As promised...

Talks by members of the New York chapter of the American Fisheries Society are now online, and you can see them here. There are some truly excellent talks here, the sound is a little hard to hear in some of the talks, but worth the effort.

This talk was my favorite, and deals with the history of the second largest lake in NY (Oneida Lake).

AFS Presentation

I presented some of the work I did over the summer at the New York Chapter of the American Fisheries Society annual meeting in Lake Placid, NY. 

                                                     

Unfortunately (or maybe fortunately for viewers) the audio-video equipment could not be set up for my presentation this year, although there are some excellent talks that were recorded there. Once they are posted to YouTube I will link them here for those interested. 

However, in case you were still interested in seeing the presentation I gave, have a quick peek at the attached video (no audio):

Fossil Ammocoetes!

Recently (in October) fossils of lampreys were reported in the Proceedings of the National Academy of Science (PNAS; link to article). Chang et al report the first fossil ammocoetes ever found, as well as fossil transformers and adult lampreys, all from the same beds! Below is a picture from their article of an ammocoete (A), a transfomer (B and C), and closeups of the head of an ammocoete (D and E) and a transformer (F and G).

Below is the the top panel A with one of my ammocoetes imposed over top of a fossil ammocoete and a picture of the live ammocoete below.

These fossils were found in Lower Cretaceous rocks 125 million years old, and as you can see they appear very similar to modern ammocoetes. This is important for understanding when lampreys evolved and if the ammocoete stage is useful for developmental biology studies. If the ammocoete stage evolved long after lampreys broke away from the rest of the fish ancestors it is not as useful at letting us understand how early fish lived. If on the other hand it has been around since lampreys first diverged we are literally looking back in time at an early fish.

This first ammocoete fossil lets us know the modern pattern of development in lampreys goes back quite a way. Lampreys probably diverged from other fish between 350 and 450 million years ago, but without more fossils we cannot narrow down the time more precisely. However, current evidence suggests that lampreys diverged from other fish (including ourselves) closer to the 450 million year ago mark. This makes lampreys (as a group) close to a half billion years old! For comparision dinosaurs don't appear until ~230 million years ago, meaning that they are only half as old as lampreys.

Citation
Chang, M., Wu, F., Miao, D., and Jiangyong, Z. 2014. Discovery of fossil lamprey larva from the Lower Cretaceous reveals its three-phased life cycle. PNAS 111 (43) 15486-15490.

Final Sampling Day of 2014

I have finished sampling for this season. The water is getting colder and higher, and the leaves are starting to cover all of my sampling sites. It felt good to finish up part of my work.

The face of a stream changes every day, but it is very obvious during the fall after the first rains. The water is rising and will cover this cobble bar probably for the rest of the year.

 A similar picture, but look at the differences in the greenery around the stream.

The net I use to keep my animals in my study area as I collect them. Here it is set around one of the pools I sample. The large tree behind them is a log that was trapped under the bridge when water levels were higher. It has been there all summer and may have been trapped there during the spring floods.

A picture looking at the same area, but a better view of the net and the box it gets stored in.

I had help from an undergraduate who volunteered from the course I am teaching. It drizzled during the day so he wore is hood down.

Here he is measuring a lamprey and preparing to take its weight.

Two pictures of the same handful of lampreys. The smallest animal immediately in between my fingers is <1 year old. This animal was washed downstream during the fall rains and made it here. I have no idea how far down it came, but it could be from quite a ways upstream. The other animals in the picture are probably about 1.5 years old now.

The other side of the bridge. The trees on the mountains have already dropped their leaves for the most part, and we are getting ready for winter.

Last Trip to the Genesee River this Season

This was my last trip to the Genesee River this season. I will return (as General MacArthur said) but not until the spring of next year. Water temperatures will be too low for me to get my little guys to emerge from the sediment, and the falling leaves make seeing them increasingly difficult. Also fall is generally a rainy time in the Northeast (though we have not had any yet) and water levels will start to rise very quickly once the rain does arrive. Finally, I am sure on sunlight. I finished with ~15 minutes left, and the days are only getting shorter. In very short order I will not be able to do a single site in a day. Hopefully next spring some of the animals I tagged will still be in the stream, although I suspect that many of them will have washed away down river by then.

One of my lampreys getting weighed and showing off all its tags. It was just about ready to be dropped into a bucket to recover.

The fall is certainly here. Willow leaves starting to build up. As the trees drop their leaves they release the nutrients stored in those leaves in the water. They also allow much more sunlight to get into the stream and algae growth booms this time of year. The rocks were well covered and very slippery.

The tree which those leaves probably came from further upstream. Only a month ago everything was bright green and growing well.

A tree that marks the site of one of the pools I sample. It has already lost almost all of its leaves. The pretty pink string marks my study site.

The same tree slightly further away. The "pool" I collect from here is really just the margin of the stream where some sediment has built up. Actually the animals I catch under here don't really move even though there are no barriers that would prevent them from doing so.

One of my smallest lampreys. I continue to catch this animal (and have since August) at the same pool. It has grown just 3 mm in 3 months. If you grew as slowly as it you would need millennia to get to adult size. Even for lampreys this is really slow. Other animals its same age are about twice as long and more than twice as heavy. This animal is probably not sick or having a problem, it probably just cannot get much to eat and has to grow very slowly. At the rate it is going it will be an adult in about a decade. It will probably get washed downriver this fall and if it does it may find growing conditions better in its new home. Obviously catching such a small fish over and over suggest that mortality is fairly low once they find a place to burrow.

One of the pools where I catch many of my study animals. There are quite literally hundreds of lampreys in this pool. I have not yet seen one other fish in the pool, which is also pretty cool. The pool is now coated in algae so catching them is a little challenging. It will be easier again once I return in the spring.

More plants marking the edge of another one of the areas I sample.

Many of the trees have lost their leaves already, but some are still losing them.

On the Delaware River before the Fall

Fall is rapidly approaching and while I was out sampling this weekend I definitely saw that. The water is getting colder and the trees are changing color.

The water level is also extremely low (as is normal during this time of the year). Here is a picture of where I work. When the water levels go back up this rock bar will be returned to the stream.

A picture looking upstream partially underwater of the same area. The water is so green because it was very cloudy.

The new rip rap put in by the NYSDEC to provide parking. This is not actually good management unfortunately. The rocks will turn the stream into the other bank and cause the river to erode into the bank just in front of the bridge. Likely DOT will need to come out in the future.

 

A small dam just upstream. Behind the dam is a pool where I catch lampreys every month. They do appear to leave here with some regularity so it is not a complete barrier to their movement.

Just before I left I took a picture of the valley from the parking lot. Quite a scenic place.

Tagging American Brook Lamprey

I returned to Dyke Creek last Saturday with my wife so I could finish sampling in one day. We had to wake up early and we did not return home until almost midnight, but we did manage to finish the entire site. Unfortunately, we did not capture any transformers, but since Cait was with me there are pictures of me. We stopped taking pictures relatively soon after arriving as we were trying to get through samples as quickly as possible so we would finish before the sun went down.

This picture was taken just to the right of the first pool and looking downriver. The stream actually braids into two separate channels just above this point, so this is about half of the stream.

Route 417 as it passes over the site. We set up our first sample processing station just under neath. Cait moved it slightly so she could sit in the sun.

Working up an animal with the syringes used to inject the color in the foreground.

Brought a chair this time so I (or Cait) did not have to sit on the cold rocks. Temperatures started off in the 50's and rose into the high 60's low 70's by the end of the day. Water temps held steady around 58°F.

A nice picture, taken by Cait, from the shore.

Setting up the blocking net before starting to shock to prevent lampreys from escaping while I worked.

Pictures of me sampling further upriver. The pool here had quite a bit of algae growth so my ability to catch the lampreys here (where Brooker lives) was low. That is not a problem for the models I use, but means that the total number of animals we needed to work up on this sampling occasion was not as high as in the past.

I am trying to go out again this weekend. If I succeed I will update the blog again. Until next time, happy lamprey hunting.