Sunday, August 16, 2015

Hudson and Delaware River

It has been a while since I posted some pictures to the blog so I have decided to rectify that problem.

A picture of some of the area in which I collect lampreys. The soft sediment is a good place for ammocoetes to bury. Also present are American eels.

Here is a close up of one of the permanent pools I sample. The rocks mark the edges of the pool. The large stick roughly divides the pool in half.

Here is view looking at some of the other ammocoete habitat in the river.

An underwater picture of a pool in which I collected lampreys from. This area is a little deeper than most of the areas I sample.

Some of the many plants growing in the stream. These plants have covered large sections of the stream, but will die back in the fall.

A quick picture upstream as I finished up working.


 My trip took me first to the Hudson River but I returned to the Delaware River upon return.



While I was working a group of common mergansers (Mergus merganser) dropped in. They initially landed and milled around but as soon as I stood up they decided it was high time to move out. To read more about these birds click here.



Excitingly many of the animals I captured were preparing for their long journey to sea. In the top picture the animal on the bottom is a "transformer" while the one on top is still an ammocoete. The other pictures are of transformers well on their way to being juvenile lamprey. The color of the body is change to help them hide in the open waters of the ocean. At this point their body appears somewhat purple, but in short order they will look more like what you think of when you think of salmon. Silver color on top and darker colors on the bottom.

And here is the smallest lamprey I have collected to date (only 11 mm, measured digitally) on the right of this relatively small ammocoete on the left.



A few shots of the stream at the low water level. By the time I return in September the water level will have gone back up, but for now you can see that some of the plants are enjoying the extra room.

The green mat to the right is a sandy/muddy pool where the ammocoetes head out. On the left is a rock bed that was moved down by the river this year. Because the cobble bar is reducing the stream width the speed of water near the ammocoete bed has increased and the bed is eroding away.

A final shot of the field immediately next to my site with the corn growing well. The day was beautiful and the valley was looking great.

Until next time.