What a difference a day makes. At this time of year it's more apparent than ever. We've had a stretch of warm weather and although we knew better many of us were thinking spring. But the reality is that water temperatures are down near the 30 mark and it only takes a bit of cold air to freeze us in again.

Our annual meeting will be held on January 24, 2010. One of the featured speakers will be Jeff Kneebone of Division of Marine Fisheries. Jeff will be discussing his current PhD research on Sand Tiger Sharks. To pique your interest and give you a bit of background, I'm reposting a DMF summary of the project. This was was originally prepared by DMF in 2008 and featured on our website....

The sand tiger shark (Carcharias taurus) is a large coastal species that ranges from the Gulf of Maine south to the Gulf of Mexico along the east coast of the United States. They are commonly found in inshore waters ranging from 6 – 600 feet in habitats such as surf zones, shallow bays and estuaries, rocky and coral reefs and near shipwrecks. Sand tigers can be identified by the presence of two large dorsal fins, a large anal fin, large thin teeth, dusky spots along the side of the animal and black coloration at the tips of the fins.

Sand tiger sharks in New England:

Sand tiger sharks are seasonal visitors to New England waters during the warmer months of June – November. In the early to mid 1900’s sand tiger sharks were considered to be one of the most common shark species in New England waters and both commercial and recreational fishermen caught large numbers of individuals as far north as southern Cape Cod Bay. During this time, a directed commercial fishery was established in Nantucket Shoals, however, this fishery was short lived due to rapid depletion of the local stock. Unfortunately, increased fishing pressure on the species along the entire east coast of the United States during the mid – late 1900’s severely depleted sand tiger populations, including those around New England. In 1997 as a precaution to stop fishing mortality, the National Marine Fisheries Service (NMFS) prohibited sand tiger sharks from being targeted and retained in both commercial and recreational fisheries. In 2005, Massachusetts state law also prohibited the targeting and retention of sand tiger sharks in state waters.

During the last few years, an increasing number of juvenile sand tiger sharks are being incidentally caught in Massachusetts coastal waters, particularly along the south shore in Plymouth, Kingston, Duxbury (PKD) Bay. Interestingly, occurrence of sand tiger sharks in this region appears to be a relatively new phenomenon as local fishermen claim they have never seen this species in this region until recent years.

Our Research:

Over the last few years the Massachusetts Shark Research Program (MSRP) has worked with commercial and recreational fishermen in the region to investigate the presence and abundance of sand tiger sharks in Massachusetts state waters. Based on recent catch records, most of the sharks inhabiting the region are young of the year (newborn) individuals. While the lack of large females in Massachusetts precludes the use of Plymouth, Kingston, Duxbury Bay for parturition (birth), it appears as though these coastal waters provide secondary nursery habitat for sand tigers that move north from southeastern pupping grounds. Given their increasing numbers in PKD Bay, this embayment may be the most important secondary nursery area for this species north of Delaware Bay.

At present, the MSRP has a study underway goaled at investigating regional movement, habitat use and the effects of capture of sand tiger sharks inhabiting New England coastal waters. Working in conjunction with local commercial and recreational fishermen, the MSRP is actively tagging sand tiger sharks with acoustic telemetry tags to quantify both regional and large-scale movement patterns and habitat use. Each acoustic tag emits a unique coded signal that can be picked up by a series of underwater receivers (listening stations) located in fixed positions within Plymouth, Kingston, Duxbury Bay and Massachusetts coastal waters. If a shark swims within range of a receiver, the unique signal of its acoustic tag will be logged and stored as a data point on the receiver. Periodically the data logged by the receivers will be downloaded onto a computer and analyzed to generate information on regional movement, habitat use and overall ecology. Fortunately, receiver arrays maintained by other researchers in other regions (i.e. Delaware Bay and North Carolina) are capable of detecting fish tagged in New England waters, allowing for the potential to learn about large-scale movements of these young fish.

Data to date

In September 2008, three sand tigers were tagged with acoustic tags within PKD Bay. In the few weeks during which they remained in the Bay, various receivers logged 2,727 detections and provided some interesting information about habitat utilization. Interestingly, one fish tagged in the Jones River in early September was detected in a receiver array near the entrance to Pamlico Sound (Cape Hatteras, North Carolina) during mid-January.

During the 2009 season, the MSRP will continue tagging sand tiger sharks with acoustic transmitters within PKD Bay. Working in conjunction with the Jones River Environmental Heritage Center, the MSRP also hopes to periodically maintain captive sand tiger sharks in a holding tank located at the Jones River Landing for experimental purposes as well as for public outreach.

If you would like more information about this project or would like to report information about sand tiger shark occurrence in Massachusetts waters, please contact the Massachusetts Shark Research Program at 508-910-6329 or 508-693-4372.

References

Bigelow, H. B. and W. C. Schroeder. 1953. Fishes of the Gulf of Maine. Fishery Bulletin of the
Fish and Wildlife Service. 53:74

Gilmore, R.G., J.W. Dodrill, and P.A. Linley. 1983. Embryonic development of the sand tiger
shark Odontaspis taurus (Rafinesque). Fishery Bulletin 81:201-225.

Skomal, G.B. 2007. Shark nursery areas in the coastal waters of Massachusetts. American
Fisheries Society Symposium 50:17-33.

When we talk about the fish in the Jones we often focus on river herring. Those of you who have participated in the fish counts at Elm St are familiar with these flashy fish that shoot up the ladder (in far fewer number than we hope for). But while we watch for these swift swimmers there is another species of fish more subtly moving up the river.

American eels (Anguilla rostrata)are another essential part of the Jones River ecology. Like river herring, american eel populations have recently declined. The same types of threats have impacted both of these species - migration obstacles (dams), over harvesting, water quality, and reduced habitat to name a few. However, so little is known about eels that it has been difficult for scientist to pinpoint population numbers, trends, and impacts.

Both river herring and eels fall into the category of 'diadromous' fish, meaning that they spend part of their life in salt water and part in fresh water. Most of us are familiar with how this relates to river herring, salmon, and other fish that afe born in freshwater, migrate out to sea, then return years later to spawn in the same waters where they were born. These are a subset of the diadromous known as 'anadromous'. Eels fall into the other subset - 'catadromous' fish. Eels are born somewhere out in the Sargasso Sea, a region out in the middle of the North Atlantic. The tiny newborn eels then find their way all the way back to the eastern coast of the Americas. For reasons unknown, they branch off and swim up thousands of different rivers along the coast. They continue to migrate upstream as far as possible until finding good safe habitat to grow. Female eels may spend as much as 40 years in our local streams and lakes growing to up to 5 feet. Then on a dark rainy fall night (when you are least likely to notice) masses of eels slither back down the rivers and head out to the Sargasso to spawn and start it all over again.

This year, JRWA and DMF have begun tracking eels in our watershed. We had some fun wrangling eels over 2 1/2 feet long. We unexpectedly found thousands of eels trying to climb the Wapping Road Dam when the water levels dropped. In 2010 we'll be increasing our efforts to understand local Eel populations. And of course we are working hard to revive the conditions needed for their survival.

....and that was just the beginning (see Part 1 below). After reemerging at my truck on Grove St we were able to drop the trash we had picked up and shed a few layers. Although, with poison ivy threatening from all angles I decided to stay fairly bundled up. We did a short assessment of the road and railroad culverts then headed to Three Rivers Basin to carry on down the river.

Here we opted for the canoe again. After paddling a short ways up Jones River Brook, we headed back into the main channel and pushed downstream. There are some very nice, secluded stretches of river here with diverging channels and low marsh all around. Eventually though, we came to an impassable wall of thorns. Now it was time to ditch the canoe and head out on foot again. Pine assured that it was "only about 600-ft" to the final culvert we were seeking to inspect. Hmmmm, may need to remeasure that Pine! The terrain in the old cranberry bog is soft, wet, hummocky grass that ranges from knee to head high. In between each small tuft of unstable high grass is mud that threatened to steal the hip waders at each step.

It seemed like many miles and many hours, but mostly it was just the tough terrain. Eventually we reached the final culvert. In the end, we were all pleased to see that although the going is pretty rough for people, there does not appear to be any major impediments to fish passage. As Brad put it "There is a lot of work to be done in here but there is no 'project'". Essentially this means that with some chainsaws, brush cutters, and a few gallons of DEET a team of volunteers could clear this stretch of river without needing heavy equipment, funding, or high paid specialists. Boy scout project anyone?!?

I could keep going with this story, but these pictures should be worth a few thousand words....(slideshow removed)

I think of the South Shore as being a fairly crowded place. Nice...but crowded. But every now and then you find yourself in some pretty wild places. Monday was one of those days. With all of our plans to remove the Wapping Road Dam, the next big question is: so what will fish encounter once they can get up there? It's been along time (at least 85 years) since any anadromous fish swam past Wapping Road. Division of Marine Fisheries (and the rest of us) were very interested in having a first hand look at the condition of the river above the dam. Obstructions, rapid changes in elevation, loss of channel definition, and other factors could have serious impacts on the ability of fish to make it upstream....and the success of our restoration efforts.

So, only one way to find out. The day started out much colder and much rainier than the forecasters predicted. So after suiting up in scavenged raincoats and trash bags we jumped in the canoe to conduct our first headwater spawning habitat assessment of 2009. (Maybe more about these assessments in another post some day).

The lake work was uneventful...and then we headed into the wilds of the Jones River. It was only a matter of minutes before Brad (Brad Chase DMF) and I lost Pine in the jungle. We headed back to the truck thinking she had too. No luck. So we dove back into the woods. After about 15 minutes we started to hear more splashing and breaking branches than what we were doing ourselves. So in knee deep mud we reconnected with Pine. At this point it was clear that we had no intentions of stopping. So they carried on while I went back to leave a truck at our next intersection about 3/4 of a mile downstream. Once parked I decided to head upstream. The choices were:

1. In the river. Fairly clear sailing except that the soft bottom threatened to turn thigh deep water into neck deep at water at any step.
2. Along the bank. somewhat dryer than the first option but much muddier, much thornier, and way more poison ivy.
3. Along a trail about 60yrds away from the river.

Although option #3 was by far the easiest it kind of missed the point. So I opted for a combination of 1 and 2.

With phone, watch, and GPS buried deep in pockets under my coat and waders I had no idea how much time had passed when I finally heard Brad and Pine Picking their way downstream. I stopped and hid quietly behind a tree hoping to scare them as they got closer. Instead, I starting looking around at all the water and woods and spooked myself. I kept thinking "I'm glad I'm not doing this in Alaska". That was right about the time I heard Brad say to Pine "I'm glad I'm not doing this in Florida."
 

More to come in Part 2.