Sea lamprey in the Delaware River

I had the opportunity to look for spawning sea lamprey in the Delaware River last week as I prepared to sample it this summer.

The image above is not of a lamprey of course, but of a dragonfly emerging into its adult form. This is a Gomphidae (family), and there was a large hatch while I was there. The rocks and nearby vegetation was covered in these guys. Bad news for any insect smaller than they. All dragonflies are accomplished and voracious predators.

Here is a great picture of a large lamprey nest. You can easily see all the cleared areas that the lamprey have prepared and the cleaned stones at the base of the nest. I did not see any adults in the nest when I came. They may have moved on or been scared off by something before I arrived. The nest is about 2-3 feet across.

The video above is of two lamprey preparing to spawn. They move stones and remove sand from the area in which the eggs will be laid. These two were alone, sometimes you can find large numbers of adults all digging nests nearby one another.

All in all a pretty interesting trip. Hopefully more great finds to come this summer in the Delaware!

American Brook Lamprey in the Genesee River

Although lampreys are frequently associated with vampires and parasites, most lampreys are actually non-parasitic, they never feed on a fish. These species are called "brook" lampreys and are often much smaller than parasitic species. In New York we have three species of brook lampreys and I went to find American brook lamprey today. I went to the Genesee River, where the NYSDEC has numerous records of American brook lamprey, to see if I could also find them.

The one above is an ammocoete.

Adults swam by me as I waded in the stream. They were on their way to find a mate and produce the new generation.

This little guy was not terribly pleased that I detained him for a pic, he gave me the evil eye before I let him go.

Above is the stream from which these guys were captured.

I also went to another site and captured this guy quickly.

This site was actually a fishing access point, I doubt many individuals looking for trout realize they are literally stepping on lampreys!

These guys were all over the place at the above site. They are actually one of our largest caddisflies. They construct cases to protect themselves. This little guy seemed very content with being picked up and scraped my fingers to see if it could find any tasty algae. Caddisflies are important indicators of water quality.

As a side note I believe I am the first person to post pictures of American brook lamprey from the Genesee River. If I am going to be part of the Rat Race I need to carve out a little section I can call my own.

The run is on!

The spring must be upon us because the lamprey are starting to run! Today I made my way to Cayuga Lake to receive a bag of sea lamprey from the New York State Department of Environmental Conservation (NYSDEC) who trap them as they try to spawn. These animals are controlled to help increase sports fish numbers and to limit the amounts of scars on angled fish. Enough chat here are the pictures:

Sea lamprey choose when to run away

Sea lamprey try to avoid the smell of certain chemicals, including the scent of rotting sea lamprey and another compound found in human spit (See it here!). Understanding how sea lamprey react to these chemicals under different conditions allows for managers to try to use these chemicals to help control lamprey populations. Recent work by Di Rocco et al (link) has just shown that temperature and the whether the lamprey was hiding or not. Lampreys in warmer water who were searching for spawning sites were must reactive, while those in cold waters that were hiding did not respond.

Check out this post for more lamprey fleeing from "the smell of death" and to learn more!

Sea lamprey like the smell of little sea lamprey...but not enough to come home

Sea lamprey do not home to natal streams like salmon. In simpler terms, sea lamprey do not seek out the stream from which they were born. Instead they rely on chemical cues to help guide them to a location that will let them reproduce successfully. One of these cues is the smell of larval sea lamprey (ammocoetes) buried within the stream beds. New work suggests that this smell, although it is important in making sure adults examine the stream to determine if they want to enter it to spawn, is not enough to actual make them swim upstream (link).

Presentation on work from this summer

I recently presented material at the annual New York American Fisheries Society conference! If you would like to see a video describing some of the results from this summer take a peak: https://www.youtube.com/watch?v=vh4isqLdTC0

Feel free to leave a comment and check out some of the other presentations if you have time, there are many more available to view on the NY AFS channel (Link).

End of the Summer

Unfortunately all summers must end, and so it is this year as well. We are wrapping up our fieldwork and focusing on the lab component. Below are a number of pictures from this summer that we had not posted yet.

Above is a damselfly perched on a leaf. Damselflies have four large wings that fold across the back. These are one of the most primitive aquatic insect groups (mayflies and dragonflies being the others). This individual was from Annsville Creek.

Another species of damselfly. All damselflies hunt on the wing capturing any small insects they can, they often then eat the prey on the wing while looking for another target.

This waterfall is a natural falls present on the Kaaterskill Creek outside of Catskill, NY. Sea lampreys are actually able to pass this barrier and spawn upstream.

This is a megalopteran, a different species, and likely a different genus (probably Sialis sp.), than the one we captured at the Black Creek. This is an adult which was out looking for a mate.

Above are black fly larvae (Simulidae) that we collected during out work. These are the larvae which are filter feeders, and also good indicators of high water quality. They secure themselves with silk threads to the end of rocks and are present in the fastest flowing sections of the water.

We found lots of lampreys in this stream under I-87. You never know what you maybe driving over top of when you are in the car.

This is a mummichog (Fundulus heteroclitus) we captured in the Muitzes Kill. This is a male, if his fins were better exposed you would see that they are actually fairly colorful.

Natural falls located at High Falls, NY. These are the lower of the two falls, with a dam at the top of the highest falls. In the spring time sea lamprey adults are regularly recorded from immediately below these falls.

An ammocoete from immediately downstream of the falls pictured above. This animal (based on the other animals we found there) was probably 3-5 years old. The nametag it had said "Bob".

Me standing sheepishly next to a rock at High Falls that was recently relocated by hurricane Sandy. The water level after the hurricane was still another 50 feet higher than me.

Looking out onto the Hudson River from the Sawkill at Bard College. The green mat is actually an invasive plant (water chestnut, Trapa natans) that has become quite a problem in the Hudson River. However, the scenery is still gorgeous.

I will continue to post on this blog about sea lamprey, although we may now expand our coverage to more than the Hudson River!