increased storm intensity and frequency, rainfall (salinity shock) may all combine to reduce the Megalops set and eventually the range of blue crabs.

 

The past three winters may soon cause a pause in the blue crab advance north it may be just temporary or could signal a decade long  habitat “reversal”. One of the factors I have noticed is that the cooler periods have become less cold and shorter.) The Megalops and star crab sizes appears to be happening later, too late to perhaps ensure good survival. By the 1930s (Jeffries Rhode Island Study) Narragansett Bay commercial blue crabbers most likely were asking the same questions as today.  From a large fishery in 1912 dwindling each year until 1938, the New England Hurricane signaled a habitat reversal of unprecedented  scale, cooler longer winters generally happened after.  By the late 1940s and 1950s winters were cold and snow filled, and New England commercial blue crabbing ended.  It is mentioned in the historic literature (not as much as staple market species), but something had happened, no one knew what, but blue crab populations were lower and in some areas now gone.  It was the time that clouds these events; habitat transitions are usually not sudden and therefore disguised by many factors, one of which is a species rehearsal, from the 1895-1905 Southern New England lobster die-off did come before on incredible surge in blue crabs. Habitat quality later improved for lobsters it could be years before legal size lobsters entered a fishery.
When Southern New England experienced critical lobster die-off in 1998 no deadlines read “Lobsters’ Demise may signal the return of blue crabs”.  We did not know the environmental fisheries history and patterns fishers call cycles.  I did not fully realize the signs as well.  It was my son Willard and his friend William who would fish for blue crabs in Essex in 2004; they didn’t take in hundreds but what they did return home with in huge buckets were huge males, very large jimmies the size to which I was not accustomed. It actually was Willard who called me in 2010 urging me to visit the Essex Town Dock as crabbers were catching hundreds of blue crabs and carrying them off “in plastic laundry tubs.”  In 2006-7 catch rates were in the dozens of crabs perhaps (4 lines), one of our best crabbing locations was the out flow of Fall Mills River off a dock, two 5 gallon pails (80 crabs about) was not uncommon; also I might add an unpleasant tug of a snapping turtle that seemed to try to pull you into the water as well.  By that time (2007) crabbing had increased all along the shore area, even into Mystic and Pawcatuck Rivers.  New Haven Harbor Monitoring studies in the 1970s (a requirement of a state permit) listed the most prevalent species in the harbor and in the middle 1970s as lobsters they were among the most numerous, blue crabs were listed as scarce. 
Many thanks to Paula Daddio, one of the Aquaculture Science teachers here at the Sound School, for providing me with a copy of New Haven Harbor Ecological Studies 1981 Summary Report 1977-1980 (prepared for the United Illuminating Company, New Haven, CT). It provides a great look at what species were prevalent in New Haven Harbor following a gradual warming that started in 1972. The report is a comprehensive survey of water quality and fish/shellfish species as part of a permit discharge requirement. One of the key charts in this report was a 1974 to 1980 ranking of the ten most prevalent epi-benthic species (New Haven Harbor) on page 76 and a surprising surge of lobsters – moving from 10th to 5th most abundant (selected sample stations, New Haven Harbor). This was perplexing to the study authors who on page 69 noted that surprising increase:
“Lobsters have shown a notable increase in catch abundance during recent years. In addition to higher catch abundances, lobsters were occasionally abundant during mid-summer. The period in previous years when densities typically declined.”

The climate was warm but not hot. Winter storms (except for the Blizzard of 1978) were less severe. Although blue crabs were sampled, they did not make the top 20. In fact, the most prevalent crab was the cooler water preferring Rock Crab (Cancer irroratus) and was noted to be consistently abundant. “Seasonally rock crabs have been collected in highest numbers during the summer (pg. 68) [Blue crabs were only occasionally sampled].

Some years none were observed. In the time span for four decades lobsters and blue crabs had reversed in prevalence (New Haven Harbor).  By 2012, blue crabs were very prevalent in New Haven Harbor.  Sampling trips by our own Island Rover research vessel small otter trawls with Jack Cardello, Jack Walsh and George Baldwin, Sound School teachers. often come up with dozens of blue crabs. The New Haven – West Haven Shoreline became a favorite area to flood light “dip” crabs. When blue crabbers experienced these dense populations it was difficult to compare to surveys in the 1970s that listed blue crabs as “scarce or unknown” in the same area.

 

What the future will bring us is uncertain, but climate conditions have changed, and some of the colder climate indicators # days snow on the ground and# days of ice on, ice off days might be helpful now. The North Atlantic Oscillation (also at times called the Arctic Oscillation) has produced a strong polar vortex sending cold waves deep into the US, “Winter kill” species included not only the blue crabs, but others that over winter in Sapropel type habitats, terrapins and even conch as well.

 

Are High Catches Sustainable?

 

Sustainable has been a fisheries buzzword for the past two decades; it has displaced our fishing in describing some of our most valued fisheries. If climate change dictates changes in habitat quality which I feel it does- than climate itself has a huge role in the fisheries  sustainability discussion.  Fishers call it cycles. I term it as habitat reversals; one of the best associations in New England to climate changes (cycles) is the striped bass.

 

As more historical information is coming in (including a recent collection of striped bass journals) the peak striped bass years were from 1896 to 1921 as recorded from catches from Boston to Monomoy, Massachusetts (pg. 10, Fishery Bulletin of the Fish and Wildlife Service; pg. 10, Studies of the Striped Bass of the Atlantic Coast). This period is within the 1880-1920 “Great Heat” period in which blue crabs, oysters and striped bass surged to levels not recorded before. Researchers were noting the fishery period, but not the heat. They were, however, investigating the range and size of stripers – in times of great cold, very small – ten pounds or less; in times of great heat, huge and often record breaking.
Researchers then were not recording climate change events; still placing most investigations into catch statistics and reproductive capacity. The climate factor, other than in very important fisher observations, was largely overlooked. The sizes of these stripers were not overlooked however and some of the largest stripers caught in New England came during “Great Heats.” This section on page 4 of the U.S. Fish and Wildlife Service Fishery Bulletin #35 1941 – Studies of the Striped Bass of the Atlantic Coast by Daniel Merriman, Yale University, New Haven, CT, Osborn Zoological Laboratory describes this situation a century ago:
-from 1941 Report by Daniel Merriman” pg. 4
Size and Range of Striped Bass

“Size and Range of the Striped Bass as referenced by the US Dept of the Interior; Studies on the Striped Bass (Roccus saxatilis) of the Atlantic Coast by Daniel Merriman (Fishery Bulletin of the Fish and Wildlife Service, Volume 50, 1941. The striped bass most commonly taken at present by commercial and sport fishermen on the Atlantic coast vary in size from less than 1 pound to about 10 pounds in weight. Individuals up to 25-30 pounds are caught, although, judging from old records, these larger fish are not as abundant as they have been in the past.  Bass above 60 pounds are now decidedly rare. The largest striped bass taken in recent years was the 65-pouder caught on rod and line in Rhode Island in October 1936 and one weighing 73 pounds was taken on rod and line in Vineyard Sound, Mass., in 1913 (Walford, 1937). Authentic records show that a striped bass weighing 112 pounds was taken at Orleans, Mass., many years ago (Bigelow and Welsh, 1925), and Smith (1907) reports several weighing 125 pounds caught in a seine near Edenton, N.C., in 1891.”

 

I can recall listening in 2009-2010 to reports about the star crabs size blue crabs in Perry Mill Pond, Fairfield.  (Some of the most interesting reports have come from kayakers). The description of blue crabs by the hundreds of thousands that carried to the 2011 blue crab year and several of the first reports listing the numbers of 3 small crabs as greater than legal size reports came from western CT.

 

The reports of small blue crabs sometimes followed crab hatches such as the one I observed several years ago off Faulkner’s Island, Guilford. Crab larvae filled the water column then for several miles but what was the source of this tremendous hatch of it wasn’t “ours” or was it the larvae that somehow drifted up into our area from southern areas such as the Chesapeake Bay region? The amount of female blue crabs there more than doubled-- 100 million to over 200 million – and if reproductive success factored in catches should have risen over the same period but they did not, instead they were level and declined. One may consider a regional climate factor instead; unfavorable winds and perhaps the Gulf Stream may have carried Megalops far to the north in larger quantities. A gradual warming allowed that set to mature here such as in areas of Perry Mill Pond in what seemed at the time to incredible densities. The warm summers of 2011 and 2012 also had reports of CT female blue crabs holding sponge egg masses and added to whatever Megalops set drifted north (Bridgeport & New Haven Harbor).  But the “new normal” may have just returned to the old normal of long ago, in times of Great Heat and low storm intensity blue crabs moved north as they did a century ago. For New England the high catches of Blue Crabs are not sustainable over time- looking at the patterns of fishery landing statistics of the past century, they change over long periods of time in large event cycles are just do not fully understand. The fishery statistics for blue crabs are high during the Great Heat 1880-1920 and low in the late 1950s and 1960s. This is also the period of a negative Northeast Atlantic Oscillation or NAO.

 

Kudos and thanks goes to Sam Sampieri of Fox TV news here in CT for during a weekend broadcast Sunday April 25 mentioned the NAO, a cold air mass was settling over New England and stated something to the effect “this is typical of a negative NAO pattern.” And is to my knowledge he was the first Connecticut forecaster to mention the NAO during a television forecast.  I was very surprised to hear it mentioned and hope that a follow-up will come- it was long overdue (my view).

 

When you examine the historical fisheries literature, most species over time show periods of abundance then decline. Researchers are now looking at the NAO for the increase in cool water fisheries such as shad and herring in the 1950s and 1960s and declines in the very warm 1974-2008 period.

 

Temperature Impacts Habitat Quality

 

As colder water contains more oxygen Connecticut River researchers rejoiced as oxygen saturation levels increased in the Connecticut River during the late 1940s often suggested in response to a lessening of pollution (Moss Douglas, The CT River) Pollution was Decreasing- writing in 1965- Director Moss writes.

“It is probably very unrealistic to hope that the Connecticut River will ever return to its original state of cleanliness and purity – the encroachment and impact of civilization is simply too great.  It is felt, however, that a tremendous amount of improvement can be accomplished. There appears to be a new awareness of the abuses and the record of regression to which our beautiful river has been subjected. This consciousness is being demonstrated by a gradual improvement in water quality. Our Water Resources Commission makes the encouraging observation:

“Over the pat several years, considerable pollution control work has been accomplished in the Connecticut River watershed, resulting in the improvement of the quality of the river. This improvement is probably best shown by comparing the results of three dissolved oxygen sampling programs carried out in the years 1914, 1929 ad 1953. In each program, samples were collected at several stations between Hartford and Bodkins Rock, Portland. The average per cent saturation for dissolved oxygen for each series was 1914—26%; 1929—43%; 1953—65%.  There appears to b e no doubt that conditions are even better today (note: per cent saturation of dissolved oxygen is often employed as a criterion for indicating water purity.)”

 

But in looking back, colder water contains more oxygen and Director Moss just reflected on a trend toward cooler waters which returned these species that liked cooler waters yet vanquished those who liked the heat. Blue crab catches in the 1950s-1960s dropped over Southern New England including the Cape and Islands of the species that appears to benefit the most from cold and stormy period is our bay scallop, the second being winter flounder.

 

After the sudden change in our winter weather at the end of December 2014 by the middle of January bay scallops had settled into all of the eastern CT Rivers.  If the summer remains average without extremely hot temperatures we may see a good fall bay scallop crop. Several of the towns on the Cape and Islands are also experiencing an uptick in record bay scallop catches, now that some of our bay bottoms have been cleared of Sapropel deposits. Bay scallop catches are also something to watch; over time their abundance has changed greatly, casting doubt if they also can be always at high levels of abundance.  The quest of sustainability will be with us for quite some time but the answer from historical recordings indicate that high catches are not sustainable for a variety of reasons most of them natural fluctuations that in the final analysis we have little influence- climate and energy cycles.

 

Eelgrass and Sapropel Cycles

One of the things you observe by looking at historical literature is certain conditions appear to repeat themselves, one of which is the Sapropel/eelgrass cycle and impacts to shellfish populations.  It could be said that a decline in oyster productivity was accompanied by an eelgrass die off perhaps the first indication of massive habitat change is ahead.  In the historical texts very often 1931 is a transition year with a cold period following striped bass.

No one would doubt that during the very warm period here 1880-1920 blue crabs flourished in northern New England areas and Sapropel deposits grew deep. Those accounts are in US Fish Commission Reports.  As energy lessened and temperatures increased, the soft upper deposits in quiet coves and bays most likely failed first – I observed that happening in Buttermilk Bay on Cape Cod in the early 1980s.  Areas that were once productive for the soft shell clams were buried by a foot or so if soft black mayonnaise.  You could feel the firm bottom below when walking (anyone who has walked in this stuff will realize it is not the same mud as found lower in estuary in places of greater tidal energy) and if you disturb it the black sands below will be exposed with dead or empty shells.  You can at times smell the sulfur but this was the material that still containing dying eelgrass and had become a popular blue crabbing spot.  Blue crabs frequently were observed near these deposits and most likely over wintered in them.  The cooler clean and green eelgrass did contain large numbers of crabs (mostly green crabs) and there is little doubt that these areas once provided food and shelter to many organisms.  But Buttermilk Bay was in a state of great habitat change, the once firm bottoms on the Cape were transitioning (and elsewhere in southern New England) to soft ones.  I believe that over wintering Blue Crabs in shallow Sapropel actually benefited – the slight waft of sulfide from it was a signal to predatory fish to stay away – levels would alarm predators but not be toxic.  That is why I believe is how eelgrass got its name – the soft tissue and preferred bait for blues and stripers also buried into this gelatinous deposit – among the eelgrass plants to escape much the same thing.  In the historical fisheries in times of ice and cold winter flounder spear fishers headed to shellfish beds (mostly soft shell clam beds) while eel fishers headed to “eelgrass.”  Spearing eels in deep soft holes is frequently mentioned and the association of eelgrass to growing organic deposits is widely acknowledged. Eels have a very complex respiratory pathway.

So, one of the questions about “winter kill” that I have heard often for the blue crabs this spring is--Is it related to cold water or is the cold water related to its ability to kill?  If the crabs hibernated in shallow Sapropel deposits – less sulfide perhaps than deep deposits with sulfide levels that could purge in a long cold winter to toxic levels?  One of the largest habitat questions related to Blue Crabs abundance is how winters kill crabs and if winter kill has any habitat characteristics.  Eelgrass itself appears to have mixed habitat services the lower reaches clean and green positive – for small crabs, the upper reaches, brown and furry negative- it could signal the beginning of massive habitat changes as it did in the 1880s  and 1950s and in August, I hope to have a large historical report on how cold water kills blue crabs, and other species.
All reports of blue crabs help our understanding of the blue crab cycle in CT. Please email your blue crab reports to: tim.visel@new-haven.k12.ct.us. All blue crab observations are valuable as we learn more about our blue crab population. Questions? Send me an email.

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

 


 

Tuesday, June 30, 2015

In case you missed it: Discovering the Monster Crabs of the Old Chesapeake

The following article and interview by Tom Pelton at WYPR in Baltimore (originally posted here in January) describes new research from my lab at the Smithsonian Environmental Research Center on ancient blue crabs. Click here for a link to the original WYPR story and podcast of the audio interview. For our paper in the Journal of Archaeological Science, click here.

Discovering the Monster Crabs of the Old Chesapeake

Blue crabs are an important part of the Chesapeake region’s culture, diet, and economy. But crab remains are rare in archeological sites around the Bay. This has led some scientists to believe that Native Americans did not eat the beautiful swimmers that today we find so delicious.
 “What we know about Native Americans ate is based on some historic records, but also on looking at the trash piles that Indians left, mostly on the shoreline of Chesapeake Bay,” said Tuck Hines, Director of the Smithsonian Environmental Research Center. “And the majority of those trash piles are made up of oyster shells. But not much in the way of blue crab remains are generally found in those trash piles or ‘middens.’”

It might make sense that Native Americans did not eat blue crabs.  After all, blue crabs were not a commercially harvested species -- even by European Americans -- until after World War II, when the crab pot was invented as an underwater trap. 
In the century before that, oysters were the most popular food from the Chesapeake.  It the past, highly targeted seafood included terrapin, American shad, and sturgeon -- all of which were over-fished nearly to extinction, until little was left to eat in the Bay except the ornery, edgy blue crabs.
Maybe Native Americans had no reason to mess with blue crabs centuries ago -- because they had so many other, larger morsels of protein they could pluck from the bay with more ease.
The problem with this theory is that records from the 1600’s show that Native Americans were interested in blue crabs as a source of food.
“If you look back at the records of when colonists arrived, and negotiated fishing peace treaties, including hunting and fishing rights in the Chesapeake Bay region, those descriptions and those treaties including rights for crabbing for finfish as well as a collection of oysters,” Hines said.
If Native Americas were negotiating for crabbing rights, why are crab shells missing from Indian archeological sites, while oyster shells and even fish bones are common?  To solve  the mystery, Hines and colleagues at the Smithsonian re-examined old trash piles around the Bay using a new technique.  They used sieves with a very fine mesh.
Scrutinizing historic sites more closely with these sieves, the researchers discovered  tiny fragments  of crab shells in 93 different Native American refuse heaps  around the Bay, some dating back more than 3,000 years, according to an article that Hines and colleagues published last month in the Journal of Archeological Science titled, “Archaeology, Taphonomy, and Historical Ecology of Chesapeake Bay Blue Crabs.”  His co-authors are Torben Rick, Matthew Ogburn, Margaret Kramer, Sean McCanty, Leslie Reeder-Myers  and Henry M. Miller.
Their conclusion was:  Native Americans, in fact, ate plenty of crabs.  But the shells broke down over the centuries, perhaps in part because of acid rain from coal fired power plant pollution in the 20th century.
“The main part of the blue crab that carries forward in these middens are the tips of the claws, which are the most calcified hard part of the crabs,” Hines said.
Analyzing the size of tips of the crab claws they found, the scientists extrapolated how large the crabs must have been. They concluded the crabs caught by Native Americans were much larger than they are now – some twice as large as the typical five inch crab caught today.
“We’ve found middens that contain crabs as large as 10 inches, which is a quite large crab,” Hines said.  “So that’s interesting.”
These giant crabs were not a different species. They just lived longer, because they faced less fishing pressure.  Crabs today typically do not live more than two or three years because most are quickly scooped up by watermen using dredges or pots. Every year, about half of all the adult crabs in the Chesapeake Bay are caught.  But back in Native American times, maybe one percent of blue crabs were harvested every year by people using baited lines and dip nets.
So blue crabs lived as much as twice as long, and grew up to twice as big. Imagine those meaty crab feasts on the Old Chesapeake Bay, with those monster crabs.
The lesson we can learn today from these ancient garbage heaps is that we can have more of what we love if we take less.
....................................
(Photo at top of Tuck Hines and blue crab from Smithsonian Environmental Research Center)

Monday, June 15, 2015

2015 Connecticut Blue Crab Special Notice #1

From Tim Visel at The Search for Megalops:


The Search for Megalops

Special Notice # 1 – Blue Crab Winter Kill
- Habitat Transition Now Apparent –

Blue Crab Research in Long Island Sound
You do not need to be a Scientist to report!

(IMEP Habitat History Newsletters can be found indexed by date on the
BlueCrab.Info™ website:  Fishing, eeling and oystering thread)
and CtFishtalk.com™-Salt Water Reports and
the http://bluecrabblog.blogspot.com/

Tim Visel, The Sound School

June 15, 2015

Blue Crab Winter Kill
This spring has been somewhat discouraging for blue crabbers along the Atlantic Coast – first as an indication that a large amount of our over wintering blue crabs have perished and second a weak showing in the 2014 Megalops set.  First winter kill reports from the Chesapeake Bay report as much as 30% have died but along our coast 60% or more from early reports.  The long cold winter is now suspected to have allowed sulfide levels to rise especially under ice – to those lethal to Blue Crabs (and perhaps over wintering Terrapins as well).  Winter kills of fish, oysters, blue crabs and turtles are not new but indications of rapid habitat change.  Fish trapped in deep holes under ice can be killed from sulfide – the by product of organic matter digestion, coastal salt ponds appear to be the most vulnerable (and unfortunately one of the few habitat refuges for blue crabs) in our area.  For example the Black Hall River in Old Lyme is now suspected if a sulfide fish kill last February (2014) when ice formed and about 1,000 striped bass were killed.  Conversations with area blue crabbers mentioned previous winter fish kills of stripers– not as large but accompanied by the smell of sulfur.  The most susceptible winter kill areas are small coves and bays with long “weak” connections to the Sound – frequently described as “poorly flushed.”  Such areas tend to collect the deepest organic deposits – when in high heat these areas undergo ammonia/sulfide generation.

In the scientific literature such deposits are mentioned as “fine muds – low oxygen sulfuric oozes” but many fishers call it Black Mayonnaise (Sapropel).  A cold winter with many powerful storms – turns over this marine compost much like a huge shovel releasing tremendous amounts of nutrients for spring algal blooms.  Areas that once held deep soft deposits of organic matter undergoing sulfate digestion (sulfur reducing bacteria) can release a sulfuric acid wash with a dramatic pH drop – increasing toxic impacts.  These kills are more frequently associated with black waters following storm events.  In time coastal storms over a period of years may transition sulfuric oozes (black in our area from iron) to sandy shelly brown mixtures with some mud but loose and not sticky.  It is these “recultivated” marine soils that can sustain heavy sets of shellfish such as the Long Island Sound and Narragansett Bay great Quahog sets in the 1950s and 1960s (cooler period more storms).

Habitat Transition -

A recent shell hash seagull survey (June 1) at the Niantic River state launching ramp (parking lot) yielded about 30% of dropped shells were in fact bay scallops (sea gulls don’t waste their time dropping empty shells to crack so this is a quick way of determining locally what’s around) and 60% were quahogs – the rest mussel, oysters and soft clam.  Around January 20th bay scallops moved into the lower reaches of eastern CT Rivers.  This is another indication of a major habitat transition – the return of bay scallops to Connecticut.  Habitat transitions are usually marked by sudden climate and energy shifts and the increased occurrences of multi species winter die offs.        

Habitat transitions in the historical literature are not quick they in the past took decades and a return of warm winters and few storms would help the blue crabs – last winter obviously did not.

Any reports of Blue Crabs (dead or alive) would be a help – all observations are important. 

Thanks for your continued interest – tim.visel@new-haven.k12.ct.us

2015 Connecticut Blue Crab Report #3

From Tim Visel at The Search for Megalops:

Megalops Report #3
The Sound School Regional Vocational Aquaculture Center
Blue Crab Research in Long Island Sound 2015
You Do Not Need to Be a Scientist to Report
May 30th, 2015
Tim Visel

  • An Early 2015 Season Forecast
  • What to Expect for The 2015 Blue Crab Year
  • The Western CT Event in 2011

Follow Megalops reports on the Blue Crab Info™ Northeast Crabbing Resources. IMEP habitat reports can also be found on the Blue Crab Forum’s™ “fishing, eeling and oystering” thread. Thanks also to Connecticut Fish Talk ™ for including Megalops Reports under the Saltwater Reports thread and the Blue Crab Blogspot™, for posting all Megalops Reports.

An Early 2015 Season Forecast 
Several crabbers have asked about a 2015 season forecast and if this upcoming blue crab season will be better than 2014.  It’s early but some indicators point to another very slow start.  The excellent 2010-2012 seasons had reports of 1-inch crabs on the open beach fronts, on shellfish beds and in shallows along miles of the Connecticut coastline.  That was in March, April and springs were warm – (Megalops report #2 April 23rd 2012).  The past two years small blue crabs appeared in September – October in deeper waters offshore.  The evidence was reported by Black Sea Bass fishers the past two years (Megalops report #6 October 24, 2013) (Megalops report #4 October 9, 2013).  This was in deep water and far from the marshes – the better habitats.  It is the creeks and head waters that provide the best protection until spring.

Recent conversations appear that the Megalops set last fall was larger than I thought and underestimated the predation by Black Sea Bass.  Reports now indicate that nickel size blue crabs extended from central Long Island Sound to eastern Long Island New York to the west of Block Island to the Rhode Island salt ponds.  The set was most likely stretched to tens of miles than a few miles concentrated in central Long Island Sound.  These small crabs were in deep water and miles from shore.  They must have suffered tremendous predation (as evidenced by Black Sea Bass catches) and faced a huge pool of potential predators.  If any of these crabs made it to shore they had the cold and storms that followed.  The presence of small crabs early along the coast would have been a good sign.  But to date such coastal reports have be slow to materialize.

Large crabs showed in the Connecticut River to Milford in 2012 (Megalops #3 June 19, 2012) even before the official season opened.  Winters were mild almost warm then and relatively quiet.  That appears to be the opposite now, although our winter was on track to be mild until December 20th (I had blooming dandelions the middle of December) then it turned colder and then proceeded to break snowfall records. 

The cold winter took a heavy toll of the Chesapeake Bay population to our south as “winter kills” reported to be 30% and I would expect the same here – perhaps more.  The worst winter kill ever recorded was following the 1976-77 winter there and reported to have killed 48% and the shallow waters suffered the worst (Krantz GE 1977). 

The last indicator I look at is the distribution of the run last year, but reflecting upon observations, most of the crabs were legal size (except for the Clinton Harbor region) and very few sublegal.  In 2010 and 2011 at times the dozens of small crabs stripped bait from hooks in minutes in Clinton Harbor (Megalops report #11 July 27, 2011).  Although this made for some frustrated rod and reel fishers it was a terrific sign to the blue crabbers and large number of small crabs were “coming up.”  Last year I observed only a few small crabs, most crabs caught were adults – giving the appearance the fishery was by sustained by previous year classes which can only last so long.  

Our fishery seems to be existing off the 2012 and 2011 perhaps even 2010 sets but that will soon “run out.”  The absence of a widespread set is a negative sign for the season, but 2011 blue crab year also started slow.  The next indication would be a set by July 1st.  Small crabs 1 to 2 inches depending upon water temperature could shed to legal size by the fall – this season.  The source of this set would most likely be a set carried north on the gulf stream, which depends upon wind shear and warm water rings that can spin off and hit eastern Long Island.  (They also bring us the interesting tropical fish from time to time).

Many years ago researchers in the Cape Cod area came to the same conclusion that such blue crab larvae did in all likelihood originate from areas further south and were transported into salt ponds on the Cape and Islands.  A 2004 report has this section “The Megalops stage lasts 6 to 20 days.  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 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” (Blue Crab Ecology Review and Discussion Regarding Tisbury Great Pond, March 2004, William M. Wilcox, Martha’s Vineyard Commission).  In a Rhode Island blue crab study Jeffries (1966 Internal Conditions Of a Diminishing Blue Crab Population) reported that after high producing years 1910-1915 in Narragansett Bay when it was possible to catch a bushel with one line on a morning tide crabs, had retreated to only two salt ponds Charlestown and Greenhill.  The last appearance of large numbers of blue crabs happened in Pt Judith Pond in 1947.  Reports during the same period in the Westport River, Buzzards Bay mention the same situation.

A Study Of The Marine Resources of the Westport River, Massachusetts Monograph Series 1968 John D. Fiske et all – (60 pages) has this comment.

“The Westport River is one of few regions the South Shore of Massachusetts where blue claw crabs (Callinectes sapidus) still occur in numbers sufficient to supply a family fishery – especially at Hix Bridge pg 39.  The Blue Crab is a species which was formerly abundant on the South Shore but has been declining in numbers for at least the last decade.  The cause of the decline of the crab in our waters is unknown.” 

And on the Cape generally the same observation – A Study of the Marine Resources of Pleasant Bay – Chatham Orleans Fiske et al (1967) – pg 48 has this comment,

“It should be noted that during the 12 month sampling period biologists did not capture or observe one blue claw crab in the estuary (Pleasant Bay).  During the course of interviews, many local fishermen expressed concern over the disappearance of blue claw crabs in the bay.  In recent years, there have been similar reports from many areas along the southern shore of Massachusetts.  Until recently many bays and tidal rivers supported substantial family fishing for these edible crabs.  Since this species appears to be in marked declining, specific investigation should be conducted to find the case of this decline and to determined possible methods of rehabilitating the crab stocks,” pg 48.

The later series never reveals any information pertaining to the Blue Crab – and this period was the height of the negative NAO period, cooler and many storms – when the warmth returned to the Cape in the 1980s – the Blue Crab also returned.

A Habitat History is Important

By the time the 1960s occurred on Cape Cod or the Massachusetts south shore few could recall that in the 1890s the New Bedford Buzzards Bay area was once the “capital” for the Massachusetts commercial blue crab fishery.  The causative factor for the southern New England Blue Crab population decline was in fact temperature related to climate patterns – cold.  The cool temperatures most likely delayed the Megalops set as we are seeing now.  Storms may have changed habitat types removing the Sapropel/eelgrass and leaving cobblestone/kelp 1950-1965.  This period is now noted for its negative NAO climate pattern.

Dr. Willard Van Engel (1985 laws regulations and environmental factors relating to the Blue Crab 1880-1940 #347 VIMS VSG 99-07) a noted blue crab researcher in southern areas looked at environmental factors and hoped that an extreme event would help signal why blue crab catches fluctuate, and comments on page 47, “Extreme variations in those factors (environmental) are more likely associated with extremes in year class strength and fishing success.  Only when accurate catch and landing data are available for times proceeding and succeeding the occurrence of any of those events can the degree of association be determined.”

Southern New England has again experienced a surge in blue crab abundance – following decades of heat, followed by a sharp reversal in winter severity – cold and many Nor’easters.  We may now have in our area the extreme example that Dr. Van Engel long searched for.     

What to look for is a widespread set of 1 inch crabs along the shore in shellfish beds by July – any sets much later than that would be good sign for 2016.  This year head to those salt pond habitats they may have larger numbers of crabs that were protected from heavy winter storms.

See you at the Docks.
Tim Visel – (Blue Chip)

  • What to Expect for the 2015 Blue Crab Year
I would like to respond to the many comments and questions about disappointing blue crab catches here last summer in Connecticut and the prospects for this season.  For many western blue crabbers, the crabs “never arrived”. [Still no crabs.] Last year this of course is in stark contrast to previous summers and should we now be looking for a habitat failure for blue crabs for this year?  I am reluctant to confirm a habitat failure, but ready to share what research information I have about cyclic habitat reversals here. I continue to appreciate the opportunity to reach so many crabbers on the Blue Crab Info™ website.

First of all, I hope that the remaining “Megalops Reporters” will continue to look for crabs, even reports of dead crabs or no crabs observed are important. I appreciate all the observations to date and no matter how brief, they add to our knowledge here of blue crabs in southern New England. As for the lackluster blue crab year (2014), so many crabbers have asked, “what happened?” and “why?” in response to disappointing catches in 2014. Almost immediately overfishing comes to mind, and I respond with a firm “No.”  Our gear here is so limiting most of the blue crabs are not caught and face a very uncertain future in the deeper predator filled Long Island Sound.  I did see crabs wasted, however (Megalops, August 2012), but overfishing did not occur in my view.  I offer these explanations for last year’s sudden decline.

1) Increase in Coastal Energy and Rains– A series of coastal storms, hurricanes and Nor’easters- small crabs were just washed out of hibernating areas or cast loose by bottom disturbance (Notable periods in the 1950s and 1960s.) It wasn’t sudden if you looked at the Megalops sets after 2012. Huge amounts of organic matter also entered our estuaries after 2011. [This can impact blooms of algae by releasing huge amounts of nitrogen compost compounds similar to a fall overturn in lakes.]

2) Decrease in Temperature 2004 onward our winters have on average been colder and longer upstate New York last year had snow in May and we had some in October. Colder winters generally over time have not resulted in large blue crab catches, only smaller. A series of cold winters in our area appear to have the lowest landing impacts.

3) Extreme Heat – As our summers warmed, they have perhaps become “too hot” driving low oxygen conditions to that of sulfide toxicity – Sulfate reduction that took any remaining oxygen while producing toxic sulfide compounds in organic deposits: the so-called Black Water deaths of the past century, crabs would leave very warm shallows and head to the deeper, cooler, more saline pockets, that is what happened in 2011 and to a lesser extent in 2012 (Megalops #6, July 19, 2012, Megalops # 7, August 9, 2012).

4) Failed Megalops Sets – Predators- A series of native Megalops sets that just came too late; did not reach the salt ponds or marshes in time to be consumed in deeper waters by predators (Megalops #6, 2013) and (Megalops #4, 2014) Black Sea Bass was the species reported to be consuming small blue crabs in deeper waters.

Any or all of these factors contribute to low blue crab numbers. One of the things you see is just before a habitat failure catches actually increase from compression this would happen just before some of the largest fish kills of the last century. This is a frequent post low oxygen events (called Jubilees down south) crabs attempt to flee low oxygen by walking ashore followed quickly by fish kills and then sulfide toxicity (the rotten egg smells mentioned in many of the last century reports). Huge fish kills often follow crab kills, at Niantic Bay in the late 1970s (personal communication B. Porter, 1985) the most infamous Black Water death event in Moriches Bay, New York in July and August of 1917. Winter Flounder trapped in the Bay during high heat died in a low-oxygen sulfide event.

Other sulfide events are associated with noxious sulfide fumes staining houses (Mackenzie NOAA 1998) and on Narrow River (sulfide levels larger than the Black Sea, Gaines 1979) Rhode Island (and personal observations) of acidic fog droplets at Niantic Bay (personal communication, B. Porter, 1985) are also in the historical literature. The sulfur cycle has a role in wintertime survival as well.
What to look for—most organic filled bottoms can still contain blue crabs at higher tides (higher oxygen).  At low tides, respiration can lower oxygen levels; this seems to be a natural tidal response – (see Tom’s Creek Study of Habitat Succession).  In these times bottoms organics rot in heat and release gas bubbles at slack tides as the gas continues to be emit “bad” smells – look for a series of gas bubbles coming to the surface (Megalops #3, July 23, 2013). When crabbers can see bubbles, crabbing activity drops off measurably, crabs may hook up but let go immediately, an incoming tide bringing fresh oxygen, cooler water into these warm shallow areas and crabbing usually improves. In Central CT, low tide crabbing is often very poor on these very hot days.

Rivers often contain such organic deposits and crabbers on the DEEP Fishing Pier at Baldwin Bridge (July 20, 2013) were amazed to see streams of bubbles coming to the surface. They had never really noticed them before.  This is a negative habitat sign, as well as hard bottoms sand and shelly before now covered with feet of Sapropel after a heavy rain. And the gas (bubbles) – in cold waters (more oxygen) tends to be methane, and in warm weather, (less oxygen) would be hydrogen sulfide gas, sulfur smelling and the rotten egg smell mentioned so many times in the historical fisheries literature. (The nighttime marsh smells of a very hot August summer is also the same process.)  At higher tides and places with currents, these gas bubbles are hard to see and crabbing is generally better. At high tides when the salt wedge is strong, the best crabbing occurs; (The DEEP Baldwin Bridge Pier has allowed hundreds of families to come to the shore and catch blue crabs; it is quite a facility for fishers).

A series of coves that has incredible amounts of Sapropel (mostly from acidic oak and maple leaves) are North Cove, Middle Cove and South Cove in Essex.  On July 20, 2014 low water the gas bubbles from organic deposits (foot of Park behind Main Street Essex Post Office) was continuous in all directions. Kayakers often report smells from these pockets of gas (sulfur) when transversing Sapropel deposits on days with little wind, similar to the “marsh gas reports” of the last century.

5) Other concerns- West Nile treatments, (see report Pesticides and Blue Crabs, July 24, 2012) salinity shock from heavy rains, low oxygen events and overfishing. I do not believe in any way it is overfishing here we have good laws and I found it to be impossible to overfish an area when the run and distribution of post Megalops was so even. In early July 2011 West Nile treatments certainly didn’t help, but it is my understanding that such treatments have been now sharply curtailed / controlled.  Salinity shock (too much rain) that is mentioned in the historical literature often and I have seen a massive die-off of 2” crabs in the Connecticut River following a heavy rain.  But some of the Megalops densest sets have come from salt ponds in the Fairfield- Western CT region and perhaps not as susceptible to rainfall events, (Perry Mill Pond). Low oxygen is possible but we should have seen massive fish kills also, but we didn’t, at least not to the extent found in the historical literature (The Great Narragansett Fish Kill of 1898).

Instead, I believe that massive amounts of organic matter have been washed compliments of recent storms (Irene, Lee and Sandy), into the lower reaches of estuaries in western CT and rotted, releasing sulfur rich Sapropel into the water column or producing hydrogen sulfide toxicity is not great for blue crabs.

Studies regarding sulfate and sulfide compounds toxicity to blue crabs find them to be extremely sulfide sensitive and result in “DIP”, “death in place” unable to escape and die almost instantaneously. If you refer to a blue crab report #12, August 2, 2011, see “western crabbers alarmed at dead crabs following intense heat and street water runoff event”. It appears that one event reduced blue crab catches in certain areas by half in just three days.

One of the limitations of compiling an environmental habitat history is that climate and storm impacts are usually reported and measured to impacts upon shore infrastructure and “us” – only - not habitat quality. Badly eroded beaches, destroyed homes or collapsed seawalls garner attention; you can see this by the federal and state response to the destruction of the 1950s and 1960s with flood and erosion control legislation. After federal authorization many coastal communities created flood and erosion control boards or committees. In the 1980s and 1990s as energy erosion events declined, they were often disbanded. High heat and the lack of energy (anoxia) was the news events for Long Island Sound in the 1990s. Very little evidence or research was being conducted about changes to finfish and shellfish habitats  or over the long-term changes in them.
One of the few consistent remarks in the records of the Great New England Hurricane of 1938 was on sandy stretches hard shell clams were often cast upon heaps in the Southern New England.  After the storm efforts focused upon the human tragedy, certainly not the habitat impacts to blue crabs. I don’t think blue crab habitat quality was on anyone’s’ radar after the 1938 hurricane. But substantial habitat changes were ahead for New England the hurricane nearly wiped out the Connecticut and Rhode Island oyster industry and shortly later had the greatest hard clam quahog sets in a half a century. Thousands of acres of eelgrass were gone and so were the habitats to sustain them, sometimes forever.

The warm period 1880-1920 a century ago was marked by extremes, hot in the summer and then mild in the winter, it wasn’t’ until 1931 that warm spells and quick freezes would kill large numbers of blue crabs in the Chesapeake Bay  (Van Engel). The Chesapeake Bay would be the region to notice the difference between our temperature to water temperatures with 1931 being the key in which energy increased and temperatures cooled (Van Engel). 1931-1932 is mentioned in many reports as a key year for habitat change. This appears to the transition period between the hot and quiet 1890s and the storm-filled, colder 1950s.

Crab losses have been noted during storms and the Chesapeake Bay area was hit by severe storms of 1878, 1888, 1897, 1933 and 1936. At certain times extremely hot temperatures have created jubilees of low oxygen/sulfide toxicity and cold “winter kill” largely sulfide or starvation. Habitats were relatively stable until about 1944. The habitats were subject to a series of powerful hurricanes. The “story” of habitat changes in New England is much harder to determine because blue crabs are considered periodic mysterious visitors. The state of Connecticut Fisheries Management Plan of 1985 for example only has three paragraphs or so for blue crabbing but three pages for lobsters.

Others have mentioned disease and that certainly deserves a close look, but I do not find reference to diseases that would eliminate all year class sizes, 5 and up, 3 to 4, 1 to 2 and Megalops all at once and only impacting only the western third of the state. If anything could be said about the 2011 crab year was masses of blue crabs were leaving the Housatonic River region and moving east, something in the water (sulfide?) could have triggered movements before and after the July 2011 heavy rainfall.  The reports of night time movements of crabs include striped bass fishers suddenly surrounded “by schools” of blue crabs. References of “ocean schools” of crabs can be found in the historical literature.

Western Blue Crabs Population Declined in Three Days - 2011
In 2011, western Connecticut was hit by immense rainfall and intense heat (Western CT Habitat Failure, August 2011, IMEP #7, September 30, 2014 – Fishing, Eeling and oystering thread). The season started slow – after the spectacular 2010 season, but then soared, and then by August catches declined by half (Megalops Report #12, August 2, 2011).

Did the increase in storms also wash Sapropel and eelgrass from coastal areas? I believe they did, 50 years ago as eelgrass populations declined so did the blue crab. The blue crab might have a better habitat association to light (not extreme) Sapropel /eelgrass organic deposits, I suspect that this habitat type to be related to storm energy and temperature, while cold (winter sulfide starvation) and energy (dislocation burial) may be negative in high heat while energy storms might be just as negative in very cold. George McNeil, a retired oyster grower who lived in Clinton once told me decades ago that winter Nor’easters could deposit as much as three feet of leaves over Hammonasset River oyster beds in a single storm and they would need to be raked off by March 15 or the oysters would suffocate. Dead oysters killed by suffocation were termed “stools” adult shells still paired even dead but empty. One can only imagine how much dead leaves and organic matter have been brought down our rivers and streams by Irene and Sandy.  The rain effects in 2011 reduced crab catches by half in three days, with reports of dead crabs and brown water.  Productive blue crab habitats in western Connecticut have never recovered from these heavy rains (from reports).

Connecticut has most likely experienced these dramatic habitat reversals before as the previous four sections indicate – each relates to a research area that can provide us with information ahead about the rise of blue crabs have after 1998- and now a possible decline.

A nearly complete inventory of all the Megalops reports can be found on the Blue Crab.info forum website, the global moderator for the site has made bulletin board space for them- see “Blue Chip” reports *under Northeast Crabbing Resources) Megalops reports. All the 2011 reports are now compiled on a Bulletin Board (Northeast Crabbing Resources) and the fishing, eeling and oystering thread on Blue Crab Forum™.

All the 2012 reports (except specialized reports) can be found on the Northeast Regional Crabbing – crabbing resources section also by date).

The 2013 reports are compiled by date and the first report 2013 is also on the current bulletin board.  I am very grateful to the Blue Crab Forum™ for continuing to archive these reports as Connecticut crabbers looking into the apparent die-off of Western CT crabs. The run distribution and history of these pre-July 2011 reports are very important to compare to today.

I hope that this report the third this year, will be of interest to Blue Crabbers and researchers investigating Long Island Sound fishing resources.

Again my thanks to these few remaining 2011 western crabbers who continue to email me their blue crab observations – let me know if blue crabs “never showed”, that observation is important also. Every blue crab observation is important (perhaps more so) in western CT and many crabbers wait for some good news about large numbers of small crabs.

Tim Visel

Email your blue crab reports to: tim.visel@new-haven.k12.ct.us. All blue crab observations are valuable as we learn more about our blue crab population. Questions? Send me an email.
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 Regional High School Agriculture Science and Technology Center enrolling students from 23 participating Connecticut communities.